| var sizes = { |
| md5: 16, |
| sha1: 20, |
| sha224: 28, |
| sha256: 32, |
| sha384: 48, |
| sha512: 64, |
| rmd160: 20, |
| ripemd160: 20 |
| } |
| |
| var createHmac = require('create-hmac') |
| var Buffer = require('safe-buffer').Buffer |
| |
| var checkParameters = require('./precondition') |
| var defaultEncoding = require('./default-encoding') |
| var toBuffer = require('./to-buffer') |
| |
| function pbkdf2 (password, salt, iterations, keylen, digest) { |
| checkParameters(iterations, keylen) |
| password = toBuffer(password, defaultEncoding, 'Password') |
| salt = toBuffer(salt, defaultEncoding, 'Salt') |
| |
| digest = digest || 'sha1' |
| |
| var DK = Buffer.allocUnsafe(keylen) |
| var block1 = Buffer.allocUnsafe(salt.length + 4) |
| salt.copy(block1, 0, 0, salt.length) |
| |
| var destPos = 0 |
| var hLen = sizes[digest] |
| var l = Math.ceil(keylen / hLen) |
| |
| for (var i = 1; i <= l; i++) { |
| block1.writeUInt32BE(i, salt.length) |
| |
| var T = createHmac(digest, password).update(block1).digest() |
| var U = T |
| |
| for (var j = 1; j < iterations; j++) { |
| U = createHmac(digest, password).update(U).digest() |
| for (var k = 0; k < hLen; k++) T[k] ^= U[k] |
| } |
| |
| T.copy(DK, destPos) |
| destPos += hLen |
| } |
| |
| return DK |
| } |
| |
| module.exports = pbkdf2 |