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-rw-r--r--lib/crypto_backend/pbkdf2_generic.c426
1 files changed, 426 insertions, 0 deletions
diff --git a/lib/crypto_backend/pbkdf2_generic.c b/lib/crypto_backend/pbkdf2_generic.c
new file mode 100644
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+++ b/lib/crypto_backend/pbkdf2_generic.c
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+/*
+ * 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 <errno.h>
+#include <alloca.h>
+#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 <stdio.h>
+
+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
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