mirror of
https://github.com/Luzifer/cloudkeys-go.git
synced 2024-11-14 08:52:44 +00:00
Knut Ahlers
a1df72edc5
commitf0db1ff1f8Author: Knut Ahlers <knut@ahlers.me> Date: Sun Dec 24 12:19:56 2017 +0100 Mark option as deprecated Signed-off-by: Knut Ahlers <knut@ahlers.me> commit9891df2a16Author: Knut Ahlers <knut@ahlers.me> Date: Sun Dec 24 12:11:56 2017 +0100 Fix: Typo Signed-off-by: Knut Ahlers <knut@ahlers.me> commit836006de64Author: Knut Ahlers <knut@ahlers.me> Date: Sun Dec 24 12:04:20 2017 +0100 Add new dependencies Signed-off-by: Knut Ahlers <knut@ahlers.me> commitd64fee60c8Author: Knut Ahlers <knut@ahlers.me> Date: Sun Dec 24 11:55:52 2017 +0100 Replace insecure password hashing Prior this commit passwords were hashed with a static salt and using the SHA1 hashing function. This could lead to passwords being attackable in case someone gets access to the raw data stored inside the database. This commit introduces password hashing using bcrypt hashing function which addresses this issue. Old passwords are not automatically re-hashed as they are unknown. Replacing the old password scheme is not that easy and needs #10 to be solved. Therefore the old hashing scheme is kept for compatibility reason. Signed-off-by: Knut Ahlers <knut@ahlers.me> Signed-off-by: Knut Ahlers <knut@ahlers.me> closes #14 closes #15
77 lines
2.4 KiB
Go
77 lines
2.4 KiB
Go
// Copyright 2012 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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/*
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Package pbkdf2 implements the key derivation function PBKDF2 as defined in RFC
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2898 / PKCS #5 v2.0.
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A key derivation function is useful when encrypting data based on a password
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or any other not-fully-random data. It uses a pseudorandom function to derive
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a secure encryption key based on the password.
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While v2.0 of the standard defines only one pseudorandom function to use,
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HMAC-SHA1, the drafted v2.1 specification allows use of all five FIPS Approved
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Hash Functions SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 for HMAC. To
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choose, you can pass the `New` functions from the different SHA packages to
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pbkdf2.Key.
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*/
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package pbkdf2 // import "golang.org/x/crypto/pbkdf2"
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import (
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"crypto/hmac"
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"hash"
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)
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// Key derives a key from the password, salt and iteration count, returning a
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// []byte of length keylen that can be used as cryptographic key. The key is
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// derived based on the method described as PBKDF2 with the HMAC variant using
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// the supplied hash function.
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//
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// For example, to use a HMAC-SHA-1 based PBKDF2 key derivation function, you
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// can get a derived key for e.g. AES-256 (which needs a 32-byte key) by
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// doing:
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//
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// dk := pbkdf2.Key([]byte("some password"), salt, 4096, 32, sha1.New)
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//
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// Remember to get a good random salt. At least 8 bytes is recommended by the
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// RFC.
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//
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// Using a higher iteration count will increase the cost of an exhaustive
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// search but will also make derivation proportionally slower.
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func Key(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte {
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prf := hmac.New(h, password)
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hashLen := prf.Size()
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numBlocks := (keyLen + hashLen - 1) / hashLen
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var buf [4]byte
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dk := make([]byte, 0, numBlocks*hashLen)
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U := make([]byte, hashLen)
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for block := 1; block <= numBlocks; block++ {
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// N.B.: || means concatenation, ^ means XOR
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// for each block T_i = U_1 ^ U_2 ^ ... ^ U_iter
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// U_1 = PRF(password, salt || uint(i))
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prf.Reset()
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prf.Write(salt)
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buf[0] = byte(block >> 24)
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buf[1] = byte(block >> 16)
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buf[2] = byte(block >> 8)
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buf[3] = byte(block)
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prf.Write(buf[:4])
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dk = prf.Sum(dk)
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T := dk[len(dk)-hashLen:]
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copy(U, T)
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// U_n = PRF(password, U_(n-1))
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for n := 2; n <= iter; n++ {
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prf.Reset()
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prf.Write(U)
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U = U[:0]
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U = prf.Sum(U)
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for x := range U {
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T[x] ^= U[x]
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}
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}
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}
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return dk[:keyLen]
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}
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