1 files changed, 75 insertions, 0 deletions
diff --git a/src/pkg/crypto/tls/ca_set.go b/src/pkg/crypto/tls/ca_set.go
new file mode 100644
index 000000000..e8cddd6f4
--- /dev/null
+++ b/src/pkg/crypto/tls/ca_set.go
@@ -0,0 +1,75 @@
+// 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";
+)
+
+// 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 name.Country + "/" + name.OrganizationalUnit + "/" + 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) {
+	var ok bool;
+
+	if len(cert.AuthorityKeyId) > 0 {
+		parent, ok = s.bySubjectKeyId[string(cert.AuthorityKeyId)]
+	} else {
+		parent, ok = s.byName[nameToKey(&cert.Issuer)]
+	}
+
+	if !ok {
+		return nil
+	}
+	return parent;
+}
+
+// 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;
+}