/* * Implementation of Password-Based Cryptography as per PKCS#5 * Copyright (C) 2002,2003 Simon Josefsson * Copyright (C) 2004 Free Software Foundation * * cryptsetup related changes * Copyright (C) 2012-2019 Red Hat, Inc. All rights reserved. * Copyright (C) 2012-2019 Milan Broz * * This file is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This file is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this file; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * */ #include #include #include "crypto_backend.h" static int hash_buf(const char *src, size_t src_len, char *dst, size_t dst_len, const char *hash_name) { struct crypt_hash *hd = NULL; int r; if (crypt_hash_init(&hd, hash_name)) return -EINVAL; r = crypt_hash_write(hd, src, src_len); if (!r) r = crypt_hash_final(hd, dst, dst_len); crypt_hash_destroy(hd); return r; } /* * 5.2 PBKDF2 * * PBKDF2 applies a pseudorandom function (see Appendix B.1 for an * example) to derive keys. The length of the derived key is essentially * unbounded. (However, the maximum effective search space for the * derived key may be limited by the structure of the underlying * pseudorandom function. See Appendix B.1 for further discussion.) * PBKDF2 is recommended for new applications. * * PBKDF2 (P, S, c, dkLen) * * Options: PRF underlying pseudorandom function (hLen * denotes the length in octets of the * pseudorandom function output) * * Input: P password, an octet string (ASCII or UTF-8) * S salt, an octet string * c iteration count, a positive integer * dkLen intended length in octets of the derived * key, a positive integer, at most * (2^32 - 1) * hLen * * Output: DK derived key, a dkLen-octet string */ /* * if hash_block_size is not zero, the HMAC key is pre-hashed * inside this function. * This prevents situation when crypto backend doesn't support * long HMAC keys or it tries hash long key in every iteration * (because of crypt_final() cannot do simple key reset. */ #define MAX_PRF_BLOCK_LEN 80 int pkcs5_pbkdf2(const char *hash, const char *P, size_t Plen, const char *S, size_t Slen, unsigned int c, unsigned int dkLen, char *DK, unsigned int hash_block_size) { struct crypt_hmac *hmac; char U[MAX_PRF_BLOCK_LEN]; char T[MAX_PRF_BLOCK_LEN]; char P_hash[MAX_PRF_BLOCK_LEN]; int i, k, rc = -EINVAL; unsigned int u, hLen, l, r; size_t tmplen = Slen + 4; char *tmp; tmp = alloca(tmplen); if (tmp == NULL) return -ENOMEM; hLen = crypt_hmac_size(hash); if (hLen == 0 || hLen > MAX_PRF_BLOCK_LEN) return -EINVAL; if (c == 0) return -EINVAL; if (dkLen == 0) return -EINVAL; /* * * Steps: * * 1. If dkLen > (2^32 - 1) * hLen, output "derived key too long" and * stop. */ if (dkLen > 4294967295U) return -EINVAL; /* * 2. Let l be the number of hLen-octet blocks in the derived key, * rounding up, and let r be the number of octets in the last * block: * * l = CEIL (dkLen / hLen) , * r = dkLen - (l - 1) * hLen . * * Here, CEIL (x) is the "ceiling" function, i.e. the smallest * integer greater than, or equal to, x. */ l = dkLen / hLen; if (dkLen % hLen) l++; r = dkLen - (l - 1) * hLen; /* * 3. For each block of the derived key apply the function F defined * below to the password P, the salt S, the iteration count c, and * the block index to compute the block: * * T_1 = F (P, S, c, 1) , * T_2 = F (P, S, c, 2) , * ... * T_l = F (P, S, c, l) , * * where the function F is defined as the exclusive-or sum of the * first c iterates of the underlying pseudorandom function PRF * applied to the password P and the concatenation of the salt S * and the block index i: * * F (P, S, c, i) = U_1 \xor U_2 \xor ... \xor U_c * * where * * U_1 = PRF (P, S || INT (i)) , * U_2 = PRF (P, U_1) , * ... * U_c = PRF (P, U_{c-1}) . * * Here, INT (i) is a four-octet encoding of the integer i, most * significant octet first. * * 4. Concatenate the blocks and extract the first dkLen octets to * produce a derived key DK: * * DK = T_1 || T_2 || ... || T_l<0..r-1> * * 5. Output the derived key DK. * * Note. The construction of the function F follows a "belt-and- * suspenders" approach. The iterates U_i are computed recursively to * remove a degree of parallelism from an opponent; they are exclusive- * ored together to reduce concerns about the recursion degenerating * into a small set of values. * */ /* If hash_block_size is provided, hash password in advance. */ if (hash_block_size > 0 && Plen > hash_block_size) { if (hash_buf(P, Plen, P_hash, hLen, hash)) return -EINVAL; if (crypt_hmac_init(&hmac, hash, P_hash, hLen)) return -EINVAL; crypt_backend_memzero(P_hash, sizeof(P_hash)); } else { if (crypt_hmac_init(&hmac, hash, P, Plen)) return -EINVAL; } for (i = 1; (unsigned int) i <= l; i++) { memset(T, 0, hLen); for (u = 1; u <= c ; u++) { if (u == 1) { memcpy(tmp, S, Slen); tmp[Slen + 0] = (i & 0xff000000) >> 24; tmp[Slen + 1] = (i & 0x00ff0000) >> 16; tmp[Slen + 2] = (i & 0x0000ff00) >> 8; tmp[Slen + 3] = (i & 0x000000ff) >> 0; if (crypt_hmac_write(hmac, tmp, tmplen)) goto out; } else { if (crypt_hmac_write(hmac, U, hLen)) goto out; } if (crypt_hmac_final(hmac, U, hLen)) goto out; for (k = 0; (unsigned int) k < hLen; k++) T[k] ^= U[k]; } memcpy(DK + (i - 1) * hLen, T, (unsigned int) i == l ? r : hLen); } rc = 0; out: crypt_hmac_destroy(hmac); crypt_backend_memzero(U, sizeof(U)); crypt_backend_memzero(T, sizeof(T)); crypt_backend_memzero(tmp, tmplen); return rc; } #if 0 #include struct test_vector { const char *hash; unsigned int hash_block_length; unsigned int iterations; const char *password; unsigned int password_length; const char *salt; unsigned int salt_length; const char *output; unsigned int output_length; }; struct test_vector test_vectors[] = { /* RFC 3962 */ { "sha1", 64, 1, "password", 8, "ATHENA.MIT.EDUraeburn", 21, "\xcd\xed\xb5\x28\x1b\xb2\xf8\x01" "\x56\x5a\x11\x22\xb2\x56\x35\x15" "\x0a\xd1\xf7\xa0\x4b\xb9\xf3\xa3" "\x33\xec\xc0\xe2\xe1\xf7\x08\x37", 32 }, { "sha1", 64, 2, "password", 8, "ATHENA.MIT.EDUraeburn", 21, "\x01\xdb\xee\x7f\x4a\x9e\x24\x3e" "\x98\x8b\x62\xc7\x3c\xda\x93\x5d" "\xa0\x53\x78\xb9\x32\x44\xec\x8f" "\x48\xa9\x9e\x61\xad\x79\x9d\x86", 32 }, { "sha1", 64, 1200, "password", 8, "ATHENA.MIT.EDUraeburn", 21, "\x5c\x08\xeb\x61\xfd\xf7\x1e\x4e" "\x4e\xc3\xcf\x6b\xa1\xf5\x51\x2b" "\xa7\xe5\x2d\xdb\xc5\xe5\x14\x2f" "\x70\x8a\x31\xe2\xe6\x2b\x1e\x13", 32 }, { "sha1", 64, 5, "password", 8, "\0224VxxV4\022", 8, // "\x1234567878563412 "\xd1\xda\xa7\x86\x15\xf2\x87\xe6" "\xa1\xc8\xb1\x20\xd7\x06\x2a\x49" "\x3f\x98\xd2\x03\xe6\xbe\x49\xa6" "\xad\xf4\xfa\x57\x4b\x6e\x64\xee", 32 }, { "sha1", 64, 1200, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 64, "pass phrase equals block size", 29, "\x13\x9c\x30\xc0\x96\x6b\xc3\x2b" "\xa5\x5f\xdb\xf2\x12\x53\x0a\xc9" "\xc5\xec\x59\xf1\xa4\x52\xf5\xcc" "\x9a\xd9\x40\xfe\xa0\x59\x8e\xd1", 32 }, { "sha1", 64, 1200, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65, "pass phrase exceeds block size", 30, "\x9c\xca\xd6\xd4\x68\x77\x0c\xd5" "\x1b\x10\xe6\xa6\x87\x21\xbe\x61" "\x1a\x8b\x4d\x28\x26\x01\xdb\x3b" "\x36\xbe\x92\x46\x91\x5e\xc8\x2a", 32 }, { "sha1", 64, 50, "\360\235\204\236", 4, // g-clef ("\xf09d849e) "EXAMPLE.COMpianist", 18, "\x6b\x9c\xf2\x6d\x45\x45\x5a\x43" "\xa5\xb8\xbb\x27\x6a\x40\x3b\x39" "\xe7\xfe\x37\xa0\xc4\x1e\x02\xc2" "\x81\xff\x30\x69\xe1\xe9\x4f\x52", 32 }, { /* RFC-6070 */ "sha1", 64, 1, "password", 8, "salt", 4, "\x0c\x60\xc8\x0f\x96\x1f\x0e\x71\xf3\xa9" "\xb5\x24\xaf\x60\x12\x06\x2f\xe0\x37\xa6", 20 }, { "sha1", 64, 2, "password", 8, "salt", 4, "\xea\x6c\x01\x4d\xc7\x2d\x6f\x8c\xcd\x1e" "\xd9\x2a\xce\x1d\x41\xf0\xd8\xde\x89\x57", 20 }, { "sha1", 64, 4096, "password", 8, "salt", 4, "\x4b\x00\x79\x01\xb7\x65\x48\x9a\xbe\xad" "\x49\xd9\x26\xf7\x21\xd0\x65\xa4\x29\xc1", 20 }, { "sha1", 64, 16777216, "password", 8, "salt", 4, "\xee\xfe\x3d\x61\xcd\x4d\xa4\xe4\xe9\x94" "\x5b\x3d\x6b\xa2\x15\x8c\x26\x34\xe9\x84", 20 }, { "sha1", 64, 4096, "passwordPASSWORDpassword", 24, "saltSALTsaltSALTsaltSALTsaltSALTsalt", 36, "\x3d\x2e\xec\x4f\xe4\x1c\x84\x9b\x80\xc8" "\xd8\x36\x62\xc0\xe4\x4a\x8b\x29\x1a\x96" "\x4c\xf2\xf0\x70\x38", 25 }, { "sha1", 64, 4096, "pass\0word", 9, "sa\0lt", 5, "\x56\xfa\x6a\xa7\x55\x48\x09\x9d\xcc\x37" "\xd7\xf0\x34\x25\xe0\xc3", 16 }, { /* empty password test */ "sha1", 64, 2, "", 0, "salt", 4, "\x13\x3a\x4c\xe8\x37\xb4\xd2\x52\x1e\xe2" "\xbf\x03\xe1\x1c\x71\xca\x79\x4e\x07\x97", 20 }, { /* Password exceeds block size test */ "sha256", 64, 1200, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65, "pass phrase exceeds block size", 30, "\x22\x34\x4b\xc4\xb6\xe3\x26\x75" "\xa8\x09\x0f\x3e\xa8\x0b\xe0\x1d" "\x5f\x95\x12\x6a\x2c\xdd\xc3\xfa" "\xcc\x4a\x5e\x6d\xca\x04\xec\x58", 32 }, { "sha512", 128, 1200, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 129, "pass phrase exceeds block size", 30, "\x0f\xb2\xed\x2c\x0e\x6e\xfb\x7d" "\x7d\x8e\xdd\x58\x01\xb4\x59\x72" "\x99\x92\x16\x30\x5e\xa4\x36\x8d" "\x76\x14\x80\xf3\xe3\x7a\x22\xb9", 32 }, { "whirlpool", 64, 1200, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65, "pass phrase exceeds block size", 30, "\x9c\x1c\x74\xf5\x88\x26\xe7\x6a" "\x53\x58\xf4\x0c\x39\xe7\x80\x89" "\x07\xc0\x31\x19\x9a\x50\xa2\x48" "\xf1\xd9\xfe\x78\x64\xe5\x84\x50", 32 } }; static void printhex(const char *s, const char *buf, size_t len) { size_t i; printf("%s: ", s); for (i = 0; i < len; i++) printf("\\x%02x", (unsigned char)buf[i]); printf("\n"); fflush(stdout); } static int pkcs5_pbkdf2_test_vectors(void) { char result[64]; unsigned int i, j; struct test_vector *vec; for (i = 0; i < (sizeof(test_vectors) / sizeof(*test_vectors)); i++) { vec = &test_vectors[i]; for (j = 1; j <= vec->output_length; j++) { if (pkcs5_pbkdf2(vec->hash, vec->password, vec->password_length, vec->salt, vec->salt_length, vec->iterations, j, result, vec->hash_block_length)) { printf("pbkdf2 failed, vector %d\n", i); return -EINVAL; } if (memcmp(result, vec->output, j) != 0) { printf("vector %u\n", i); printhex(" got", result, j); printhex("want", vec->output, j); return -EINVAL; } memset(result, 0, sizeof(result)); } } return 0; } #endif