1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* 27 * Portions of this code from crypt_bsdmd5.so (bsdmd5.c) : 28 * ---------------------------------------------------------------------------- 29 * "THE BEER-WARE LICENSE" (Revision 42): 30 * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you 31 * can do whatever you want with this stuff. If we meet some day, and you think 32 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 33 * ---------------------------------------------------------------------------- 34 * 35 * $FreeBSD: crypt.c,v 1.5 1996/10/14 08:34:02 phk Exp $ 36 * 37 */ 38 39 /* 40 * Implements the specification from: 41 * 42 * From http://people.redhat.com/drepper/SHA-crypt.txt 43 * 44 * Portions of the code taken from inspired by or verified against the 45 * source in the above document which is licensed as: 46 * 47 * "Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>." 48 */ 49 50 51 #include <sys/types.h> 52 #include <sys/stat.h> 53 #include <sys/sysmacros.h> 54 #include <fcntl.h> 55 #include <unistd.h> 56 #include <string.h> 57 #include <stdio.h> 58 #include <errno.h> 59 #include <stdlib.h> 60 #include <alloca.h> 61 62 #include <sha2.h> 63 #include <crypt.h> 64 65 #define MAX_SALT_LEN 16 66 #define ROUNDS_DEFAULT 5000 67 #define ROUNDS_MIN 1000 68 #define ROUNDS_MAX 999999999 69 70 #ifdef CRYPT_SHA256 71 72 #define DIGEST_CTX SHA256_CTX 73 #define DIGESTInit SHA256Init 74 #define DIGESTUpdate SHA256Update 75 #define DIGESTFinal SHA256Final 76 #define DIGEST_LEN SHA256_DIGEST_LENGTH 77 #define MIXCHARS 32 78 static const char crypt_alg_magic[] = "$5$"; 79 80 #elif CRYPT_SHA512 81 82 #define DIGEST_CTX SHA512_CTX 83 #define DIGESTInit SHA512Init 84 #define DIGESTUpdate SHA512Update 85 #define DIGESTFinal SHA512Final 86 #define DIGEST_LEN SHA512_DIGEST_LENGTH 87 #define MIXCHARS 64 88 static const char crypt_alg_magic[] = "$6$"; 89 90 #else 91 #error "One of CRYPT_256 or CRYPT_512 must be defined" 92 #endif 93 94 static const int crypt_alg_magic_len = sizeof (crypt_alg_magic) - 1; 95 static const char rounds_prefix[] = "rounds="; 96 97 98 static uchar_t b64t[] = /* 0 ... 63 => ascii - 64 */ 99 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 100 101 #define b64_from_24bit(B2, B1, B0, N) \ 102 { \ 103 uint_t w = ((B2) << 16) | ((B1) << 8) | (B0); \ 104 int n = (N); \ 105 while (--n >= 0 && ctbufflen > 0) { \ 106 *p++ = b64t[w & 0x3f]; \ 107 w >>= 6; \ 108 ctbufflen--; \ 109 } \ 110 } 111 112 static void 113 to64(char *s, uint64_t v, int n) 114 { 115 while (--n >= 0) { 116 *s++ = b64t[v&0x3f]; 117 v >>= 6; 118 } 119 } 120 121 char * 122 crypt_genhash_impl(char *ctbuffer, 123 size_t ctbufflen, 124 const char *plaintext, 125 const char *switchsalt, 126 const char **params) 127 { 128 int salt_len, plaintext_len, i; 129 char *salt; 130 uchar_t A[DIGEST_LEN]; 131 uchar_t B[DIGEST_LEN]; 132 uchar_t DP[DIGEST_LEN]; 133 uchar_t DS[DIGEST_LEN]; 134 DIGEST_CTX ctxA, ctxB, ctxC, ctxDP, ctxDS; 135 int rounds = ROUNDS_DEFAULT; 136 boolean_t custom_rounds = B_FALSE; 137 char *p; 138 char *P, *Pp; 139 char *S, *Sp; 140 141 /* Refine the salt */ 142 salt = (char *)switchsalt; 143 144 /* skip our magic string */ 145 if (strncmp((char *)salt, crypt_alg_magic, crypt_alg_magic_len) == 0) { 146 salt += crypt_alg_magic_len; 147 } 148 149 if (strncmp(salt, rounds_prefix, sizeof (rounds_prefix) - 1) == 0) { 150 char *num = salt + sizeof (rounds_prefix) - 1; 151 char *endp; 152 ulong_t srounds = strtoul(num, &endp, 10); 153 if (*endp == '$') { 154 salt = endp + 1; 155 rounds = MAX(ROUNDS_MIN, MIN(srounds, ROUNDS_MAX)); 156 custom_rounds = B_TRUE; 157 } 158 } 159 160 salt_len = MIN(strcspn(salt, "$"), MAX_SALT_LEN); 161 plaintext_len = strlen(plaintext); 162 163 /* 1. */ 164 DIGESTInit(&ctxA); 165 166 /* 2. The password first, since that is what is most unknown */ 167 DIGESTUpdate(&ctxA, plaintext, plaintext_len); 168 169 /* 3. Then the raw salt */ 170 DIGESTUpdate(&ctxA, salt, salt_len); 171 172 /* 4. - 8. */ 173 DIGESTInit(&ctxB); 174 DIGESTUpdate(&ctxB, plaintext, plaintext_len); 175 DIGESTUpdate(&ctxB, salt, salt_len); 176 DIGESTUpdate(&ctxB, plaintext, plaintext_len); 177 DIGESTFinal(B, &ctxB); 178 179 /* 9. - 10. */ 180 for (i = plaintext_len; i > MIXCHARS; i -= MIXCHARS) 181 DIGESTUpdate(&ctxA, B, MIXCHARS); 182 DIGESTUpdate(&ctxA, B, i); 183 184 /* 11. */ 185 for (i = plaintext_len; i > 0; i >>= 1) { 186 if ((i & 1) != 0) { 187 DIGESTUpdate(&ctxA, B, MIXCHARS); 188 } else { 189 DIGESTUpdate(&ctxA, plaintext, plaintext_len); 190 } 191 } 192 193 /* 12. */ 194 DIGESTFinal(A, &ctxA); 195 196 /* 13. - 15. */ 197 DIGESTInit(&ctxDP); 198 for (i = 0; i < plaintext_len; i++) 199 DIGESTUpdate(&ctxDP, plaintext, plaintext_len); 200 DIGESTFinal(DP, &ctxDP); 201 202 /* 16. */ 203 Pp = P = alloca(plaintext_len); 204 for (i = plaintext_len; i >= MIXCHARS; i -= MIXCHARS) { 205 Pp = (char *)(memcpy(Pp, DP, MIXCHARS)) + MIXCHARS; 206 } 207 memcpy(Pp, DP, i); 208 209 /* 17. - 19. */ 210 DIGESTInit(&ctxDS); 211 for (i = 0; i < 16 + (uint8_t)A[0]; i++) 212 DIGESTUpdate(&ctxDS, salt, salt_len); 213 DIGESTFinal(DS, &ctxDS); 214 215 /* 20. */ 216 Sp = S = alloca(salt_len); 217 for (i = salt_len; i >= MIXCHARS; i -= MIXCHARS) { 218 Sp = (char *)(memcpy(Sp, DS, MIXCHARS)) + MIXCHARS; 219 } 220 memcpy(Sp, DS, i); 221 222 /* 21. */ 223 for (i = 0; i < rounds; i++) { 224 DIGESTInit(&ctxC); 225 226 if ((i & 1) != 0) { 227 DIGESTUpdate(&ctxC, P, plaintext_len); 228 } else { 229 if (i == 0) 230 DIGESTUpdate(&ctxC, A, MIXCHARS); 231 else 232 DIGESTUpdate(&ctxC, DP, MIXCHARS); 233 } 234 235 if (i % 3 != 0) { 236 DIGESTUpdate(&ctxC, S, salt_len); 237 } 238 239 if (i % 7 != 0) { 240 DIGESTUpdate(&ctxC, P, plaintext_len); 241 } 242 243 if ((i & 1) != 0) { 244 if (i == 0) 245 DIGESTUpdate(&ctxC, A, MIXCHARS); 246 else 247 DIGESTUpdate(&ctxC, DP, MIXCHARS); 248 } else { 249 DIGESTUpdate(&ctxC, P, plaintext_len); 250 } 251 DIGESTFinal(DP, &ctxC); 252 } 253 254 /* 22. Now make the output string */ 255 (void) strlcpy(ctbuffer, crypt_alg_magic, ctbufflen); 256 if (custom_rounds) { 257 (void) snprintf(ctbuffer, ctbufflen, 258 "%srounds=%zu$", ctbuffer, rounds); 259 } 260 261 (void) strncat(ctbuffer, (const char *)salt, salt_len); 262 (void) strlcat(ctbuffer, "$", ctbufflen); 263 p = ctbuffer + strlen(ctbuffer); 264 ctbufflen -= strlen(ctbuffer); 265 266 #ifdef CRYPT_SHA256 267 b64_from_24bit(DP[ 0], DP[10], DP[20], 4); 268 b64_from_24bit(DP[21], DP[ 1], DP[11], 4); 269 b64_from_24bit(DP[12], DP[22], DP[ 2], 4); 270 b64_from_24bit(DP[ 3], DP[13], DP[23], 4); 271 b64_from_24bit(DP[24], DP[ 4], DP[14], 4); 272 b64_from_24bit(DP[15], DP[25], DP[ 5], 4); 273 b64_from_24bit(DP[ 6], DP[16], DP[26], 4); 274 b64_from_24bit(DP[27], DP[ 7], DP[17], 4); 275 b64_from_24bit(DP[18], DP[28], DP[ 8], 4); 276 b64_from_24bit(DP[ 9], DP[19], DP[29], 4); 277 b64_from_24bit(0, DP[31], DP[30], 3); 278 #elif CRYPT_SHA512 279 b64_from_24bit(DP[ 0], DP[21], DP[42], 4); 280 b64_from_24bit(DP[22], DP[43], DP[ 1], 4); 281 b64_from_24bit(DP[44], DP[ 2], DP[23], 4); 282 b64_from_24bit(DP[ 3], DP[24], DP[45], 4); 283 b64_from_24bit(DP[25], DP[46], DP[ 4], 4); 284 b64_from_24bit(DP[47], DP[ 5], DP[26], 4); 285 b64_from_24bit(DP[ 6], DP[27], DP[48], 4); 286 b64_from_24bit(DP[28], DP[49], DP[ 7], 4); 287 b64_from_24bit(DP[50], DP[ 8], DP[29], 4); 288 b64_from_24bit(DP[ 9], DP[30], DP[51], 4); 289 b64_from_24bit(DP[31], DP[52], DP[10], 4); 290 b64_from_24bit(DP[53], DP[11], DP[32], 4); 291 b64_from_24bit(DP[12], DP[33], DP[54], 4); 292 b64_from_24bit(DP[34], DP[55], DP[13], 4); 293 b64_from_24bit(DP[56], DP[14], DP[35], 4); 294 b64_from_24bit(DP[15], DP[36], DP[57], 4); 295 b64_from_24bit(DP[37], DP[58], DP[16], 4); 296 b64_from_24bit(DP[59], DP[17], DP[38], 4); 297 b64_from_24bit(DP[18], DP[39], DP[60], 4); 298 b64_from_24bit(DP[40], DP[61], DP[19], 4); 299 b64_from_24bit(DP[62], DP[20], DP[41], 4); 300 b64_from_24bit(0, 0, DP[63], 2); 301 #endif 302 *p = '\0'; 303 304 (void) memset(A, 0, sizeof (A)); 305 (void) memset(B, 0, sizeof (B)); 306 (void) memset(DP, 0, sizeof (DP)); 307 (void) memset(DS, 0, sizeof (DS)); 308 309 return (ctbuffer); 310 } 311 312 char * 313 crypt_gensalt_impl(char *gsbuffer, 314 size_t gsbufflen, 315 const char *oldsalt, 316 const struct passwd *userinfo, 317 const char **params) 318 { 319 int fd; 320 int err; 321 ssize_t got; 322 uint64_t rndval; 323 324 if ((fd = open("/dev/urandom", O_RDONLY)) == -1) { 325 return (NULL); 326 } 327 328 (void) strlcpy(gsbuffer, crypt_alg_magic, gsbufflen); 329 330 got = read(fd, &rndval, sizeof (rndval)); 331 if (got < sizeof (rndval)) { 332 err = errno; 333 (void) close(fd); 334 errno = err; 335 return (NULL); 336 } 337 338 to64(&gsbuffer[strlen(crypt_alg_magic)], rndval, sizeof (rndval)); 339 340 (void) close(fd); 341 342 return (gsbuffer); 343 } 344