// 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 /** * @requires encoding/base64 * @requires enums * @requires config * @module encoding/armor */ var base64 = require('./base64.js'), enums = require('../enums.js'), config = require('../config'); /** * Finds out which Ascii Armoring type is used. Throws error if unknown type. * @private * @param {String} text [String] ascii armored text * @returns {Integer} 0 = MESSAGE PART n of m * 1 = MESSAGE PART n * 2 = SIGNED MESSAGE * 3 = PGP MESSAGE * 4 = PUBLIC KEY BLOCK * 5 = PRIVATE KEY BLOCK */ function getType(text) { var reHeader = /^-----BEGIN PGP (MESSAGE, PART \d+\/\d+|MESSAGE, PART \d+|SIGNED MESSAGE|MESSAGE|PUBLIC KEY BLOCK|PRIVATE KEY BLOCK|SIGNATURE)-----$\n/m; var header = text.match(reHeader); if (!header) { throw new Error('Unknow ASCII armor type'); } // BEGIN PGP MESSAGE, PART X/Y // Used for multi-part messages, where the armor is split amongst Y // parts, and this is the Xth part out of Y. if (header[1].match(/MESSAGE, PART \d+\/\d+/)) { return enums.armor.multipart_section; } else // BEGIN PGP MESSAGE, PART X // Used for multi-part messages, where this is the Xth part of an // unspecified number of parts. Requires the MESSAGE-ID Armor // Header to be used. if (header[1].match(/MESSAGE, PART \d+/)) { return enums.armor.multipart_last; } else // BEGIN PGP SIGNATURE // Used for detached signatures, OpenPGP/MIME signatures, and // cleartext signatures. Note that PGP 2.x uses BEGIN PGP MESSAGE // for detached signatures. if (header[1].match(/SIGNED MESSAGE/)) { return enums.armor.signed; } else // BEGIN PGP MESSAGE // Used for signed, encrypted, or compressed files. if (header[1].match(/MESSAGE/)) { return enums.armor.message; } else // BEGIN PGP PUBLIC KEY BLOCK // Used for armoring public keys. if (header[1].match(/PUBLIC KEY BLOCK/)) { return enums.armor.public_key; } else // BEGIN PGP PRIVATE KEY BLOCK // Used for armoring private keys. if (header[1].match(/PRIVATE KEY BLOCK/)) { return enums.armor.private_key; } } /** * Add additional information to the armor version of an OpenPGP binary * packet block. * @author Alex * @version 2011-12-16 * @returns {String} The header information */ function addheader() { var result = ""; if (config.show_version) { result += "Version: " + config.versionstring + '\r\n'; } if (config.show_comment) { result += "Comment: " + config.commentstring + '\r\n'; } result += '\r\n'; return result; } /** * Calculates a checksum over the given data and returns it base64 encoded * @param {String} data Data to create a CRC-24 checksum for * @return {String} Base64 encoded checksum */ function getCheckSum(data) { var c = createcrc24(data); var str = "" + String.fromCharCode(c >> 16) + String.fromCharCode((c >> 8) & 0xFF) + String.fromCharCode(c & 0xFF); return base64.encode(str); } /** * Calculates the checksum over the given data and compares it with the * given base64 encoded checksum * @param {String} data Data to create a CRC-24 checksum for * @param {String} checksum Base64 encoded checksum * @return {Boolean} True if the given checksum is correct; otherwise false */ function verifyCheckSum(data, checksum) { var c = getCheckSum(data); var d = checksum; return c[0] == d[0] && c[1] == d[1] && c[2] == d[2] && c[3] == d[3]; } /** * Internal function to calculate a CRC-24 checksum over a given string (data) * @param {String} data Data to create a CRC-24 checksum for * @return {Integer} The CRC-24 checksum as number */ var crc_table = [ 0x00000000, 0x00864cfb, 0x018ad50d, 0x010c99f6, 0x0393e6e1, 0x0315aa1a, 0x021933ec, 0x029f7f17, 0x07a18139, 0x0727cdc2, 0x062b5434, 0x06ad18cf, 0x043267d8, 0x04b42b23, 0x05b8b2d5, 0x053efe2e, 0x0fc54e89, 0x0f430272, 0x0e4f9b84, 0x0ec9d77f, 0x0c56a868, 0x0cd0e493, 0x0ddc7d65, 0x0d5a319e, 0x0864cfb0, 0x08e2834b, 0x09ee1abd, 0x09685646, 0x0bf72951, 0x0b7165aa, 0x0a7dfc5c, 0x0afbb0a7, 0x1f0cd1e9, 0x1f8a9d12, 0x1e8604e4, 0x1e00481f, 0x1c9f3708, 0x1c197bf3, 0x1d15e205, 0x1d93aefe, 0x18ad50d0, 0x182b1c2b, 0x192785dd, 0x19a1c926, 0x1b3eb631, 0x1bb8faca, 0x1ab4633c, 0x1a322fc7, 0x10c99f60, 0x104fd39b, 0x11434a6d, 0x11c50696, 0x135a7981, 0x13dc357a, 0x12d0ac8c, 0x1256e077, 0x17681e59, 0x17ee52a2, 0x16e2cb54, 0x166487af, 0x14fbf8b8, 0x147db443, 0x15712db5, 0x15f7614e, 0x3e19a3d2, 0x3e9fef29, 0x3f9376df, 0x3f153a24, 0x3d8a4533, 0x3d0c09c8, 0x3c00903e, 0x3c86dcc5, 0x39b822eb, 0x393e6e10, 0x3832f7e6, 0x38b4bb1d, 0x3a2bc40a, 0x3aad88f1, 0x3ba11107, 0x3b275dfc, 0x31dced5b, 0x315aa1a0, 0x30563856, 0x30d074ad, 0x324f0bba, 0x32c94741, 0x33c5deb7, 0x3343924c, 0x367d6c62, 0x36fb2099, 0x37f7b96f, 0x3771f594, 0x35ee8a83, 0x3568c678, 0x34645f8e, 0x34e21375, 0x2115723b, 0x21933ec0, 0x209fa736, 0x2019ebcd, 0x228694da, 0x2200d821, 0x230c41d7, 0x238a0d2c, 0x26b4f302, 0x2632bff9, 0x273e260f, 0x27b86af4, 0x252715e3, 0x25a15918, 0x24adc0ee, 0x242b8c15, 0x2ed03cb2, 0x2e567049, 0x2f5ae9bf, 0x2fdca544, 0x2d43da53, 0x2dc596a8, 0x2cc90f5e, 0x2c4f43a5, 0x2971bd8b, 0x29f7f170, 0x28fb6886, 0x287d247d, 0x2ae25b6a, 0x2a641791, 0x2b688e67, 0x2beec29c, 0x7c3347a4, 0x7cb50b5f, 0x7db992a9, 0x7d3fde52, 0x7fa0a145, 0x7f26edbe, 0x7e2a7448, 0x7eac38b3, 0x7b92c69d, 0x7b148a66, 0x7a181390, 0x7a9e5f6b, 0x7801207c, 0x78876c87, 0x798bf571, 0x790db98a, 0x73f6092d, 0x737045d6, 0x727cdc20, 0x72fa90db, 0x7065efcc, 0x70e3a337, 0x71ef3ac1, 0x7169763a, 0x74578814, 0x74d1c4ef, 0x75dd5d19, 0x755b11e2, 0x77c46ef5, 0x7742220e, 0x764ebbf8, 0x76c8f703, 0x633f964d, 0x63b9dab6, 0x62b54340, 0x62330fbb, 0x60ac70ac, 0x602a3c57, 0x6126a5a1, 0x61a0e95a, 0x649e1774, 0x64185b8f, 0x6514c279, 0x65928e82, 0x670df195, 0x678bbd6e, 0x66872498, 0x66016863, 0x6cfad8c4, 0x6c7c943f, 0x6d700dc9, 0x6df64132, 0x6f693e25, 0x6fef72de, 0x6ee3eb28, 0x6e65a7d3, 0x6b5b59fd, 0x6bdd1506, 0x6ad18cf0, 0x6a57c00b, 0x68c8bf1c, 0x684ef3e7, 0x69426a11, 0x69c426ea, 0x422ae476, 0x42aca88d, 0x43a0317b, 0x43267d80, 0x41b90297, 0x413f4e6c, 0x4033d79a, 0x40b59b61, 0x458b654f, 0x450d29b4, 0x4401b042, 0x4487fcb9, 0x461883ae, 0x469ecf55, 0x479256a3, 0x47141a58, 0x4defaaff, 0x4d69e604, 0x4c657ff2, 0x4ce33309, 0x4e7c4c1e, 0x4efa00e5, 0x4ff69913, 0x4f70d5e8, 0x4a4e2bc6, 0x4ac8673d, 0x4bc4fecb, 0x4b42b230, 0x49ddcd27, 0x495b81dc, 0x4857182a, 0x48d154d1, 0x5d26359f, 0x5da07964, 0x5cace092, 0x5c2aac69, 0x5eb5d37e, 0x5e339f85, 0x5f3f0673, 0x5fb94a88, 0x5a87b4a6, 0x5a01f85d, 0x5b0d61ab, 0x5b8b2d50, 0x59145247, 0x59921ebc, 0x589e874a, 0x5818cbb1, 0x52e37b16, 0x526537ed, 0x5369ae1b, 0x53efe2e0, 0x51709df7, 0x51f6d10c, 0x50fa48fa, 0x507c0401, 0x5542fa2f, 0x55c4b6d4, 0x54c82f22, 0x544e63d9, 0x56d11cce, 0x56575035, 0x575bc9c3, 0x57dd8538 ]; function createcrc24(input) { var crc = 0xB704CE; var index = 0; while ((input.length - index) > 16) { crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 1)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 2)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 3)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 4)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 5)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 6)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 7)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 8)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 9)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 10)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 11)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 12)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 13)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 14)) & 0xff]; crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index + 15)) & 0xff]; index += 16; } for (var j = index; j < input.length; j++) { crc = (crc << 8) ^ crc_table[((crc >> 16) ^ input.charCodeAt(index++)) & 0xff]; } return crc & 0xffffff; } /** * Splits a message into two parts, the headers and the body. This is an internal function * @param {String} text OpenPGP armored message part * @returns {(Boolean|Object)} Either false in case of an error * or an object with attribute "headers" containing the headers and * and an attribute "body" containing the body. */ function splitHeaders(text) { // empty line with whitespace characters var reEmptyLine = /^[ \f\r\t\u00a0\u2000-\u200a\u202f\u205f\u3000]*\n/m; var headers = ''; var body = text; var matchResult = reEmptyLine.exec(text); if (matchResult !== null) { headers = text.slice(0, matchResult.index); body = text.slice(matchResult.index + matchResult[0].length); } else { throw new Error('Mandatory blank line missing between armor headers and armor data'); } headers = headers.split('\n'); // remove empty entry headers.pop(); return { headers: headers, body: body }; } /** * Verify armored headers. RFC4880, section 6.3: "OpenPGP should consider improperly formatted * Armor Headers to be corruption of the ASCII Armor." * @private * @param {Array} headers Armor headers */ function verifyHeaders(headers) { for (var i = 0; i < headers.length; i++) { if (!headers[i].match(/^(Version|Comment|MessageID|Hash|Charset): .+$/)) { throw new Error('Improperly formatted armor header: ' + headers[i]);; } } } /** * Splits a message into two parts, the body and the checksum. This is an internal function * @param {String} text OpenPGP armored message part * @returns {(Boolean|Object)} Either false in case of an error * or an object with attribute "body" containing the body * and an attribute "checksum" containing the checksum. */ function splitChecksum(text) { var reChecksumStart = /^=/m; var body = text; var checksum = ""; var matchResult = reChecksumStart.exec(text); if (matchResult !== null) { body = text.slice(0, matchResult.index); checksum = text.slice(matchResult.index + 1); } return { body: body, checksum: checksum }; } /** * DeArmor an OpenPGP armored message; verify the checksum and return * the encoded bytes * @param {String} text OpenPGP armored message * @returns {Object} An object with attribute "text" containing the message text, * an attribute "data" containing the bytes and "type" for the ASCII armor type * @static */ function dearmor(text) { var reSplit = /^-----[^-]+-----$\n/m; // remove trailing whitespace at end of line text = text.replace(/[\t\r ]+\n/g, '\n'); var type = getType(text); var splittext = text.split(reSplit); // IE has a bug in split with a re. If the pattern matches the beginning of the // string it doesn't create an empty array element 0. So we need to detect this // so we know the index of the data we are interested in. var indexBase = 1; var result, checksum, msg; if (text.search(reSplit) != splittext[0].length) { indexBase = 0; } if (type != 2) { msg = splitHeaders(splittext[indexBase]); var msg_sum = splitChecksum(msg.body); result = { data: base64.decode(msg_sum.body), headers: msg.headers, type: type }; checksum = msg_sum.checksum; } else { // Reverse dash-escaping for msg msg = splitHeaders(splittext[indexBase].replace(/^- /mg, '')); var sig = splitHeaders(splittext[indexBase + 1].replace(/^- /mg, '')); verifyHeaders(sig.headers); var sig_sum = splitChecksum(sig.body); result = { text: msg.body.replace(/\n$/, '').replace(/\n/g, "\r\n"), data: base64.decode(sig_sum.body), headers: msg.headers, type: type }; checksum = sig_sum.checksum; } checksum = checksum.substr(0, 4); if (!verifyCheckSum(result.data, checksum)) { throw new Error("Ascii armor integrity check on message failed: '" + checksum + "' should be '" + getCheckSum(result.data) + "'"); } verifyHeaders(result.headers); return result; } /** * Armor an OpenPGP binary packet block * @param {Integer} messagetype type of the message * @param body * @param {Integer} partindex * @param {Integer} parttotal * @returns {String} Armored text * @static */ function armor(messagetype, body, partindex, parttotal) { var result = ""; switch (messagetype) { case enums.armor.multipart_section: result += "-----BEGIN PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n"; result += addheader(); result += base64.encode(body); result += "\r\n=" + getCheckSum(body) + "\r\n"; result += "-----END PGP MESSAGE, PART " + partindex + "/" + parttotal + "-----\r\n"; break; case enums.armor.multipart_last: result += "-----BEGIN PGP MESSAGE, PART " + partindex + "-----\r\n"; result += addheader(); result += base64.encode(body); result += "\r\n=" + getCheckSum(body) + "\r\n"; result += "-----END PGP MESSAGE, PART " + partindex + "-----\r\n"; break; case enums.armor.signed: result += "\r\n-----BEGIN PGP SIGNED MESSAGE-----\r\n"; result += "Hash: " + body.hash + "\r\n\r\n"; result += body.text.replace(/\n-/g, "\n- -"); result += "\r\n-----BEGIN PGP SIGNATURE-----\r\n"; result += addheader(); result += base64.encode(body.data); result += "\r\n=" + getCheckSum(body.data) + "\r\n"; result += "-----END PGP SIGNATURE-----\r\n"; break; case enums.armor.message: result += "-----BEGIN PGP MESSAGE-----\r\n"; result += addheader(); result += base64.encode(body); result += "\r\n=" + getCheckSum(body) + "\r\n"; result += "-----END PGP MESSAGE-----\r\n"; break; case enums.armor.public_key: result += "-----BEGIN PGP PUBLIC KEY BLOCK-----\r\n"; result += addheader(); result += base64.encode(body); result += "\r\n=" + getCheckSum(body) + "\r\n"; result += "-----END PGP PUBLIC KEY BLOCK-----\r\n\r\n"; break; case enums.armor.private_key: result += "-----BEGIN PGP PRIVATE KEY BLOCK-----\r\n"; result += addheader(); result += base64.encode(body); result += "\r\n=" + getCheckSum(body) + "\r\n"; result += "-----END PGP PRIVATE KEY BLOCK-----\r\n"; break; } return result; } module.exports = { encode: armor, decode: dearmor };