crypto/x509/pkix: make 'v1' the default CRL version.

PKIX versions are off-by-one, so v1 is actually a zero on the wire, v2
is a one, and so on.

The RFC says that the version in a CRL is optional, but doesn't say what
the default is. Since v2 is the only accepted version, I had made the
default v2. However, OpenSSL considers the default to be v1. Also, if
the default is v2 and the element is optional then we'll never actually
write v2 on the wire. That's contrary to the RFC which clearly assumes
that v2 will be expressed on the wire in some cases.

Therefore, this change aligns with OpenSSL and assumes that v1 is the
default CRL version.

Fixes #13931

[1] https://tools.ietf.org/html/rfc5280#section-5.1

Change-Id: Ic0f638ebdd21981d92a99a882affebf3a77ab71a
Reviewed-on: https://go-review.googlesource.com/20544
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/crypto/x509/pkix/pkix.go b/src/crypto/x509/pkix/pkix.go
index 1b3e3c0440e9de6c123e865621e25c225ac4b92b..faad4061fc71347f1459fa1ea665f0159e4af622 100644 (file)
--- a/src/crypto/x509/pkix/pkix.go
+++ b/src/crypto/x509/pkix/pkix.go
@@ -177,7 +177,7 @@ func (certList *CertificateList) HasExpired(now time.Time) bool {
 // 5280, section 5.1.
 type TBSCertificateList struct {
        Raw                 asn1.RawContent
-       Version             int `asn1:"optional,default:1"`
+       Version             int `asn1:"optional,default:0"`
        Signature           AlgorithmIdentifier
        Issuer              RDNSequence
        ThisUpdate          time.Time