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- var md5 = require('create-hash/md5')
- var rmd160 = require('ripemd160')
- var sha = require('sha.js')
-
- var checkParameters = require('./precondition')
- var defaultEncoding = require('./default-encoding')
- var Buffer = require('safe-buffer').Buffer
- var ZEROS = Buffer.alloc(128)
- var sizes = {
- md5: 16,
- sha1: 20,
- sha224: 28,
- sha256: 32,
- sha384: 48,
- sha512: 64,
- rmd160: 20,
- ripemd160: 20
- }
-
- function Hmac (alg, key, saltLen) {
- var hash = getDigest(alg)
- var blocksize = (alg === 'sha512' || alg === 'sha384') ? 128 : 64
-
- if (key.length > blocksize) {
- key = hash(key)
- } else if (key.length < blocksize) {
- key = Buffer.concat([key, ZEROS], blocksize)
- }
-
- var ipad = Buffer.allocUnsafe(blocksize + sizes[alg])
- var opad = Buffer.allocUnsafe(blocksize + sizes[alg])
- for (var i = 0; i < blocksize; i++) {
- ipad[i] = key[i] ^ 0x36
- opad[i] = key[i] ^ 0x5C
- }
-
- var ipad1 = Buffer.allocUnsafe(blocksize + saltLen + 4)
- ipad.copy(ipad1, 0, 0, blocksize)
- this.ipad1 = ipad1
- this.ipad2 = ipad
- this.opad = opad
- this.alg = alg
- this.blocksize = blocksize
- this.hash = hash
- this.size = sizes[alg]
- }
-
- Hmac.prototype.run = function (data, ipad) {
- data.copy(ipad, this.blocksize)
- var h = this.hash(ipad)
- h.copy(this.opad, this.blocksize)
- return this.hash(this.opad)
- }
-
- function getDigest (alg) {
- function shaFunc (data) {
- return sha(alg).update(data).digest()
- }
-
- if (alg === 'rmd160' || alg === 'ripemd160') return rmd160
- if (alg === 'md5') return md5
- return shaFunc
- }
-
- function pbkdf2 (password, salt, iterations, keylen, digest) {
- checkParameters(password, salt, iterations, keylen)
-
- if (!Buffer.isBuffer(password)) password = Buffer.from(password, defaultEncoding)
- if (!Buffer.isBuffer(salt)) salt = Buffer.from(salt, defaultEncoding)
-
- digest = digest || 'sha1'
-
- var hmac = new Hmac(digest, password, salt.length)
-
- 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 = hmac.run(block1, hmac.ipad1)
- var U = T
-
- for (var j = 1; j < iterations; j++) {
- U = hmac.run(U, hmac.ipad2)
- for (var k = 0; k < hLen; k++) T[k] ^= U[k]
- }
-
- T.copy(DK, destPos)
- destPos += hLen
- }
-
- return DK
- }
-
- module.exports = pbkdf2
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