--- /dev/null
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package pbkdf2 implements the key derivation function PBKDF2 as defined in RFC
+2898 / PKCS #5 v2.0.
+
+A key derivation function is useful when encrypting data based on a password
+or any other not-fully-random data. It uses a pseudorandom function to derive
+a secure encryption key based on the password.
+
+While v2.0 of the standard defines only one pseudorandom function to use,
+HMAC-SHA1, the drafted v2.1 specification allows use of all five FIPS Approved
+Hash Functions SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 for HMAC. To
+choose, you can pass the `New` functions from the different SHA packages to
+pbkdf2.Key.
+*/
+package pbkdf2
+
+import (
+ "crypto/hmac"
+ "hash"
+)
+
+// Key derives a key from the password, salt and iteration count, returning a
+// []byte of length keyLength that can be used as cryptographic key. The key is
+// derived based on the method described as PBKDF2 with the HMAC variant using
+// the supplied hash function.
+//
+// For example, to use a HMAC-SHA-1 based PBKDF2 key derivation function, you
+// can get a derived key for e.g. AES-256 (which needs a 32-byte key) by
+// doing:
+//
+// dk := pbkdf2.Key(sha1.New, []byte("some password"), salt, 4096, 32)
+//
+// Remember to get a good random salt. At least 8 bytes is recommended by the
+// RFC.
+//
+// Using a higher iteration count will increase the cost of an exhaustive
+// search but will also make derivation proportionally slower.
+func Key[Hash hash.Hash](h func() Hash, password string, salt []byte, iter, keyLength int) ([]byte, error) {
+ prf := hmac.New(func() hash.Hash { return h() }, []byte(password))
+ hashLen := prf.Size()
+ numBlocks := (keyLength + hashLen - 1) / hashLen
+
+ var buf [4]byte
+ dk := make([]byte, 0, numBlocks*hashLen)
+ U := make([]byte, hashLen)
+ for block := 1; block <= numBlocks; block++ {
+ // N.B.: || means concatenation, ^ means XOR
+ // for each block T_i = U_1 ^ U_2 ^ ... ^ U_iter
+ // U_1 = PRF(password, salt || uint(i))
+ prf.Reset()
+ prf.Write(salt)
+ buf[0] = byte(block >> 24)
+ buf[1] = byte(block >> 16)
+ buf[2] = byte(block >> 8)
+ buf[3] = byte(block)
+ prf.Write(buf[:4])
+ dk = prf.Sum(dk)
+ T := dk[len(dk)-hashLen:]
+ copy(U, T)
+
+ // U_n = PRF(password, U_(n-1))
+ for n := 2; n <= iter; n++ {
+ prf.Reset()
+ prf.Write(U)
+ U = U[:0]
+ U = prf.Sum(U)
+ for x := range U {
+ T[x] ^= U[x]
+ }
+ }
+ }
+ return dk[:keyLength], nil
+}
--- /dev/null
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pbkdf2_test
+
+import (
+ "bytes"
+ "crypto/pbkdf2"
+ "crypto/sha1"
+ "crypto/sha256"
+ "hash"
+ "testing"
+)
+
+type testVector struct {
+ password string
+ salt string
+ iter int
+ output []byte
+}
+
+// Test vectors from RFC 6070, http://tools.ietf.org/html/rfc6070
+var sha1TestVectors = []testVector{
+ {
+ "password",
+ "salt",
+ 1,
+ []byte{
+ 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
+ 0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
+ 0x2f, 0xe0, 0x37, 0xa6,
+ },
+ },
+ {
+ "password",
+ "salt",
+ 2,
+ []byte{
+ 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
+ 0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
+ 0xd8, 0xde, 0x89, 0x57,
+ },
+ },
+ {
+ "password",
+ "salt",
+ 4096,
+ []byte{
+ 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
+ 0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
+ 0x65, 0xa4, 0x29, 0xc1,
+ },
+ },
+ // // This one takes too long
+ // {
+ // "password",
+ // "salt",
+ // 16777216,
+ // []byte{
+ // 0xee, 0xfe, 0x3d, 0x61, 0xcd, 0x4d, 0xa4, 0xe4,
+ // 0xe9, 0x94, 0x5b, 0x3d, 0x6b, 0xa2, 0x15, 0x8c,
+ // 0x26, 0x34, 0xe9, 0x84,
+ // },
+ // },
+ {
+ "passwordPASSWORDpassword",
+ "saltSALTsaltSALTsaltSALTsaltSALTsalt",
+ 4096,
+ []byte{
+ 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
+ 0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
+ 0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
+ 0x38,
+ },
+ },
+ {
+ "pass\000word",
+ "sa\000lt",
+ 4096,
+ []byte{
+ 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
+ 0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3,
+ },
+ },
+}
+
+// Test vectors from
+// http://stackoverflow.com/questions/5130513/pbkdf2-hmac-sha2-test-vectors
+var sha256TestVectors = []testVector{
+ {
+ "password",
+ "salt",
+ 1,
+ []byte{
+ 0x12, 0x0f, 0xb6, 0xcf, 0xfc, 0xf8, 0xb3, 0x2c,
+ 0x43, 0xe7, 0x22, 0x52, 0x56, 0xc4, 0xf8, 0x37,
+ 0xa8, 0x65, 0x48, 0xc9,
+ },
+ },
+ {
+ "password",
+ "salt",
+ 2,
+ []byte{
+ 0xae, 0x4d, 0x0c, 0x95, 0xaf, 0x6b, 0x46, 0xd3,
+ 0x2d, 0x0a, 0xdf, 0xf9, 0x28, 0xf0, 0x6d, 0xd0,
+ 0x2a, 0x30, 0x3f, 0x8e,
+ },
+ },
+ {
+ "password",
+ "salt",
+ 4096,
+ []byte{
+ 0xc5, 0xe4, 0x78, 0xd5, 0x92, 0x88, 0xc8, 0x41,
+ 0xaa, 0x53, 0x0d, 0xb6, 0x84, 0x5c, 0x4c, 0x8d,
+ 0x96, 0x28, 0x93, 0xa0,
+ },
+ },
+ {
+ "passwordPASSWORDpassword",
+ "saltSALTsaltSALTsaltSALTsaltSALTsalt",
+ 4096,
+ []byte{
+ 0x34, 0x8c, 0x89, 0xdb, 0xcb, 0xd3, 0x2b, 0x2f,
+ 0x32, 0xd8, 0x14, 0xb8, 0x11, 0x6e, 0x84, 0xcf,
+ 0x2b, 0x17, 0x34, 0x7e, 0xbc, 0x18, 0x00, 0x18,
+ 0x1c,
+ },
+ },
+ {
+ "pass\000word",
+ "sa\000lt",
+ 4096,
+ []byte{
+ 0x89, 0xb6, 0x9d, 0x05, 0x16, 0xf8, 0x29, 0x89,
+ 0x3c, 0x69, 0x62, 0x26, 0x65, 0x0a, 0x86, 0x87,
+ },
+ },
+}
+
+func testHash(t *testing.T, h func() hash.Hash, hashName string, vectors []testVector) {
+ for i, v := range vectors {
+ o, err := pbkdf2.Key(h, v.password, []byte(v.salt), v.iter, len(v.output))
+ if err != nil {
+ t.Error(err)
+ }
+ if !bytes.Equal(o, v.output) {
+ t.Errorf("%s %d: expected %x, got %x", hashName, i, v.output, o)
+ }
+ }
+}
+
+func TestWithHMACSHA1(t *testing.T) {
+ testHash(t, sha1.New, "SHA1", sha1TestVectors)
+}
+
+func TestWithHMACSHA256(t *testing.T) {
+ testHash(t, sha256.New, "SHA256", sha256TestVectors)
+}
+
+var sink uint8
+
+func benchmark(b *testing.B, h func() hash.Hash) {
+ var err error
+ password := make([]byte, h().Size())
+ salt := make([]byte, 8)
+ for i := 0; i < b.N; i++ {
+ password, err = pbkdf2.Key(h, string(password), salt, 4096, len(password))
+ if err != nil {
+ b.Error(err)
+ }
+ }
+ sink += password[0]
+}
+
+func BenchmarkHMACSHA1(b *testing.B) {
+ benchmark(b, sha1.New)
+}
+
+func BenchmarkHMACSHA256(b *testing.B) {
+ benchmark(b, sha256.New)
+}