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/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 */ 132