<?php
/*
* This file is part of SwiftMailer.
* (c) 2004-2009 Chris Corbyn
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
/**
* DomainKey Signer used to apply DomainKeys Signature to a message.
*
* @author Xavier De Cock <xdecock@gmail.com>
*/
class Swift_Signers_DomainKeySigner implements Swift_Signers_HeaderSigner
{
/**
* PrivateKey.
*
* @var string
*/
protected $_privateKey;
/**
* DomainName.
*
* @var string
*/
protected $_domainName;
/**
* Selector.
*
* @var string
*/
protected $_selector;
/**
* Hash algorithm used.
*
* @var string
*/
protected $_hashAlgorithm = 'rsa-sha1';
/**
* Canonisation method.
*
* @var string
*/
protected $_canon = 'simple';
/**
* Headers not being signed.
*
* @var array
*/
protected $_ignoredHeaders = array();
/**
* Signer identity.
*
* @var string
*/
protected $_signerIdentity;
/**
* Must we embed signed headers?
*
* @var bool
*/
protected $_debugHeaders = false;
// work variables
/**
* Headers used to generate hash.
*
* @var array
*/
private $_signedHeaders = array();
/**
* Stores the signature header.
*
* @var Swift_Mime_Headers_ParameterizedHeader
*/
protected $_domainKeyHeader;
/**
* Hash Handler.
*
* @var resource|null
*/
private $_hashHandler;
private $_hash;
private $_canonData = '';
private $_bodyCanonEmptyCounter = 0;
private $_bodyCanonIgnoreStart = 2;
private $_bodyCanonSpace = false;
private $_bodyCanonLastChar = null;
private $_bodyCanonLine = '';
private $_bound = array();
/**
* Constructor.
*
* @param string $privateKey
* @param string $domainName
* @param string $selector
*/
public function __construct($privateKey, $domainName, $selector)
{
$this->_privateKey = $privateKey;
$this->_domainName = $domainName;
$this->_signerIdentity = '@'.$domainName;
$this->_selector = $selector;
}
/**
* Instanciate DomainKeySigner.
*
* @param string $privateKey
* @param string $domainName
* @param string $selector
*
* @return self
*/
public static function newInstance($privateKey, $domainName, $selector)
{
return new static($privateKey, $domainName, $selector);
}
/**
* Resets internal states.
*
* @return $this
*/
public function reset()
{
$this->_hash = null;
$this->_hashHandler = null;
$this->_bodyCanonIgnoreStart = 2;
$this->_bodyCanonEmptyCounter = 0;
$this->_bodyCanonLastChar = null;
$this->_bodyCanonSpace = false;
return $this;
}
/**
* Writes $bytes to the end of the stream.
*
* Writing may not happen immediately if the stream chooses to buffer. If
* you want to write these bytes with immediate effect, call {@link commit()}
* after calling write().
*
* This method returns the sequence ID of the write (i.e. 1 for first, 2 for
* second, etc etc).
*
* @param string $bytes
*
* @throws Swift_IoException
*
* @return $this
*/
public function write($bytes)
{
$this->_canonicalizeBody($bytes);
foreach ($this->_bound as $is) {
$is->write($bytes);
}
return $this;
}
/**
* For any bytes that are currently buffered inside the stream, force them
* off the buffer.
*
* @throws Swift_IoException
*
* @return $this
*/
public function commit()
{
// Nothing to do
return $this;
}
/**
* Attach $is to this stream.
* The stream acts as an observer, receiving all data that is written.
* All {@link write()} and {@link flushBuffers()} operations will be mirrored.
*
* @param Swift_InputByteStream $is
*
* @return $this
*/
public function bind(Swift_InputByteStream $is)
{
// Don't have to mirror anything
$this->_bound[] = $is;
return $this;
}
/**
* Remove an already bound stream.
* If $is is not bound, no errors will be raised.
* If the stream currently has any buffered data it will be written to $is
* before unbinding occurs.
*
* @param Swift_InputByteStream $is
*
* @return $this
*/
public function unbind(Swift_InputByteStream $is)
{
// Don't have to mirror anything
foreach ($this->_bound as $k => $stream) {
if ($stream === $is) {
unset($this->_bound[$k]);
break;
}
}
return $this;
}
/**
* Flush the contents of the stream (empty it) and set the internal pointer
* to the beginning.
*
* @throws Swift_IoException
*
* @return $this
*/
public function flushBuffers()
{
$this->reset();
return $this;
}
/**
* Set hash_algorithm, must be one of rsa-sha256 | rsa-sha1 defaults to rsa-sha256.
*
* @param string $hash
*
* @return $this
*/
public function setHashAlgorithm($hash)
{
$this->_hashAlgorithm = 'rsa-sha1';
return $this;
}
/**
* Set the canonicalization algorithm.
*
* @param string $canon simple | nofws defaults to simple
*
* @return $this
*/
public function setCanon($canon)
{
if ($canon == 'nofws') {
$this->_canon = 'nofws';
} else {
$this->_canon = 'simple';
}
return $this;
}
/**
* Set the signer identity.
*
* @param string $identity
*
* @return $this
*/
public function setSignerIdentity($identity)
{
$this->_signerIdentity = $identity;
return $this;
}
/**
* Enable / disable the DebugHeaders.
*
* @param bool $debug
*
* @return $this
*/
public function setDebugHeaders($debug)
{
$this->_debugHeaders = (bool) $debug;
return $this;
}
/**
* Start Body.
*/
public function startBody()
{
}
/**
* End Body.
*/
public function endBody()
{
$this->_endOfBody();
}
/**
* Returns the list of Headers Tampered by this plugin.
*
* @return array
*/
public function getAlteredHeaders()
{
if ($this->_debugHeaders) {
return array('DomainKey-Signature', 'X-DebugHash');
}
return array('DomainKey-Signature');
}
/**
* Adds an ignored Header.
*
* @param string $header_name
*
* @return $this
*/
public function ignoreHeader($header_name)
{
$this->_ignoredHeaders[strtolower($header_name)] = true;
return $this;
}
/**
* Set the headers to sign.
*
* @param Swift_Mime_HeaderSet $headers
*
* @return $this
*/
public function setHeaders(Swift_Mime_HeaderSet $headers)
{
$this->_startHash();
$this->_canonData = '';
// Loop through Headers
$listHeaders = $headers->listAll();
foreach ($listHeaders as $hName) {
// Check if we need to ignore Header
if (!isset($this->_ignoredHeaders[strtolower($hName)])) {
if ($headers->has($hName)) {
$tmp = $headers->getAll($hName);
foreach ($tmp as $header) {
if ($header->getFieldBody() != '') {
$this->_addHeader($header->toString());
$this->_signedHeaders[] = $header->getFieldName();
}
}
}
}
}
$this->_endOfHeaders();
return $this;
}
/**
* Add the signature to the given Headers.
*
* @param Swift_Mime_HeaderSet $headers
*
* @return $this
*/
public function addSignature(Swift_Mime_HeaderSet $headers)
{
// Prepare the DomainKey-Signature Header
$params = array('a' => $this->_hashAlgorithm, 'b' => chunk_split(base64_encode($this->_getEncryptedHash()), 73, ' '), 'c' => $this->_canon, 'd' => $this->_domainName, 'h' => implode(': ', $this->_signedHeaders), 'q' => 'dns', 's' => $this->_selector);
$string = '';
foreach ($params as $k => $v) {
$string .= $k.'='.$v.'; ';
}
$string = trim($string);
$headers->addTextHeader('DomainKey-Signature', $string);
return $this;
}
/* Private helpers */
protected function _addHeader($header)
{
switch ($this->_canon) {
case 'nofws':
// Prepare Header and cascade
$exploded = explode(':', $header, 2);
$name = strtolower(trim($exploded[0]));
$value = str_replace("\r\n", '', $exploded[1]);
$value = preg_replace("/[ \t][ \t]+/", ' ', $value);
$header = $name.':'.trim($value)."\r\n";
case 'simple':
// Nothing to do
}
$this->_addToHash($header);
}
protected function _endOfHeaders()
{
$this->_bodyCanonEmptyCounter = 1;
}
protected function _canonicalizeBody($string)
{
$len = strlen($string);
$canon = '';
$nofws = ($this->_canon == 'nofws');
for ($i = 0; $i < $len; ++$i) {
if ($this->_bodyCanonIgnoreStart > 0) {
--$this->_bodyCanonIgnoreStart;
continue;
}
switch ($string[$i]) {
case "\r":
$this->_bodyCanonLastChar = "\r";
break;
case "\n":
if ($this->_bodyCanonLastChar == "\r") {
if ($nofws) {
$this->_bodyCanonSpace = false;
}
if ($this->_bodyCanonLine == '') {
++$this->_bodyCanonEmptyCounter;
} else {
$this->_bodyCanonLine = '';
$canon .= "\r\n";
}
} else {
// Wooops Error
throw new Swift_SwiftException('Invalid new line sequence in mail found \n without preceding \r');
}
break;
case ' ':
case "\t":
case "\x09": //HTAB
if ($nofws) {
$this->_bodyCanonSpace = true;
break;
}
default:
if ($this->_bodyCanonEmptyCounter > 0) {
$canon .= str_repeat("\r\n", $this->_bodyCanonEmptyCounter);
$this->_bodyCanonEmptyCounter = 0;
}
$this->_bodyCanonLine .= $string[$i];
$canon .= $string[$i];
}
}
$this->_addToHash($canon);
}
protected function _endOfBody()
{
if (strlen($this->_bodyCanonLine) > 0) {
$this->_addToHash("\r\n");
}
$this->_hash = hash_final($this->_hashHandler, true);
}
private function _addToHash($string)
{
$this->_canonData .= $string;
hash_update($this->_hashHandler, $string);
}
private function _startHash()
{
// Init
switch ($this->_hashAlgorithm) {
case 'rsa-sha1':
$this->_hashHandler = hash_init('sha1');
break;
}
$this->_bodyCanonLine = '';
}
/**
* @throws Swift_SwiftException
*
* @return string
*/
private function _getEncryptedHash()
{
$signature = '';
$pkeyId = openssl_get_privatekey($this->_privateKey);
if (!$pkeyId) {
throw new Swift_SwiftException('Unable to load DomainKey Private Key ['.openssl_error_string().']');
}
if (openssl_sign($this->_canonData, $signature, $pkeyId, OPENSSL_ALGO_SHA1)) {
return $signature;
}
throw new Swift_SwiftException('Unable to sign DomainKey Hash ['.openssl_error_string().']');
}
}