pki: improve serial number generation + fix team association

Replace math/rand by crypto/rand.

Fix big when associating certificate with leading zero: nginx prepend 0 wherehas we don't.

admin/api/certificate.go

@@ -1,11 +1,12 @@
 package api
 
 import (
+	"crypto/rand"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"math/rand"
 	"io/ioutil"
+	"math/big"
 	"os"
 	"path"
 	"time"
@@ -87,10 +88,19 @@ func getTeamP12File(cert fic.Certificate, _ []byte) (interface{}, error) {
 
 func generateClientCert(_ httprouter.Params, _ []byte) (interface{}, error) {
 	// First, generate a new, unique, serial
-	serial := rand.Int63()
-	for fic.ExistingCertSerial(serial) {
-		serial = rand.Int63()
+	var serial_gen [8]byte
+	if _, err := rand.Read(serial_gen[:]); err != nil {
+		return nil, err
 	}
+	for fic.ExistingCertSerial(serial_gen) {
+		if _, err := rand.Read(serial_gen[:]); err != nil {
+			return nil, err
+		}
+	}
+
+	var serial_b big.Int
+	serial_b.SetBytes(serial_gen[:])
+	serial := serial_b.Uint64()
 
 	// Let's pick a random password
 	password, err := pki.GeneratePassword()
@@ -148,7 +158,10 @@ func updateCertificateAssociation(cert fic.Certificate, body []byte) (interface{
 	// moreover, backend doesn't update the DB at registration, it only creates a symlink
 	cert.IdTeam = uc.Team
 
-	dstLinkPath := path.Join(TeamsDir, fmt.Sprintf("_AUTH_ID_%X", cert.Id))
+	var serial big.Int
+	serial.SetUint64(cert.Id)
+
+	dstLinkPath := path.Join(TeamsDir, fmt.Sprintf("_AUTH_ID_%0X", serial.Bytes()))
 
 	if uc.Team != nil {
 		srcLinkPath := fmt.Sprintf("%d", *uc.Team)

admin/api/handlers.go

@@ -282,7 +282,7 @@ func fileHandler(f func(fic.EFile,[]byte) (interface{}, error)) func (httprouter
 
 func certificateHandler(f func(fic.Certificate,[]byte) (interface{}, error)) func (httprouter.Params,[]byte) (interface{}, error) {
 	return func (ps httprouter.Params, body []byte) (interface{}, error) {
-		if certid, err := strconv.ParseInt(string(ps.ByName("certid")), 10, 64); err != nil {
+		if certid, err := strconv.ParseUint(string(ps.ByName("certid")), 10, 64); err != nil {
 			return nil, err
 		} else if cert, err := fic.GetCertificate(certid); err != nil {
 			return nil, err

admin/pki/client.go

@@ -13,21 +13,23 @@ import (
 	"time"
 )
 
-func ClientCertificatePath(serial int64) string {
+func ClientCertificatePath(serial uint64) string {
 	return path.Join(PKIDir, fmt.Sprintf("%d", serial), "cert.pem")
 }
 
-func ClientPrivkeyPath(serial int64) string {
+func ClientPrivkeyPath(serial uint64) string {
 	return path.Join(PKIDir, fmt.Sprintf("%d", serial), "privkey.pem")
 }
 
-func ClientP12Path(serial int64) string {
+func ClientP12Path(serial uint64) string {
 	return path.Join(PKIDir, fmt.Sprintf("%d", serial), "team.p12")
 }
 
-func GenerateClient(serial int64, notBefore time.Time, notAfter time.Time, parent_cert *x509.Certificate, parent_priv *ecdsa.PrivateKey) error {
+func GenerateClient(serial uint64, notBefore time.Time, notAfter time.Time, parent_cert *x509.Certificate, parent_priv *ecdsa.PrivateKey) error {
+	var certid big.Int
+	certid.SetUint64(serial)
 	client := &x509.Certificate{
-		SerialNumber: big.NewInt(serial),
+		SerialNumber: &certid,
 		Subject: pkix.Name{
 			Organization:       []string{"EPITA"},
 			OrganizationalUnit: []string{"SRS laboratory"},
@@ -69,7 +71,7 @@ func GenerateClient(serial int64, notBefore time.Time, notAfter time.Time, paren
 	return nil
 }
 
-func WriteP12(serial int64, password string) error {
+func WriteP12(serial uint64, password string) error {
 	cmd := exec.Command("/usr/bin/openssl", "pkcs12", "-export",
 		"-inkey", ClientPrivkeyPath(serial),
 		"-in", ClientCertificatePath(serial),

libfic/certificate.go

@@ -2,11 +2,12 @@ package fic
 
 import (
 	"database/sql"
+	"math/big"
 	"time"
 )
 
 type Certificate struct {
-	Id       int64      `json:"id,string"`
+	Id       uint64     `json:"id,string"`
 	Creation time.Time  `json:"creation"`
 	Password string     `json:"password"`
 	IdTeam   *int64     `json:"id_team"`
@@ -49,17 +50,20 @@ func GetTeamCertificates(team Team) (certificates []Certificate, err error) {
 	return
 }
 
-func GetCertificate(serial int64) (c Certificate, err error) {
+func GetCertificate(serial uint64) (c Certificate, err error) {
 	err = DBQueryRow("SELECT id_cert, creation, password, id_team, revoked FROM certificates WHERE id_cert = ?", serial).Scan(&c.Id, &c.Creation, &c.Password, &c.IdTeam, &c.Revoked)
 	return
 }
 
-func ExistingCertSerial(serial int64) (bool) {
-	c, _ := GetCertificate(serial)
+func ExistingCertSerial(serial [8]byte) (bool) {
+	var m big.Int
+	m.SetBytes(serial[:])
+
+	c, _ := GetCertificate(m.Uint64())
 	return c.Id > 0
 }
 
-func RegisterCertificate(serial int64, password string) (Certificate, error) {
+func RegisterCertificate(serial uint64, password string) (Certificate, error) {
 	now := time.Now()
 	if _, err := DBExec("INSERT INTO certificates (id_cert, creation, password) VALUES (?, ?, ?)", serial, now, password); err != nil {
 		return Certificate{}, err

libfic/db.go

@@ -84,7 +84,7 @@ CREATE TABLE IF NOT EXISTS teams(
 	}
 	if _, err := db.Exec(`
 CREATE TABLE IF NOT EXISTS certificates(
-  id_cert BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
+  id_cert BIGINT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
   creation TIMESTAMP NOT NULL,
   password VARCHAR(255) NOT NULL,
   id_team INTEGER NULL,