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