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Diffstat (limited to 'node_modules/public-encrypt/publicEncrypt.js')
-rw-r--r-- | node_modules/public-encrypt/publicEncrypt.js | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/node_modules/public-encrypt/publicEncrypt.js b/node_modules/public-encrypt/publicEncrypt.js new file mode 100644 index 000000000..f1ce40461 --- /dev/null +++ b/node_modules/public-encrypt/publicEncrypt.js @@ -0,0 +1,95 @@ +var parseKeys = require('parse-asn1'); +var randomBytes = require('randombytes'); +var createHash = require('create-hash'); +var mgf = require('./mgf'); +var xor = require('./xor'); +var bn = require('bn.js'); +var withPublic = require('./withPublic'); +var crt = require('browserify-rsa'); + +var constants = { + RSA_PKCS1_OAEP_PADDING: 4, + RSA_PKCS1_PADDIN: 1, + RSA_NO_PADDING: 3 +}; + +module.exports = function publicEncrypt(public_key, msg, reverse) { + var padding; + if (public_key.padding) { + padding = public_key.padding; + } else if (reverse) { + padding = 1; + } else { + padding = 4; + } + var key = parseKeys(public_key); + var paddedMsg; + if (padding === 4) { + paddedMsg = oaep(key, msg); + } else if (padding === 1) { + paddedMsg = pkcs1(key, msg, reverse); + } else if (padding === 3) { + paddedMsg = new bn(msg); + if (paddedMsg.cmp(key.modulus) >= 0) { + throw new Error('data too long for modulus'); + } + } else { + throw new Error('unknown padding'); + } + if (reverse) { + return crt(paddedMsg, key); + } else { + return withPublic(paddedMsg, key); + } +}; + +function oaep(key, msg){ + var k = key.modulus.byteLength(); + var mLen = msg.length; + var iHash = createHash('sha1').update(new Buffer('')).digest(); + var hLen = iHash.length; + var hLen2 = 2 * hLen; + if (mLen > k - hLen2 - 2) { + throw new Error('message too long'); + } + var ps = new Buffer(k - mLen - hLen2 - 2); + ps.fill(0); + var dblen = k - hLen - 1; + var seed = randomBytes(hLen); + var maskedDb = xor(Buffer.concat([iHash, ps, new Buffer([1]), msg], dblen), mgf(seed, dblen)); + var maskedSeed = xor(seed, mgf(maskedDb, hLen)); + return new bn(Buffer.concat([new Buffer([0]), maskedSeed, maskedDb], k)); +} +function pkcs1(key, msg, reverse){ + var mLen = msg.length; + var k = key.modulus.byteLength(); + if (mLen > k - 11) { + throw new Error('message too long'); + } + var ps; + if (reverse) { + ps = new Buffer(k - mLen - 3); + ps.fill(0xff); + } else { + ps = nonZero(k - mLen - 3); + } + return new bn(Buffer.concat([new Buffer([0, reverse?1:2]), ps, new Buffer([0]), msg], k)); +} +function nonZero(len, crypto) { + var out = new Buffer(len); + var i = 0; + var cache = randomBytes(len*2); + var cur = 0; + var num; + while (i < len) { + if (cur === cache.length) { + cache = randomBytes(len*2); + cur = 0; + } + num = cache[cur++]; + if (num) { + out[i++] = num; + } + } + return out; +}
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