checker-http/checker/rules_redirect.go
Pierre-Olivier Mercier f4b8941a3d
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checker: judge HTTPS redirect by chain, not FinalURL
The probe stops at scheme-changing redirects, so FinalURL keeps the
pre-redirect http:// URL while the chain records the real https://
target. Prefer the last redirect hop's destination so a correct
http→https redirect is no longer mis-flagged as no_https_redirect.
2026-06-18 10:35:28 +09:00

74 lines
2.6 KiB
Go

// This file is part of the happyDomain (R) project.
// Copyright (c) 2020-2026 happyDomain
// Authors: Pierre-Olivier Mercier, et al.
package checker
import (
"context"
"fmt"
"net/url"
"strings"
sdk "git.happydns.org/checker-sdk-go/checker"
)
func init() { RegisterRule(&httpsRedirectRule{}) }
// httpsRedirectRule verifies that plain HTTP either redirects to HTTPS or
// fails (which is acceptable when HTTP is intentionally not served).
type httpsRedirectRule struct{}
func (r *httpsRedirectRule) Name() string { return "http.https_redirect" }
func (r *httpsRedirectRule) Description() string {
return "Plain HTTP responses must redirect to an HTTPS URL on the same host."
}
func (r *httpsRedirectRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
data, errSt := loadHTTPData(ctx, obs)
if errSt != nil {
return []sdk.CheckState{*errSt}
}
require := sdk.GetBoolOption(opts, OptionRequireHTTPS, true)
const okMsg = "HTTP redirects to HTTPS on every reachable IP."
return EvalAggregateByScheme(data, "http", "http.https_redirect", okMsg, func(p HTTPProbe, emit func(sdk.CheckState)) {
if !p.TCPConnected || p.StatusCode == 0 {
// Reachability rule handles this; an HTTP server that is
// simply not running is fine for redirect-purposes.
return
}
// Prefer the last redirect hop's destination over FinalURL. When the
// probe stops at a scheme-changing redirect (http→https), it does not
// follow the hop, so FinalURL stays the pre-redirect http:// URL while
// the chain records the real https:// target. Judging by FinalURL alone
// would mis-flag a correct http→https redirect as no_https_redirect.
final := p.FinalURL
if len(p.RedirectChain) > 0 {
final = p.RedirectChain[len(p.RedirectChain)-1].To
}
isHTTPS := false
if u, err := url.Parse(final); err == nil {
isHTTPS = strings.EqualFold(u.Scheme, "https")
}
switch {
case isHTTPS:
// Good. Aggregated below as a single OK.
case require:
emit(sdk.CheckState{
Status: sdk.StatusWarn,
Code: "http.no_https_redirect",
Subject: p.Address,
Message: fmt.Sprintf("HTTP response on %s did not redirect to HTTPS (final URL: %s, status %d)", p.Address, final, p.StatusCode),
Meta: map[string]any{"fix": "Configure your web server to redirect every plain-HTTP request to https://."},
})
default:
emit(sdk.CheckState{
Status: sdk.StatusInfo,
Code: "http.plain_http_served",
Subject: p.Address,
Message: fmt.Sprintf("HTTP responded directly without redirect (status %d)", p.StatusCode),
})
}
})
}