FreeBSD/Linux Kernel Cross Reference
sys/geom/eli/pkcs5v2.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #ifdef _KERNEL
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #else
37 #include <sys/resource.h>
38 #include <stdint.h>
39 #include <strings.h>
40 #endif
41
42 #include <geom/eli/g_eli.h>
43 #include <geom/eli/pkcs5v2.h>
44
45 static __inline void
46 xor(uint8_t *dst, const uint8_t *src, size_t size)
47 {
48
49 for (; size > 0; size--)
50 *dst++ ^= *src++;
51 }
52
53 void
54 pkcs5v2_genkey(uint8_t *key, unsigned keylen, const uint8_t *salt,
55 size_t saltsize, const char *passphrase, u_int iterations)
56 {
57 uint8_t md[SHA512_MDLEN], saltcount[saltsize + sizeof(uint32_t)];
58 uint8_t *counter, *keyp;
59 u_int i, bsize, passlen;
60 uint32_t count;
61 struct hmac_ctx startpoint, ctx;
62
63 passlen = strlen(passphrase);
64 bzero(key, keylen);
65 bcopy(salt, saltcount, saltsize);
66 counter = saltcount + saltsize;
67
68 keyp = key;
69 for (count = 1; keylen > 0; count++, keylen -= bsize, keyp += bsize) {
70 bsize = MIN(keylen, sizeof(md));
71
72 be32enc(counter, count);
73
74 g_eli_crypto_hmac_init(&startpoint, passphrase, passlen);
75 ctx = startpoint;
76 g_eli_crypto_hmac_update(&ctx, saltcount, sizeof(saltcount));
77 g_eli_crypto_hmac_final(&ctx, md, sizeof(md));
78 xor(keyp, md, bsize);
79
80 for(i = 1; i < iterations; i++) {
81 ctx = startpoint;
82 g_eli_crypto_hmac_update(&ctx, md, sizeof(md));
83 g_eli_crypto_hmac_final(&ctx, md, sizeof(md));
84 xor(keyp, md, bsize);
85 }
86 }
87 explicit_bzero(&startpoint, sizeof(startpoint));
88 explicit_bzero(&ctx, sizeof(ctx));
89 }
90
91 #ifndef _KERNEL
92 #ifndef _STANDALONE
93 /*
94 * Return the number of microseconds needed for 'interations' iterations.
95 */
96 static int
97 pkcs5v2_probe(int iterations)
98 {
99 uint8_t key[G_ELI_USERKEYLEN], salt[G_ELI_SALTLEN];
100 const char passphrase[] = "passphrase";
101 struct rusage start, end;
102 int usecs;
103
104 getrusage(RUSAGE_SELF, &start);
105 pkcs5v2_genkey(key, sizeof(key), salt, sizeof(salt), passphrase,
106 iterations);
107 getrusage(RUSAGE_SELF, &end);
108
109 usecs = end.ru_utime.tv_sec - start.ru_utime.tv_sec;
110 usecs *= 1000000;
111 usecs += end.ru_utime.tv_usec - start.ru_utime.tv_usec;
112 return (usecs);
113 }
114
115 /*
116 * Return the number of iterations which takes 'usecs' microseconds.
117 */
118 int
119 pkcs5v2_calculate(int usecs)
120 {
121 int iterations, v;
122
123 for (iterations = 1; ; iterations <<= 1) {
124 v = pkcs5v2_probe(iterations);
125 if (v > 2000000)
126 break;
127 }
128 return (((intmax_t)iterations * (intmax_t)usecs) / v);
129 }
130 #endif /* !_STANDALONE */
131 #endif /* !_KERNEL */
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