From 567b18c1b28fd8942260307326df0e4b5a61841a Mon Sep 17 00:00:00 2001
From: Stephen Paul Weber <singpolyma@singpolyma.net>
Date: Sat, 26 Jan 2013 11:08:18 -0500
Subject: [PATCH] Support 3DES

---
 ...pt.php => openpgp_crypt_aes_tripledes.php} |  18 +++++++++++++-----
 tests/data/symmetric-3des.gpg                 | Bin 0 -> 71 bytes
 tests/phpseclib_suite.php                     |   8 ++++++--
 3 files changed, 19 insertions(+), 7 deletions(-)
 rename lib/{openpgp_phpseclib_crypt.php => openpgp_crypt_aes_tripledes.php} (71%)
 create mode 100644 tests/data/symmetric-3des.gpg

diff --git a/lib/openpgp_phpseclib_crypt.php b/lib/openpgp_crypt_aes_tripledes.php
similarity index 71%
rename from lib/openpgp_phpseclib_crypt.php
rename to lib/openpgp_crypt_aes_tripledes.php
index cd14c04..8e0d27b 100644
--- a/lib/openpgp_phpseclib_crypt.php
+++ b/lib/openpgp_crypt_aes_tripledes.php
@@ -2,12 +2,18 @@
 
 require_once dirname(__FILE__).'/openpgp.php';
 require_once 'Crypt/AES.php';
+require_once 'Crypt/TripleDES.php';
 
-class OpenPGP_phpseclib_Crypt {
+class OpenPGP_Crypt_AES_TripleDES {
   public static function decryptSymmetric($pass, $m) {
     foreach($m as $p) {
       if($p instanceof OpenPGP_SymmetricSessionKeyPacket) {
         switch($p->symmetric_algorithm) {
+          case 2:
+            $cipher = new Crypt_TripleDES(CRYPT_DES_MODE_CFB);
+            $key_bytes = 24;
+            $key_block_bytes = 8;
+            break;
           case 7:
             $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB);
             $cipher->setKeyLength(128);
@@ -22,17 +28,19 @@ class OpenPGP_phpseclib_Crypt {
             break;
         }
         if(!$cipher) continue; // Unsupported cipher
+        if(!isset($key_bytes)) $key_bytes = $cipher->key_size;
+        if(!isset($key_block_bytes)) $key_block_bytes = $cipher->block_size;
 
-        $cipher->setKey($p->s2k->make_key($pass, $cipher->key_size));
+        $cipher->setKey($p->s2k->make_key($pass, $key_bytes));
         $epacket = self::getEncryptedData($m);
-        $padAmount = $cipher->block_size - (strlen($epacket->data) % $cipher->block_size);
+        $padAmount = $key_block_bytes - (strlen($epacket->data) % $key_block_bytes);
 
         if(strlen($p->encrypted_data) < 1) {
           if($epacket instanceof OpenPGP_IntegrityProtectedDataPacket) {
 				 $data = substr($cipher->decrypt($epacket->data . str_repeat("\0", $padAmount)), 0, strlen($epacket->data));
-				 $prefix = substr($data, 0, $cipher->block_size + 2);
+				 $prefix = substr($data, 0, $key_block_bytes + 2);
 				 $mdc = substr(substr($data, -22, 22), 2);
-				 $data = substr($data, $cipher->block_size + 2, -22);
+				 $data = substr($data, $key_block_bytes + 2, -22);
 
              $mkMDC = hash("sha1", $prefix . $data . "\xD3\x14", true);
              if($mkMDC !== $mdc) return false;
diff --git a/tests/data/symmetric-3des.gpg b/tests/data/symmetric-3des.gpg
new file mode 100644
index 0000000000000000000000000000000000000000..0029caece648aa06ae12418a6341345290d06b54
GIT binary patch
literal 71
zcmV-N0J#5*4Fm!M0^)EABgKS59AMHm0j!n(7TSmJyc<$OyV>u!G?U@!XE@fQjsV36
dc;~RSXP<rA%dOk`MS)|hEx7i!*S+BNrH7Z9CF}qI

literal 0
HcmV?d00001

diff --git a/tests/phpseclib_suite.php b/tests/phpseclib_suite.php
index 559be3d..9501268 100644
--- a/tests/phpseclib_suite.php
+++ b/tests/phpseclib_suite.php
@@ -4,7 +4,7 @@
 
 require_once dirname(__FILE__).'/../lib/openpgp.php';
 require_once dirname(__FILE__).'/../lib/openpgp_crypt_rsa.php';
-require_once dirname(__FILE__).'/../lib/openpgp_phpseclib_crypt.php';
+require_once dirname(__FILE__).'/../lib/openpgp_crypt_aes_tripledes.php';
 
 class MessageVerification extends PHPUnit_Framework_TestCase {
   public function oneMessageRSA($pkey, $path) {
@@ -67,7 +67,7 @@ class KeyVerification extends PHPUnit_Framework_TestCase {
 class Decryption extends PHPUnit_Framework_TestCase {
   public function oneSymmetric($pass, $cnt, $path) {
     $m = OpenPGP_Message::parse(file_get_contents(dirname(__FILE__) . '/data/' . $path));
-    $m2 = OpenPGP_phpseclib_Crypt::decryptSymmetric($pass, $m);
+    $m2 = OpenPGP_Crypt_AES_TripleDES::decryptSymmetric($pass, $m);
     while($m2[0] instanceof OpenPGP_CompressedDataPacket) $m2 = $m2[0]->data;
     foreach($m2 as $p) {
       if($p instanceof OpenPGP_LiteralDataPacket) {
@@ -80,6 +80,10 @@ class Decryption extends PHPUnit_Framework_TestCase {
     $this->oneSymmetric("hello", "PGP\n", "symmetric-aes.gpg");
   }
 
+  public function testDecrypt3DES() {
+    $this->oneSymmetric("hello", "PGP\n", "symmetric-3des.gpg");
+  }
+
 /* TODO
   public function testDecryptSessionKey() {
     $this->oneSymmetric("hello", "PGP\n", "symmetric-with-session-key.gpg");