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Diffstat (limited to 'Godeps/_workspace/src/golang.org/x/crypto/pbkdf2')
-rw-r--r-- | Godeps/_workspace/src/golang.org/x/crypto/pbkdf2/pbkdf2.go | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/Godeps/_workspace/src/golang.org/x/crypto/pbkdf2/pbkdf2.go b/Godeps/_workspace/src/golang.org/x/crypto/pbkdf2/pbkdf2.go deleted file mode 100644 index c02b4d5a7..000000000 --- a/Godeps/_workspace/src/golang.org/x/crypto/pbkdf2/pbkdf2.go +++ /dev/null @@ -1,77 +0,0 @@ -// 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 keylen 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([]byte("some password"), salt, 4096, 32, sha1.New) -// -// 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(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte { - prf := hmac.New(h, password) - hashLen := prf.Size() - numBlocks := (keyLen + 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[:keyLen] -} |