1 /* $NetBSD: skeyinit.c,v 1.29 2009/04/14 09:53:08 lukem Exp $ */ 2 3 /* S/KEY v1.1b (skeyinit.c) 4 * 5 * Authors: 6 * Neil M. Haller <nmh (at) thumper.bellcore.com> 7 * Philip R. Karn <karn (at) chicago.qualcomm.com> 8 * John S. Walden <jsw (at) thumper.bellcore.com> 9 * Scott Chasin <chasin (at) crimelab.com> 10 * 11 * Modifications: 12 * Todd C. Miller <Todd.Miller (at) courtesan.com> 13 * 14 * S/KEY initialization and seed update 15 */ 16 17 #include <sys/cdefs.h> 18 19 #ifndef lint 20 __RCSID("$NetBSD: skeyinit.c,v 1.29 2009/04/14 09:53:08 lukem Exp $"); 21 #endif 22 23 #include <sys/param.h> 24 #include <sys/time.h> 25 #include <sys/resource.h> 26 27 #include <ctype.h> 28 #include <err.h> 29 #include <errno.h> 30 #include <fcntl.h> 31 #include <paths.h> 32 #include <pwd.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <time.h> 37 #include <unistd.h> 38 39 #include <skey.h> 40 41 #ifndef SKEY_NAMELEN 42 #define SKEY_NAMELEN 4 43 #endif 44 45 int main(int argc, char **argv) 46 { 47 int rval, nn, i; 48 size_t l; 49 int n = 0, defaultsetup = 1, zerokey = 0, hexmode = 0; 50 int argpass = 0, argkey = 0; 51 time_t now; 52 char hostname[MAXHOSTNAMELEN + 1]; 53 char seed[SKEY_MAX_PW_LEN+2], key[SKEY_BINKEY_SIZE], defaultseed[SKEY_MAX_SEED_LEN+1]; 54 char passwd[SKEY_MAX_PW_LEN+2], passwd2[SKEY_MAX_PW_LEN+2], tbuf[27], buf[80]; 55 char lastc, me[LOGIN_NAME_MAX+1], *p, *pw, *ht = NULL; 56 const char *salt; 57 struct skey skey; 58 struct passwd *pp; 59 struct tm *tm; 60 int c; 61 62 pw = NULL; /* XXX gcc -Wuninitialized [sh3] */ 63 64 /* 65 * Make sure using stdin/stdout/stderr is safe 66 * after opening any file. 67 */ 68 i = open(_PATH_DEVNULL, O_RDWR); 69 while (i >= 0 && i < 2) 70 i = dup(i); 71 if (i > 2) 72 close(i); 73 74 if (geteuid() != 0) 75 errx(1, "must be setuid root."); 76 77 if (gethostname(hostname, sizeof(hostname)) < 0) 78 err(1, "gethostname"); 79 80 /* 81 * Copy the hostname into the default seed, eliminating any 82 * non alpha-numeric characters. 83 */ 84 for (i = 0, l = 0; l < sizeof(defaultseed); i++) { 85 if (hostname[i] == '\0') { 86 defaultseed[l] = hostname[i]; 87 break; 88 } 89 if (isalnum((unsigned char)hostname[i])) 90 defaultseed[l++] = hostname[i]; 91 } 92 93 defaultseed[SKEY_NAMELEN] = '\0'; 94 (void)time(&now); 95 (void)snprintf(tbuf, sizeof(tbuf), "%05ld", (long) (now % 100000)); 96 (void)strlcat(defaultseed, tbuf, sizeof(defaultseed)); 97 98 if ((pp = getpwuid(getuid())) == NULL) 99 err(1, "no user with uid %ld", (u_long)getuid()); 100 (void)strlcpy(me, pp->pw_name, sizeof(me)); 101 102 if ((pp = getpwnam(me)) == NULL) 103 err(1, "Who are you?"); 104 salt = pp->pw_passwd; 105 106 while((c = getopt(argc, argv, "k:n:p:t:sxz")) != -1) { 107 switch(c) { 108 case 'k': 109 argkey = 1; 110 if (strlen(optarg) > SKEY_MAX_PW_LEN) 111 errx(1, "key too long"); 112 strlcpy(passwd, optarg, sizeof(passwd)); 113 strlcpy(passwd2, optarg, sizeof(passwd)); 114 break; 115 case 'n': 116 n = atoi(optarg); 117 if(n < 1 || n > SKEY_MAX_SEQ) 118 errx(1, "count must be between 1 and %d", SKEY_MAX_SEQ); 119 break; 120 case 'p': 121 if (strlen(optarg) >= _PASSWORD_LEN) 122 errx(1, "password too long"); 123 if ((pw = malloc(_PASSWORD_LEN + 1)) == NULL) 124 err(1, "no memory for password"); 125 strlcpy(pw, optarg, _PASSWORD_LEN + 1); 126 break; 127 case 't': 128 if(skey_set_algorithm(optarg) == NULL) 129 errx(1, "Unknown hash algorithm %s", optarg); 130 ht = optarg; 131 break; 132 case 's': 133 defaultsetup = 0; 134 break; 135 case 'x': 136 hexmode = 1; 137 break; 138 case 'z': 139 zerokey = 1; 140 break; 141 default: 142 errx(1, "usage: %s skeyinit [-sxz] [-k passphrase] " 143 "[-n count] [-p password] [-t hash] [user]", 144 argv[0]); 145 } 146 } 147 148 if(argc > optind) { 149 pp = getpwnam(argv[optind]); 150 if (pp == NULL) 151 errx(1, "User %s unknown", argv[optind]); 152 } 153 154 if (strcmp(pp->pw_name, me) != 0) { 155 if (getuid() != 0) { 156 /* Only root can change other's passwds */ 157 errx(1, "Permission denied."); 158 } 159 } 160 161 if (getuid() != 0) { 162 if (!argpass) 163 pw = getpass("Password:"); 164 p = crypt(pw, salt); 165 166 if (strcmp(p, pp->pw_passwd)) { 167 errx(1, "Password incorrect."); 168 } 169 } 170 171 rval = skeylookup(&skey, pp->pw_name); 172 switch (rval) { 173 case -1: 174 err(1, "cannot open database"); 175 case 0: 176 /* comment out user if asked to */ 177 if (zerokey) 178 exit(skeyzero(&skey, pp->pw_name)); 179 180 printf("[Updating %s]\n", pp->pw_name); 181 printf("Old key: [%s] %s\n", skey_get_algorithm(), skey.seed); 182 183 /* 184 * lets be nice if they have a skey.seed that 185 * ends in 0-8 just add one 186 */ 187 l = strlen(skey.seed); 188 if (l > 0) { 189 lastc = skey.seed[l - 1]; 190 if (isdigit((unsigned char)lastc) && lastc != '9') { 191 (void)strlcpy(defaultseed, skey.seed, 192 sizeof(defaultseed)); 193 defaultseed[l - 1] = lastc + 1; 194 } 195 if (isdigit((unsigned char)lastc) && lastc == '9' && 196 l < 16) { 197 (void)strlcpy(defaultseed, skey.seed, 198 sizeof(defaultseed)); 199 defaultseed[l - 1] = '0'; 200 defaultseed[l] = '0'; 201 defaultseed[l + 1] = '\0'; 202 } 203 } 204 break; 205 case 1: 206 if (zerokey) 207 errx(1, "You have no entry to zero."); 208 printf("[Adding %s]\n", pp->pw_name); 209 break; 210 } 211 212 if (n==0) 213 n = 100; 214 215 /* Set hash type if asked to */ 216 if (ht) { 217 /* Need to zero out old key when changing algorithm */ 218 if (strcmp(ht, skey_get_algorithm()) && skey_set_algorithm(ht)) 219 zerokey = 1; 220 } 221 222 if (!defaultsetup) { 223 printf("You need the 6 english words generated from the \"skey\" command.\n"); 224 for (i = 0;; i++) { 225 if (i >= 2) 226 exit(1); 227 printf("Enter sequence count from 1 to %d: ", SKEY_MAX_SEQ); 228 fgets(buf, sizeof(buf), stdin); 229 n = atoi(buf); 230 if (n > 0 && n < SKEY_MAX_SEQ) 231 break; /* Valid range */ 232 printf("\nError: Count must be between 0 and %d\n", SKEY_MAX_SEQ); 233 } 234 235 for (i = 0;; i++) { 236 if (i >= 2) 237 exit(1); 238 239 printf("Enter new seed [default %s]: ", defaultseed); 240 fflush(stdout); 241 fgets(seed, sizeof(seed), stdin); 242 rip(seed); 243 for (p = seed; *p; p++) { 244 if (isalpha((unsigned char)*p)) { 245 *p = tolower((unsigned char)*p); 246 } else if (!isdigit((unsigned char)*p)) { 247 (void)puts("Error: seed may only contain alphanumeric characters"); 248 break; 249 } 250 } 251 if (*p == '\0') 252 break; /* Valid seed */ 253 } 254 if (strlen(seed) > SKEY_MAX_SEED_LEN) { 255 printf("Notice: Seed truncated to %d characters.\n", SKEY_MAX_SEED_LEN); 256 seed[SKEY_MAX_SEED_LEN] = '\0'; 257 } 258 if (seed[0] == '\0') 259 (void)strlcpy(seed, defaultseed, sizeof(seed)); 260 261 for (i = 0;; i++) { 262 if (i >= 2) 263 exit(1); 264 265 printf("otp-%s %d %s\ns/key access password: ", 266 skey_get_algorithm(), n, seed); 267 fgets(buf, sizeof(buf), stdin); 268 rip(buf); 269 backspace(buf); 270 271 if (buf[0] == '?') { 272 puts("Enter 6 English words from secure S/Key calculation."); 273 continue; 274 } else if (buf[0] == '\0') { 275 exit(1); 276 } 277 if (etob(key, buf) == 1 || atob8(key, buf) == 0) 278 break; /* Valid format */ 279 (void)puts("Invalid format - try again with 6 English words."); 280 } 281 } else { 282 /* Get user's secret password */ 283 puts("Reminder - Only use this method if you are directly connected\n" 284 " or have an encrypted channel. If you are using telnet\n" 285 " or rlogin, exit with no password and use skeyinit -s.\n"); 286 287 for (i = 0;; i++) { 288 if (i >= 2) 289 exit(1); 290 291 if (!argkey) { 292 printf("Enter secret password: "); 293 readpass(passwd, sizeof(passwd)); 294 if (passwd[0] == '\0') 295 exit(1); 296 } 297 298 if (strlen(passwd) < SKEY_MIN_PW_LEN) { 299 (void)fprintf(stderr, 300 "Your password must be at least %d characters long.\n", SKEY_MIN_PW_LEN); 301 continue; 302 } else if (strcmp(passwd, pp->pw_name) == 0) { 303 (void)fputs("Your password may not be the same as your user name.\n", stderr); 304 continue; 305 } 306 #if 0 307 else if (strspn(passwd, "abcdefghijklmnopqrstuvwxyz") == strlen(passwd)) { 308 (void)fputs("Your password must contain more than just lower case letters.\n" 309 "Whitespace, numbers, and puctuation are suggested.\n", stderr); 310 continue; 311 } 312 #endif 313 314 if (!argkey) { 315 printf("Again secret password: "); 316 readpass(passwd2, sizeof(passwd)); 317 if (passwd2[0] == '\0') 318 exit(1); 319 } 320 321 if (strcmp(passwd, passwd2) == 0) 322 break; 323 324 puts("Passwords do not match."); 325 } 326 327 /* Crunch seed and password into starting key */ 328 (void)strlcpy(seed, defaultseed, sizeof(seed)); 329 if (keycrunch(key, seed, passwd) != 0) 330 err(2, "key crunch failed"); 331 nn = n; 332 while (nn-- != 0) 333 f(key); 334 } 335 (void)time(&now); 336 tm = localtime(&now); 337 (void)strftime(tbuf, sizeof(tbuf), " %b %d,%Y %T", tm); 338 339 if ((skey.val = (char *)malloc(16 + 1)) == NULL) 340 err(1, "Can't allocate memory"); 341 342 /* Zero out old key if necessary (entry would change size) */ 343 if (zerokey) { 344 (void)skeyzero(&skey, pp->pw_name); 345 /* Re-open keys file and seek to the end */ 346 if (skeylookup(&skey, pp->pw_name) == -1) 347 err(1, "cannot open database"); 348 } 349 350 btoa8(skey.val, key); 351 352 /* 353 * Obtain an exclusive lock on the key file so we don't 354 * clobber someone authenticating themselves at the same time. 355 */ 356 for (i = 0; i < 300; i++) { 357 if ((rval = flock(fileno(skey.keyfile), LOCK_EX|LOCK_NB)) == 0 358 || errno != EWOULDBLOCK) 359 break; 360 usleep(100000); /* Sleep for 0.1 seconds */ 361 } 362 if (rval == -1) { /* Can't get exclusive lock */ 363 errno = EAGAIN; 364 err(1, "cannot open database"); 365 } 366 367 /* Don't save algorithm type for md4 (keep record length same) */ 368 if (strcmp(skey_get_algorithm(), "md4") == 0) 369 (void)fprintf(skey.keyfile, "%s %04d %-16s %s %-21s\n", 370 pp->pw_name, n, seed, skey.val, tbuf); 371 else 372 (void)fprintf(skey.keyfile, "%s %s %04d %-16s %s %-21s\n", 373 pp->pw_name, skey_get_algorithm(), n, seed, skey.val, tbuf); 374 375 (void)fclose(skey.keyfile); 376 377 (void)printf("\nID %s skey is otp-%s %d %s\n", pp->pw_name, 378 skey_get_algorithm(), n, seed); 379 (void)printf("Next login password: %s\n\n", 380 hexmode ? put8(buf, key) : btoe(buf, key)); 381 382 return(0); 383 } 384
Indexes created Sat Sep 20 22:09:52 GMT 2025