th5/ca_set.go
Adam Langley f4b6e2236c crypto/x509, crypto/tls: improve root matching and observe CA flag.
The key/value format of X.500 names means that it's possible to encode
a name with multiple values for, say, organisation. RFC5280
doesn't seem to consider this, but there are Verisign root
certificates which do this and, in order to find the correct
root certificate in some cases, we need to handle it.

Also, CA certificates should set the CA flag and we now check
this. After looking at the other X.509 extensions it appears
that they are universally ignored/bit rotted away so we ignore
them.

R=rsc
CC=golang-dev
https://golang.org/cl/2249042
2010-09-20 12:17:31 -04:00

69 lines
1.8 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tls
import (
"crypto/x509"
"encoding/pem"
"strings"
)
// A CASet is a set of certificates.
type CASet struct {
bySubjectKeyId map[string]*x509.Certificate
byName map[string]*x509.Certificate
}
func NewCASet() *CASet {
return &CASet{
make(map[string]*x509.Certificate),
make(map[string]*x509.Certificate),
}
}
func nameToKey(name *x509.Name) string {
return strings.Join(name.Country, ",") + "/" + strings.Join(name.Organization, ",") + "/" + strings.Join(name.OrganizationalUnit, ",") + "/" + name.CommonName
}
// FindParent attempts to find the certificate in s which signs the given
// certificate. If no such certificate can be found, it returns nil.
func (s *CASet) FindParent(cert *x509.Certificate) (parent *x509.Certificate) {
if len(cert.AuthorityKeyId) > 0 {
return s.bySubjectKeyId[string(cert.AuthorityKeyId)]
}
return s.byName[nameToKey(&cert.Issuer)]
}
// SetFromPEM attempts to parse a series of PEM encoded root certificates. It
// appends any certificates found to s and returns true if any certificates
// were successfully parsed. On many Linux systems, /etc/ssl/cert.pem will
// contains the system wide set of root CAs in a format suitable for this
// function.
func (s *CASet) SetFromPEM(pemCerts []byte) (ok bool) {
for len(pemCerts) > 0 {
var block *pem.Block
block, pemCerts = pem.Decode(pemCerts)
if block == nil {
break
}
if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
continue
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
continue
}
if len(cert.SubjectKeyId) > 0 {
s.bySubjectKeyId[string(cert.SubjectKeyId)] = cert
}
s.byName[nameToKey(&cert.Subject)] = cert
ok = true
}
return
}