1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #ifdef _KERNEL
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #else
34 #include <sys/resource.h>
35 #include <stdint.h>
36 #include <strings.h>
37 #endif
38
39 #include <geom/eli/g_eli.h>
40 #include <geom/eli/pkcs5v2.h>
41
42 static __inline void
xor(uint8_t * dst,const uint8_t * src,size_t size)43 xor(uint8_t *dst, const uint8_t *src, size_t size)
44 {
45
46 for (; size > 0; size--)
47 *dst++ ^= *src++;
48 }
49
50 void
pkcs5v2_genkey(uint8_t * key,unsigned keylen,const uint8_t * salt,size_t saltsize,const char * passphrase,u_int iterations)51 pkcs5v2_genkey(uint8_t *key, unsigned keylen, const uint8_t *salt,
52 size_t saltsize, const char *passphrase, u_int iterations)
53 {
54
55 pkcs5v2_genkey_raw(key, keylen, salt, saltsize, passphrase,
56 strlen(passphrase), iterations);
57 }
58
59 void
pkcs5v2_genkey_raw(uint8_t * key,unsigned keylen,const uint8_t * salt,size_t saltsize,const uint8_t * passphrase,size_t passlen,u_int iterations)60 pkcs5v2_genkey_raw(uint8_t *key, unsigned keylen, const uint8_t *salt,
61 size_t saltsize, const uint8_t *passphrase, size_t passlen,
62 u_int iterations)
63 {
64 uint8_t md[SHA512_MDLEN], saltcount[saltsize + sizeof(uint32_t)];
65 uint8_t *counter, *keyp;
66 u_int i, bsize;
67 uint32_t count;
68 struct hmac_ctx startpoint, ctx;
69
70 bzero(key, keylen);
71 bcopy(salt, saltcount, saltsize);
72 counter = saltcount + saltsize;
73
74 keyp = key;
75 for (count = 1; keylen > 0; count++, keylen -= bsize, keyp += bsize) {
76 bsize = MIN(keylen, sizeof(md));
77
78 be32enc(counter, count);
79
80 g_eli_crypto_hmac_init(&startpoint, passphrase, passlen);
81 ctx = startpoint;
82 g_eli_crypto_hmac_update(&ctx, saltcount, sizeof(saltcount));
83 g_eli_crypto_hmac_final(&ctx, md, sizeof(md));
84 xor(keyp, md, bsize);
85
86 for(i = 1; i < iterations; i++) {
87 ctx = startpoint;
88 g_eli_crypto_hmac_update(&ctx, md, sizeof(md));
89 g_eli_crypto_hmac_final(&ctx, md, sizeof(md));
90 xor(keyp, md, bsize);
91 }
92 }
93 explicit_bzero(&startpoint, sizeof(startpoint));
94 explicit_bzero(&ctx, sizeof(ctx));
95 }
96
97 #ifndef _KERNEL
98 #ifndef _STANDALONE
99 /*
100 * Return the number of microseconds needed for 'interations' iterations.
101 */
102 static int
pkcs5v2_probe(int iterations)103 pkcs5v2_probe(int iterations)
104 {
105 uint8_t key[G_ELI_USERKEYLEN], salt[G_ELI_SALTLEN];
106 const char passphrase[] = "passphrase";
107 struct rusage start, end;
108 int usecs;
109
110 getrusage(RUSAGE_SELF, &start);
111 pkcs5v2_genkey(key, sizeof(key), salt, sizeof(salt), passphrase,
112 iterations);
113 getrusage(RUSAGE_SELF, &end);
114
115 usecs = end.ru_utime.tv_sec - start.ru_utime.tv_sec;
116 usecs *= 1000000;
117 usecs += end.ru_utime.tv_usec - start.ru_utime.tv_usec;
118 return (usecs);
119 }
120
121 /*
122 * Return the number of iterations which takes 'usecs' microseconds.
123 */
124 int
pkcs5v2_calculate(int usecs)125 pkcs5v2_calculate(int usecs)
126 {
127 int iterations, v;
128
129 for (iterations = 1; ; iterations <<= 1) {
130 v = pkcs5v2_probe(iterations);
131 if (v > 2000000)
132 break;
133 }
134 return (((intmax_t)iterations * (intmax_t)usecs) / v);
135 }
136 #endif /* !_STANDALONE */
137 #endif /* !_KERNEL */
138