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 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #include <strings.h> 31 #include <unistd.h> 32 #include <ctype.h> 33 #include <errno.h> 34 #include <syslog.h> 35 #include <netdb.h> 36 #include <sys/param.h> 37 #include <kerberosv5/krb5.h> 38 #include <kerberosv5/com_err.h> 39 40 #include <smbsrv/libsmb.h> 41 #include <smbns_krb.h> 42 43 static char *spn_prefix[] = {"host/", "nfs/", "HTTP/", "root/"}; 44 45 static int smb_krb5_open_wrfile(krb5_context ctx, char *fname, 46 krb5_keytab *kt); 47 static int smb_krb5_ktadd(krb5_context ctx, krb5_keytab kt, 48 const krb5_principal princ, krb5_enctype enctype, krb5_kvno kvno, 49 const char *pw); 50 51 /* 52 * smb_krb5_get_spn 53 * 54 * Gets Service Principal Name. 55 * Caller must free the memory allocated for the spn. 56 */ 57 char * 58 smb_krb5_get_spn(smb_krb5_spn_idx_t idx, char *fqhost) 59 { 60 int len; 61 char *princ; 62 char *spn; 63 64 if (!fqhost) 65 return (NULL); 66 67 if ((idx < 0) || (idx >= SMBKRB5_SPN_IDX_MAX)) 68 return (NULL); 69 70 spn = spn_prefix[idx]; 71 len = strlen(spn) + strlen(fqhost) + 1; 72 princ = (char *)malloc(len); 73 74 if (!princ) 75 return (NULL); 76 77 (void) snprintf(princ, len, "%s%s", spn, fqhost); 78 return (princ); 79 } 80 81 /* 82 * smb_krb5_get_upn 83 * 84 * Gets User Principal Name. 85 * Caller must free the memory allocated for the upn. 86 */ 87 char * 88 smb_krb5_get_upn(char *spn, char *domain) 89 { 90 int len; 91 char *realm; 92 char *upn; 93 94 if (!spn || !domain) 95 return (NULL); 96 97 realm = strdup(domain); 98 if (!realm) 99 return (NULL); 100 101 (void) smb_strupr(realm); 102 103 len = strlen(spn) + 1 + strlen(realm) + 1; 104 upn = (char *)malloc(len); 105 if (!upn) { 106 free(realm); 107 return (NULL); 108 } 109 110 (void) snprintf(upn, len, "%s@%s", spn, realm); 111 free(realm); 112 113 return (upn); 114 } 115 116 /* 117 * smb_krb5_get_host_upn 118 * 119 * Derives UPN by the given fully-qualified hostname. 120 * Caller must free the memory allocated for the upn. 121 */ 122 static char * 123 smb_krb5_get_host_upn(const char *fqhn) 124 { 125 char *upn; 126 char *realm; 127 char *dom; 128 int len; 129 130 if ((dom = strchr(fqhn, '.')) == NULL) 131 return (NULL); 132 133 if ((realm = strdup(++dom)) == NULL) 134 return (NULL); 135 136 (void) smb_strupr(realm); 137 138 len = strlen(spn_prefix[SMBKRB5_SPN_IDX_HOST]) + strlen(fqhn) + 139 + 1 + strlen(realm) + 1; 140 if ((upn = malloc(len)) == NULL) { 141 free(realm); 142 return (NULL); 143 } 144 145 (void) snprintf(upn, len, "%s%s@%s", spn_prefix[SMBKRB5_SPN_IDX_HOST], 146 fqhn, realm); 147 148 free(realm); 149 return (upn); 150 } 151 152 /* 153 * smb_krb5_ctx_init 154 * 155 * Initialize the kerberos context. 156 * Return 0 on success. Otherwise, return -1. 157 */ 158 int 159 smb_krb5_ctx_init(krb5_context *ctx) 160 { 161 if (krb5_init_context(ctx) != 0) 162 return (-1); 163 164 return (0); 165 } 166 167 /* 168 * smb_krb5_get_principals 169 * 170 * Setup the krb5_principal array given the principals in string format. 171 * Return 0 on success. Otherwise, return -1. 172 */ 173 int 174 smb_krb5_get_principals(char *domain, krb5_context ctx, 175 krb5_principal *krb5princs) 176 { 177 char fqhn[MAXHOSTNAMELEN]; 178 int i; 179 char *spn, *upn; 180 181 if (smb_gethostname(fqhn, MAXHOSTNAMELEN, 0) != 0) 182 return (-1); 183 184 (void) snprintf(fqhn, MAXHOSTNAMELEN, "%s.%s", fqhn, 185 domain); 186 187 for (i = 0; i < SMBKRB5_SPN_IDX_MAX; i++) { 188 189 if ((spn = smb_krb5_get_spn(i, fqhn)) == NULL) { 190 return (-1); 191 } 192 193 upn = smb_krb5_get_upn(spn, domain); 194 free(spn); 195 196 if (krb5_parse_name(ctx, upn, &krb5princs[i]) != 0) { 197 smb_krb5_free_principals(ctx, krb5princs, i - 1); 198 free(upn); 199 return (-1); 200 } 201 free(upn); 202 } 203 return (0); 204 } 205 206 void 207 smb_krb5_free_principals(krb5_context ctx, krb5_principal *krb5princs, 208 size_t num) 209 { 210 int i; 211 212 for (i = 0; i < num; i++) 213 krb5_free_principal(ctx, krb5princs[i]); 214 } 215 216 /* 217 * smb_krb5_ctx_fini 218 * 219 * Free the kerberos context. 220 */ 221 void 222 smb_krb5_ctx_fini(krb5_context ctx) 223 { 224 krb5_free_context(ctx); 225 } 226 227 /* 228 * smb_ksetpw 229 * 230 * Set the workstation trust account password. 231 * Returns 0 on success. Otherwise, returns non-zero value. 232 */ 233 int 234 smb_krb5_setpwd(krb5_context ctx, krb5_principal princ, char *passwd) 235 { 236 krb5_error_code code; 237 krb5_ccache cc = NULL; 238 int result_code; 239 krb5_data result_code_string, result_string; 240 241 (void) memset(&result_code_string, 0, sizeof (result_code_string)); 242 (void) memset(&result_string, 0, sizeof (result_string)); 243 244 if ((code = krb5_cc_default(ctx, &cc)) != 0) { 245 syslog(LOG_ERR, "smb_krb5_setpwd: failed to find a ccache\n"); 246 return (-1); 247 } 248 249 code = krb5_set_password_using_ccache(ctx, cc, passwd, princ, 250 &result_code, &result_code_string, &result_string); 251 252 krb5_cc_close(ctx, cc); 253 254 if (code != 0) 255 (void) syslog(LOG_ERR, 256 "smb_krb5_setpwd: Result: %.*s (%d) %.*s\n", 257 result_code == 0 ? 258 strlen("success") : result_code_string.length, 259 result_code == 0 ? "success" : result_code_string.data, 260 result_code, result_string.length, result_string.data); 261 262 free(result_code_string.data); 263 free(result_string.data); 264 return (code); 265 } 266 267 /* 268 * smb_krb5_open_wrfile 269 * 270 * Open the keytab file for writing. 271 * The keytab should be closed by calling krb5_kt_close(). 272 */ 273 static int 274 smb_krb5_open_wrfile(krb5_context ctx, char *fname, krb5_keytab *kt) 275 { 276 char *ktname; 277 int len; 278 279 *kt = NULL; 280 len = snprintf(NULL, 0, "WRFILE:%s", fname) + 1; 281 if ((ktname = malloc(len)) == NULL) { 282 syslog(LOG_ERR, "smb_krb5_write_keytab: resource shortage"); 283 return (-1); 284 } 285 286 (void) snprintf(ktname, len, "WRFILE:%s", fname); 287 288 if (krb5_kt_resolve(ctx, ktname, kt) != 0) { 289 syslog(LOG_ERR, "smb_krb5_write_keytab: failed to open/create " 290 "keytab %s\n", fname); 291 free(ktname); 292 return (-1); 293 } 294 295 free(ktname); 296 return (0); 297 } 298 299 /* 300 * smb_krb5_add_keytab_entries 301 * 302 * Update the keys for the specified principal in the keytab. 303 * Returns 0 on success. Otherwise, returns -1. 304 */ 305 int 306 smb_krb5_add_keytab_entries(krb5_context ctx, krb5_principal *princs, 307 char *fname, krb5_kvno kvno, char *passwd, krb5_enctype *enctypes, 308 int enctype_count) 309 { 310 krb5_keytab kt = NULL; 311 int i, j; 312 313 if (smb_krb5_open_wrfile(ctx, fname, &kt) != 0) 314 return (-1); 315 316 for (j = 0; j < SMBKRB5_SPN_IDX_MAX; j++) { 317 for (i = 0; i < enctype_count; i++) { 318 if (smb_krb5_ktadd(ctx, kt, princs[j], enctypes[i], 319 kvno, passwd) != 0) { 320 krb5_kt_close(ctx, kt); 321 return (-1); 322 } 323 } 324 325 } 326 krb5_kt_close(ctx, kt); 327 return (0); 328 } 329 330 boolean_t 331 smb_krb5_find_keytab_entries(const char *fqhn, char *fname) 332 { 333 krb5_context ctx; 334 krb5_keytab kt; 335 krb5_keytab_entry entry; 336 krb5_principal princ; 337 char ktname[MAXPATHLEN]; 338 char *upn; 339 boolean_t found = B_FALSE; 340 341 if (!fqhn || !fname) 342 return (found); 343 344 if ((upn = smb_krb5_get_host_upn((char *)fqhn)) == NULL) 345 return (found); 346 347 if (smb_krb5_ctx_init(&ctx) != 0) { 348 free(upn); 349 return (found); 350 } 351 352 if (krb5_parse_name(ctx, upn, &princ) != 0) { 353 free(upn); 354 smb_krb5_ctx_fini(ctx); 355 return (found); 356 } 357 358 free(upn); 359 (void) snprintf(ktname, MAXPATHLEN, "FILE:%s", fname); 360 if (krb5_kt_resolve(ctx, ktname, &kt) == 0) { 361 if (krb5_kt_get_entry(ctx, kt, princ, 0, 0, &entry) == 0) { 362 found = B_TRUE; 363 krb5_kt_free_entry(ctx, &entry); 364 } 365 366 krb5_kt_close(ctx, kt); 367 } 368 369 krb5_free_principal(ctx, princ); 370 smb_krb5_ctx_fini(ctx); 371 return (found); 372 } 373 374 /* 375 * smb_krb5_ktadd 376 * 377 * Add a Keberos key to the keytab file. 378 * Returns 0 on success. Otherwise, returns -1. 379 */ 380 static int 381 smb_krb5_ktadd(krb5_context ctx, krb5_keytab kt, const krb5_principal princ, 382 krb5_enctype enctype, krb5_kvno kvno, const char *pw) 383 { 384 krb5_keytab_entry *entry; 385 krb5_data password, salt; 386 krb5_keyblock key; 387 krb5_error_code code; 388 char buf[100]; 389 int rc = 0; 390 391 if ((code = krb5_enctype_to_string(enctype, buf, sizeof (buf)))) { 392 syslog(LOG_ERR, "smb_krb5_ktadd[%d]: unknown enctype", 393 enctype); 394 return (-1); 395 } 396 397 if ((entry = (krb5_keytab_entry *) malloc(sizeof (*entry))) == NULL) { 398 syslog(LOG_ERR, "smb_krb5_ktadd[%d]: resource shortage", 399 enctype); 400 return (-1); 401 } 402 403 (void) memset((char *)entry, 0, sizeof (*entry)); 404 405 password.length = strlen(pw); 406 password.data = (char *)pw; 407 408 if ((code = krb5_principal2salt(ctx, princ, &salt)) != 0) { 409 syslog(LOG_ERR, "smb_krb5_ktadd[%d]: failed to compute salt", 410 enctype); 411 free(entry); 412 return (-1); 413 } 414 415 code = krb5_c_string_to_key(ctx, enctype, &password, &salt, &key); 416 krb5_xfree(salt.data); 417 if (code != 0) { 418 syslog(LOG_ERR, "smb_krb5_ktadd[%d]: failed to generate key", 419 enctype); 420 free(entry); 421 return (-1); 422 } 423 424 (void) memcpy(&entry->key, &key, sizeof (krb5_keyblock)); 425 entry->vno = kvno; 426 entry->principal = princ; 427 428 if ((code = krb5_kt_add_entry(ctx, kt, entry)) != 0) { 429 syslog(LOG_ERR, "smb_krb5_ktadd[%d] failed to add entry to " 430 "keytab (%d)", enctype, code); 431 rc = -1; 432 } 433 434 free(entry); 435 if (key.length) 436 krb5_free_keyblock_contents(ctx, &key); 437 return (rc); 438 } 439