diff --git a/.drone-manifest.yml b/.drone-manifest.yml new file mode 100644 index 0000000..462c6eb --- /dev/null +++ b/.drone-manifest.yml @@ -0,0 +1,22 @@ +image: happydomain/checker-tls:{{#if build.tag}}{{trimPrefix "v" build.tag}}{{else}}latest{{/if}} +{{#if build.tags}} +tags: +{{#each build.tags}} + - {{this}} +{{/each}} +{{/if}} +manifests: + - image: happydomain/checker-tls:{{#if build.tag}}{{trimPrefix "v" build.tag}}-{{/if}}linux-amd64 + platform: + architecture: amd64 + os: linux + - image: happydomain/checker-tls:{{#if build.tag}}{{trimPrefix "v" build.tag}}-{{/if}}linux-arm64 + platform: + architecture: arm64 + os: linux + variant: v8 + - image: happydomain/checker-tls:{{#if build.tag}}{{trimPrefix "v" build.tag}}-{{/if}}linux-arm + platform: + architecture: arm + os: linux + variant: v7 diff --git a/.drone.yml b/.drone.yml new file mode 100644 index 0000000..60c8449 --- /dev/null +++ b/.drone.yml @@ -0,0 +1,187 @@ +--- +kind: pipeline +type: docker +name: build-amd64 + +platform: + os: linux + arch: amd64 + +steps: + - name: checker build + image: golang:1-alpine + commands: + - apk add --no-cache git make + - make + environment: + CHECKER_VERSION: "${DRONE_BRANCH}-${DRONE_COMMIT}" + CGO_ENABLED: 0 + when: + event: + exclude: + - tag + + - name: checker build tag + image: golang:1-alpine + commands: + - apk add --no-cache git make + - make + environment: + CHECKER_VERSION: "${DRONE_SEMVER}" + CGO_ENABLED: 0 + when: + event: + - tag + + - name: publish on Docker Hub + image: plugins/docker + settings: + repo: happydomain/checker-tls + auto_tag: true + auto_tag_suffix: ${DRONE_STAGE_OS}-${DRONE_STAGE_ARCH} + dockerfile: Dockerfile + build_args: + - CHECKER_VERSION=${DRONE_BRANCH}-${DRONE_COMMIT} + username: + from_secret: docker_username + password: + from_secret: docker_password + when: + event: + exclude: + - tag + + - name: publish on Docker Hub (tag) + image: plugins/docker + settings: + repo: happydomain/checker-tls + auto_tag: true + auto_tag_suffix: ${DRONE_STAGE_OS}-${DRONE_STAGE_ARCH} + dockerfile: Dockerfile + build_args: + - CHECKER_VERSION=${DRONE_SEMVER} + username: + from_secret: docker_username + password: + from_secret: docker_password + when: + event: + - tag + +trigger: + branch: + exclude: + - renovate/* + event: + - cron + - push + - tag + +--- +kind: pipeline +type: docker +name: build-arm64 + +platform: + os: linux + arch: arm64 + +steps: + - name: checker build + image: golang:1-alpine + commands: + - apk add --no-cache git make + - make + environment: + CHECKER_VERSION: "${DRONE_BRANCH}-${DRONE_COMMIT}" + CGO_ENABLED: 0 + when: + event: + exclude: + - tag + + - name: checker build tag + image: golang:1-alpine + commands: + - apk add --no-cache git make + - make + environment: + CHECKER_VERSION: "${DRONE_SEMVER}" + CGO_ENABLED: 0 + when: + event: + - tag + + - name: publish on Docker Hub + image: plugins/docker + settings: + repo: happydomain/checker-tls + auto_tag: true + auto_tag_suffix: ${DRONE_STAGE_OS}-${DRONE_STAGE_ARCH} + dockerfile: Dockerfile + build_args: + - CHECKER_VERSION=${DRONE_BRANCH}-${DRONE_COMMIT} + username: + from_secret: docker_username + password: + from_secret: docker_password + when: + event: + exclude: + - tag + + - name: publish on Docker Hub (tag) + image: plugins/docker + settings: + repo: happydomain/checker-tls + auto_tag: true + auto_tag_suffix: ${DRONE_STAGE_OS}-${DRONE_STAGE_ARCH} + dockerfile: Dockerfile + build_args: + - CHECKER_VERSION=${DRONE_SEMVER} + username: + from_secret: docker_username + password: + from_secret: docker_password + when: + event: + - tag + +trigger: + event: + - cron + - push + - tag + +--- +kind: pipeline +name: docker-manifest + +platform: + os: linux + arch: arm64 + +steps: + - name: publish on Docker Hub + image: plugins/manifest + settings: + auto_tag: true + ignore_missing: true + spec: .drone-manifest.yml + username: + from_secret: docker_username + password: + from_secret: docker_password + +trigger: + branch: + exclude: + - renovate/* + event: + - cron + - push + - tag + +depends_on: + - build-amd64 + - build-arm64 diff --git a/Dockerfile b/Dockerfile index ea99603..c4abb45 100644 --- a/Dockerfile +++ b/Dockerfile @@ -6,9 +6,12 @@ WORKDIR /src COPY go.mod go.sum ./ RUN go mod download COPY . . -RUN CGO_ENABLED=0 go build -ldflags "-X main.Version=${CHECKER_VERSION}" -o /checker-tls . +RUN CGO_ENABLED=0 go build -tags standalone -ldflags "-X main.Version=${CHECKER_VERSION}" -o /checker-tls . FROM scratch COPY --from=builder /checker-tls /checker-tls +USER 65534:65534 EXPOSE 8080 +HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \ + CMD ["/checker-tls", "-healthcheck"] ENTRYPOINT ["/checker-tls"] diff --git a/Makefile b/Makefile index bf1467e..8ebb85f 100644 --- a/Makefile +++ b/Makefile @@ -6,12 +6,12 @@ CHECKER_SOURCES := main.go $(wildcard checker/*.go) GO_LDFLAGS := -X main.Version=$(CHECKER_VERSION) -.PHONY: all plugin docker clean +.PHONY: all plugin docker test clean all: $(CHECKER_NAME) $(CHECKER_NAME): $(CHECKER_SOURCES) - go build -ldflags "$(GO_LDFLAGS)" -o $@ . + go build -tags standalone -ldflags "$(GO_LDFLAGS)" -o $@ . plugin: $(CHECKER_NAME).so @@ -21,5 +21,8 @@ $(CHECKER_NAME).so: $(CHECKER_SOURCES) $(wildcard plugin/*.go) docker: docker build --build-arg CHECKER_VERSION=$(CHECKER_VERSION) -t $(CHECKER_IMAGE) . +test: + go test -tags standalone ./... + clean: rm -f $(CHECKER_NAME) $(CHECKER_NAME).so diff --git a/README.md b/README.md index f94547a..5cbad63 100644 --- a/README.md +++ b/README.md @@ -119,7 +119,7 @@ Observation data written under `tls_probes`: } ``` -The map is keyed by `contract.Ref(ep)` — the same value the host exposes +The map is keyed by `contract.Ref(ep)`, the same value the host exposes on the lineage side so that a consumer knows which probe corresponds to which entry it originally published. @@ -129,14 +129,32 @@ existing downstream parsers. ## Issues reported -- `tcp_unreachable` — dial failed. -- `handshake_failed` — TLS handshake or STARTTLS upgrade failed. -- `starttls_not_offered` — server didn't advertise STARTTLS. Severity is +- `tcp_unreachable`, dial failed. +- `handshake_failed`, TLS handshake or STARTTLS upgrade failed. +- `starttls_not_offered`, server didn't advertise STARTTLS. Severity is `crit` when `TLSEndpoint.RequireSTARTTLS` is `true`, `warn` otherwise. -- `chain_invalid` — leaf does not chain to a system-trusted root. -- `hostname_mismatch` — cert SANs don't cover the SNI. -- `expired` / `expiring_soon` — cert expiry posture. -- `weak_tls_version` — negotiated TLS < 1.2. +- `chain_invalid`, leaf does not chain to a system-trusted root. +- `hostname_mismatch`, cert SANs don't cover the SNI. +- `expired` / `expiring_soon`, cert expiry posture. +- `weak_tls_version`, negotiated TLS < 1.2. + +## Rules + +| Code | Description | Severity | +|---------------------------------|---------------------------------------------------------------------------------------------------|---------------------| +| `tls.endpoints_discovered` | Verifies that at least one TLS endpoint has been discovered for this target. | INFO | +| `tls.reachability` | Verifies that every discovered TLS endpoint accepts a TCP connection. | CRITICAL | +| `tls.handshake` | Verifies the TLS handshake completes on every reachable endpoint. | CRITICAL | +| `tls.starttls_advertised` | Verifies that STARTTLS endpoints advertise the upgrade capability. | CRITICAL | +| `tls.starttls_dialect_supported`| Verifies that discovered STARTTLS dialects are implemented by the checker. | CRITICAL | +| `tls.peer_certificate_present` | Verifies the server presented a certificate during the TLS handshake. | CRITICAL | +| `tls.chain_validity` | Verifies the presented certificate chain validates against the system trust store. | CRITICAL | +| `tls.hostname_match` | Verifies the leaf certificate covers the probed hostname (SNI). | CRITICAL | +| `tls.expiry` | Flags expired or soon-to-expire leaf certificates. | CRITICAL | +| `tls.version` | Flags endpoints negotiating a TLS version below the recommended TLS 1.2. | WARNING | +| `tls.cipher_suite` | Reports the cipher suite negotiated on each endpoint. | INFO | +| `tls.enum.versions` | Flags endpoints that still accept TLS versions below TLS 1.2 (requires the enumerate option). | WARNING | +| `tls.enum.ciphers` | Flags endpoints that accept broken cipher suites (NULL, anonymous, EXPORT, RC4, 3DES). | WARNING | ## Options @@ -144,6 +162,38 @@ existing downstream parsers. | ---------------- | ------ | ------- | -------------------------------------------- | | `probeTimeoutMs` | number | 10000 | Per-endpoint dial + handshake timeout in ms. | +## For embedders: certificate-fetch helpers + +The `checker` package also exports a small, stable surface for hosts that +want to reuse the dial/STARTTLS/handshake plumbing outside of a +`Collect` cycle — typically an HTTP handler that prefills a TLSA editor +from a live endpoint. + +```go +import tls "git.happydns.org/checker-tls/checker" + +starttls := req.STARTTLS +if starttls == "" { + starttls = tls.AutoSTARTTLS(req.Port) // well-known port → dialect +} + +certs, err := tls.FetchChain(ctx, host, req.Port, starttls, 10*time.Second) +if err != nil { + return err +} +chain := tls.BuildChain(certs) // []tls.CertInfo, leaf first +``` + +| Symbol | Role | +| ----------------- | ----------------------------------------------------------------------------------------------------- | +| `FetchChain` | Dials, runs the STARTTLS upgrade if requested, and returns the peer `*x509.Certificate` chain (leaf first). Uses `InsecureSkipVerify` so the chain is returned even when PKIX would reject it — callers do their own validation. | +| `BuildChain` | Projects an `[]*x509.Certificate` to `[]CertInfo`, with the four DANE/TLSA `(selector, matching_type)` hashes precomputed. Same projection `Collect` writes into observations. | +| `AutoSTARTTLS` | Maps a well-known port (25, 110, 143, 389, 587, 5222) to the STARTTLS dialect `FetchChain` should drive. Returns `""` when no mapping applies. | +| `CertInfo` | DANE-friendly per-certificate view: DN, expiry, DER, SPKI DER, and `(cert\|spki) × (sha256\|sha512)` hex digests. | + +These three helpers are part of the package's public contract: signatures +will not change without a bump of the importing module's `go.mod`. + ## Running ```bash diff --git a/checker/collect.go b/checker/collect.go index ff8f60b..d576fb3 100644 --- a/checker/collect.go +++ b/checker/collect.go @@ -22,6 +22,7 @@ func (p *tlsProvider) Collect(ctx context.Context, opts sdk.CheckerOptions) (any timeoutMs = DefaultProbeTimeoutMs } timeout := time.Duration(timeoutMs) * time.Millisecond + enumerate := sdk.GetBoolOption(opts, OptionEnumerateCiphers, false) entries, warnings := contract.ParseEntries(raw) for _, w := range warnings { @@ -40,15 +41,36 @@ func (p *tlsProvider) Collect(ctx context.Context, opts sdk.CheckerOptions) (any var mu sync.Mutex var wg sync.WaitGroup sem := make(chan struct{}, MaxConcurrentProbes) +dispatch: for _, e := range entries { + select { + case sem <- struct{}{}: + case <-ctx.Done(): + break dispatch + } wg.Add(1) - sem <- struct{}{} go func() { defer wg.Done() defer func() { <-sem }() pr := probe(ctx, e.Endpoint, timeout) - log.Printf("checker-tls: %s %s:%d → tls=%s issues=%d elapsed=%dms err=%q", - pr.Type, pr.Host, pr.Port, pr.TLSVersion, len(pr.Issues), pr.ElapsedMS, pr.Error) + log.Printf("checker-tls: %s %s:%d → tls=%s handshake_ok=%t elapsed=%dms err=%q", + pr.Type, pr.Host, pr.Port, pr.TLSVersion, pr.TLSHandshakeOK, pr.ElapsedMS, pr.Error) + if enumerate && pr.TLSHandshakeOK { + enumRes, skipReason := enumerateEndpoint(ctx, e.Endpoint, enumerationBudget) + switch { + case enumRes != nil && enumRes.Skipped != "": + pr.Enum = enumRes + log.Printf("checker-tls: enum %s:%d → error: %s (duration=%dms)", + pr.Host, pr.Port, enumRes.Skipped, enumRes.DurationMS) + case enumRes != nil: + pr.Enum = enumRes + log.Printf("checker-tls: enum %s:%d → versions=%d duration=%dms", + pr.Host, pr.Port, len(enumRes.Versions), enumRes.DurationMS) + case skipReason != "": + log.Printf("checker-tls: enum %s:%d → skipped: %s", + pr.Host, pr.Port, skipReason) + } + } mu.Lock() probes[e.Ref] = pr mu.Unlock() diff --git a/checker/definition.go b/checker/definition.go index 31c996d..4fd166a 100644 --- a/checker/definition.go +++ b/checker/definition.go @@ -29,6 +29,13 @@ func (p *tlsProvider) Definition() *sdk.CheckerDefinition { Description: "Maximum time allowed for dial + STARTTLS + TLS handshake on a single endpoint.", Default: float64(DefaultProbeTimeoutMs), }, + { + Id: OptionEnumerateCiphers, + Type: "boolean", + Label: "Enumerate accepted TLS versions and cipher suites", + Description: "When enabled, each direct-TLS endpoint is swept with one ClientHello per (version, cipher) pair to discover the exact set the server accepts. Adds ~50 handshakes per endpoint.", + Default: false, + }, }, RunOpts: []sdk.CheckerOptionDocumentation{ { @@ -40,9 +47,7 @@ func (p *tlsProvider) Definition() *sdk.CheckerDefinition { }, }, }, - Rules: []sdk.CheckRule{ - Rule(), - }, + Rules: Rules(), Interval: &sdk.CheckIntervalSpec{ Min: 6 * time.Hour, Max: 7 * 24 * time.Hour, diff --git a/checker/enumerate.go b/checker/enumerate.go new file mode 100644 index 0000000..61e76ef --- /dev/null +++ b/checker/enumerate.go @@ -0,0 +1,68 @@ +package checker + +import ( + "context" + "net" + "strconv" + "strings" + "time" + + "git.happydns.org/checker-tls/contract" + "git.happydns.org/checker-tls/tlsenum" +) + +// enumerationProbeTimeout caps each individual sub-probe. It is intentionally +// shorter than the main probe timeout: a sweep does dozens of handshakes and +// most rejections come back in tens of ms, so 3s is enough to absorb a slow +// network without dragging the total cost. +const enumerationProbeTimeout = 3 * time.Second + +// enumerateEndpoint runs a (version × cipher) sweep against an endpoint — +// direct TLS or STARTTLS — and returns the result in the wire-format consumed +// by rules. It returns (nil, "") to signal the sweep was deliberately +// skipped. +func enumerateEndpoint(ctx context.Context, ep contract.TLSEndpoint, totalBudget time.Duration) (*TLSEnumeration, string) { + host := strings.TrimSuffix(ep.Host, ".") + addr := net.JoinHostPort(host, strconv.Itoa(int(ep.Port))) + sni := ep.SNI + if sni == "" { + sni = host + } + + upgrader, ok := upgraderFor(ep.STARTTLS, sni) + if !ok { + return nil, "unsupported starttls dialect: " + ep.STARTTLS + } + + sweepCtx := ctx + if totalBudget > 0 { + var cancel context.CancelFunc + sweepCtx, cancel = context.WithTimeout(ctx, totalBudget) + defer cancel() + } + + start := time.Now() + res, err := tlsenum.Enumerate(sweepCtx, addr, sni, tlsenum.EnumerateOptions{ + ProbeTimeout: enumerationProbeTimeout, + Upgrader: upgrader, + }) + elapsed := time.Since(start).Milliseconds() + if err != nil { + return &TLSEnumeration{Skipped: "enumeration error: " + err.Error(), DurationMS: elapsed}, "" + } + + out := &TLSEnumeration{DurationMS: elapsed} + for _, v := range res.SupportedVersions { + ev := EnumVersion{Version: v, Name: tlsenum.VersionName(v)} + for _, c := range res.CiphersByVersion[v] { + ev.Ciphers = append(ev.Ciphers, EnumCipher{ID: c.ID, Name: c.Name}) + } + out.Versions = append(out.Versions, ev) + } + return out, "" +} + +// enumerationBudget is the upper bound we give one endpoint's sweep. ~50 +// handshakes × enumerationProbeTimeout would be 2-3 minutes worst case; we +// cap at 60s so a black-holing target can't stall the whole collect run. +const enumerationBudget = 60 * time.Second diff --git a/checker/enumerate_test.go b/checker/enumerate_test.go new file mode 100644 index 0000000..02484bc --- /dev/null +++ b/checker/enumerate_test.go @@ -0,0 +1,198 @@ +package checker + +import ( + "context" + "crypto/ecdsa" + "crypto/elliptic" + "crypto/rand" + "crypto/tls" + "crypto/x509" + "crypto/x509/pkix" + "encoding/pem" + "io" + "math/big" + "net" + "strconv" + "testing" + "time" + + "git.happydns.org/checker-tls/contract" +) + +// startEnumTestServer spins up a TCP listener that, for every accepted +// connection: (1) optionally drives a fake STARTTLS dialect handshake, then +// (2) lets the standard library terminate TLS with the provided cert. It +// keeps accepting until the test closes the listener. +// +// We use the stdlib tls.Server (not utls) on the server side: the point of +// these tests is to exercise the *checker* glue (upgraderFor + enumerate) +// against the real client-side code, not to replay tlsenum's internals. +func startEnumTestServer(t *testing.T, withSTARTTLS bool, cert tls.Certificate) net.Listener { + t.Helper() + ln, err := net.Listen("tcp", "127.0.0.1:0") + if err != nil { + t.Fatalf("listen: %v", err) + } + go func() { + for { + c, err := ln.Accept() + if err != nil { + return + } + go handleEnumConn(c, withSTARTTLS, cert) + } + }() + return ln +} + +func handleEnumConn(c net.Conn, withSTARTTLS bool, cert tls.Certificate) { + defer c.Close() + if withSTARTTLS { + // Pretend to be SMTP: 220 banner, EHLO ack, STARTTLS ack. The + // implementation of starttlsSMTP only requires the server to + // advertise STARTTLS in its EHLO response and to reply with a 2xx + // to the STARTTLS verb — exact verbs come from RFC 3207. + if _, err := io.WriteString(c, "220 enum.test ESMTP\r\n"); err != nil { + return + } + buf := make([]byte, 1024) + // EHLO line + if _, err := c.Read(buf); err != nil { + return + } + if _, err := io.WriteString(c, "250-enum.test\r\n250 STARTTLS\r\n"); err != nil { + return + } + // STARTTLS line + if _, err := c.Read(buf); err != nil { + return + } + if _, err := io.WriteString(c, "220 ready\r\n"); err != nil { + return + } + } + tc := tls.Server(c, &tls.Config{ + Certificates: []tls.Certificate{cert}, + MinVersion: tls.VersionTLS12, + MaxVersion: tls.VersionTLS12, // narrow surface so the sweep is fast + }) + defer tc.Close() + _ = tc.Handshake() +} + +// enumTestCert is a one-time self-signed ECDSA cert reused across tests. +func enumTestCert(t *testing.T) tls.Certificate { + t.Helper() + key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader) + if err != nil { + t.Fatalf("genkey: %v", err) + } + tmpl := x509.Certificate{ + SerialNumber: big.NewInt(1), + Subject: pkix.Name{CommonName: "enum.test"}, + NotBefore: time.Now().Add(-time.Hour), + NotAfter: time.Now().Add(time.Hour), + DNSNames: []string{"enum.test"}, + KeyUsage: x509.KeyUsageDigitalSignature, + ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}, + } + der, err := x509.CreateCertificate(rand.Reader, &tmpl, &tmpl, &key.PublicKey, key) + if err != nil { + t.Fatalf("createcert: %v", err) + } + keyDER, err := x509.MarshalECPrivateKey(key) + if err != nil { + t.Fatalf("marshal key: %v", err) + } + c, err := tls.X509KeyPair( + pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der}), + pem.EncodeToMemory(&pem.Block{Type: "EC PRIVATE KEY", Bytes: keyDER}), + ) + if err != nil { + t.Fatalf("keypair: %v", err) + } + return c +} + +func portOf(t *testing.T, ln net.Listener) uint16 { + t.Helper() + _, p, err := net.SplitHostPort(ln.Addr().String()) + if err != nil { + t.Fatalf("split addr: %v", err) + } + n, err := strconv.ParseUint(p, 10, 16) + if err != nil { + t.Fatalf("parse port: %v", err) + } + return uint16(n) +} + +// TestEnumerateEndpoint_DirectTLS asserts the sweep returns at least one +// supported version + cipher when the endpoint is plain TLS — proving the +// nil-upgrader path of upgraderFor wires correctly. +func TestEnumerateEndpoint_DirectTLS(t *testing.T) { + cert := enumTestCert(t) + ln := startEnumTestServer(t, false, cert) + defer ln.Close() + + res, skip := enumerateEndpoint(context.Background(), contract.TLSEndpoint{ + Host: "127.0.0.1", + Port: portOf(t, ln), + SNI: "enum.test", + }, 30*time.Second) + if skip != "" { + t.Fatalf("unexpected skip reason: %q", skip) + } + if res == nil || len(res.Versions) == 0 { + t.Fatalf("expected at least one supported version, got %+v", res) + } + gotTLS12 := false + for _, v := range res.Versions { + if v.Version == tls.VersionTLS12 && len(v.Ciphers) > 0 { + gotTLS12 = true + } + } + if !gotTLS12 { + t.Fatalf("expected TLS 1.2 with at least one cipher, got %+v", res.Versions) + } +} + +// TestEnumerateEndpoint_SMTP_STARTTLS asserts the sweep drives the SMTP +// dialect upgrade on every sub-probe and still discovers ciphers — proving +// the upgraderFor("smtp", sni) path is wired into Enumerate. +func TestEnumerateEndpoint_SMTP_STARTTLS(t *testing.T) { + cert := enumTestCert(t) + ln := startEnumTestServer(t, true, cert) + defer ln.Close() + + res, skip := enumerateEndpoint(context.Background(), contract.TLSEndpoint{ + Host: "127.0.0.1", + Port: portOf(t, ln), + SNI: "enum.test", + STARTTLS: "smtp", + }, 60*time.Second) + if skip != "" { + t.Fatalf("unexpected skip reason: %q", skip) + } + if res == nil || len(res.Versions) == 0 { + t.Fatalf("expected at least one supported version through STARTTLS, got %+v", res) + } +} + +// TestEnumerateEndpoint_UnknownDialect asserts an unsupported STARTTLS +// dialect is rejected with a non-empty skip reason and no result — the +// observation must record *why* enumeration didn't run, not silently report +// "no versions accepted". +func TestEnumerateEndpoint_UnknownDialect(t *testing.T) { + res, skip := enumerateEndpoint(context.Background(), contract.TLSEndpoint{ + Host: "127.0.0.1", + Port: 1, // unreachable on purpose; we never get past the dialect check + STARTTLS: "no-such-dialect", + }, time.Second) + if res != nil { + t.Fatalf("expected nil result for unknown dialect, got %+v", res) + } + if skip == "" { + t.Fatalf("expected non-empty skip reason for unknown dialect") + } +} diff --git a/checker/fetch.go b/checker/fetch.go new file mode 100644 index 0000000..1a078d1 --- /dev/null +++ b/checker/fetch.go @@ -0,0 +1,108 @@ +// This file is part of the happyDomain (R) project. +// Copyright (c) 2020-2026 happyDomain +// Authors: Pierre-Olivier Mercier, et al. +// +// This program is offered under a commercial and under the AGPL license. +// For commercial licensing, contact us at . +// +// For AGPL licensing: +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see . + +package checker + +import ( + "context" + "crypto/tls" + "crypto/x509" + "fmt" + "net" + "strconv" + "strings" + "time" +) + +// FetchChain dials host:port, optionally upgrades the connection via STARTTLS, +// completes a TLS handshake (InsecureSkipVerify so callers receive the chain +// even when PKIX would reject it), and returns the peer certificates leaf +// first. +// +// starttls is the protocol name as registered (smtp, submission, imap, pop3, +// ldap, xmpp-client, ...); pass "" for direct TLS. AutoSTARTTLS provides +// well-known port defaults. +func FetchChain(ctx context.Context, host string, port uint16, starttls string, timeout time.Duration) ([]*x509.Certificate, error) { + host = strings.TrimSuffix(host, ".") + addr := net.JoinHostPort(host, strconv.Itoa(int(port))) + + dialCtx, cancel := context.WithTimeout(ctx, timeout) + defer cancel() + + conn, err := (&net.Dialer{}).DialContext(dialCtx, "tcp", addr) + if err != nil { + return nil, fmt.Errorf("dial %s: %w", addr, err) + } + defer conn.Close() + if dl, ok := dialCtx.Deadline(); ok { + _ = conn.SetDeadline(dl) + } + + if starttls != "" { + up, ok := starttlsUpgraders[starttls] + if !ok { + return nil, fmt.Errorf("unsupported starttls protocol %q", starttls) + } + if err := up(conn, host); err != nil { + return nil, fmt.Errorf("starttls-%s: %w", starttls, err) + } + } + + tlsConn := tls.Client(conn, &tls.Config{ + ServerName: host, + InsecureSkipVerify: true, // #nosec G402 -- intentional: caller receives the chain even when PKIX rejects it + }) + if err := tlsConn.HandshakeContext(dialCtx); err != nil { + return nil, fmt.Errorf("tls handshake: %w", err) + } + state := tlsConn.ConnectionState() + if len(state.PeerCertificates) == 0 { + return nil, fmt.Errorf("server presented no certificate") + } + return state.PeerCertificates, nil +} + +// BuildChain produces a CertInfo per peer certificate (leaf first), with the +// four (selector, matching_type) DANE hash pairs precomputed. This is the +// same projection probe() applies internally; exported so HTTP handlers can +// reuse it without re-deriving the format. +func BuildChain(certs []*x509.Certificate) []CertInfo { + return buildChain(certs) +} + +// AutoSTARTTLS maps a well-known port to the STARTTLS dialect FetchChain +// should drive. Returns "" when the port has no auto-mapping (caller should +// then use direct TLS or pass an explicit dialect). +func AutoSTARTTLS(port uint16) string { + switch port { + case 25, 587: + return "smtp" + case 143: + return "imap" + case 110: + return "pop3" + case 389: + return "ldap" + case 5222: + return "xmpp-client" + } + return "" +} diff --git a/checker/interactive.go b/checker/interactive.go index 85a7dc3..048b7a8 100644 --- a/checker/interactive.go +++ b/checker/interactive.go @@ -1,3 +1,5 @@ +//go:build standalone + package checker import ( @@ -24,7 +26,7 @@ func starttlsChoices() []string { return protos } -// RenderForm satisfies sdk.CheckerInteractive. The fields mirror the inputs +// RenderForm satisfies server.Interactive. The fields mirror the inputs // a producer checker would put into a contract.TLSEndpoint; a human fills // them in directly when running the checker standalone. func (p *tlsProvider) RenderForm() []sdk.CheckerOptionField { @@ -75,7 +77,7 @@ func (p *tlsProvider) RenderForm() []sdk.CheckerOptionField { } } -// ParseForm satisfies sdk.CheckerInteractive. It turns the human inputs into +// ParseForm satisfies server.Interactive. It turns the human inputs into // a single contract.TLSEndpoint, wraps it in a DiscoveryEntry, and returns // CheckerOptions shaped as if a happyDomain host had auto-filled // OptionEndpoints via AutoFillDiscoveryEntries. diff --git a/checker/prober.go b/checker/prober.go index fcbe88d..1aa25ee 100644 --- a/checker/prober.go +++ b/checker/prober.go @@ -33,6 +33,7 @@ func buildChain(certs []*x509.Certificate) []CertInfo { DERBase64: base64.StdEncoding.EncodeToString(c.Raw), Subject: c.Subject.String(), Issuer: c.Issuer.String(), + NotAfter: c.NotAfter, CertSHA256: hex.EncodeToString(certSum256[:]), CertSHA512: hex.EncodeToString(certSum512[:]), SPKISHA256: hex.EncodeToString(spkiSum256[:]), @@ -57,8 +58,11 @@ func probeTypeString(ep contract.TLSEndpoint) string { // probe performs a TLS handshake (or STARTTLS upgrade + handshake) on the // given endpoint and returns a populated TLSProbe. It never returns an error: -// transport/handshake failures are recorded on the probe so the caller can -// still surface them in the report. +// transport/handshake failures are recorded on the probe as raw fields so +// rules can classify them. +// +// This function MUST NOT decide severity or pass/fail: it only gathers +// observation data. All judgement happens in CheckRules (see rules_*.go). func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) TLSProbe { start := time.Now() host := strings.TrimSuffix(ep.Host, ".") @@ -69,11 +73,13 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) } p := TLSProbe{ - Host: host, - Port: ep.Port, - Endpoint: addr, - Type: probeTypeString(ep), - SNI: sni, + Host: host, + Port: ep.Port, + Endpoint: addr, + Type: probeTypeString(ep), + SNI: sni, + RequireSTARTTLS: ep.RequireSTARTTLS, + STARTTLSDialect: ep.STARTTLS, } dialCtx, cancel := context.WithTimeout(ctx, timeout) @@ -82,13 +88,8 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) d := &net.Dialer{} conn, err := d.DialContext(dialCtx, "tcp", addr) if err != nil { + p.TCPError = err.Error() p.Error = "dial: " + err.Error() - p.Issues = append(p.Issues, Issue{ - Code: "tcp_unreachable", - Severity: SeverityCrit, - Message: fmt.Sprintf("Cannot open TCP connection to %s: %v", addr, err), - Fix: "Check DNS, firewall, and that the service listens on this port.", - }) p.ElapsedMS = time.Since(start).Milliseconds() return p } @@ -100,23 +101,28 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) tlsConn, err := handshake(conn, ep, sni) if err != nil { + p.HandshakeError = err.Error() p.Error = err.Error() - p.Issues = append(p.Issues, classifyHandshakeError(ep, err)) + if ep.STARTTLS != "" && isStartTLSUnsupported(err) { + p.STARTTLSNotOffered = true + } + if errors.Is(err, errUnsupportedStartTLSProto) { + p.STARTTLSUnsupportedProto = true + } p.ElapsedMS = time.Since(start).Milliseconds() return p } defer tlsConn.Close() + p.TLSHandshakeOK = true state := tlsConn.ConnectionState() + p.TLSVersionNum = state.Version p.TLSVersion = tls.VersionName(state.Version) p.CipherSuite = tls.CipherSuiteName(state.CipherSuite) + p.CipherSuiteID = state.CipherSuite if len(state.PeerCertificates) == 0 { - p.Issues = append(p.Issues, Issue{ - Code: "no_peer_cert", - Severity: SeverityCrit, - Message: "Server presented no certificate.", - }) + p.NoPeerCert = true p.ElapsedMS = time.Since(start).Milliseconds() return p } @@ -129,16 +135,16 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) p.IssuerAKI = strings.ToUpper(hex.EncodeToString(leaf.AuthorityKeyId)) } p.Subject = leaf.Subject.CommonName - p.DNSNames = append(p.DNSNames, leaf.DNSNames...) + p.DNSNames = leaf.DNSNames p.Chain = buildChain(state.PeerCertificates) hostnameMatch := leaf.VerifyHostname(sni) == nil p.HostnameMatch = &hostnameMatch // Chain verification against system roots, using intermediates presented - // by the server. We run this independently from Go's tls.Config - // verification so we can report a dedicated "chain invalid" issue rather - // than failing the whole handshake. + // by the server. Running it separately from tls.Config verification + // means we can record it as a raw observation rather than aborting the + // handshake, rules classify it afterwards. intermediates := x509.NewCertPool() for _, c := range state.PeerCertificates[1:] { intermediates.AddCert(c) @@ -151,48 +157,8 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) }) chainValid := verifyErr == nil p.ChainValid = &chainValid - if !chainValid { - msg := "Invalid certificate chain" - if verifyErr != nil { - msg = "Invalid certificate chain: " + verifyErr.Error() - } - p.Issues = append(p.Issues, Issue{ - Code: "chain_invalid", - Severity: SeverityCrit, - Message: msg, - Fix: "Serve the full intermediate chain and ensure the root is trusted.", - }) - } - if !hostnameMatch { - p.Issues = append(p.Issues, Issue{ - Code: "hostname_mismatch", - Severity: SeverityCrit, - Message: fmt.Sprintf("Certificate does not cover %q (SANs: %s)", sni, strings.Join(leaf.DNSNames, ", ")), - Fix: "Re-issue the certificate with a matching SAN.", - }) - } - if leaf.NotAfter.Before(now) { - p.Issues = append(p.Issues, Issue{ - Code: "expired", - Severity: SeverityCrit, - Message: "Certificate expired on " + leaf.NotAfter.Format(time.RFC3339), - Fix: "Renew the certificate.", - }) - } else if leaf.NotAfter.Sub(now) < 14*24*time.Hour { - p.Issues = append(p.Issues, Issue{ - Code: "expiring_soon", - Severity: SeverityWarn, - Message: "Certificate expires in less than 14 days (" + leaf.NotAfter.Format(time.RFC3339) + ")", - Fix: "Renew before expiry.", - }) - } - if state.Version < tls.VersionTLS12 { - p.Issues = append(p.Issues, Issue{ - Code: "weak_tls_version", - Severity: SeverityWarn, - Message: "Negotiated TLS version " + p.TLSVersion + " is below the recommended TLS 1.2.", - Fix: "Disable TLS 1.0/1.1 on the server.", - }) + if verifyErr != nil { + p.ChainVerifyErr = verifyErr.Error() } p.ElapsedMS = time.Since(start).Milliseconds() @@ -201,12 +167,12 @@ func probe(ctx context.Context, ep contract.TLSEndpoint, timeout time.Duration) // handshake performs STARTTLS upgrade (when ep.STARTTLS is non-empty) and // then a TLS handshake. InsecureSkipVerify is true on purpose: we verify -// the chain separately in probe so an invalid chain becomes a structured -// Issue rather than aborting the handshake. +// the chain separately in probe so an invalid chain becomes a raw +// observation rather than aborting the handshake. func handshake(conn net.Conn, ep contract.TLSEndpoint, sni string) (*tls.Conn, error) { cfg := &tls.Config{ ServerName: sni, - InsecureSkipVerify: true, + InsecureSkipVerify: true, // #nosec G402 -- intentional: chain verified separately in probe() } if ep.STARTTLS == "" { @@ -219,7 +185,7 @@ func handshake(conn net.Conn, ep contract.TLSEndpoint, sni string) (*tls.Conn, e up, ok := starttlsUpgraders[ep.STARTTLS] if !ok { - return nil, fmt.Errorf("unsupported starttls protocol %q", ep.STARTTLS) + return nil, fmt.Errorf("%w: %q", errUnsupportedStartTLSProto, ep.STARTTLS) } if err := up(conn, sni); err != nil { return nil, fmt.Errorf("starttls-%s: %w", ep.STARTTLS, err) @@ -231,34 +197,10 @@ func handshake(conn net.Conn, ep contract.TLSEndpoint, sni string) (*tls.Conn, e return tlsConn, nil } -// classifyHandshakeError converts a dial/handshake error into a structured -// Issue, distinguishing "server doesn't offer STARTTLS" (which is opportunistic -// for some endpoints) from hard failures. -func classifyHandshakeError(ep contract.TLSEndpoint, err error) Issue { - msg := err.Error() - - if ep.STARTTLS != "" && isStartTLSUnsupported(err) { - sev := SeverityWarn - if ep.RequireSTARTTLS { - sev = SeverityCrit - } - return Issue{ - Code: "starttls_not_offered", - Severity: sev, - Message: fmt.Sprintf("Server on %s:%d does not advertise STARTTLS: %s", ep.Host, ep.Port, msg), - Fix: "Enable STARTTLS on the server or publish a direct-TLS endpoint.", - } - } - - return Issue{ - Code: "handshake_failed", - Severity: SeverityCrit, - Message: fmt.Sprintf("TLS handshake failed on %s:%d: %s", ep.Host, ep.Port, msg), - Fix: "Inspect the server's TLS configuration and certificate.", - } -} - -var errStartTLSNotOffered = errors.New("starttls not advertised by server") +var ( + errStartTLSNotOffered = errors.New("starttls not advertised by server") + errUnsupportedStartTLSProto = errors.New("unsupported starttls protocol") +) func isStartTLSUnsupported(err error) bool { return errors.Is(err, errStartTLSNotOffered) diff --git a/checker/prober_test.go b/checker/prober_test.go index 4023e58..ad7e288 100644 --- a/checker/prober_test.go +++ b/checker/prober_test.go @@ -60,11 +60,8 @@ func TestProbe_TCPUnreachable(t *testing.T) { Port: uint16(addr.Port), }, 1*time.Second) - if probe.Error == "" { - t.Errorf("expected an error for unreachable port") - } - if len(probe.Issues) == 0 || probe.Issues[0].Code != "tcp_unreachable" { - t.Errorf("expected tcp_unreachable issue, got %+v", probe.Issues) + if probe.TCPError == "" { + t.Errorf("expected a TCP error for unreachable port") } } diff --git a/checker/rule.go b/checker/rule.go index 310c283..ad9d626 100644 --- a/checker/rule.go +++ b/checker/rule.go @@ -8,140 +8,83 @@ import ( sdk "git.happydns.org/checker-sdk-go/checker" ) -// Rule returns the rule that aggregates per-endpoint TLS probe outcomes into -// a single status for this checker run. -func Rule() sdk.CheckRule { - return &tlsRule{} +// Rules returns the full list of CheckRules exposed by the TLS checker. +// Each rule covers a single concern (reachability, handshake, chain, hostname, +// expiry, TLS version, STARTTLS advertisement, cipher suite, …) so the UI can +// surface a passing-list rather than a single aggregated code. +func Rules() []sdk.CheckRule { + return []sdk.CheckRule{ + &endpointsDiscoveredRule{}, + &reachabilityRule{}, + &tlsHandshakeRule{}, + &starttlsAdvertisedRule{}, + &starttlsSupportedRule{}, + &peerCertificateRule{}, + &chainValidityRule{}, + &hostnameMatchRule{}, + &expiryRule{}, + &tlsVersionRule{}, + &cipherSuiteRule{}, + &versionEnumerationRule{}, + &weakCipherRule{}, + } } -type tlsRule struct{} - -func (r *tlsRule) Name() string { return "tls_posture" } - -func (r *tlsRule) Description() string { - return "Summarises TLS handshake, certificate validity, hostname match and expiry across all probed endpoints" -} - -func (r *tlsRule) ValidateOptions(opts sdk.CheckerOptions) error { - return nil -} - -func (r *tlsRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState { +// loadData fetches the TLS observation. On error, returns a single error +// state the caller should emit. +func loadData(ctx context.Context, obs sdk.ObservationGetter) (*TLSData, *sdk.CheckState) { var data TLSData if err := obs.Get(ctx, ObservationKeyTLSProbes, &data); err != nil { - return []sdk.CheckState{{ + return nil, &sdk.CheckState{ Status: sdk.StatusError, - Message: fmt.Sprintf("Failed to read tls_probes: %v", err), - Code: "tls_observation_error", - }} - } - - // Steady state when no producer has published entries for this target - // yet (or when the last producer run cleared them). Report Unknown so - // we don't flap red during the eventual-consistency window between a - // fresh enrollment and the first producer cycle. - if len(data.Probes) == 0 { - return []sdk.CheckState{{ - Status: sdk.StatusUnknown, - Message: "No TLS endpoints have been discovered for this target yet", - Code: "tls_no_endpoints", - }} + Message: fmt.Sprintf("failed to load tls_probes observation: %v", err), + Code: "tls.observation_error", + } } + return &data, nil +} +// sortedRefs returns the probe refs in deterministic order. Rules iterate +// this sorted list so CheckState output is stable. +func sortedRefs(data *TLSData) []string { refs := make([]string, 0, len(data.Probes)) for ref := range data.Probes { refs = append(refs, ref) } sort.Strings(refs) - - out := make([]sdk.CheckState, 0, len(refs)) - for _, ref := range refs { - p := data.Probes[ref] - out = append(out, evaluateProbe(p)) - } - return out + return refs } -// evaluateProbe distills a single TLSProbe into a CheckState. Subject is the -// probed endpoint so the host can correlate states across runs and surface -// them per-target in the UI. Message describes the finding only -- the UI -// renders Subject separately. -func evaluateProbe(p TLSProbe) sdk.CheckState { - subject := fmt.Sprintf("%s://%s", p.Type, p.Endpoint) - meta := map[string]any{ - "type": p.Type, - "host": p.Host, - "port": p.Port, - "sni": p.SNI, - "issues": len(p.Issues), +// subjectOf formats the UI-facing subject for a single probe. +func subjectOf(p TLSProbe) string { + return fmt.Sprintf("%s://%s", p.Type, p.Endpoint) +} + +// metaOf returns a compact meta map to attach to a CheckState. +func metaOf(p TLSProbe) map[string]any { + m := map[string]any{ + "type": p.Type, + "host": p.Host, + "port": p.Port, + "sni": p.SNI, } if p.TLSVersion != "" { - meta["tls_version"] = p.TLSVersion - } - if !p.NotAfter.IsZero() { - meta["not_after"] = p.NotAfter - } - - worst, critMsg, warnMsg := summarize(p.Issues) - switch worst { - case SeverityCrit: - return sdk.CheckState{ - Status: sdk.StatusCrit, - Message: critMsg, - Code: "tls_critical", - Subject: subject, - Meta: meta, - } - case SeverityWarn: - return sdk.CheckState{ - Status: sdk.StatusWarn, - Message: warnMsg, - Code: "tls_warning", - Subject: subject, - Meta: meta, - } - default: - msg := "TLS endpoint OK" - if p.TLSVersion != "" { - msg = fmt.Sprintf("TLS endpoint OK (%s)", p.TLSVersion) - } - return sdk.CheckState{ - Status: sdk.StatusOK, - Message: msg, - Code: "tls_ok", - Subject: subject, - Meta: meta, - } + m["tls_version"] = p.TLSVersion } + return m } -// summarize walks the issues once and returns (worst severity, first -// critical message, first warning message). Picking the messages during the -// same pass avoids a second iteration in the caller. -func summarize(issues []Issue) (worst, firstCrit, firstWarn string) { - for _, is := range issues { - msg := is.Message - if msg == "" { - msg = is.Code - } - switch is.Severity { - case SeverityCrit: - worst = SeverityCrit - if firstCrit == "" { - firstCrit = msg - } - case SeverityWarn: - if worst == "" || worst == SeverityInfo { - worst = SeverityWarn - } - if firstWarn == "" { - firstWarn = msg - } - case SeverityInfo: - if worst == "" { - worst = SeverityInfo - } - } - } - return +// passState / infoState / unknownState helpers. +func passState(code, message string) sdk.CheckState { + return sdk.CheckState{Status: sdk.StatusOK, Code: code, Message: message} +} +func unknownState(code, message string) sdk.CheckState { + return sdk.CheckState{Status: sdk.StatusUnknown, Code: code, Message: message} +} + +// emptyCaseState returns a single state describing "no probes to evaluate". +// Rules call this when len(data.Probes) == 0 to avoid returning an empty +// slice (see CheckRule.Evaluate contract). +func emptyCaseState(code string) sdk.CheckState { + return unknownState(code, "No TLS endpoints have been discovered for this target yet.") } diff --git a/checker/rules_certificate.go b/checker/rules_certificate.go new file mode 100644 index 0000000..2fc2f4c --- /dev/null +++ b/checker/rules_certificate.go @@ -0,0 +1,233 @@ +package checker + +import ( + "context" + "fmt" + "strings" + "time" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// peerCertificateRule flags successful handshakes in which the server sent +// no certificate. This is distinct from chain validity: if no cert was sent, +// hostname/chain/expiry cannot be evaluated. +type peerCertificateRule struct{} + +func (r *peerCertificateRule) Name() string { return "tls.peer_certificate_present" } +func (r *peerCertificateRule) Description() string { + return "Verifies the server presented a certificate during the TLS handshake." +} + +func (r *peerCertificateRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.peer_certificate_present.no_endpoints")} + } + + var out []sdk.CheckState + anyHandshake := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if !p.TLSHandshakeOK { + continue + } + anyHandshake = true + if !p.NoPeerCert { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.peer_certificate_present.missing", + Subject: subjectOf(p), + Message: fmt.Sprintf("Server on %s completed the handshake but presented no certificate.", p.Endpoint), + Meta: metaOf(p), + }) + } + if !anyHandshake { + return []sdk.CheckState{unknownState( + "tls.peer_certificate_present.skipped", + "No endpoint completed a TLS handshake.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.peer_certificate_present.ok", + "Every endpoint presented a certificate.", + )} + } + return out +} + +// chainValidityRule flags invalid certificate chains. +type chainValidityRule struct{} + +func (r *chainValidityRule) Name() string { return "tls.chain_validity" } +func (r *chainValidityRule) Description() string { + return "Verifies the presented certificate chain validates against the system trust store." +} + +func (r *chainValidityRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.chain_validity.no_endpoints")} + } + + var out []sdk.CheckState + any := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.ChainValid == nil { + continue + } + any = true + if *p.ChainValid { + continue + } + msg := "Invalid certificate chain" + if p.ChainVerifyErr != "" { + msg = "Invalid certificate chain: " + p.ChainVerifyErr + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.chain_validity.invalid", + Subject: subjectOf(p), + Message: msg, + Meta: metaOf(p), + }) + } + if !any { + return []sdk.CheckState{unknownState( + "tls.chain_validity.skipped", + "No endpoint yielded a certificate chain to verify.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.chain_validity.ok", + "Every presented chain validates against the system trust store.", + )} + } + return out +} + +// hostnameMatchRule flags endpoints whose leaf cert does not cover the SNI +// the probe used. +type hostnameMatchRule struct{} + +func (r *hostnameMatchRule) Name() string { return "tls.hostname_match" } +func (r *hostnameMatchRule) Description() string { + return "Verifies the leaf certificate covers the probed hostname (SNI)." +} + +func (r *hostnameMatchRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.hostname_match.no_endpoints")} + } + + var out []sdk.CheckState + any := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.HostnameMatch == nil { + continue + } + any = true + if *p.HostnameMatch { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.hostname_match.mismatch", + Subject: subjectOf(p), + Message: fmt.Sprintf("Certificate does not cover %q (SANs: %s)", p.SNI, strings.Join(p.DNSNames, ", ")), + Meta: metaOf(p), + }) + } + if !any { + return []sdk.CheckState{unknownState( + "tls.hostname_match.skipped", + "No endpoint yielded a certificate to hostname-match.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.hostname_match.ok", + "Every certificate covers its probed SNI.", + )} + } + return out +} + +// expiryRule flags expired or near-expiry certificates. +type expiryRule struct{} + +func (r *expiryRule) Name() string { return "tls.expiry" } +func (r *expiryRule) Description() string { + return "Flags expired or soon-to-expire leaf certificates." +} + +func (r *expiryRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.expiry.no_endpoints")} + } + + now := time.Now() + var out []sdk.CheckState + any := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.NotAfter.IsZero() { + continue + } + any = true + meta := metaOf(p) + meta["not_after"] = p.NotAfter + if p.NotAfter.Before(now) { + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.expiry.expired", + Subject: subjectOf(p), + Message: "Certificate expired on " + p.NotAfter.Format(time.RFC3339), + Meta: meta, + }) + continue + } + if p.NotAfter.Sub(now) < ExpiringSoonThreshold { + out = append(out, sdk.CheckState{ + Status: sdk.StatusWarn, + Code: "tls.expiry.expiring_soon", + Subject: subjectOf(p), + Message: "Certificate expires in less than 14 days (" + p.NotAfter.Format(time.RFC3339) + ")", + Meta: meta, + }) + } + } + if !any { + return []sdk.CheckState{unknownState( + "tls.expiry.skipped", + "No endpoint yielded a certificate with an expiry to check.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.expiry.ok", + "Every leaf certificate is valid for more than 14 days.", + )} + } + return out +} diff --git a/checker/rules_discovery.go b/checker/rules_discovery.go new file mode 100644 index 0000000..738b235 --- /dev/null +++ b/checker/rules_discovery.go @@ -0,0 +1,34 @@ +package checker + +import ( + "context" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// endpointsDiscoveredRule surfaces the "no producer has published endpoints +// for this target yet" steady state. Kept as its own rule so it does not +// contaminate per-endpoint findings when discovery is in flight. +type endpointsDiscoveredRule struct{} + +func (r *endpointsDiscoveredRule) Name() string { return "tls.endpoints_discovered" } +func (r *endpointsDiscoveredRule) Description() string { + return "Verifies that at least one TLS endpoint has been discovered for this target." +} + +func (r *endpointsDiscoveredRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{unknownState( + "tls.endpoints_discovered.none", + "No TLS endpoints have been discovered for this target yet.", + )} + } + return []sdk.CheckState{passState( + "tls.endpoints_discovered.ok", + "TLS endpoints were discovered for this target.", + )} +} diff --git a/checker/rules_enumeration.go b/checker/rules_enumeration.go new file mode 100644 index 0000000..6757be0 --- /dev/null +++ b/checker/rules_enumeration.go @@ -0,0 +1,197 @@ +package checker + +import ( + "context" + "crypto/tls" + "fmt" + "sort" + "strings" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// hasEnum returns true when at least one probe carries enumeration data. +// Rules use this to short-circuit to "skipped" when the user hasn't enabled +// the enumerate option (rather than falsely emitting a "passing" verdict). +func hasEnum(data *TLSData) bool { + for _, p := range data.Probes { + if p.Enum != nil && len(p.Enum.Versions) > 0 { + return true + } + } + return false +} + +// versionEnumerationRule reports the full set of protocol versions accepted +// by each endpoint, and flags any acceptance below the TLS 1.2 floor — the +// regular handshake rule only sees the *negotiated* version, so a server +// that still accepts TLS 1.0 alongside TLS 1.3 would otherwise look healthy. +type versionEnumerationRule struct{} + +func (r *versionEnumerationRule) Name() string { return "tls.enum.versions" } +func (r *versionEnumerationRule) Description() string { + return "Flags endpoints that still accept TLS versions below TLS 1.2 (requires the enumerate option)." +} + +func (r *versionEnumerationRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.enum.versions.no_endpoints")} + } + if !hasEnum(data) { + return []sdk.CheckState{unknownState( + "tls.enum.versions.skipped", + "TLS version/cipher enumeration was not run for any endpoint (enable the enumerateCiphers option).", + )} + } + + var out []sdk.CheckState + anyEnum := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.Enum == nil || len(p.Enum.Versions) == 0 { + continue + } + anyEnum = true + + var legacy []string + for _, v := range p.Enum.Versions { + if v.Version < tls.VersionTLS12 { + legacy = append(legacy, v.Name) + } + } + if len(legacy) == 0 { + continue + } + sort.Strings(legacy) + out = append(out, sdk.CheckState{ + Status: sdk.StatusWarn, + Code: "tls.enum.versions.legacy_accepted", + Subject: subjectOf(p), + Message: fmt.Sprintf("Endpoint accepts legacy protocol version(s): %s.", strings.Join(legacy, ", ")), + Meta: metaOf(p), + }) + } + if !anyEnum { + return []sdk.CheckState{unknownState( + "tls.enum.versions.skipped", + "No endpoint produced enumeration data.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.enum.versions.ok", + "No endpoint accepts a protocol version below TLS 1.2.", + )} + } + return out +} + +// weakCipherRule flags endpoints that accept cipher suites widely considered +// broken or insecure: NULL, anonymous, EXPORT, RC4, 3DES, and any other CBC +// suite using SHA-1 in MAC-then-encrypt mode is *not* flagged here because +// real-world servers still need them for legacy clients; this rule limits +// itself to the set with no defensible use in 2026. +type weakCipherRule struct{} + +func (r *weakCipherRule) Name() string { return "tls.enum.ciphers" } +func (r *weakCipherRule) Description() string { + return "Flags endpoints that accept broken cipher suites (NULL, anonymous, EXPORT, RC4, 3DES)." +} + +// classifyCipher returns a non-empty category when the named cipher belongs +// to a class with no defensible modern use. The check is by substring on the +// IANA name because every entry follows the TLS__WITH__ +// convention. +func classifyCipher(name string) string { + upper := strings.ToUpper(name) + switch { + case strings.Contains(upper, "_NULL_"), strings.HasSuffix(upper, "_NULL"): + return "NULL" + case strings.Contains(upper, "_ANON_"): + return "anonymous" + case strings.Contains(upper, "_EXPORT_"): + return "EXPORT" + case strings.Contains(upper, "_RC4_"): + return "RC4" + case strings.Contains(upper, "_3DES_"), strings.Contains(upper, "_DES_"): + return "3DES/DES" + } + return "" +} + +func (r *weakCipherRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.enum.ciphers.no_endpoints")} + } + if !hasEnum(data) { + return []sdk.CheckState{unknownState( + "tls.enum.ciphers.skipped", + "TLS version/cipher enumeration was not run for any endpoint (enable the enumerateCiphers option).", + )} + } + + var out []sdk.CheckState + anyEnum := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.Enum == nil || len(p.Enum.Versions) == 0 { + continue + } + anyEnum = true + + // Aggregate by category so a server accepting six EXPORT suites + // produces one finding, not six. + byCategory := map[string][]string{} + for _, v := range p.Enum.Versions { + for _, c := range v.Ciphers { + cat := classifyCipher(c.Name) + if cat == "" { + continue + } + byCategory[cat] = append(byCategory[cat], c.Name) + } + } + if len(byCategory) == 0 { + continue + } + cats := make([]string, 0, len(byCategory)) + for c := range byCategory { + cats = append(cats, c) + } + sort.Strings(cats) + parts := make([]string, 0, len(cats)) + for _, c := range cats { + parts = append(parts, fmt.Sprintf("%s (%d)", c, len(byCategory[c]))) + } + meta := metaOf(p) + meta["weak_ciphers"] = byCategory + out = append(out, sdk.CheckState{ + Status: sdk.StatusWarn, + Code: "tls.enum.ciphers.weak_accepted", + Subject: subjectOf(p), + Message: "Endpoint accepts broken cipher suites: " + strings.Join(parts, ", ") + ".", + Meta: meta, + }) + } + if !anyEnum { + return []sdk.CheckState{unknownState( + "tls.enum.ciphers.skipped", + "No endpoint produced enumeration data.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.enum.ciphers.ok", + "No endpoint accepts a known-broken cipher suite (NULL/anonymous/EXPORT/RC4/3DES).", + )} + } + return out +} diff --git a/checker/rules_enumeration_test.go b/checker/rules_enumeration_test.go new file mode 100644 index 0000000..3097477 --- /dev/null +++ b/checker/rules_enumeration_test.go @@ -0,0 +1,135 @@ +package checker + +import ( + "context" + "crypto/tls" + "encoding/json" + "strings" + "testing" + "time" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// stubObs is a minimal ObservationGetter that serves a pre-built TLSData +// payload and ignores related lookups. It is local to this file rather than +// promoted to a shared helper to keep the rule tests self-contained. +type stubObs struct{ data TLSData } + +func (s stubObs) Get(_ context.Context, key sdk.ObservationKey, dest any) error { + if key != ObservationKeyTLSProbes { + return nil + } + raw, _ := json.Marshal(s.data) + return json.Unmarshal(raw, dest) +} +func (s stubObs) GetRelated(_ context.Context, _ sdk.ObservationKey) ([]sdk.RelatedObservation, error) { + return nil, nil +} + +func newProbeWithEnum(versions ...EnumVersion) TLSProbe { + return TLSProbe{ + Host: "example.test", Port: 443, Endpoint: "example.test:443", Type: "tls", + TLSHandshakeOK: true, TLSVersionNum: tls.VersionTLS13, + Enum: &TLSEnumeration{Versions: versions}, + } +} + +func TestVersionEnumerationRule_Skipped_NoEnum(t *testing.T) { + obs := stubObs{data: TLSData{ + Probes: map[string]TLSProbe{"a": {Host: "x", Port: 443, Endpoint: "x:443", Type: "tls", TLSHandshakeOK: true}}, + CollectedAt: time.Now(), + }} + got := (&versionEnumerationRule{}).Evaluate(context.Background(), obs, nil) + if len(got) != 1 || got[0].Code != "tls.enum.versions.skipped" { + t.Fatalf("want a single skipped state, got %+v", got) + } +} + +func TestVersionEnumerationRule_OK_OnlyModern(t *testing.T) { + obs := stubObs{data: TLSData{ + Probes: map[string]TLSProbe{ + "a": newProbeWithEnum( + EnumVersion{Version: tls.VersionTLS12, Name: "TLS 1.2"}, + EnumVersion{Version: tls.VersionTLS13, Name: "TLS 1.3"}, + ), + }, + }} + got := (&versionEnumerationRule{}).Evaluate(context.Background(), obs, nil) + if len(got) != 1 || got[0].Status != sdk.StatusOK || got[0].Code != "tls.enum.versions.ok" { + t.Fatalf("want a single OK state, got %+v", got) + } +} + +func TestVersionEnumerationRule_LegacyAccepted(t *testing.T) { + obs := stubObs{data: TLSData{ + Probes: map[string]TLSProbe{ + "a": newProbeWithEnum( + EnumVersion{Version: tls.VersionTLS10, Name: "TLS 1.0"}, + EnumVersion{Version: tls.VersionTLS12, Name: "TLS 1.2"}, + ), + }, + }} + got := (&versionEnumerationRule{}).Evaluate(context.Background(), obs, nil) + if len(got) != 1 || got[0].Status != sdk.StatusWarn || got[0].Code != "tls.enum.versions.legacy_accepted" { + t.Fatalf("want a single warn state, got %+v", got) + } + if !strings.Contains(got[0].Message, "TLS 1.0") { + t.Fatalf("warn message should mention the legacy version, got %q", got[0].Message) + } +} + +func TestClassifyCipher(t *testing.T) { + cases := map[string]string{ + "TLS_RSA_WITH_NULL_SHA": "NULL", + "TLS_DH_anon_WITH_AES_128_CBC_SHA": "anonymous", + "TLS_RSA_EXPORT_WITH_RC4_40_MD5": "EXPORT", + "TLS_ECDHE_RSA_WITH_RC4_128_SHA": "RC4", + "TLS_RSA_WITH_3DES_EDE_CBC_SHA": "3DES/DES", + "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256": "", + "TLS_AES_256_GCM_SHA384": "", + "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256": "", + } + for name, want := range cases { + if got := classifyCipher(name); got != want { + t.Errorf("classifyCipher(%q) = %q, want %q", name, got, want) + } + } +} + +func TestWeakCipherRule_Detects(t *testing.T) { + obs := stubObs{data: TLSData{ + Probes: map[string]TLSProbe{ + "a": newProbeWithEnum( + EnumVersion{Version: tls.VersionTLS12, Name: "TLS 1.2", Ciphers: []EnumCipher{ + {ID: 0xC02F, Name: "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"}, + {ID: 0x000A, Name: "TLS_RSA_WITH_3DES_EDE_CBC_SHA"}, + {ID: 0x0005, Name: "TLS_RSA_WITH_RC4_128_SHA"}, + }}, + ), + }, + }} + got := (&weakCipherRule{}).Evaluate(context.Background(), obs, nil) + if len(got) != 1 || got[0].Status != sdk.StatusWarn || got[0].Code != "tls.enum.ciphers.weak_accepted" { + t.Fatalf("want a single weak warn state, got %+v", got) + } + if !strings.Contains(got[0].Message, "RC4") || !strings.Contains(got[0].Message, "3DES/DES") { + t.Fatalf("warn message should list the broken categories, got %q", got[0].Message) + } +} + +func TestWeakCipherRule_OK_OnlyModern(t *testing.T) { + obs := stubObs{data: TLSData{ + Probes: map[string]TLSProbe{ + "a": newProbeWithEnum( + EnumVersion{Version: tls.VersionTLS13, Name: "TLS 1.3", Ciphers: []EnumCipher{ + {ID: 0x1301, Name: "TLS_AES_128_GCM_SHA256"}, + }}, + ), + }, + }} + got := (&weakCipherRule{}).Evaluate(context.Background(), obs, nil) + if len(got) != 1 || got[0].Status != sdk.StatusOK || got[0].Code != "tls.enum.ciphers.ok" { + t.Fatalf("want a single OK state, got %+v", got) + } +} diff --git a/checker/rules_handshake.go b/checker/rules_handshake.go new file mode 100644 index 0000000..2ee343c --- /dev/null +++ b/checker/rules_handshake.go @@ -0,0 +1,60 @@ +package checker + +import ( + "context" + "fmt" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// tlsHandshakeRule flags reachable endpoints on which the TLS handshake +// failed. STARTTLS-specific shortfalls (server not advertising the upgrade) +// are surfaced by starttlsAdvertisedRule / starttlsSupportedRule instead, +// so this rule skips them. +type tlsHandshakeRule struct{} + +func (r *tlsHandshakeRule) Name() string { return "tls.handshake" } +func (r *tlsHandshakeRule) Description() string { + return "Verifies the TLS handshake completes on every reachable endpoint." +} + +func (r *tlsHandshakeRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.handshake.no_endpoints")} + } + + var out []sdk.CheckState + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.TCPError != "" { + continue // reachability covers this. + } + if p.STARTTLSNotOffered || p.STARTTLSUnsupportedProto { + continue // starttls-specific rules cover these. + } + if p.TLSHandshakeOK { + continue + } + if p.HandshakeError == "" { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.handshake.failed", + Subject: subjectOf(p), + Message: fmt.Sprintf("TLS handshake failed on %s: %s", p.Endpoint, p.HandshakeError), + Meta: metaOf(p), + }) + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.handshake.ok", + "TLS handshake succeeded on every reachable endpoint.", + )} + } + return out +} diff --git a/checker/rules_protocol.go b/checker/rules_protocol.go new file mode 100644 index 0000000..6153b38 --- /dev/null +++ b/checker/rules_protocol.go @@ -0,0 +1,120 @@ +package checker + +import ( + "context" + "crypto/tls" + "fmt" + "sort" + "strings" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// tlsVersionRule flags endpoints negotiating a protocol version below the +// recommended TLS 1.2 floor. +type tlsVersionRule struct{} + +func (r *tlsVersionRule) Name() string { return "tls.version" } +func (r *tlsVersionRule) Description() string { + return "Flags endpoints negotiating a TLS version below the recommended TLS 1.2." +} + +func (r *tlsVersionRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.version.no_endpoints")} + } + + var out []sdk.CheckState + any := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.TLSVersionNum == 0 { + continue + } + any = true + if p.TLSVersionNum >= tls.VersionTLS12 { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusWarn, + Code: "tls.version.weak", + Subject: subjectOf(p), + Message: fmt.Sprintf("Negotiated TLS version %s is below the recommended TLS 1.2.", p.TLSVersion), + Meta: metaOf(p), + }) + } + if !any { + return []sdk.CheckState{unknownState( + "tls.version.skipped", + "No endpoint completed a TLS handshake.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.version.ok", + "Every endpoint negotiates TLS 1.2 or higher.", + )} + } + return out +} + +// cipherSuiteRule reports the negotiated cipher suite for visibility. +// It does not currently classify suites as weak/strong: go's crypto/tls +// refuses to negotiate the known-weak suites anyway. The rule exists so the +// UI can expose the suite in the passing-list rather than leaving it buried +// in the raw observation. +type cipherSuiteRule struct{} + +func (r *cipherSuiteRule) Name() string { return "tls.cipher_suite" } +func (r *cipherSuiteRule) Description() string { + return "Reports the cipher suite negotiated on each endpoint." +} + +func (r *cipherSuiteRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.cipher_suite.no_endpoints")} + } + + // Collapse per-endpoint cipher suites into a single info state. One + // row per endpoint drowns out actionable rules in the UI on domains + // with many endpoints; an aggregated list is enough for visibility. + suites := map[string]int{} + endpoints := map[string][]string{} + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.CipherSuite == "" { + continue + } + suites[p.CipherSuite]++ + endpoints[p.CipherSuite] = append(endpoints[p.CipherSuite], p.Endpoint) + } + if len(suites) == 0 { + return []sdk.CheckState{unknownState( + "tls.cipher_suite.skipped", + "No endpoint completed a TLS handshake.", + )} + } + names := make([]string, 0, len(suites)) + for s := range suites { + names = append(names, s) + } + sort.Strings(names) + parts := make([]string, 0, len(names)) + for _, n := range names { + parts = append(parts, fmt.Sprintf("%s (%d)", n, suites[n])) + } + return []sdk.CheckState{{ + Status: sdk.StatusInfo, + Code: "tls.cipher_suite.negotiated", + Message: "Negotiated cipher suites: " + strings.Join(parts, ", "), + Meta: map[string]any{"suites": endpoints}, + }} +} diff --git a/checker/rules_reachability.go b/checker/rules_reachability.go new file mode 100644 index 0000000..6540059 --- /dev/null +++ b/checker/rules_reachability.go @@ -0,0 +1,48 @@ +package checker + +import ( + "context" + "fmt" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// reachabilityRule flags endpoints that did not accept a TCP connection. +type reachabilityRule struct{} + +func (r *reachabilityRule) Name() string { return "tls.reachability" } +func (r *reachabilityRule) Description() string { + return "Verifies that every discovered TLS endpoint accepts a TCP connection." +} + +func (r *reachabilityRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.reachability.no_endpoints")} + } + + var out []sdk.CheckState + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.TCPError == "" { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusCrit, + Code: "tls.reachability.tcp_unreachable", + Subject: subjectOf(p), + Message: fmt.Sprintf("Cannot open TCP connection to %s: %s", p.Endpoint, p.TCPError), + Meta: metaOf(p), + }) + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.reachability.ok", + "All discovered endpoints accepted a TCP connection.", + )} + } + return out +} diff --git a/checker/rules_starttls.go b/checker/rules_starttls.go new file mode 100644 index 0000000..cea5cdc --- /dev/null +++ b/checker/rules_starttls.go @@ -0,0 +1,108 @@ +package checker + +import ( + "context" + "fmt" + + sdk "git.happydns.org/checker-sdk-go/checker" +) + +// starttlsAdvertisedRule flags STARTTLS endpoints whose server did not +// advertise the upgrade. Severity depends on RequireSTARTTLS: opportunistic +// STARTTLS degrades to a warning; mandatory STARTTLS is critical. +type starttlsAdvertisedRule struct{} + +func (r *starttlsAdvertisedRule) Name() string { return "tls.starttls_advertised" } +func (r *starttlsAdvertisedRule) Description() string { + return "Verifies that STARTTLS endpoints advertise the upgrade capability." +} + +func (r *starttlsAdvertisedRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.starttls_advertised.no_endpoints")} + } + + var out []sdk.CheckState + anySTARTTLS := false + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if p.STARTTLSDialect == "" { + continue + } + anySTARTTLS = true + if !p.STARTTLSNotOffered { + continue + } + status := sdk.StatusWarn + if p.RequireSTARTTLS { + status = sdk.StatusCrit + } + out = append(out, sdk.CheckState{ + Status: status, + Code: "tls.starttls_advertised.missing", + Subject: subjectOf(p), + Message: fmt.Sprintf("Server on %s does not advertise STARTTLS.", p.Endpoint), + Meta: metaOf(p), + }) + } + if !anySTARTTLS { + return []sdk.CheckState{unknownState( + "tls.starttls_advertised.not_applicable", + "No STARTTLS endpoint in the discovered set.", + )} + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.starttls_advertised.ok", + "STARTTLS is advertised on every STARTTLS endpoint.", + )} + } + return out +} + +// starttlsSupportedRule flags endpoints whose STARTTLS dialect is not +// implemented by this checker. A misconfigured discovery entry (typo, new +// protocol) should be visible as its own concern rather than blending into +// generic handshake failures. +type starttlsSupportedRule struct{} + +func (r *starttlsSupportedRule) Name() string { return "tls.starttls_dialect_supported" } +func (r *starttlsSupportedRule) Description() string { + return "Verifies that discovered STARTTLS dialects are implemented by the checker." +} + +func (r *starttlsSupportedRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState { + data, errSt := loadData(ctx, obs) + if errSt != nil { + return []sdk.CheckState{*errSt} + } + if len(data.Probes) == 0 { + return []sdk.CheckState{emptyCaseState("tls.starttls_dialect_supported.no_endpoints")} + } + + var out []sdk.CheckState + for _, ref := range sortedRefs(data) { + p := data.Probes[ref] + if !p.STARTTLSUnsupportedProto { + continue + } + out = append(out, sdk.CheckState{ + Status: sdk.StatusError, + Code: "tls.starttls_dialect_supported.unknown", + Subject: subjectOf(p), + Message: fmt.Sprintf("Unsupported STARTTLS dialect %q for %s.", p.STARTTLSDialect, p.Endpoint), + Meta: metaOf(p), + }) + } + if len(out) == 0 { + return []sdk.CheckState{passState( + "tls.starttls_dialect_supported.ok", + "Every STARTTLS dialect encountered is implemented.", + )} + } + return out +} diff --git a/checker/starttls.go b/checker/starttls.go index 8fb1edd..b06adf6 100644 --- a/checker/starttls.go +++ b/checker/starttls.go @@ -1,6 +1,41 @@ package checker -import "net" +import ( + "bufio" + "fmt" + "io" + "net" +) + +// maxSTARTTLSLineBytes caps the length of a single line read from a STARTTLS +// peer. Real banners and CAPABILITY responses are well under 1 KiB; this +// bound prevents a malicious or buggy server from exhausting memory by +// withholding the line terminator. +const maxSTARTTLSLineBytes = 8 * 1024 + +// readLineLimited reads bytes from r up to and including the next '\n', or +// until maxSTARTTLSLineBytes have been read without one (in which case it +// returns an error). The returned string keeps the trailing '\n' so callers +// can use the same parsing logic as bufio.Reader.ReadString('\n'). +func readLineLimited(r *bufio.Reader) (string, error) { + out := make([]byte, 0, 128) + for { + b, err := r.ReadByte() + if err != nil { + if err == io.EOF && len(out) > 0 { + return string(out), io.ErrUnexpectedEOF + } + return string(out), err + } + out = append(out, b) + if b == '\n' { + return string(out), nil + } + if len(out) >= maxSTARTTLSLineBytes { + return string(out), fmt.Errorf("line exceeds %d bytes without terminator", maxSTARTTLSLineBytes) + } + } +} // starttlsUpgrader performs the plaintext portion of a STARTTLS upgrade on // conn, leaving conn ready for tls.Client(conn, …).Handshake(). On success @@ -13,3 +48,18 @@ var starttlsUpgraders = map[string]starttlsUpgrader{} func registerStartTLS(protocol string, upgrader starttlsUpgrader) { starttlsUpgraders[protocol] = upgrader } + +// upgraderFor returns a tlsenum-compatible upgrader callback for a given +// STARTTLS dialect, plus an ok flag. An empty dialect means direct TLS and +// returns (nil, true) — tlsenum will skip the upgrade phase. An unknown +// dialect returns (nil, false) so the caller can record the skip reason. +func upgraderFor(dialect, sni string) (func(net.Conn) error, bool) { + if dialect == "" { + return nil, true + } + up, ok := starttlsUpgraders[dialect] + if !ok { + return nil, false + } + return func(c net.Conn) error { return up(c, sni) }, true +} diff --git a/checker/starttls_imap.go b/checker/starttls_imap.go index 7a7a6fb..4c04010 100644 --- a/checker/starttls_imap.go +++ b/checker/starttls_imap.go @@ -15,7 +15,7 @@ func init() { func starttlsIMAP(conn net.Conn, sni string) error { rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn)) - if _, err := rw.ReadString('\n'); err != nil { + if _, err := readLineLimited(rw.Reader); err != nil { return fmt.Errorf("read greeting: %w", err) } @@ -23,12 +23,12 @@ func starttlsIMAP(conn net.Conn, sni string) error { return fmt.Errorf("write CAPABILITY: %w", err) } if err := rw.Flush(); err != nil { - return err + return fmt.Errorf("flush CAPABILITY: %w", err) } supportsSTARTTLS := false for { - line, err := rw.ReadString('\n') + line, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read CAPABILITY: %w", err) } @@ -36,6 +36,10 @@ func starttlsIMAP(conn net.Conn, sni string) error { supportsSTARTTLS = true } if strings.HasPrefix(line, "A001 ") { + rest := strings.TrimSpace(line[len("A001 "):]) + if !strings.HasPrefix(strings.ToUpper(rest), "OK") { + return fmt.Errorf("CAPABILITY rejected by server: %s", rest) + } break } } @@ -44,13 +48,13 @@ func starttlsIMAP(conn net.Conn, sni string) error { } if _, err := rw.WriteString("A002 STARTTLS\r\n"); err != nil { - return err + return fmt.Errorf("write STARTTLS: %w", err) } if err := rw.Flush(); err != nil { - return err + return fmt.Errorf("flush STARTTLS: %w", err) } for { - line, err := rw.ReadString('\n') + line, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read STARTTLS response: %w", err) } diff --git a/checker/starttls_ldap.go b/checker/starttls_ldap.go index 30b47d3..40d1c5d 100644 --- a/checker/starttls_ldap.go +++ b/checker/starttls_ldap.go @@ -52,7 +52,10 @@ func starttlsLDAP(conn net.Conn, sni string) error { if err != nil { return fmt.Errorf("read response length: %w", err) } - if length <= 0 || length > 4096 { + // 16 KiB comfortably accommodates an ExtendedResponse with a verbose + // diagnosticMessage while still bounding memory against a hostile peer. + const maxLDAPResponseBytes = 16 * 1024 + if length <= 0 || length > maxLDAPResponseBytes { return fmt.Errorf("unreasonable LDAP response length %d", length) } body := make([]byte, length) diff --git a/checker/starttls_pop3.go b/checker/starttls_pop3.go index 887933a..f46414c 100644 --- a/checker/starttls_pop3.go +++ b/checker/starttls_pop3.go @@ -15,7 +15,7 @@ func init() { func starttlsPOP3(conn net.Conn, sni string) error { rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn)) - greeting, err := rw.ReadString('\n') + greeting, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read greeting: %w", err) } @@ -24,19 +24,19 @@ func starttlsPOP3(conn net.Conn, sni string) error { } if _, err := rw.WriteString("CAPA\r\n"); err != nil { - return err + return fmt.Errorf("write CAPA: %w", err) } if err := rw.Flush(); err != nil { - return err + return fmt.Errorf("flush CAPA: %w", err) } - first, err := rw.ReadString('\n') + first, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read CAPA: %w", err) } supportsSTLS := false if strings.HasPrefix(first, "+OK") { for { - line, err := rw.ReadString('\n') + line, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read CAPA body: %w", err) } @@ -54,12 +54,12 @@ func starttlsPOP3(conn net.Conn, sni string) error { } if _, err := rw.WriteString("STLS\r\n"); err != nil { - return err + return fmt.Errorf("write STLS: %w", err) } if err := rw.Flush(); err != nil { - return err + return fmt.Errorf("flush STLS: %w", err) } - resp, err := rw.ReadString('\n') + resp, err := readLineLimited(rw.Reader) if err != nil { return fmt.Errorf("read STLS response: %w", err) } diff --git a/checker/starttls_smtp.go b/checker/starttls_smtp.go index 39db327..ccc0211 100644 --- a/checker/starttls_smtp.go +++ b/checker/starttls_smtp.go @@ -7,6 +7,11 @@ import ( "strings" ) +// EHLOHostname is the hostname sent in the SMTP EHLO command during STARTTLS +// negotiation. Override it at startup (e.g. via -ldflags or programmatically) +// to match the identity of the host running the checker. +var EHLOHostname = "checker.localhost" + func init() { registerStartTLS("smtp", starttlsSMTP) registerStartTLS("submission", starttlsSMTP) @@ -20,7 +25,7 @@ func starttlsSMTP(conn net.Conn, sni string) error { return fmt.Errorf("read greeting: %w", err) } - if _, err := rw.WriteString("EHLO checker.happydomain.org\r\n"); err != nil { + if _, err := fmt.Fprintf(rw, "EHLO %s\r\n", EHLOHostname); err != nil { return fmt.Errorf("write ehlo: %w", err) } if err := rw.Flush(); err != nil { @@ -60,7 +65,7 @@ func readSMTPGreeting(r *bufio.Reader) error { func readSMTPResponse(r *bufio.Reader) ([]string, error) { var out []string for { - line, err := r.ReadString('\n') + line, err := readLineLimited(r) if err != nil { return out, err } diff --git a/checker/starttls_test.go b/checker/starttls_test.go new file mode 100644 index 0000000..0f76ebd --- /dev/null +++ b/checker/starttls_test.go @@ -0,0 +1,431 @@ +package checker + +import ( + "bufio" + "errors" + "io" + "net" + "strings" + "testing" + "time" +) + +// runStartTLS drives upgrader against a fake server. The server callback runs +// on the peer end of an in-memory pipe and may read/write the plaintext +// dialect transcript. The test deadline guards both ends from hanging. +func runStartTLS(t *testing.T, upgrader func(net.Conn, string) error, sni string, server func(net.Conn) error) error { + t.Helper() + clientConn, serverConn := net.Pipe() + deadline := time.Now().Add(2 * time.Second) + _ = clientConn.SetDeadline(deadline) + _ = serverConn.SetDeadline(deadline) + + srvErr := make(chan error, 1) + go func() { + defer serverConn.Close() + srvErr <- server(serverConn) + }() + + clientErr := upgrader(clientConn, sni) + clientConn.Close() + + if err := <-srvErr; err != nil && !errors.Is(err, io.EOF) && !errors.Is(err, io.ErrClosedPipe) { + t.Logf("server side returned: %v", err) + } + return clientErr +} + +// readLineCRLF reads one CRLF-terminated line. +func readLineCRLF(r *bufio.Reader) (string, error) { + line, err := r.ReadString('\n') + return strings.TrimRight(line, "\r\n"), err +} + +func TestStartTLS_SMTP_OK(t *testing.T) { + err := runStartTLS(t, starttlsSMTP, "mail.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + if _, err := io.WriteString(c, "220 mail.example.com ESMTP\r\n"); err != nil { + return err + } + ehlo, err := readLineCRLF(br) + if err != nil { + return err + } + if !strings.HasPrefix(ehlo, "EHLO ") { + return errors.New("expected EHLO") + } + if _, err := io.WriteString(c, "250-mail.example.com\r\n250-SIZE 10485760\r\n250 STARTTLS\r\n"); err != nil { + return err + } + stls, err := readLineCRLF(br) + if err != nil { + return err + } + if stls != "STARTTLS" { + return errors.New("expected STARTTLS") + } + _, err = io.WriteString(c, "220 ready\r\n") + return err + }) + if err != nil { + t.Fatalf("expected success, got: %v", err) + } +} + +func TestStartTLS_SMTP_NotAdvertised(t *testing.T) { + err := runStartTLS(t, starttlsSMTP, "mail.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "220 mail.example.com ESMTP\r\n") + if _, err := readLineCRLF(br); err != nil { + return err + } + _, err := io.WriteString(c, "250-mail.example.com\r\n250 SIZE 10485760\r\n") + return err + }) + if !errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("expected errStartTLSNotOffered, got: %v", err) + } +} + +func TestStartTLS_SMTP_Refused(t *testing.T) { + err := runStartTLS(t, starttlsSMTP, "mail.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "220 mail.example.com ESMTP\r\n") + _, _ = readLineCRLF(br) + _, _ = io.WriteString(c, "250-mail.example.com\r\n250 STARTTLS\r\n") + _, _ = readLineCRLF(br) + _, err := io.WriteString(c, "454 TLS not available\r\n") + return err + }) + if err == nil { + t.Fatal("expected refusal error") + } + if errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("refusal should not be classified as not-offered: %v", err) + } +} + +func TestStartTLS_IMAP_OK(t *testing.T) { + err := runStartTLS(t, starttlsIMAP, "imap.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "* OK IMAP4rev1 ready\r\n") + cap1, err := readLineCRLF(br) + if err != nil { + return err + } + if !strings.HasSuffix(cap1, "CAPABILITY") { + return errors.New("expected CAPABILITY") + } + _, _ = io.WriteString(c, "* CAPABILITY IMAP4rev1 STARTTLS LOGINDISABLED\r\nA001 OK CAPABILITY completed\r\n") + stls, err := readLineCRLF(br) + if err != nil { + return err + } + if !strings.HasSuffix(stls, "STARTTLS") { + return errors.New("expected STARTTLS") + } + _, err = io.WriteString(c, "A002 OK Begin TLS\r\n") + return err + }) + if err != nil { + t.Fatalf("expected success, got: %v", err) + } +} + +func TestStartTLS_IMAP_Refused(t *testing.T) { + err := runStartTLS(t, starttlsIMAP, "imap.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "* OK IMAP4rev1 ready\r\n") + _, _ = readLineCRLF(br) + _, _ = io.WriteString(c, "* CAPABILITY IMAP4rev1 STARTTLS\r\nA001 OK CAPABILITY completed\r\n") + _, _ = readLineCRLF(br) + _, err := io.WriteString(c, "A002 NO STARTTLS unavailable\r\n") + return err + }) + if err == nil { + t.Fatal("expected refusal error") + } + if errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("refusal should not be classified as not-offered: %v", err) + } +} + +func TestStartTLS_IMAP_NotAdvertised(t *testing.T) { + err := runStartTLS(t, starttlsIMAP, "imap.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "* OK IMAP4rev1 ready\r\n") + _, _ = readLineCRLF(br) + _, err := io.WriteString(c, "* CAPABILITY IMAP4rev1 LOGINDISABLED\r\nA001 OK CAPABILITY completed\r\n") + return err + }) + if !errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("expected errStartTLSNotOffered, got: %v", err) + } +} + +func TestStartTLS_POP3_OK(t *testing.T) { + err := runStartTLS(t, starttlsPOP3, "pop.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "+OK POP3 ready\r\n") + capa, err := readLineCRLF(br) + if err != nil { + return err + } + if capa != "CAPA" { + return errors.New("expected CAPA") + } + _, _ = io.WriteString(c, "+OK capa list\r\nUSER\r\nSTLS\r\n.\r\n") + stls, err := readLineCRLF(br) + if err != nil { + return err + } + if stls != "STLS" { + return errors.New("expected STLS") + } + _, err = io.WriteString(c, "+OK begin TLS\r\n") + return err + }) + if err != nil { + t.Fatalf("expected success, got: %v", err) + } +} + +func TestStartTLS_POP3_NotAdvertised(t *testing.T) { + err := runStartTLS(t, starttlsPOP3, "pop.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "+OK POP3 ready\r\n") + _, _ = readLineCRLF(br) + _, err := io.WriteString(c, "+OK capa list\r\nUSER\r\n.\r\n") + return err + }) + if !errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("expected errStartTLSNotOffered, got: %v", err) + } +} + +func TestStartTLS_POP3_Refused(t *testing.T) { + err := runStartTLS(t, starttlsPOP3, "pop.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + _, _ = io.WriteString(c, "+OK POP3 ready\r\n") + _, _ = readLineCRLF(br) + _, _ = io.WriteString(c, "+OK capa list\r\nUSER\r\nSTLS\r\n.\r\n") + _, _ = readLineCRLF(br) + _, err := io.WriteString(c, "-ERR STLS unavailable\r\n") + return err + }) + if err == nil { + t.Fatal("expected refusal error") + } + if errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("refusal should not be classified as not-offered: %v", err) + } +} + +func TestStartTLS_XMPP_OK(t *testing.T) { + err := runStartTLS(t, starttlsXMPPClient, "xmpp.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + // Read the client's stream header (one line is enough for our writer). + buf := make([]byte, 1024) + if _, err := br.Read(buf); err != nil { + return err + } + _, _ = io.WriteString(c, + ``+ + ``) + // Read the request from the client. + if _, err := br.Read(buf); err != nil { + return err + } + _, err := io.WriteString(c, ``) + return err + }) + if err != nil { + t.Fatalf("expected success, got: %v", err) + } +} + +func TestStartTLS_XMPP_NotAdvertised(t *testing.T) { + err := runStartTLS(t, starttlsXMPPClient, "xmpp.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + buf := make([]byte, 1024) + if _, err := br.Read(buf); err != nil { + return err + } + _, err := io.WriteString(c, + ``+ + `PLAIN`) + return err + }) + if !errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("expected errStartTLSNotOffered, got: %v", err) + } +} + +func TestStartTLS_XMPP_Refused(t *testing.T) { + err := runStartTLS(t, starttlsXMPPClient, "xmpp.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + buf := make([]byte, 1024) + if _, err := br.Read(buf); err != nil { + return err + } + _, _ = io.WriteString(c, + ``+ + ``) + if _, err := br.Read(buf); err != nil { + return err + } + _, err := io.WriteString(c, ``) + return err + }) + if err == nil { + t.Fatal("expected failure error") + } + if errors.Is(err, errStartTLSNotOffered) { + t.Fatalf(" should not be classified as not-offered: %v", err) + } +} + +func TestStartTLS_XMPP_StreamError(t *testing.T) { + err := runStartTLS(t, starttlsXMPPClient, "xmpp.example.com", func(c net.Conn) error { + br := bufio.NewReader(c) + buf := make([]byte, 1024) + if _, err := br.Read(buf); err != nil { + return err + } + _, err := io.WriteString(c, + ``+ + ``) + return err + }) + if err == nil { + t.Fatal("expected stream:error to surface as error") + } +} + +func TestStartTLS_LDAP_OK(t *testing.T) { + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + // Drain the StartTLS request (fixed 31 bytes: 0x30 0x1d + 29 bytes). + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + // Build a minimal ExtendedResponse with resultCode=0. + // LDAPMessage SEQUENCE { messageID INTEGER 1, [APPLICATION 24] SEQUENCE { resultCode ENUMERATED 0, matchedDN "", diagnosticMessage "" } } + resp := []byte{ + 0x30, 0x0c, // SEQUENCE, length 12 + 0x02, 0x01, 0x01, // messageID = 1 + 0x78, 0x07, // [APPLICATION 24], length 7 + 0x0a, 0x01, 0x00, // resultCode ENUMERATED 0 + 0x04, 0x00, // matchedDN "" + 0x04, 0x00, // diagnosticMessage "" + } + _, err := c.Write(resp) + return err + }) + if err != nil { + t.Fatalf("expected success, got: %v", err) + } +} + +func TestStartTLS_LDAP_WrongTag(t *testing.T) { + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + _, err := c.Write([]byte{0x42, 0x00}) + return err + }) + if err == nil { + t.Fatal("expected error for wrong tag") + } + if errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("malformed response should not be classified as not-offered: %v", err) + } +} + +func TestStartTLS_LDAP_OversizedLength(t *testing.T) { + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + // SEQUENCE with long-form length = 0x10000 (64 KiB) — beyond our 16 KiB cap. + _, err := c.Write([]byte{0x30, 0x83, 0x01, 0x00, 0x00}) + return err + }) + if err == nil { + t.Fatal("expected oversized-length error") + } +} + +func TestStartTLS_LDAP_TruncatedBody(t *testing.T) { + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + // Announce 12 bytes of body, only send 5 then close. + _, err := c.Write([]byte{0x30, 0x0c, 0x02, 0x01, 0x01, 0x78, 0x07}) + return err + }) + if err == nil { + t.Fatal("expected error on truncated body") + } +} + +func TestStartTLS_LDAP_DiagnosticMessageOver4KiB(t *testing.T) { + // A real-world response with a verbose diagnosticMessage can exceed the + // previous 4 KiB cap. Confirm the bumped 16 KiB cap accepts it. + const diagLen = 8000 + diag := make([]byte, diagLen) + for i := range diag { + diag[i] = 'x' + } + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + // Body: messageID(3) + extResp tag(1) + extResp len(3) + resultCode(3) + matchedDN(2) + diag tag+long-len(4) + diag bytes + // extResp inner length = resultCode(3) + matchedDN(2) + diagTLV(4+diagLen) = 9 + diagLen + extInner := 9 + diagLen + // Outer SEQUENCE inner length = messageID(3) + extResp TLV(1+3+extInner) + outerInner := 3 + 4 + extInner + buf := []byte{0x30, 0x82, byte(outerInner >> 8), byte(outerInner & 0xff)} + buf = append(buf, 0x02, 0x01, 0x01) // messageID + buf = append(buf, 0x78, 0x82, byte(extInner>>8), byte(extInner&0xff)) + buf = append(buf, 0x0a, 0x01, 0x00) // resultCode = success + buf = append(buf, 0x04, 0x00) // matchedDN "" + buf = append(buf, 0x04, 0x82, byte(diagLen>>8), byte(diagLen&0xff)) + buf = append(buf, diag...) + _, err := c.Write(buf) + return err + }) + if err != nil { + t.Fatalf("expected success with verbose diagnosticMessage, got: %v", err) + } +} + +func TestStartTLS_LDAP_Refused(t *testing.T) { + err := runStartTLS(t, starttlsLDAP, "ldap.example.com", func(c net.Conn) error { + req := make([]byte, 31) + if _, err := io.ReadFull(c, req); err != nil { + return err + } + // resultCode = 53 (unwillingToPerform) -> classified as not-offered. + resp := []byte{ + 0x30, 0x0c, + 0x02, 0x01, 0x01, + 0x78, 0x07, + 0x0a, 0x01, 0x35, + 0x04, 0x00, + 0x04, 0x00, + } + _, err := c.Write(resp) + return err + }) + if !errors.Is(err, errStartTLSNotOffered) { + t.Fatalf("expected errStartTLSNotOffered for resultCode 53, got: %v", err) + } +} diff --git a/checker/starttls_xmpp.go b/checker/starttls_xmpp.go index d810654..7b6e1ad 100644 --- a/checker/starttls_xmpp.go +++ b/checker/starttls_xmpp.go @@ -22,45 +22,66 @@ func starttlsXMPPServer(conn net.Conn, sni string) error { return starttlsXMPP(conn, sni, "jabber:server") } +// xmppPreTLSReadLimit caps the bytes the XML decoder may pull from an +// untrusted peer before the TLS handshake. The legitimate pre-TLS exchange +// ( opening + + ) is well under +// 1 KiB; 64 KiB is generous for non-malicious servers while bounding memory +// against a peer that streams unbounded XML to exhaust the prober. +const xmppPreTLSReadLimit = 64 * 1024 + func starttlsXMPP(conn net.Conn, sni, ns string) error { header := fmt.Sprintf(``, ns, sni) if _, err := io.WriteString(conn, header); err != nil { return fmt.Errorf("write stream header: %w", err) } - dec := xml.NewDecoder(conn) + dec := xml.NewDecoder(&io.LimitedReader{R: conn, N: xmppPreTLSReadLimit}) // Read the inbound opening and its . + // A peer that opens with (or anything other than features) + // is not going to advertise STARTTLS: surface that immediately rather + // than spinning on tokens until the deadline fires. hasStartTLS := false +outer: for { tok, err := dec.Token() if err != nil { return fmt.Errorf("read stream features: %w", err) } - if se, ok := tok.(xml.StartElement); ok { - if se.Name.Local == "features" { - // Scan features children. - for { - t2, err := dec.Token() - if err != nil { - return fmt.Errorf("read features body: %w", err) + se, ok := tok.(xml.StartElement) + if !ok { + continue + } + switch se.Name.Local { + case "stream": + // Outer opening. Continue reading children. + continue + case "features": + for { + t2, err := dec.Token() + if err != nil { + return fmt.Errorf("read features body: %w", err) + } + switch ee := t2.(type) { + case xml.StartElement: + if ee.Name.Local == "starttls" { + hasStartTLS = true } - switch ee := t2.(type) { - case xml.StartElement: - if ee.Name.Local == "starttls" { - hasStartTLS = true - } - _ = dec.Skip() - case xml.EndElement: - if ee.Name.Local == "features" { - goto doneFeatures - } + if err := dec.Skip(); err != nil { + return fmt.Errorf("skip feature %q: %w", ee.Name.Local, err) + } + case xml.EndElement: + if ee.Name.Local == "features" { + break outer } } } + case "error": + return fmt.Errorf("server returned before features") + default: + return fmt.Errorf("%w: unexpected element %q before features", errStartTLSNotOffered, se.Name.Local) } } -doneFeatures: if !hasStartTLS { return fmt.Errorf("%w: XMPP features did not advertise starttls", errStartTLSNotOffered) } diff --git a/checker/types.go b/checker/types.go index 81e59bd..a0d5389 100644 --- a/checker/types.go +++ b/checker/types.go @@ -9,8 +9,9 @@ const ObservationKeyTLSProbes = "tls_probes" // Option ids on CheckerOptions. const ( - OptionEndpoints = "endpoints" - OptionProbeTimeoutMs = "probeTimeoutMs" + OptionEndpoints = "endpoints" + OptionProbeTimeoutMs = "probeTimeoutMs" + OptionEnumerateCiphers = "enumerateCiphers" ) // Defaults shared between the definition's Default field and the runtime @@ -22,33 +23,67 @@ const ( MaxConcurrentProbes = 32 ) -// Severity values used in Issue.Severity (lowercase, ascii). -const ( - SeverityCrit = "crit" - SeverityWarn = "warn" - SeverityInfo = "info" -) - // TLSData is the full collected payload written under ObservationKeyTLSProbes. type TLSData struct { Probes map[string]TLSProbe `json:"probes"` CollectedAt time.Time `json:"collected_at"` } -// TLSProbe captures the outcome of probing a single endpoint. Field names -// mirror what consumers already parse (checker-xmpp's tlsProbeView). +// TLSProbe captures the outcome of probing a single endpoint. +// +// Only raw observation fields live here. Judgement (severity, pass/fail, +// human-facing messages) is derived from these fields by CheckRules. type TLSProbe struct { - Host string `json:"host"` - Port uint16 `json:"port"` - Endpoint string `json:"endpoint"` - Type string `json:"type"` - SNI string `json:"sni,omitempty"` - TLSVersion string `json:"tls_version,omitempty"` - CipherSuite string `json:"cipher_suite,omitempty"` - HostnameMatch *bool `json:"hostname_match,omitempty"` - ChainValid *bool `json:"chain_valid,omitempty"` - NotAfter time.Time `json:"not_after,omitempty"` - Issuer string `json:"issuer,omitempty"` + Host string `json:"host"` + Port uint16 `json:"port"` + Endpoint string `json:"endpoint"` + Type string `json:"type"` + SNI string `json:"sni,omitempty"` + + // RequireSTARTTLS is copied from the discovery entry so rules can tell + // whether a missing STARTTLS advertisement is a hard or soft failure. + RequireSTARTTLS bool `json:"require_starttls,omitempty"` + + // STARTTLSDialect mirrors contract.TLSEndpoint.STARTTLS verbatim. An + // empty value means direct TLS. + STARTTLSDialect string `json:"starttls_dialect,omitempty"` + + // Raw error strings. Exactly one of TCPError or HandshakeError is set + // when the probe failed before gathering handshake data. + TCPError string `json:"tcp_error,omitempty"` + HandshakeError string `json:"handshake_error,omitempty"` + + // STARTTLSNotOffered is true when HandshakeError was produced because + // the server did not advertise STARTTLS (errStartTLSNotOffered). + STARTTLSNotOffered bool `json:"starttls_not_offered,omitempty"` + + // STARTTLSUnsupportedProto is true when the STARTTLS dialect is not + // implemented by this checker. + STARTTLSUnsupportedProto bool `json:"starttls_unsupported_proto,omitempty"` + + // TLSHandshakeOK is true when a TLS handshake completed. It is + // independent from chain validity. + TLSHandshakeOK bool `json:"tls_handshake_ok,omitempty"` + + // TLSVersionNum is the numeric TLS version negotiated (uint16 from + // crypto/tls). Zero means no handshake occurred. Kept as an unsigned + // integer so rules can compare against tls.VersionTLS12 without + // re-parsing a string. + TLSVersionNum uint16 `json:"tls_version_num,omitempty"` + + TLSVersion string `json:"tls_version,omitempty"` + CipherSuite string `json:"cipher_suite,omitempty"` + CipherSuiteID uint16 `json:"cipher_suite_id,omitempty"` + + // NoPeerCert is true when the handshake succeeded but the server sent + // no certificate. + NoPeerCert bool `json:"no_peer_cert,omitempty"` + + HostnameMatch *bool `json:"hostname_match,omitempty"` + ChainValid *bool `json:"chain_valid,omitempty"` + ChainVerifyErr string `json:"chain_verify_err,omitempty"` + NotAfter time.Time `json:"not_after,omitempty"` + Issuer string `json:"issuer,omitempty"` // IssuerDN is the leaf's issuer as an RFC 2253 DN string, suitable for // matching the CCADB CAA Identifiers CSV "Subject" column when the AKI // lookup misses. @@ -56,17 +91,26 @@ type TLSProbe struct { // IssuerAKI is the uppercase hex of the leaf's Authority Key Identifier // extension (i.e. the issuer cert's SKI). This is the primary lookup key // into the CCADB CAA Identifiers CSV ("Subject Key Identifier (Hex)"). - IssuerAKI string `json:"issuer_aki,omitempty"` - Subject string `json:"subject,omitempty"` - DNSNames []string `json:"dns_names,omitempty"` + IssuerAKI string `json:"issuer_aki,omitempty"` + Subject string `json:"subject,omitempty"` + DNSNames []string `json:"dns_names,omitempty"` // Chain carries one entry per certificate presented by the server // (leaf first, then intermediates in order). Each entry precomputes // the four TLSA selector×matching_type hashes plus the raw DER so // DANE consumers can match without re-handshaking or re-parsing. - Chain []CertInfo `json:"chain,omitempty"` - ElapsedMS int64 `json:"elapsed_ms,omitempty"` - Error string `json:"error,omitempty"` - Issues []Issue `json:"issues,omitempty"` + Chain []CertInfo `json:"chain,omitempty"` + ElapsedMS int64 `json:"elapsed_ms,omitempty"` + + // Enum carries the protocol-version and cipher-suite sweep. It is only + // populated when the user enables OptionEnumerateCiphers. Direct TLS and + // supported STARTTLS dialects are both swept; a STARTTLS endpoint with + // an unknown dialect is skipped with a reason recorded in Enum.Skipped. + Enum *TLSEnumeration `json:"enum,omitempty"` + + // Error is a compatibility summary of whichever raw error applies. + // Left for any external consumer still inspecting it; rules should + // look at TCPError / HandshakeError instead. + Error string `json:"error,omitempty"` } // CertInfo describes one certificate in the presented chain together with @@ -84,6 +128,10 @@ type CertInfo struct { Subject string `json:"subject,omitempty"` Issuer string `json:"issuer,omitempty"` + // NotAfter is the certificate's expiry. Carried so editors can show + // "expires on …" without re-parsing the DER. + NotAfter time.Time `json:"not_after,omitempty"` + // Selector 0 = full certificate. CertSHA256 string `json:"cert_sha256,omitempty"` CertSHA512 string `json:"cert_sha512,omitempty"` @@ -97,10 +145,35 @@ type CertInfo struct { SPKIDERBase64 string `json:"spki_der_base64,omitempty"` } -// Issue is a single TLS finding surfaced to the consumer. -type Issue struct { - Code string `json:"code"` - Severity string `json:"severity"` - Message string `json:"message,omitempty"` - Fix string `json:"fix,omitempty"` +// Expiry thresholds shared by rules. +const ( + ExpiringSoonThreshold = 14 * 24 * time.Hour +) + +// TLSEnumeration is the result of sweeping a (version × cipher) matrix +// against an endpoint. The exact set the server accepts (rather than just the +// one combination it negotiated under default Go preferences) lets rules flag +// legacy versions and weak cipher suites that would otherwise stay invisible. +type TLSEnumeration struct { + // Versions lists every protocol version for which at least one cipher + // was accepted, with the matching cipher suites. + Versions []EnumVersion `json:"versions,omitempty"` + // Skipped is set when enumeration was not attempted (e.g. STARTTLS + // endpoint, prior handshake failure). Empty when enumeration ran. + Skipped string `json:"skipped,omitempty"` + // DurationMS is the wall-clock time spent enumerating, for ops visibility. + DurationMS int64 `json:"duration_ms,omitempty"` +} + +// EnumVersion is one accepted protocol version plus the ciphers it accepted. +type EnumVersion struct { + Version uint16 `json:"version"` + Name string `json:"name"` + Ciphers []EnumCipher `json:"ciphers,omitempty"` +} + +// EnumCipher is one accepted cipher suite. +type EnumCipher struct { + ID uint16 `json:"id"` + Name string `json:"name"` } diff --git a/checker/upgrader_for_test.go b/checker/upgrader_for_test.go new file mode 100644 index 0000000..3803649 --- /dev/null +++ b/checker/upgrader_for_test.go @@ -0,0 +1,91 @@ +package checker + +import ( + "errors" + "net" + "testing" +) + +// TestUpgraderFor_DirectTLS verifies that an empty dialect returns a nil +// upgrader with ok=true: tlsenum's contract is that nil means "no upgrade +// phase", so direct-TLS endpoints must round-trip through this branch +// without producing a shim that would call into the registry. +func TestUpgraderFor_DirectTLS(t *testing.T) { + up, ok := upgraderFor("", "example.test") + if !ok { + t.Fatalf("expected ok=true for empty dialect") + } + if up != nil { + t.Fatalf("expected nil upgrader for empty dialect, got %T", up) + } +} + +func TestUpgraderFor_UnknownDialect(t *testing.T) { + up, ok := upgraderFor("totally-not-a-dialect", "example.test") + if ok { + t.Fatalf("expected ok=false for unknown dialect") + } + if up != nil { + t.Fatalf("expected nil upgrader for unknown dialect, got %T", up) + } +} + +// TestUpgraderFor_KnownDialect_ForwardsSNI registers a temporary fake dialect +// in the registry, asks upgraderFor for its callback, invokes the callback, +// and asserts the registered upgrader received the expected SNI. We can't +// reuse a real dialect for this because they all read/write protocol-specific +// banners on the connection — the point of this test is the SNI plumbing in +// the closure, not the dialect's own behavior. +func TestUpgraderFor_KnownDialect_ForwardsSNI(t *testing.T) { + const dialect = "test-fake" + const wantSNI = "host.example.test" + + var ( + gotSNI string + gotConn net.Conn + ) + wantErr := errors.New("sentinel from fake upgrader") + registerStartTLS(dialect, func(c net.Conn, sni string) error { + gotConn = c + gotSNI = sni + return wantErr + }) + defer delete(starttlsUpgraders, dialect) + + up, ok := upgraderFor(dialect, wantSNI) + if !ok || up == nil { + t.Fatalf("expected non-nil upgrader and ok=true, got nil=%v ok=%v", up == nil, ok) + } + + // Use a closed pipe end as a sentinel net.Conn — the registered upgrader + // captures it without doing I/O, so a real connection is unnecessary. + a, b := net.Pipe() + _ = a.Close() + _ = b.Close() + + if err := up(a); !errors.Is(err, wantErr) { + t.Fatalf("expected sentinel error to propagate, got %v", err) + } + if gotSNI != wantSNI { + t.Fatalf("registered upgrader received SNI %q, want %q", gotSNI, wantSNI) + } + if gotConn != a { + t.Fatalf("registered upgrader received a different conn than the one passed in") + } +} + +// TestUpgraderFor_RealDialects_AllRegistered guards against silently dropping +// a dialect from the registry: every protocol referenced by the contract's +// STARTTLS values must resolve to a non-nil upgrader. The list mirrors the +// dialects implemented in starttls_*.go. +func TestUpgraderFor_RealDialects_AllRegistered(t *testing.T) { + dialects := []string{"smtp", "submission", "imap", "pop3", "xmpp-client", "xmpp-server", "ldap"} + for _, d := range dialects { + t.Run(d, func(t *testing.T) { + up, ok := upgraderFor(d, "host.example") + if !ok || up == nil { + t.Fatalf("dialect %q is not registered", d) + } + }) + } +} diff --git a/contract/contract.go b/contract/contract.go index bc038b0..76f7e07 100644 --- a/contract/contract.go +++ b/contract/contract.go @@ -16,6 +16,7 @@ import ( "encoding/hex" "encoding/json" "fmt" + "strings" sdk "git.happydns.org/checker-sdk-go/checker" ) @@ -58,10 +59,27 @@ type TLSEndpoint struct { RequireSTARTTLS bool `json:"require,omitempty"` } +// Validate rejects endpoints that cannot be probed: empty Host or zero Port. +// STARTTLS dialect is intentionally not checked here (the checker surfaces +// unsupported dialects at runtime via the tls.starttls_dialect_supported +// rule), and SNI defaults to Host downstream. +func (ep TLSEndpoint) Validate() error { + if strings.TrimSpace(strings.TrimSuffix(ep.Host, ".")) == "" { + return fmt.Errorf("contract: TLSEndpoint.Host is required") + } + if ep.Port == 0 { + return fmt.Errorf("contract: TLSEndpoint.Port must be 1-65535") + } + return nil +} + // NewEntry wraps ep in an sdk.DiscoveryEntry with Type, a deterministic Ref // derived from ep, and a marshaled Payload. The returned entry can be // returned as-is from a DiscoveryPublisher implementation. func NewEntry(ep TLSEndpoint) (sdk.DiscoveryEntry, error) { + if err := ep.Validate(); err != nil { + return sdk.DiscoveryEntry{}, err + } payload, err := json.Marshal(ep) if err != nil { return sdk.DiscoveryEntry{}, fmt.Errorf("contract: marshal TLSEndpoint: %w", err) @@ -95,7 +113,7 @@ func Ref(ep TLSEndpoint) string { req = "1" } canonical := fmt.Sprintf("%s|%d|%s|%s|%s", ep.Host, ep.Port, sni, ep.STARTTLS, req) - sum := sha1.Sum([]byte(canonical)) + sum := sha1.Sum([]byte(canonical)) // #nosec G401 G505 -- non-cryptographic stable key; see doc comment above return hex.EncodeToString(sum[:8]) } @@ -109,6 +127,9 @@ func ParseEntry(e sdk.DiscoveryEntry) (TLSEndpoint, error) { if err := json.Unmarshal(e.Payload, &ep); err != nil { return TLSEndpoint{}, fmt.Errorf("contract: unmarshal TLSEndpoint: %w", err) } + if err := ep.Validate(); err != nil { + return TLSEndpoint{}, err + } return ep, nil } @@ -123,7 +144,7 @@ type Entry struct { } // ParseEntries filters entries to those of Type and decodes each payload. -// Entries of other types are ignored silently — they belong to other +// Entries of other types are ignored silently, they belong to other // contracts. Entries of this type whose Payload fails to unmarshal are // skipped and returned as warnings so a single malformed payload cannot // starve the checker of the rest of its workload. diff --git a/go.mod b/go.mod index 416eb47..c23c67d 100644 --- a/go.mod +++ b/go.mod @@ -2,4 +2,12 @@ module git.happydns.org/checker-tls go 1.25.0 -require git.happydns.org/checker-sdk-go v1.2.0 +require git.happydns.org/checker-sdk-go v1.5.0 + +require ( + github.com/andybalholm/brotli v1.0.6 // indirect + github.com/klauspost/compress v1.17.4 // indirect + github.com/refraction-networking/utls v1.8.2 // indirect + golang.org/x/crypto v0.36.0 // indirect + golang.org/x/sys v0.31.0 // indirect +) diff --git a/go.sum b/go.sum index 272600a..c811775 100644 --- a/go.sum +++ b/go.sum @@ -1,2 +1,12 @@ -git.happydns.org/checker-sdk-go v1.2.0 h1:v4MpKAz0W3PwP+bxx3pya8w893sVH5xTD1of1cc0TV8= -git.happydns.org/checker-sdk-go v1.2.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI= +git.happydns.org/checker-sdk-go v1.5.0 h1:5uD5Cm6xJ+lwnhbJ09iCXGHbYS9zRh+Yh0NeBHkAPBY= +git.happydns.org/checker-sdk-go v1.5.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI= +github.com/andybalholm/brotli v1.0.6 h1:Yf9fFpf49Zrxb9NlQaluyE92/+X7UVHlhMNJN2sxfOI= +github.com/andybalholm/brotli v1.0.6/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig= +github.com/klauspost/compress v1.17.4 h1:Ej5ixsIri7BrIjBkRZLTo6ghwrEtHFk7ijlczPW4fZ4= +github.com/klauspost/compress v1.17.4/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM= +github.com/refraction-networking/utls v1.8.2 h1:j4Q1gJj0xngdeH+Ox/qND11aEfhpgoEvV+S9iJ2IdQo= +github.com/refraction-networking/utls v1.8.2/go.mod h1:jkSOEkLqn+S/jtpEHPOsVv/4V4EVnelwbMQl4vCWXAM= +golang.org/x/crypto v0.36.0 h1:AnAEvhDddvBdpY+uR+MyHmuZzzNqXSe/GvuDeob5L34= +golang.org/x/crypto v0.36.0/go.mod h1:Y4J0ReaxCR1IMaabaSMugxJES1EpwhBHhv2bDHklZvc= +golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik= +golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k= diff --git a/main.go b/main.go index f781e37..c967401 100644 --- a/main.go +++ b/main.go @@ -4,20 +4,28 @@ import ( "flag" "log" - sdk "git.happydns.org/checker-sdk-go/checker" + "git.happydns.org/checker-sdk-go/checker/server" tls "git.happydns.org/checker-tls/checker" ) var Version = "custom-build" +// EHLOHostname is set via -ldflags to identify this checker instance in SMTP +// EHLO greetings. Falls back to the package default ("checker.localhost") when +// left empty. +var EHLOHostname = "" + var listenAddr = flag.String("listen", ":8080", "HTTP listen address") func main() { flag.Parse() tls.Version = Version + if EHLOHostname != "" { + tls.EHLOHostname = EHLOHostname + } - server := sdk.NewServer(tls.Provider()) - if err := server.ListenAndServe(*listenAddr); err != nil { + srv := server.New(tls.Provider()) + if err := srv.ListenAndServe(*listenAddr); err != nil { log.Fatalf("server error: %v", err) } } diff --git a/plugin/plugin.go b/plugin/plugin.go index 6648452..991152a 100644 --- a/plugin/plugin.go +++ b/plugin/plugin.go @@ -9,5 +9,6 @@ var Version = "custom-build" func NewCheckerPlugin() (*sdk.CheckerDefinition, sdk.ObservationProvider, error) { tls.Version = Version - return tls.Definition(), tls.Provider(), nil + prvd := tls.Provider() + return prvd.(sdk.CheckerDefinitionProvider).Definition(), prvd, nil } diff --git a/tlsenum/ciphers.go b/tlsenum/ciphers.go new file mode 100644 index 0000000..303bfdd --- /dev/null +++ b/tlsenum/ciphers.go @@ -0,0 +1,103 @@ +package tlsenum + +// CipherSuite pairs an IANA TLS cipher suite ID with its standard name. +// +// The catalog below intentionally covers the "real-world" set: modern AEAD +// suites used by TLS 1.2/1.3, plus a long tail of legacy CBC/RC4/3DES/EXPORT +// suites we want to *detect* on remote servers (so we can flag them), even +// though Go's stdlib refuses to negotiate them. utls lets us put any 16-bit +// value in the offered list, so the server's accept/reject decision is the +// source of truth. +type CipherSuite struct { + ID uint16 + Name string + // TLS13 is true for the five TLS 1.3 AEAD suites; those must only be + // offered with TLS 1.3 ClientHellos. + TLS13 bool +} + +// TLS13Ciphers are the AEAD suites defined for TLS 1.3 (RFC 8446 §B.4). +var TLS13Ciphers = []CipherSuite{ + {0x1301, "TLS_AES_128_GCM_SHA256", true}, + {0x1302, "TLS_AES_256_GCM_SHA384", true}, + {0x1303, "TLS_CHACHA20_POLY1305_SHA256", true}, + {0x1304, "TLS_AES_128_CCM_SHA256", true}, + {0x1305, "TLS_AES_128_CCM_8_SHA256", true}, +} + +// LegacyCiphers covers TLS 1.0/1.1/1.2 (and SSLv3) suites. Not exhaustive of +// the IANA registry, but it includes everything any modern audit cares about: +// ECDHE/DHE/RSA/PSK kex, AES-GCM/CCM/CBC, ChaCha20, 3DES, RC4, NULL, EXPORT, +// anonymous, and a handful of GOST/CAMELLIA/ARIA entries seen in the wild. +var LegacyCiphers = []CipherSuite{ + // ECDHE-ECDSA + {0xC02B, "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256", false}, + {0xC02C, "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384", false}, + {0xCCA9, "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256", false}, + {0xC023, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256", false}, + {0xC024, "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384", false}, + {0xC009, "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA", false}, + {0xC00A, "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA", false}, + {0xC008, "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA", false}, + {0xC007, "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA", false}, + {0xC006, "TLS_ECDHE_ECDSA_WITH_NULL_SHA", false}, + + // ECDHE-RSA + {0xC02F, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256", false}, + {0xC030, "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384", false}, + {0xCCA8, "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256", false}, + {0xC027, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256", false}, + {0xC028, "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384", false}, + {0xC013, "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA", false}, + {0xC014, "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA", false}, + {0xC012, "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA", false}, + {0xC011, "TLS_ECDHE_RSA_WITH_RC4_128_SHA", false}, + {0xC010, "TLS_ECDHE_RSA_WITH_NULL_SHA", false}, + + // DHE-RSA + {0x009E, "TLS_DHE_RSA_WITH_AES_128_GCM_SHA256", false}, + {0x009F, "TLS_DHE_RSA_WITH_AES_256_GCM_SHA384", false}, + {0xCCAA, "TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256", false}, + {0x0067, "TLS_DHE_RSA_WITH_AES_128_CBC_SHA256", false}, + {0x006B, "TLS_DHE_RSA_WITH_AES_256_CBC_SHA256", false}, + {0x0033, "TLS_DHE_RSA_WITH_AES_128_CBC_SHA", false}, + {0x0039, "TLS_DHE_RSA_WITH_AES_256_CBC_SHA", false}, + {0x0016, "TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA", false}, + + // Plain RSA + {0x009C, "TLS_RSA_WITH_AES_128_GCM_SHA256", false}, + {0x009D, "TLS_RSA_WITH_AES_256_GCM_SHA384", false}, + {0x003C, "TLS_RSA_WITH_AES_128_CBC_SHA256", false}, + {0x003D, "TLS_RSA_WITH_AES_256_CBC_SHA256", false}, + {0x002F, "TLS_RSA_WITH_AES_128_CBC_SHA", false}, + {0x0035, "TLS_RSA_WITH_AES_256_CBC_SHA", false}, + {0x000A, "TLS_RSA_WITH_3DES_EDE_CBC_SHA", false}, + {0x0005, "TLS_RSA_WITH_RC4_128_SHA", false}, + {0x0004, "TLS_RSA_WITH_RC4_128_MD5", false}, + {0x003B, "TLS_RSA_WITH_NULL_SHA256", false}, + {0x0002, "TLS_RSA_WITH_NULL_SHA", false}, + {0x0001, "TLS_RSA_WITH_NULL_MD5", false}, + + // Anonymous (broken by design — flag if seen) + {0x006D, "TLS_DH_anon_WITH_AES_256_CBC_SHA256", false}, + {0x0034, "TLS_DH_anon_WITH_AES_128_CBC_SHA", false}, + {0x003A, "TLS_DH_anon_WITH_AES_256_CBC_SHA", false}, + {0xC018, "TLS_ECDH_anon_WITH_AES_128_CBC_SHA", false}, + {0xC019, "TLS_ECDH_anon_WITH_AES_256_CBC_SHA", false}, + + // EXPORT (40-bit, illegal since ~2000 — flag if seen) + {0x0008, "TLS_RSA_EXPORT_WITH_DES40_CBC_SHA", false}, + {0x0014, "TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA", false}, + {0x0017, "TLS_DH_anon_EXPORT_WITH_RC4_40_MD5", false}, + {0x0019, "TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA", false}, + {0x0003, "TLS_RSA_EXPORT_WITH_RC4_40_MD5", false}, + {0x0006, "TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5", false}, +} + +// AllCiphers concatenates legacy and TLS 1.3 cipher suites. +func AllCiphers() []CipherSuite { + out := make([]CipherSuite, 0, len(LegacyCiphers)+len(TLS13Ciphers)) + out = append(out, LegacyCiphers...) + out = append(out, TLS13Ciphers...) + return out +} diff --git a/tlsenum/tlsenum.go b/tlsenum/tlsenum.go new file mode 100644 index 0000000..b2a7562 --- /dev/null +++ b/tlsenum/tlsenum.go @@ -0,0 +1,283 @@ +// Package tlsenum probes a remote endpoint to discover the exact set of +// SSL/TLS protocol versions and cipher suites it accepts. +// +// The Go stdlib's crypto/tls only negotiates a curated subset of modern +// suites and refuses to even offer legacy ones (RC4, 3DES, EXPORT, NULL, +// anonymous, …), so it cannot be used to *audit* what a server accepts. +// Instead we use github.com/refraction-networking/utls to craft a fully +// custom ClientHello carrying a single (version, cipher) pair and let the +// server tell us — by ServerHello or alert — whether it accepts it. +// +// Scope of the minimal version: +// - TLS 1.0, 1.1, 1.2, 1.3 (negotiated via the SupportedVersions extension). +// - Direct TLS only; STARTTLS upgrade is the caller's responsibility for +// now (the existing checker package owns those dialect handlers). +// - SSLv3 and SSLv2 are deliberately out of scope; SSLv2 has a different +// wire format and would require either raw byte crafting or a legacy +// OpenSSL sidecar. +package tlsenum + +import ( + "context" + "errors" + "fmt" + "net" + "strconv" + "time" + + utls "github.com/refraction-networking/utls" +) + +// AllVersions is the set of protocol versions Probe knows how to offer. +var AllVersions = []uint16{ + utls.VersionTLS10, + utls.VersionTLS11, + utls.VersionTLS12, + utls.VersionTLS13, +} + +// VersionName returns a human-readable label for a TLS protocol version. +func VersionName(v uint16) string { + switch v { + case utls.VersionTLS10: + return "TLS 1.0" + case utls.VersionTLS11: + return "TLS 1.1" + case utls.VersionTLS12: + return "TLS 1.2" + case utls.VersionTLS13: + return "TLS 1.3" + default: + return "0x" + strconv.FormatUint(uint64(v), 16) + } +} + +// ProbeResult is the outcome of a single (version, cipher) attempt. +type ProbeResult struct { + OfferedVersion uint16 + OfferedCipher uint16 + + // Accepted is true when the server completed enough of the handshake to + // echo back a ServerHello with our offered version and cipher. We do not + // require a fully successful handshake (certificate verification can fail + // for unrelated reasons); ServerHello acceptance is what we measure. + Accepted bool + + // NegotiatedVersion / NegotiatedCipher are populated when Accepted is + // true. They should match the offered values; if they differ, the server + // is misbehaving (or downgrading). + NegotiatedVersion uint16 + NegotiatedCipher uint16 + + // Err is the underlying error from the dial or handshake. For a clean + // "server rejected this combination" outcome it will typically be a TLS + // alert (handshake_failure, protocol_version, insufficient_security…). + Err error +} + +// ProbeOptions controls a single Probe call. +type ProbeOptions struct { + // Timeout bounds dial + (optional) upgrade + handshake. A zero value + // means no deadline beyond the parent context's. + Timeout time.Duration + + // Upgrader, when non-nil, is invoked on the freshly-dialed connection + // before the TLS ClientHello is sent. It is the injection point for + // STARTTLS dialect handlers (SMTP, IMAP, POP3, …): the callback drives + // the plaintext exchange that requests the upgrade and returns nil once + // the connection is ready for tls.Client. tlsenum stays agnostic of the + // dialect; the caller owns that knowledge. + Upgrader func(net.Conn) error +} + +// Probe attempts a TLS handshake against addr offering exactly one protocol +// version and one cipher suite. It never panics; transport / handshake errors +// are reported on the returned ProbeResult. +// +// addr must be host:port. sni is the SNI to send (pass the host if unsure). +func Probe(ctx context.Context, addr, sni string, version, cipher uint16, opts ProbeOptions) ProbeResult { + res := ProbeResult{OfferedVersion: version, OfferedCipher: cipher} + + dialCtx := ctx + if opts.Timeout > 0 { + var cancel context.CancelFunc + dialCtx, cancel = context.WithTimeout(ctx, opts.Timeout) + defer cancel() + } + + d := &net.Dialer{} + raw, err := d.DialContext(dialCtx, "tcp", addr) + if err != nil { + res.Err = fmt.Errorf("dial: %w", err) + return res + } + defer raw.Close() + if dl, ok := dialCtx.Deadline(); ok { + _ = raw.SetDeadline(dl) + } + + if opts.Upgrader != nil { + if err := opts.Upgrader(raw); err != nil { + res.Err = fmt.Errorf("upgrade: %w", err) + return res + } + } + + cfg := &utls.Config{ + ServerName: sni, + InsecureSkipVerify: true, // #nosec G402 -- enumeration; we only care about handshake outcome + } + uc := utls.UClient(raw, cfg, utls.HelloCustom) + spec := buildSpec(version, cipher, sni) + if err := uc.ApplyPreset(&spec); err != nil { + res.Err = fmt.Errorf("apply-preset: %w", err) + return res + } + + err = uc.Handshake() + state := uc.ConnectionState() + if err == nil { + res.Accepted = true + res.NegotiatedVersion = state.Version + res.NegotiatedCipher = state.CipherSuite + return res + } + + // Some servers complete ServerHello (so we know they accepted version + + // cipher) but fail later — for example, certificate-mismatch or the + // client failing to verify. If state has a non-zero Version/CipherSuite + // matching what we offered, we still count it as accepted. + if state.Version == version && state.CipherSuite == cipher && state.CipherSuite != 0 { + res.Accepted = true + res.NegotiatedVersion = state.Version + res.NegotiatedCipher = state.CipherSuite + } + res.Err = err + return res +} + +// EnumerateOptions controls Enumerate. +type EnumerateOptions struct { + // Timeout for each individual probe. Defaults to 5s when zero. + ProbeTimeout time.Duration + // Versions to try. Defaults to AllVersions when nil. + Versions []uint16 + // Ciphers to try. Defaults to AllCiphers() when nil. The TLS13 flag is + // honored: TLS 1.3 ciphers are only offered with TLS 1.3 probes, and + // vice-versa. + Ciphers []CipherSuite + // Upgrader, when non-nil, is forwarded to every sub-probe (see + // ProbeOptions.Upgrader). It is invoked on a freshly-dialed connection + // before each ClientHello, so STARTTLS dialect handlers run once per + // probe, not once for the whole sweep. + Upgrader func(net.Conn) error +} + +// EnumerationResult is the aggregate outcome of an enumeration sweep. +type EnumerationResult struct { + // SupportedVersions lists protocol versions for which at least one + // cipher was accepted. + SupportedVersions []uint16 + // CiphersByVersion lists, per accepted version, the cipher suites the + // server agreed to negotiate. + CiphersByVersion map[uint16][]CipherSuite +} + +// Enumerate sweeps a (version × cipher) matrix against addr and returns what +// the server actually accepts. Probes are performed sequentially; concurrency +// can be added later but tends to upset some middleboxes when probing too +// hard. +func Enumerate(ctx context.Context, addr, sni string, opts EnumerateOptions) (EnumerationResult, error) { + if opts.ProbeTimeout == 0 { + opts.ProbeTimeout = 5 * time.Second + } + versions := opts.Versions + if versions == nil { + versions = AllVersions + } + ciphers := opts.Ciphers + if ciphers == nil { + ciphers = AllCiphers() + } + + out := EnumerationResult{ + CiphersByVersion: make(map[uint16][]CipherSuite), + } + seenVersion := make(map[uint16]bool) + + for _, v := range versions { + isTLS13 := v == utls.VersionTLS13 + for _, c := range ciphers { + if c.TLS13 != isTLS13 { + continue + } + if err := ctx.Err(); err != nil { + return out, err + } + r := Probe(ctx, addr, sni, v, c.ID, ProbeOptions{ + Timeout: opts.ProbeTimeout, + Upgrader: opts.Upgrader, + }) + if !r.Accepted { + continue + } + out.CiphersByVersion[v] = append(out.CiphersByVersion[v], c) + if !seenVersion[v] { + seenVersion[v] = true + out.SupportedVersions = append(out.SupportedVersions, v) + } + } + } + return out, nil +} + +// buildSpec assembles a ClientHelloSpec offering exactly one cipher and one +// protocol version. For TLS 1.3 the legacy version field stays at TLS 1.2 and +// the real version is signalled through the SupportedVersions extension, per +// RFC 8446 §4.1.2 / §4.2.1. +func buildSpec(version, cipher uint16, sni string) utls.ClientHelloSpec { + tlsVersMin := version + tlsVersMax := version + if version == utls.VersionTLS13 { + // utls inspects TLSVersMax to decide whether to drive TLS 1.3 + // machinery; the on-the-wire legacy_version stays TLS 1.2. + tlsVersMin = utls.VersionTLS12 + } + + exts := []utls.TLSExtension{ + &utls.SNIExtension{ServerName: sni}, + &utls.SupportedCurvesExtension{Curves: []utls.CurveID{ + utls.X25519, utls.CurveP256, utls.CurveP384, utls.CurveP521, + }}, + &utls.SupportedPointsExtension{SupportedPoints: []byte{0}}, // uncompressed + &utls.SignatureAlgorithmsExtension{SupportedSignatureAlgorithms: []utls.SignatureScheme{ + utls.ECDSAWithP256AndSHA256, utls.ECDSAWithP384AndSHA384, utls.ECDSAWithP521AndSHA512, + utls.PSSWithSHA256, utls.PSSWithSHA384, utls.PSSWithSHA512, + utls.PKCS1WithSHA256, utls.PKCS1WithSHA384, utls.PKCS1WithSHA512, + utls.PKCS1WithSHA1, utls.ECDSAWithSHA1, + }}, + &utls.RenegotiationInfoExtension{Renegotiation: utls.RenegotiateOnceAsClient}, + } + + if version == utls.VersionTLS13 { + exts = append(exts, + &utls.SupportedVersionsExtension{Versions: []uint16{utls.VersionTLS13}}, + &utls.KeyShareExtension{KeyShares: []utls.KeyShare{ + {Group: utls.X25519}, + }}, + &utls.PSKKeyExchangeModesExtension{Modes: []uint8{utls.PskModeDHE}}, + ) + } + + return utls.ClientHelloSpec{ + TLSVersMin: tlsVersMin, + TLSVersMax: tlsVersMax, + CipherSuites: []uint16{cipher}, + CompressionMethods: []byte{0}, // null + Extensions: exts, + } +} + +// ErrNoVersions is returned when an enumeration request asks for an empty set +// of versions or ciphers. +var ErrNoVersions = errors.New("tlsenum: no versions or ciphers to probe") diff --git a/tlsenum/tlsenum_test.go b/tlsenum/tlsenum_test.go new file mode 100644 index 0000000..7d94670 --- /dev/null +++ b/tlsenum/tlsenum_test.go @@ -0,0 +1,223 @@ +package tlsenum + +import ( + "context" + "crypto/ecdsa" + "crypto/elliptic" + "crypto/rand" + stdtls "crypto/tls" + "crypto/x509" + "crypto/x509/pkix" + "encoding/pem" + "errors" + "fmt" + "io" + "math/big" + "net" + "os" + "testing" + "time" + + utls "github.com/refraction-networking/utls" +) + +// selfSignedCert returns a brand-new in-memory self-signed cert + key for +// "test.local", suitable for stdlib tls.Server. +func selfSignedCert() (stdtls.Certificate, error) { + key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader) + if err != nil { + return stdtls.Certificate{}, err + } + tmpl := x509.Certificate{ + SerialNumber: big.NewInt(1), + Subject: pkix.Name{CommonName: "test.local"}, + NotBefore: time.Now().Add(-time.Hour), + NotAfter: time.Now().Add(time.Hour), + DNSNames: []string{"test.local"}, + KeyUsage: x509.KeyUsageDigitalSignature, + ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}, + } + der, err := x509.CreateCertificate(rand.Reader, &tmpl, &tmpl, &key.PublicKey, key) + if err != nil { + return stdtls.Certificate{}, err + } + keyDER, err := x509.MarshalECPrivateKey(key) + if err != nil { + return stdtls.Certificate{}, err + } + certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der}) + keyPEM := pem.EncodeToMemory(&pem.Block{Type: "EC PRIVATE KEY", Bytes: keyDER}) + return stdtls.X509KeyPair(certPEM, keyPEM) +} + +// runFakeStartTLSServer accepts one connection, expects a "STARTTLS\r\n" +// line, replies "OK\r\n", then runs a TLS handshake. It returns once the +// handshake completes (or fails) and the connection is closed. +func runFakeStartTLSServer(ln net.Listener, cert stdtls.Certificate) error { + c, err := ln.Accept() + if err != nil { + return err + } + defer c.Close() + buf := make([]byte, len("STARTTLS\r\n")) + if _, err := io.ReadFull(c, buf); err != nil { + return err + } + if string(buf) != "STARTTLS\r\n" { + return fmt.Errorf("unexpected pre-tls line: %q", string(buf)) + } + if _, err := c.Write([]byte("OK\r\n")); err != nil { + return err + } + tc := stdtls.Server(c, &stdtls.Config{ + Certificates: []stdtls.Certificate{cert}, + MinVersion: stdtls.VersionTLS12, + }) + defer tc.Close() + return tc.Handshake() +} + +// liveTarget returns a host:port to enumerate against, or skips the test if +// the environment hasn't opted in. Network tests are gated behind +// TLSENUM_LIVE=1 so the unit-test suite stays hermetic. +func liveTarget(t *testing.T) (addr, sni string) { + t.Helper() + if os.Getenv("TLSENUM_LIVE") == "" { + t.Skip("set TLSENUM_LIVE=1 to run live enumeration tests") + } + host := os.Getenv("TLSENUM_HOST") + if host == "" { + host = "tls-v1-2.badssl.com" + } + port := os.Getenv("TLSENUM_PORT") + if port == "" { + port = "1012" + } + return net.JoinHostPort(host, port), host +} + +func TestProbe_TLS12_AESGCM(t *testing.T) { + addr, sni := liveTarget(t) + ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second) + defer cancel() + + r := Probe(ctx, addr, sni, utls.VersionTLS12, 0xC02F /* ECDHE-RSA-AES128-GCM-SHA256 */, ProbeOptions{Timeout: 5 * time.Second}) + if !r.Accepted { + t.Fatalf("expected ECDHE-RSA-AES128-GCM-SHA256 to be accepted on TLS 1.2 target; got err=%v", r.Err) + } + if r.NegotiatedVersion != utls.VersionTLS12 { + t.Fatalf("negotiated version = %x, want %x", r.NegotiatedVersion, utls.VersionTLS12) + } +} + +func TestEnumerate_BasicShape(t *testing.T) { + addr, sni := liveTarget(t) + ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute) + defer cancel() + + res, err := Enumerate(ctx, addr, sni, EnumerateOptions{ + ProbeTimeout: 5 * time.Second, + }) + if err != nil { + t.Fatalf("Enumerate: %v", err) + } + if len(res.SupportedVersions) == 0 { + t.Fatalf("no supported versions discovered") + } + for v, ciphers := range res.CiphersByVersion { + if len(ciphers) == 0 { + t.Errorf("version %s listed as supported but no ciphers recorded", VersionName(v)) + } + t.Logf("%s: %d cipher(s)", VersionName(v), len(ciphers)) + } +} + +// TestProbe_UpgraderInvoked uses a tiny in-memory STARTTLS-style server: a +// goroutine listens, reads one "STARTTLS\r\n" line, replies "OK\r\n", then +// performs a real Go-stdlib TLS handshake. We probe through the matching +// Upgrader and assert the handshake succeeds — proving the callback runs in +// the right place between dial and ClientHello. +func TestProbe_UpgraderInvoked(t *testing.T) { + cert, err := selfSignedCert() + if err != nil { + t.Fatalf("self-signed cert: %v", err) + } + ln, err := net.Listen("tcp", "127.0.0.1:0") + if err != nil { + t.Fatalf("listen: %v", err) + } + defer ln.Close() + + srvDone := make(chan error, 1) + go func() { srvDone <- runFakeStartTLSServer(ln, cert) }() + + upgrader := func(c net.Conn) error { + if _, err := c.Write([]byte("STARTTLS\r\n")); err != nil { + return err + } + buf := make([]byte, 16) + n, err := c.Read(buf) + if err != nil { + return err + } + if got := string(buf[:n]); got != "OK\r\n" { + return fmt.Errorf("unexpected reply: %q", got) + } + return nil + } + + ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) + defer cancel() + r := Probe(ctx, ln.Addr().String(), "test.local", + utls.VersionTLS12, 0xC02B, /* ECDHE-ECDSA-AES128-GCM-SHA256 (matches the P-256 cert) */ + ProbeOptions{Timeout: 3 * time.Second, Upgrader: upgrader}) + if !r.Accepted { + t.Fatalf("expected handshake to succeed through upgrader; err=%v", r.Err) + } + if r.NegotiatedVersion != utls.VersionTLS12 { + t.Fatalf("negotiated %#x, want %#x", r.NegotiatedVersion, utls.VersionTLS12) + } + if err := <-srvDone; err != nil { + t.Logf("fake server done with: %v", err) // accept clean close from utls + } +} + +func TestProbe_UpgraderError(t *testing.T) { + ln, err := net.Listen("tcp", "127.0.0.1:0") + if err != nil { + t.Fatalf("listen: %v", err) + } + defer ln.Close() + go func() { + c, _ := ln.Accept() + if c != nil { + c.Close() + } + }() + + wantErr := errors.New("plaintext refused starttls") + r := Probe(context.Background(), ln.Addr().String(), "x", + utls.VersionTLS12, 0xC02F, + ProbeOptions{Timeout: 2 * time.Second, Upgrader: func(net.Conn) error { return wantErr }}) + if r.Accepted { + t.Fatalf("expected probe to fail when upgrader returns error") + } + if r.Err == nil || !errors.Is(r.Err, wantErr) { + t.Fatalf("expected wrapped upgrader error, got %v", r.Err) + } +} + +func TestVersionName(t *testing.T) { + cases := map[uint16]string{ + utls.VersionTLS10: "TLS 1.0", + utls.VersionTLS11: "TLS 1.1", + utls.VersionTLS12: "TLS 1.2", + utls.VersionTLS13: "TLS 1.3", + 0x9999: "0x9999", + } + for v, want := range cases { + if got := VersionName(v); got != want { + t.Errorf("VersionName(%#x) = %q, want %q", v, got, want) + } + } +}