// GPG4Browsers - An OpenPGP implementation in javascript
// Copyright (C) 2011 Recurity Labs GmbH
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
// The GPG4Browsers symmetric crypto interface
/**
* Symmetrically encrypts data using prefixedrandom, a key with length
* depending on the algorithm in openpgp_cfb mode with or without resync
* (MDC style)
* @param {String} prefixrandom Secure random bytes as string in
* length equal to the block size of the algorithm used (use
* openpgp_crypto_getPrefixRandom(algo) to retrieve that string
* @param {Integer} algo Algorithm to use (see RFC4880 9.2)
* @param {String} key Key as string. length is depending on the algorithm used
* @param {String} data Data to encrypt
* @param {Boolean} openpgp_cfb
* @return {String} Encrypted data
*/
function openpgp_crypto_symmetricEncrypt(prefixrandom, algo, key, data, openpgp_cfb) {
switch(algo) {
case 0: // Plaintext or unencrypted data
return data; // blockcipherencryptfn, plaintext, block_size, key
case 2: // TripleDES (DES-EDE, [SCHNEIER] [HAC] - 168 bit key derived from 192)
return openpgp_cfb_encrypt(prefixrandom, desede, data,8,key, openpgp_cfb).substring(0, data.length + 10);
case 3: // CAST5 (128 bit key, as per [RFC2144])
return openpgp_cfb_encrypt(prefixrandom, cast5_encrypt, data,8,key, openpgp_cfb).substring(0, data.length + 10);
case 4: // Blowfish (128 bit key, 16 rounds) [BLOWFISH]
return openpgp_cfb_encrypt(prefixrandom, BFencrypt, data,8,key, openpgp_cfb).substring(0, data.length + 10);
case 7: // AES with 128-bit key [AES]
case 8: // AES with 192-bit key
case 9: // AES with 256-bit key
return openpgp_cfb_encrypt(prefixrandom, AESencrypt, data, 16, keyExpansion(key), openpgp_cfb).substring(0, data.length + 18);
case 10: // Twofish with 256-bit key [TWOFISH]
return openpgp_cfb_encrypt(prefixrandom, TFencrypt, data,16, key, openpgp_cfb).substring(0, data.length + 18);
case 1: // IDEA [IDEA]
util.print_error("IDEA Algorithm not implemented");
return null;
default:
return null;
}
}
/**
* Symmetrically decrypts data using a key with length depending on the
* algorithm in openpgp_cfb mode with or without resync (MDC style)
* @param {Integer} algo Algorithm to use (see RFC4880 9.2)
* @param {String} key Key as string. length is depending on the algorithm used
* @param {String} data Data to be decrypted
* @param {Boolean} openpgp_cfb If true use the resync (for encrypteddata);
* otherwise use without the resync (for MDC encrypted data)
* @return {String} Plaintext data
*/
function openpgp_crypto_symmetricDecrypt(algo, key, data, openpgp_cfb) {
util.print_debug_hexstr_dump("openpgp_crypto_symmetricDecrypt:\nalgo:"+algo+"\nencrypteddata:",data);
var n = 0;
if (!openpgp_cfb)
n = 2;
switch(algo) {
case 0: // Plaintext or unencrypted data
return data;
case 2: // TripleDES (DES-EDE, [SCHNEIER] [HAC] - 168 bit key derived from 192)
return openpgp_cfb_decrypt(desede, 8, key, data, openpgp_cfb).substring(n, (data.length+n)-10);
case 3: // CAST5 (128 bit key, as per [RFC2144])
return openpgp_cfb_decrypt(cast5_encrypt, 8, key, data, openpgp_cfb).substring(n, (data.length+n)-10);
case 4: // Blowfish (128 bit key, 16 rounds) [BLOWFISH]
return openpgp_cfb_decrypt(BFencrypt, 8, key, data, openpgp_cfb).substring(n, (data.length+n)-10);
case 7: // AES with 128-bit key [AES]
case 8: // AES with 192-bit key
case 9: // AES with 256-bit key
return openpgp_cfb_decrypt(AESencrypt, 16, keyExpansion(key), data, openpgp_cfb).substring(n, (data.length+n)-18);
case 10: // Twofish with 256-bit key [TWOFISH]
var result = openpgp_cfb_decrypt(TFencrypt, 16, key, data, openpgp_cfb).substring(n, (data.length+n)-18);
return result;
case 1: // IDEA [IDEA]
util.print_error(""+ (algo == 1 ? "IDEA Algorithm not implemented" : "Twofish Algorithm not implemented"));
return null;
default:
}
return null;
}