Merge pull request #329 from 1and1/master

Optimized memory footprint for encrypting and decrypting

src/crypto/cfb.js

@@ -178,7 +178,7 @@ module.exports = {
     var iblock = new Uint8Array(block_size);
     var ablock = new Uint8Array(block_size);
     var i, n = '';
-    var text = '';
+    var text = [];
 
     // initialisation vector
     for (i = 0; i < block_size; i++) {
@@ -200,11 +200,11 @@ module.exports = {
     }
 
     /*  RFC4880: Tag 18 and Resync:
-		 *  [...] Unlike the Symmetrically Encrypted Data Packet, no
+     *  [...] Unlike the Symmetrically Encrypted Data Packet, no
-		 *  special CFB resynchronization is done after encrypting this prefix
+     *  special CFB resynchronization is done after encrypting this prefix
-		 *  data.  See "OpenPGP CFB Mode" below for more details.
+     *  data.  See "OpenPGP CFB Mode" below for more details.
 
-		 */
+     */
 
     if (resync) {
       for (i = 0; i < block_size; i++) {
@@ -215,7 +215,7 @@ module.exports = {
 
         for (i = 0; i < block_size && i + n < ciphertext.length; i++) {
           iblock[i] = ciphertext.charCodeAt(n + i);
-          text += String.fromCharCode(ablock[i] ^ iblock[i]);
+          text.push(String.fromCharCode(ablock[i] ^ iblock[i]));
         }
       }
     } else {
@@ -226,19 +226,18 @@ module.exports = {
         ablock = cipherfn.encrypt(iblock);
         for (i = 0; i < block_size && i + n < ciphertext.length; i++) {
           iblock[i] = ciphertext.charCodeAt(n + i);
-          text += String.fromCharCode(ablock[i] ^ iblock[i]);
+          text.push(String.fromCharCode(ablock[i] ^ iblock[i]));
         }
       }
     }
-
+    if (!resync)
-    n = resync ? 0 : 2;
+    {
-
+      text.splice(0, 2);
-    text = text.substring(n, ciphertext.length - block_size - 2 + n);
+    }
-
+    text.splice(ciphertext.length - block_size - 2);
     return text;
   },
 
-
   normalEncrypt: function(cipherfn, key, plaintext, iv) {
     cipherfn = new cipher[cipherfn](key);
     var block_size = cipherfn.blockSize;

src/encoding/armor.js

@@ -350,56 +350,56 @@ function dearmor(text) {
  * @static
  */
 function armor(messagetype, body, partindex, parttotal) {
-  var result = "";
+  var result = [];
   switch (messagetype) {
     case enums.armor.multipart_section:
-      result += "-----BEGIN PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n";
+      result.push("-----BEGIN PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body);
+      result.push(base64.encode(body));
-      result += "\r\n=" + getCheckSum(body) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body) + "\r\n");
-      result += "-----END PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n";
+      result.push("-----END PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n");
       break;
     case enums.armor.multipart_last:
-      result += "-----BEGIN PGP MESSAGE, PART " + partindex + "-----\r\n";
+      result.push("-----BEGIN PGP MESSAGE, PART " + partindex + "-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body);
+      result.push(base64.encode(body));
-      result += "\r\n=" + getCheckSum(body) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body) + "\r\n");
-      result += "-----END PGP MESSAGE, PART " + partindex + "-----\r\n";
+      result.push("-----END PGP MESSAGE, PART " + partindex + "-----\r\n");
       break;
     case enums.armor.signed:
-      result += "\r\n-----BEGIN PGP SIGNED MESSAGE-----\r\n";
+      result.push("\r\n-----BEGIN PGP SIGNED MESSAGE-----\r\n");
-      result += "Hash: " + body.hash + "\r\n\r\n";
+      result.push("Hash: " + body.hash + "\r\n\r\n");
-      result += body.text.replace(/\n-/g, "\n- -");
+      result.push(body.text.replace(/\n-/g, "\n- -"));
-      result += "\r\n-----BEGIN PGP SIGNATURE-----\r\n";
+      result.push("\r\n-----BEGIN PGP SIGNATURE-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body.data);
+      result.push(base64.encode(body.data));
-      result += "\r\n=" + getCheckSum(body.data) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body.data) + "\r\n");
-      result += "-----END PGP SIGNATURE-----\r\n";
+      result.push("-----END PGP SIGNATURE-----\r\n");
       break;
     case enums.armor.message:
-      result += "-----BEGIN PGP MESSAGE-----\r\n";
+      result.push("-----BEGIN PGP MESSAGE-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body);
+      result.push(base64.encode(body));
-      result += "\r\n=" + getCheckSum(body) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body) + "\r\n");
-      result += "-----END PGP MESSAGE-----\r\n";
+      result.push("-----END PGP MESSAGE-----\r\n");
       break;
     case enums.armor.public_key:
-      result += "-----BEGIN PGP PUBLIC KEY BLOCK-----\r\n";
+      result.push("-----BEGIN PGP PUBLIC KEY BLOCK-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body);
+      result.push(base64.encode(body));
-      result += "\r\n=" + getCheckSum(body) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body) + "\r\n");
-      result += "-----END PGP PUBLIC KEY BLOCK-----\r\n\r\n";
+      result.push("-----END PGP PUBLIC KEY BLOCK-----\r\n\r\n");
       break;
     case enums.armor.private_key:
-      result += "-----BEGIN PGP PRIVATE KEY BLOCK-----\r\n";
+      result.push("-----BEGIN PGP PRIVATE KEY BLOCK-----\r\n");
-      result += addheader();
+      result.push(addheader());
-      result += base64.encode(body);
+      result.push(base64.encode(body));
-      result += "\r\n=" + getCheckSum(body) + "\r\n";
+      result.push("\r\n=" + getCheckSum(body) + "\r\n");
-      result += "-----END PGP PRIVATE KEY BLOCK-----\r\n";
+      result.push("-----END PGP PRIVATE KEY BLOCK-----\r\n");
       break;
   }
 
-  return result;
+  return result.join('');
 }
 
 module.exports = {

src/encoding/base64.js

@@ -23,51 +23,55 @@ var b64s = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
  * @returns {string} radix-64 version of input string
  * @static
  */
-function s2r(t) {
+function s2r(t, o) {
+  // TODO check btoa alternative
   var a, c, n;
-  var r = '',
+  var r = o ? o : [],
-    l = 0,
+      l = 0,
-    s = 0;
+      s = 0;
   var tl = t.length;
 
   for (n = 0; n < tl; n++) {
     c = t.charCodeAt(n);
     if (s === 0) {
-      r += b64s.charAt((c >> 2) & 63);
+      r.push(b64s.charAt((c >> 2) & 63));
       a = (c & 3) << 4;
     } else if (s == 1) {
-      r += b64s.charAt((a | (c >> 4) & 15));
+      r.push(b64s.charAt((a | (c >> 4) & 15)));
       a = (c & 15) << 2;
     } else if (s == 2) {
-      r += b64s.charAt(a | ((c >> 6) & 3));
+      r.push(b64s.charAt(a | ((c >> 6) & 3)));
       l += 1;
       if ((l % 60) === 0)
-        r += "\n";
+        r.push("\n");
-      r += b64s.charAt(c & 63);
+      r.push(b64s.charAt(c & 63));
     }
     l += 1;
     if ((l % 60) === 0)
-      r += "\n";
+      r.push("\n");
 
     s += 1;
     if (s == 3)
       s = 0;
   }
   if (s > 0) {
-    r += b64s.charAt(a);
+    r.push(b64s.charAt(a));
     l += 1;
     if ((l % 60) === 0)
-      r += "\n";
+      r.push("\n");
-    r += '=';
+    r.push('=');
     l += 1;
   }
   if (s == 1) {
     if ((l % 60) === 0)
-      r += "\n";
+      r.push("\n");
-    r += '=';
+    r.push('=');
   }
-
+  if (o)
-  return r;
+  {
+    return;
+  }
+  return r.join('');
 }
 
 /**
@@ -77,22 +81,23 @@ function s2r(t) {
  * @static
  */
 function r2s(t) {
+  // TODO check atob alternative
   var c, n;
-  var r = '',
+  var r = [],
-    s = 0,
+      s = 0,
-    a = 0;
+      a = 0;
   var tl = t.length;
 
   for (n = 0; n < tl; n++) {
     c = b64s.indexOf(t.charAt(n));
     if (c >= 0) {
       if (s)
-        r += String.fromCharCode(a | (c >> (6 - s)) & 255);
+        r.push(String.fromCharCode(a | (c >> (6 - s)) & 255));
       s = (s + 2) & 7;
       a = (c << s) & 255;
     }
   }
-  return r;
+  return r.join('');
 }
 
 module.exports = {

src/packet/sym_encrypted_integrity_protected.js

@@ -93,8 +93,12 @@ SymEncryptedIntegrityProtected.prototype.encrypt = function (sessionKeyAlgorithm
 
 
   this.encrypted = crypto.cfb.encrypt(prefixrandom,
-    sessionKeyAlgorithm, tohash, key, false).substring(0,
+      sessionKeyAlgorithm, tohash, key, false);
-    prefix.length + tohash.length);
+
+  if (prefix.length + tohash.length != this.encrypted.length)
+  {
+    this.encrypted = this.encrypted.substring(0, prefix.length + tohash.length);
+  }
 };
 
 /**
@@ -110,17 +114,20 @@ SymEncryptedIntegrityProtected.prototype.decrypt = function (sessionKeyAlgorithm
   var decrypted = crypto.cfb.decrypt(
     sessionKeyAlgorithm, key, this.encrypted, false);
 
+  var mdc = decrypted.slice(decrypted.length - 20, decrypted.length).join('');
+
+  decrypted.splice(decrypted.length - 20);
 
   // there must be a modification detection code packet as the
   // last packet and everything gets hashed except the hash itself
   this.hash = crypto.hash.sha1(
-    crypto.cfb.mdc(sessionKeyAlgorithm, key, this.encrypted) + decrypted.substring(0, decrypted.length - 20));
+    crypto.cfb.mdc(sessionKeyAlgorithm, key, this.encrypted) + decrypted.join(''));
 
 
-  var mdc = decrypted.substr(decrypted.length - 20, 20);
-
   if (this.hash != mdc) {
     throw new Error('Modification detected.');
-  } else
+  } else {
-    this.packets.read(decrypted.substr(0, decrypted.length - 22));
+    decrypted.splice(decrypted.length - 2);
+    this.packets.read(decrypted.join(''));
+  }
 };

src/packet/sym_encrypted_session_key.js

@@ -119,6 +119,7 @@ SymEncryptedSessionKey.prototype.decrypt = function(passphrase) {
   } else {
     var decrypted = crypto.cfb.decrypt(
       this.sessionKeyEncryptionAlgorithm, key, this.encrypted, true);
+    decrypted = decrypted.join('');
 
     this.sessionKeyAlgorithm = enums.read(enums.symmetric,
       decrypted[0].keyCodeAt());

src/packet/symmetrically_encrypted.js

@@ -65,7 +65,7 @@ SymmetricallyEncrypted.prototype.decrypt = function (sessionKeyAlgorithm, key) {
   var decrypted = crypto.cfb.decrypt(
     sessionKeyAlgorithm, key, this.encrypted, true);
 
-  this.packets.read(decrypted);
+  this.packets.read(decrypted.join(''))
 };
 
 SymmetricallyEncrypted.prototype.encrypt = function (algo, key) {

src/util.js

@@ -202,11 +202,11 @@ module.exports = {
    * @return {String} String representation of the array
    */
   Uint8Array2str: function (bin) {
-    var result = '';
+    var result = [];
     for (var i = 0; i < bin.length; i++) {
-      result += String.fromCharCode(bin[i]);
+      result[i] = String.fromCharCode(bin[i]);
     }
-    return result;
+    return result.join('');
   },
 
   /**

test/crypto/crypto.js

@@ -261,7 +261,7 @@ describe('API functional testing', function() {
       symmAlgos.forEach(function(algo) {
         var symmKey = openpgp.crypto.generateSessionKey(algo);
         var symmencData = openpgp.crypto.cfb.encrypt(openpgp.crypto.getPrefixRandom(algo), algo, plaintext, symmKey, resync);
-        var text = openpgp.crypto.cfb.decrypt(algo, symmKey, symmencData, resync);
+        var text = openpgp.crypto.cfb.decrypt(algo, symmKey, symmencData, resync).join('');
         expect(text).to.equal(plaintext);
       });
     }