// Copyright 2011 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 packet
import (
"io"
"io/ioutil"
"strings"
)
// UserId contains text that is intended to represent the name and email
// address of the key holder. See RFC 4880, section 5.11. By convention, this
// takes the form "Full Name (Comment) <email@example.com>"
type UserId struct {
Id string // By convention, this takes the form "Full Name (Comment) <email@example.com>" which is split out in the fields below.
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 error) {
// RFC 4880, section 5.11
b, err := ioutil.ReadAll(r)
if err != nil {
return
}
uid.Id = string(b)
uid.Name, uid.Comment, uid.Email = parseUserId(uid.Id)
return
}
// Serialize marshals uid to w in the form of an OpenPGP packet, including
// header.
func (uid *UserId) Serialize(w io.Writer) 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) {
var n, c, e struct {
start, end int
}
var state int
for offset, rune := range id {
switch state {
case 0:
// Entering name
n.start = offset
state = 1
fallthrough
case 1:
// In name
if rune == '(' {
state = 2
n.end = offset
} else if rune == '<' {
state = 5
n.end = offset
}
case 2:
// Entering comment
c.start = offset
state = 3
fallthrough
case 3:
// In comment
if rune == ')' {
state = 4
c.end = offset
}
case 4:
// Between comment and email
if rune == '<' {
state = 5
}
case 5:
// Entering email
e.start = offset
state = 6
fallthrough
case 6:
// In email
if rune == '>' {
state = 7
e.end = offset
}
default:
// After email
}
}
switch state {
case 1:
// ended in the name
n.end = len(id)
case 3:
// ended in comment
c.end = len(id)
case 6:
// ended in email
e.end = len(id)
}
name = strings.TrimSpace(id[n.start:n.end])
comment = strings.TrimSpace(id[c.start:c.end])
email = strings.TrimSpace(id[e.start:e.end])
return
}
