Revert "crypto/x509: reject serial numbers longer than 20 octets"
This reverts commit 8524931a2cdc6a57afdf6f4b3375cb261c2557da.
Reason for revert: It turns out, basically no one in private PKIs can
get this right. It causes way too much breakage, and every other impl
also ignores it, so we'll continue to be in good company.
Change-Id: I2da808b411ec12f72112c49079faf9f68ae465c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/589615
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/doc/godebug.md b/doc/godebug.md
index 41f88ca..86e02e8 100644
--- a/doc/godebug.md
+++ b/doc/godebug.md
@@ -185,11 +185,6 @@
serial numbers that are negative. This change can be reverted with
the [`x509negativeserial` setting](/pkg/crypto/x509/#ParseCertificate).
-Go 1.23 changed the behavior of
-[crypto/x509.ParseCertificate](/pkg/crypto/x509/#ParseCertificate) to reject
-serial numbers that are longer than 20 octets. This change can be reverted with
-the [`x509seriallength` setting](/pkg/crypto/x509/#ParseCertificate).
-
Go 1.23 re-enabled support in html/template for ECMAScript 6 template literals by default.
The [`jstmpllitinterp` setting](/pkg/html/template#hdr-Security_Model) no longer has
any effect.
diff --git a/src/crypto/x509/parser.go b/src/crypto/x509/parser.go
index 5cc0c77..3ba5f6a 100644
--- a/src/crypto/x509/parser.go
+++ b/src/crypto/x509/parser.go
@@ -825,7 +825,6 @@
}
var x509negativeserial = godebug.New("x509negativeserial")
-var x509seriallength = godebug.New("x509seriallength")
func parseCertificate(der []byte) (*Certificate, error) {
cert := &Certificate{}
@@ -866,27 +865,10 @@
return nil, errors.New("x509: invalid version")
}
- var serialBytes cryptobyte.String
- if !tbs.ReadASN1Element(&serialBytes, cryptobyte_asn1.INTEGER) {
- return nil, errors.New("x509: malformed serial number")
- }
- // We add two bytes for the tag and length (if the length was multi-byte,
- // which is possible, the length of the serial would be more than 256 bytes,
- // so this condition would trigger anyway).
- if len(serialBytes) > 20+2 {
- if x509seriallength.Value() != "1" {
- return nil, errors.New("x509: serial number too long (>20 octets)")
- } else {
- x509seriallength.IncNonDefault()
- }
- }
serial := new(big.Int)
- if !serialBytes.ReadASN1Integer(serial) {
+ if !tbs.ReadASN1Integer(serial) {
return nil, errors.New("x509: malformed serial number")
}
- // We do not reject zero serials, because they are unfortunately common
- // in important root certificates which will not expire for a number of
- // years.
if serial.Sign() == -1 {
if x509negativeserial.Value() != "1" {
return nil, errors.New("x509: negative serial number")
@@ -1034,10 +1016,6 @@
// Before Go 1.23, ParseCertificate accepted certificates with negative serial
// numbers. This behavior can be restored by including "x509negativeserial=1" in
// the GODEBUG environment variable.
-//
-// Before Go 1.23, ParseCertificate accepted certificates with serial numbers
-// longer than 20 octets. This behavior can be restored by including
-// "x509seriallength=1" in the GODEBUG environment variable.
func ParseCertificate(der []byte) (*Certificate, error) {
cert, err := parseCertificate(der)
if err != nil {
diff --git a/src/crypto/x509/x509_test.go b/src/crypto/x509/x509_test.go
index d40fd83..a9483b7 100644
--- a/src/crypto/x509/x509_test.go
+++ b/src/crypto/x509/x509_test.go
@@ -4086,26 +4086,3 @@
t.Fatalf("ParseCertificate() unexpected error: %v, want: %s", err, expectedErr)
}
}
-
-func TestSerialTooLong(t *testing.T) {
- template := Certificate{
- Subject: pkix.Name{CommonName: "Cert"},
- NotBefore: time.Unix(1000, 0),
- NotAfter: time.Unix(100000, 0),
- }
- for _, serial := range []*big.Int{
- big.NewInt(0).SetBytes(bytes.Repeat([]byte{5}, 21)),
- big.NewInt(0).SetBytes(bytes.Repeat([]byte{255}, 20)),
- } {
- template.SerialNumber = serial
- certDER, err := CreateCertificate(rand.Reader, &template, &template, rsaPrivateKey.Public(), rsaPrivateKey)
- if err != nil {
- t.Fatalf("CreateCertificate() unexpected error: %v", err)
- }
- expectedErr := "x509: serial number too long (>20 octets)"
- _, err = ParseCertificate(certDER)
- if err == nil || err.Error() != expectedErr {
- t.Fatalf("ParseCertificate() unexpected error: %v, want: %s", err, expectedErr)
- }
- }
-}
diff --git a/src/internal/godebugs/table.go b/src/internal/godebugs/table.go
index b44fc78..eb51255 100644
--- a/src/internal/godebugs/table.go
+++ b/src/internal/godebugs/table.go
@@ -57,7 +57,6 @@
{Name: "winsymlink", Package: "os", Changed: 22, Old: "0"},
{Name: "x509keypairleaf", Package: "crypto/tls", Changed: 23, Old: "0"},
{Name: "x509negativeserial", Package: "crypto/x509", Changed: 23, Old: "1"},
- {Name: "x509seriallength", Package: "crypto/x509", Changed: 23, Old: "1"},
{Name: "x509sha1", Package: "crypto/x509"},
{Name: "x509usefallbackroots", Package: "crypto/x509"},
{Name: "x509usepolicies", Package: "crypto/x509"},
diff --git a/src/runtime/metrics/doc.go b/src/runtime/metrics/doc.go
index 85db574..c1d0ca907 100644
--- a/src/runtime/metrics/doc.go
+++ b/src/runtime/metrics/doc.go
@@ -340,11 +340,6 @@
package due to a non-default GODEBUG=x509negativeserial=...
setting.
- /godebug/non-default-behavior/x509seriallength:events
- The number of non-default behaviors executed by the crypto/x509
- package due to a non-default GODEBUG=x509seriallength=...
- setting.
-
/godebug/non-default-behavior/x509sha1:events
The number of non-default behaviors executed by the crypto/x509
package due to a non-default GODEBUG=x509sha1=... setting.
