<?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.
*/
/**
* MIME Message Signer used to apply S/MIME Signature/Encryption to a message.
*
* @author Romain-Geissler
* @author Sebastiaan Stok <[email protected]>
* @author Jan Flora <[email protected]>
*/
class Swift_Signers_SMimeSigner implements Swift_Signers_BodySigner
{
protected $signCertificate;
protected $signPrivateKey;
protected $encryptCert;
protected $signThenEncrypt = true;
protected $signLevel;
protected $encryptLevel;
protected $signOptions;
protected $encryptOptions;
protected $encryptCipher;
protected $extraCerts = null;
protected $wrapFullMessage = false;
/**
* @var Swift_StreamFilters_StringReplacementFilterFactory
*/
protected $replacementFactory;
/**
* @var Swift_Mime_SimpleHeaderFactory
*/
protected $headerFactory;
/**
* Constructor.
*
* @param string|null $signCertificate
* @param string|null $signPrivateKey
* @param string|null $encryptCertificate
*/
public function __construct($signCertificate = null, $signPrivateKey = null, $encryptCertificate = null)
{
if (null !== $signPrivateKey) {
$this->setSignCertificate($signCertificate, $signPrivateKey);
}
if (null !== $encryptCertificate) {
$this->setEncryptCertificate($encryptCertificate);
}
$this->replacementFactory = Swift_DependencyContainer::getInstance()
->lookup('transport.replacementfactory');
$this->signOptions = PKCS7_DETACHED;
$this->encryptCipher = OPENSSL_CIPHER_AES_128_CBC;
}
/**
* Set the certificate location to use for signing.
*
* @see https://secure.php.net/manual/en/openssl.pkcs7.flags.php
*
* @param string $certificate
* @param string|array $privateKey If the key needs an passphrase use array('file-location', 'passphrase') instead
* @param int $signOptions Bitwise operator options for openssl_pkcs7_sign()
* @param string $extraCerts A file containing intermediate certificates needed by the signing certificate
*
* @return $this
*/
public function setSignCertificate($certificate, $privateKey = null, $signOptions = PKCS7_DETACHED, $extraCerts = null)
{
$this->signCertificate = 'file://'.str_replace('\\', '/', realpath($certificate));
if (null !== $privateKey) {
if (is_array($privateKey)) {
$this->signPrivateKey = $privateKey;
$this->signPrivateKey[0] = 'file://'.str_replace('\\', '/', realpath($privateKey[0]));
} else {
$this->signPrivateKey = 'file://'.str_replace('\\', '/', realpath($privateKey));
}
}
$this->signOptions = $signOptions;
$this->extraCerts = $extraCerts ? realpath($extraCerts) : null;
return $this;
}
/**
* Set the certificate location to use for encryption.
*
* @see https://secure.php.net/manual/en/openssl.pkcs7.flags.php
* @see https://secure.php.net/manual/en/openssl.ciphers.php
*
* @param string|array $recipientCerts Either an single X.509 certificate, or an assoc array of X.509 certificates.
* @param int $cipher
*
* @return $this
*/
public function setEncryptCertificate($recipientCerts, $cipher = null)
{
if (is_array($recipientCerts)) {
$this->encryptCert = [];
foreach ($recipientCerts as $cert) {
$this->encryptCert[] = 'file://'.str_replace('\\', '/', realpath($cert));
}
} else {
$this->encryptCert = 'file://'.str_replace('\\', '/', realpath($recipientCerts));
}
if (null !== $cipher) {
$this->encryptCipher = $cipher;
}
return $this;
}
/**
* @return string
*/
public function getSignCertificate()
{
return $this->signCertificate;
}
/**
* @return string
*/
public function getSignPrivateKey()
{
return $this->signPrivateKey;
}
/**
* Set perform signing before encryption.
*
* The default is to first sign the message and then encrypt.
* But some older mail clients, namely Microsoft Outlook 2000 will work when the message first encrypted.
* As this goes against the official specs, its recommended to only use 'encryption -> signing' when specifically targeting these 'broken' clients.
*
* @param bool $signThenEncrypt
*
* @return $this
*/
public function setSignThenEncrypt($signThenEncrypt = true)
{
$this->signThenEncrypt = $signThenEncrypt;
return $this;
}
/**
* @return bool
*/
public function isSignThenEncrypt()
{
return $this->signThenEncrypt;
}
/**
* Resets internal states.
*
* @return $this
*/
public function reset()
{
return $this;
}
/**
* Specify whether to wrap the entire MIME message in the S/MIME message.
*
* According to RFC5751 section 3.1:
* In order to protect outer, non-content-related message header fields
* (for instance, the "Subject", "To", "From", and "Cc" fields), the
* sending client MAY wrap a full MIME message in a message/rfc822
* wrapper in order to apply S/MIME security services to these header
* fields. It is up to the receiving client to decide how to present
* this "inner" header along with the unprotected "outer" header.
*
* @param bool $wrap
*
* @return $this
*/
public function setWrapFullMessage($wrap)
{
$this->wrapFullMessage = $wrap;
}
/**
* Change the Swift_Message to apply the signing.
*
* @return $this
*/
public function signMessage(Swift_Message $message)
{
if (null === $this->signCertificate && null === $this->encryptCert) {
return $this;
}
if ($this->signThenEncrypt) {
$this->smimeSignMessage($message);
$this->smimeEncryptMessage($message);
} else {
$this->smimeEncryptMessage($message);
$this->smimeSignMessage($message);
}
}
/**
* Return the list of header a signer might tamper.
*
* @return array
*/
public function getAlteredHeaders()
{
return ['Content-Type', 'Content-Transfer-Encoding', 'Content-Disposition'];
}
/**
* Sign a Swift message.
*/
protected function smimeSignMessage(Swift_Message $message)
{
// If we don't have a certificate we can't sign the message
if (null === $this->signCertificate) {
return;
}
// Work on a clone of the original message
$signMessage = clone $message;
$signMessage->clearSigners();
if ($this->wrapFullMessage) {
// The original message essentially becomes the body of the new
// wrapped message
$signMessage = $this->wrapMimeMessage($signMessage);
} else {
// Only keep header needed to parse the body correctly
$this->clearAllHeaders($signMessage);
$this->copyHeaders(
$message,
$signMessage,
[
'Content-Type',
'Content-Transfer-Encoding',
'Content-Disposition',
]
);
}
// Copy the cloned message into a temporary file stream
$messageStream = new Swift_ByteStream_TemporaryFileByteStream();
$signMessage->toByteStream($messageStream);
$messageStream->commit();
$signedMessageStream = new Swift_ByteStream_TemporaryFileByteStream();
// Sign the message using openssl
if (!openssl_pkcs7_sign(
$messageStream->getPath(),
$signedMessageStream->getPath(),
$this->signCertificate,
$this->signPrivateKey,
[],
$this->signOptions,
$this->extraCerts
)
) {
throw new Swift_IoException(sprintf('Failed to sign S/Mime message. Error: "%s".', openssl_error_string()));
}
// Parse the resulting signed message content back into the Swift message
// preserving the original headers
$this->parseSSLOutput($signedMessageStream, $message);
}
/**
* Encrypt a Swift message.
*/
protected function smimeEncryptMessage(Swift_Message $message)
{
// If we don't have a certificate we can't encrypt the message
if (null === $this->encryptCert) {
return;
}
// Work on a clone of the original message
$encryptMessage = clone $message;
$encryptMessage->clearSigners();
if ($this->wrapFullMessage) {
// The original message essentially becomes the body of the new
// wrapped message
$encryptMessage = $this->wrapMimeMessage($encryptMessage);
} else {
// Only keep header needed to parse the body correctly
$this->clearAllHeaders($encryptMessage);
$this->copyHeaders(
$message,
$encryptMessage,
[
'Content-Type',
'Content-Transfer-Encoding',
'Content-Disposition',
]
);
}
// Convert the message content (including headers) to a string
// and place it in a temporary file
$messageStream = new Swift_ByteStream_TemporaryFileByteStream();
$encryptMessage->toByteStream($messageStream);
$messageStream->commit();
$encryptedMessageStream = new Swift_ByteStream_TemporaryFileByteStream();
// Encrypt the message
if (!openssl_pkcs7_encrypt(
$messageStream->getPath(),
$encryptedMessageStream->getPath(),
$this->encryptCert,
[],
0,
$this->encryptCipher
)
) {
throw new Swift_IoException(sprintf('Failed to encrypt S/Mime message. Error: "%s".', openssl_error_string()));
}
// Parse the resulting signed message content back into the Swift message
// preserving the original headers
$this->parseSSLOutput($encryptedMessageStream, $message);
}
/**
* Copy named headers from one Swift message to another.
*/
protected function copyHeaders(
Swift_Message $fromMessage,
Swift_Message $toMessage,
array $headers = []
) {
foreach ($headers as $header) {
$this->copyHeader($fromMessage, $toMessage, $header);
}
}
/**
* Copy a single header from one Swift message to another.
*
* @param string $headerName
*/
protected function copyHeader(Swift_Message $fromMessage, Swift_Message $toMessage, $headerName)
{
$header = $fromMessage->getHeaders()->get($headerName);
if (!$header) {
return;
}
$headers = $toMessage->getHeaders();
switch ($header->getFieldType()) {
case Swift_Mime_Header::TYPE_TEXT:
$headers->addTextHeader($header->getFieldName(), $header->getValue());
break;
case Swift_Mime_Header::TYPE_PARAMETERIZED:
$headers->addParameterizedHeader(
$header->getFieldName(),
$header->getValue(),
$header->getParameters()
);
break;
}
}
/**
* Remove all headers from a Swift message.
*/
protected function clearAllHeaders(Swift_Message $message)
{
$headers = $message->getHeaders();
foreach ($headers->listAll() as $header) {
$headers->removeAll($header);
}
}
/**
* Wraps a Swift_Message in a message/rfc822 MIME part.
*
* @return Swift_MimePart
*/
protected function wrapMimeMessage(Swift_Message $message)
{
// Start by copying the original message into a message stream
$messageStream = new Swift_ByteStream_TemporaryFileByteStream();
$message->toByteStream($messageStream);
$messageStream->commit();
// Create a new MIME part that wraps the original stream
$wrappedMessage = new Swift_MimePart($messageStream, 'message/rfc822');
$wrappedMessage->setEncoder(new Swift_Mime_ContentEncoder_PlainContentEncoder('7bit'));
return $wrappedMessage;
}
protected function parseSSLOutput(Swift_InputByteStream $inputStream, Swift_Message $message)
{
$messageStream = new Swift_ByteStream_TemporaryFileByteStream();
$this->copyFromOpenSSLOutput($inputStream, $messageStream);
$this->streamToMime($messageStream, $message);
}
/**
* Merges an OutputByteStream from OpenSSL to a Swift_Message.
*/
protected function streamToMime(Swift_OutputByteStream $fromStream, Swift_Message $message)
{
// Parse the stream into headers and body
list($headers, $messageStream) = $this->parseStream($fromStream);
// Get the original message headers
$messageHeaders = $message->getHeaders();
// Let the stream determine the headers describing the body content,
// since the body of the original message is overwritten by the body
// coming from the stream.
// These are all content-* headers.
// Default transfer encoding is 7bit if not set
$encoding = '';
// Remove all existing transfer encoding headers
$messageHeaders->removeAll('Content-Transfer-Encoding');
// See whether the stream sets the transfer encoding
if (isset($headers['content-transfer-encoding'])) {
$encoding = $headers['content-transfer-encoding'];
}
// We use the null content encoder, since the body is already encoded
// according to the transfer encoding specified in the stream
$message->setEncoder(new Swift_Mime_ContentEncoder_NullContentEncoder($encoding));
// Set the disposition, if present
if (isset($headers['content-disposition'])) {
$messageHeaders->addTextHeader('Content-Disposition', $headers['content-disposition']);
}
// Copy over the body from the stream using the content type dictated
// by the stream content
$message->setChildren([]);
$message->setBody($messageStream, $headers['content-type']);
}
/**
* This message will parse the headers of a MIME email byte stream
* and return an array that contains the headers as an associative
* array and the email body as a string.
*
* @return array
*/
protected function parseStream(Swift_OutputByteStream $emailStream)
{
$bufferLength = 78;
$headerData = '';
$headerBodySeparator = "\r\n\r\n";
$emailStream->setReadPointer(0);
// Read out the headers section from the stream to a string
while (false !== ($buffer = $emailStream->read($bufferLength))) {
$headerData .= $buffer;
$headersPosEnd = strpos($headerData, $headerBodySeparator);
// Stop reading if we found the end of the headers
if (false !== $headersPosEnd) {
break;
}
}
// Split the header data into lines
$headerData = trim(substr($headerData, 0, $headersPosEnd));
$headerLines = explode("\r\n", $headerData);
unset($headerData);
$headers = [];
$currentHeaderName = '';
// Transform header lines into an associative array
foreach ($headerLines as $headerLine) {
// Handle headers that span multiple lines
if (false === strpos($headerLine, ':')) {
$headers[$currentHeaderName] .= ' '.trim($headerLine);
continue;
}
$header = explode(':', $headerLine, 2);
$currentHeaderName = strtolower($header[0]);
$headers[$currentHeaderName] = trim($header[1]);
}
// Read the entire email body into a byte stream
$bodyStream = new Swift_ByteStream_TemporaryFileByteStream();
// Skip the header and separator and point to the body
$emailStream->setReadPointer($headersPosEnd + strlen($headerBodySeparator));
while (false !== ($buffer = $emailStream->read($bufferLength))) {
$bodyStream->write($buffer);
}
$bodyStream->commit();
return [$headers, $bodyStream];
}
protected function copyFromOpenSSLOutput(Swift_OutputByteStream $fromStream, Swift_InputByteStream $toStream)
{
$bufferLength = 4096;
$filteredStream = new Swift_ByteStream_TemporaryFileByteStream();
$filteredStream->addFilter($this->replacementFactory->createFilter("\r\n", "\n"), 'CRLF to LF');
$filteredStream->addFilter($this->replacementFactory->createFilter("\n", "\r\n"), 'LF to CRLF');
while (false !== ($buffer = $fromStream->read($bufferLength))) {
$filteredStream->write($buffer);
}
$filteredStream->flushBuffers();
while (false !== ($buffer = $filteredStream->read($bufferLength))) {
$toStream->write($buffer);
}
$toStream->commit();
}
}