1 files changed, 56 insertions, 0 deletions
diff --git a/src/pkg/crypto/openpgp/packet/userid.go b/src/pkg/crypto/openpgp/packet/userid.go
index ed2ad7774..0580ba3ed 100644
--- a/src/pkg/crypto/openpgp/packet/userid.go
+++ b/src/pkg/crypto/openpgp/packet/userid.go
@@ -20,6 +20,51 @@ type UserId struct {
 	Name, Comment, Email string
 }
 
+func hasInvalidCharacters(s string) bool {
+	for _, c := range s {
+		switch c {
+		case '(', ')', '<', '>', 0:
+			return true
+		}
+	}
+	return false
+}
+
+// NewUserId returns a UserId or nil if any of the arguments contain invalid
+// characters. The invalid characters are '\x00', '(', ')', '<' and '>'
+func NewUserId(name, comment, email string) *UserId {
+	// RFC 4880 doesn't deal with the structure of userid strings; the
+	// name, comment and email form is just a convention. However, there's
+	// no convention about escaping the metacharacters and GPG just refuses
+	// to create user ids where, say, the name contains a '('. We mirror
+	// this behaviour.
+
+	if hasInvalidCharacters(name) || hasInvalidCharacters(comment) || hasInvalidCharacters(email) {
+		return nil
+	}
+
+	uid := new(UserId)
+	uid.Name, uid.Comment, uid.Email = name, comment, email
+	uid.Id = name
+	if len(comment) > 0 {
+		if len(uid.Id) > 0 {
+			uid.Id += " "
+		}
+		uid.Id += "("
+		uid.Id += comment
+		uid.Id += ")"
+	}
+	if len(email) > 0 {
+		if len(uid.Id) > 0 {
+			uid.Id += " "
+		}
+		uid.Id += "<"
+		uid.Id += email
+		uid.Id += ">"
+	}
+	return uid
+}
+
 func (uid *UserId) parse(r io.Reader) (err os.Error) {
 	// RFC 4880, section 5.11
 	b, err := ioutil.ReadAll(r)
@@ -31,6 +76,17 @@ func (uid *UserId) parse(r io.Reader) (err os.Error) {
 	return
 }
 
+// Serialize marshals uid to w in the form of an OpenPGP packet, including
+// header.
+func (uid *UserId) Serialize(w io.Writer) os.Error {
+	err := serializeHeader(w, packetTypeUserId, len(uid.Id))
+	if err != nil {
+		return err
+	}
+	_, err = w.Write([]byte(uid.Id))
+	return err
+}
+
 // parseUserId extracts the name, comment and email from a user id string that
 // is formatted as "Full Name (Comment) <email@example.com>".
 func parseUserId(id string) (name, comment, email string) {