1 /* 2 * mod_vhostdb_ldap - virtual hosts mapping from backend LDAP database 3 * 4 * Copyright(c) 2017 Glenn Strauss gstrauss()gluelogic.com All rights reserved 5 * License: BSD 3-clause (same as lighttpd) 6 */ 7 #include "first.h" 8 9 #include <ldap.h> 10 11 #include <string.h> 12 #include <stdlib.h> 13 14 #include "base.h" 15 #include "http_vhostdb.h" 16 #include "log.h" 17 #include "plugin.h" 18 19 /* 20 * virtual host plugin using LDAP for domain to directory lookups 21 */ 22 23 typedef struct { 24 LDAP *ldap; 25 const buffer *filter; 26 log_error_st *errh; 27 28 const char *attr; 29 const char *host; 30 const char *basedn; 31 const char *binddn; 32 const char *bindpw; 33 const char *cafile; 34 unsigned short starttls; 35 struct timeval timeout; 36 } vhostdb_config; 37 38 typedef struct { 39 void *vdata; 40 } plugin_config; 41 42 typedef struct { 43 PLUGIN_DATA; 44 plugin_config defaults; 45 plugin_config conf; 46 } plugin_data; 47 48 static void mod_vhostdb_dbconf_free (void *vdata) 49 { 50 vhostdb_config *dbconf = (vhostdb_config *)vdata; 51 if (!dbconf) return; 52 if (NULL != dbconf->ldap) ldap_unbind_ext_s(dbconf->ldap, NULL, NULL); 53 free(dbconf); 54 } 55 56 /*(copied from mod_authn_ldap.c)*/ 57 static void mod_vhostdb_dbconf_add_scheme (server *srv, buffer *host) 58 { 59 if (!buffer_string_is_empty(host)) { 60 /* reformat hostname(s) as LDAP URIs (scheme://host:port) */ 61 static const char *schemes[] = { 62 "ldap://", "ldaps://", "ldapi://", "cldap://" 63 }; 64 char *b, *e = host->ptr; 65 buffer * const tb = srv->tmp_buf; 66 buffer_clear(tb); 67 while (*(b = e)) { 68 unsigned int j; 69 while (*b==' '||*b=='\t'||*b=='\r'||*b=='\n'||*b==',') ++b; 70 if (*b == '\0') break; 71 e = b; 72 while (*e!=' '&&*e!='\t'&&*e!='\r'&&*e!='\n'&&*e!=','&&*e!='\0') 73 ++e; 74 if (!buffer_string_is_empty(tb)) 75 buffer_append_string_len(tb, CONST_STR_LEN(",")); 76 for (j = 0; j < sizeof(schemes)/sizeof(char *); ++j) { 77 if (buffer_eq_icase_ssn(b, schemes[j], strlen(schemes[j]))) { 78 break; 79 } 80 } 81 if (j == sizeof(schemes)/sizeof(char *)) 82 buffer_append_string_len(tb, CONST_STR_LEN("ldap://")); 83 buffer_append_string_len(tb, b, (size_t)(e - b)); 84 } 85 buffer_copy_buffer(host, tb); 86 } 87 } 88 89 static int mod_vhostdb_dbconf_setup (server *srv, const array *opts, void **vdata) 90 { 91 const buffer *filter = NULL; 92 const char *attr = "documentRoot"; 93 const char *basedn=NULL,*binddn=NULL,*bindpw=NULL,*host=NULL,*cafile=NULL; 94 unsigned short starttls = 0; 95 long timeout = 2000000; /* set 2 sec default timeout (instead of infinite) */ 96 97 for (size_t i = 0; i < opts->used; ++i) { 98 data_string *ds = (data_string *)opts->data[i]; 99 if (ds->type == TYPE_STRING) { 100 if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("filter"))) { 101 filter = &ds->value; 102 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("attr"))) { 103 if (!buffer_string_is_empty(&ds->value)) attr = ds->value.ptr; 104 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("host"))) { 105 mod_vhostdb_dbconf_add_scheme(srv, &ds->value); 106 host = ds->value.ptr; 107 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("base-dn"))) { 108 if (!buffer_string_is_empty(&ds->value)) basedn = ds->value.ptr; 109 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("bind-dn"))) { 110 if (!buffer_string_is_empty(&ds->value)) binddn = ds->value.ptr; 111 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("bind-pw"))) { 112 bindpw = ds->value.ptr; 113 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("ca-file"))) { 114 if (!buffer_string_is_empty(&ds->value)) cafile = ds->value.ptr; 115 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("starttls"))) { 116 starttls = config_plugin_value_tobool((data_unset *)ds, 1); 117 } else if (buffer_is_equal_caseless_string(&ds->key, CONST_STR_LEN("timeout"))) { 118 timeout = strtol(ds->value.ptr, NULL, 10); 119 } 120 } 121 } 122 123 /* required: 124 * - host 125 * - filter (LDAP query) 126 * - base-dn 127 * 128 * optional: 129 * - attr (LDAP attribute with docroot; default "documentRoot") 130 * - bind-dn 131 * - bind-pw 132 * - ca-file 133 * - starttls 134 */ 135 136 if (!buffer_string_is_empty(filter) && NULL != host && NULL != basedn) { 137 vhostdb_config *dbconf; 138 139 if (NULL == strchr(filter->ptr, '?')) { 140 log_error(srv->errh, __FILE__, __LINE__, 141 "ldap: filter is missing a replace-operator '?'"); 142 return -1; 143 } 144 145 /* openldap sets FD_CLOEXEC on database socket descriptors 146 * (still race between creation of socket and fcntl FD_CLOEXEC) 147 * (YMMV with other LDAP client libraries) */ 148 149 dbconf = (vhostdb_config *)calloc(1, sizeof(*dbconf)); 150 dbconf->ldap = NULL; 151 dbconf->filter = filter; 152 dbconf->attr = attr; 153 dbconf->host = host; 154 dbconf->basedn = basedn; 155 dbconf->binddn = binddn; 156 dbconf->bindpw = bindpw; 157 dbconf->cafile = cafile; 158 dbconf->starttls = starttls; 159 dbconf->timeout.tv_sec = timeout / 1000000; 160 dbconf->timeout.tv_usec = timeout % 1000000; 161 *vdata = dbconf; 162 } 163 164 return 0; 165 } 166 167 /* 168 * Note: a large portion of the LDAP code is copied verbatim from mod_authn_ldap 169 * with only changes being use of vhostdb_config instead of plugin_config struct 170 * and (const char *) strings in vhostdb_config instead of (buffer *). 171 */ 172 173 __attribute_cold__ 174 static void mod_authn_ldap_err(log_error_st *errh, const char *file, unsigned long line, const char *fn, int err) 175 { 176 log_error(errh, file, line, "ldap: %s: %s", fn, ldap_err2string(err)); 177 } 178 179 __attribute_cold__ 180 static void mod_authn_ldap_opt_err(log_error_st *errh, const char *file, unsigned long line, const char *fn, LDAP *ld) 181 { 182 int err; 183 ldap_get_option(ld, LDAP_OPT_ERROR_NUMBER, &err); 184 mod_authn_ldap_err(errh, file, line, fn, err); 185 } 186 187 static void mod_authn_append_ldap_filter_escape(buffer * const filter, const buffer * const raw) { 188 /* [RFC4515] 3. String Search Filter Definition 189 * 190 * [...] 191 * 192 * The <valueencoding> rule ensures that the entire filter string is a 193 * valid UTF-8 string and provides that the octets that represent the 194 * ASCII characters "*" (ASCII 0x2a), "(" (ASCII 0x28), ")" (ASCII 195 * 0x29), "\" (ASCII 0x5c), and NUL (ASCII 0x00) are represented as a 196 * backslash "\" (ASCII 0x5c) followed by the two hexadecimal digits 197 * representing the value of the encoded octet. 198 * 199 * [...] 200 * 201 * As indicated by the <valueencoding> rule, implementations MUST escape 202 * all octets greater than 0x7F that are not part of a valid UTF-8 203 * encoding sequence when they generate a string representation of a 204 * search filter. Implementations SHOULD accept as input strings that 205 * are not valid UTF-8 strings. This is necessary because RFC 2254 did 206 * not clearly define the term "string representation" (and in 207 * particular did not mention that the string representation of an LDAP 208 * search filter is a string of UTF-8-encoded Unicode characters). 209 * 210 * 211 * https://www.ldap.com/ldap-filters 212 * Although not required, you may escape any other characters that you want 213 * in the assertion value (or substring component) of a filter. This may be 214 * accomplished by prefixing the hexadecimal representation of each byte of 215 * the UTF-8 encoding of the character to escape with a backslash character. 216 */ 217 const char * const b = raw->ptr; 218 const size_t rlen = buffer_string_length(raw); 219 for (size_t i = 0; i < rlen; ++i) { 220 size_t len = i; 221 char *f; 222 do { 223 /* encode all UTF-8 chars with high bit set 224 * (instead of validating UTF-8 and escaping only invalid UTF-8) */ 225 if (((unsigned char *)b)[len] > 0x7f) 226 break; 227 switch (b[len]) { 228 default: 229 continue; 230 case '\0': case '(': case ')': case '*': case '\\': 231 break; 232 } 233 break; 234 } while (++len < rlen); 235 len -= i; 236 237 if (len) { 238 buffer_append_string_len(filter, b+i, len); 239 if ((i += len) == rlen) break; 240 } 241 242 /* escape * ( ) \ NUL ('\0') (and all UTF-8 chars with high bit set) */ 243 buffer_string_prepare_append(filter, 3); 244 f = filter->ptr + buffer_string_length(filter); 245 f[0] = '\\'; 246 f[1] = "0123456789abcdef"[(((unsigned char *)b)[i] >> 4) & 0xf]; 247 f[2] = "0123456789abcdef"[(((unsigned char *)b)[i] ) & 0xf]; 248 buffer_commit(filter, 3); 249 } 250 } 251 252 static LDAP * mod_authn_ldap_host_init(log_error_st *errh, vhostdb_config *s) { 253 LDAP *ld; 254 int ret; 255 256 ret = ldap_initialize(&ld, s->host); 257 if (LDAP_SUCCESS != ret) { 258 log_perror(errh, __FILE__, __LINE__, "ldap: ldap_initialize()"); 259 return NULL; 260 } 261 262 ret = LDAP_VERSION3; 263 ret = ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &ret); 264 if (LDAP_OPT_SUCCESS != ret) { 265 mod_authn_ldap_err(errh, __FILE__, __LINE__, "ldap_set_options()", ret); 266 ldap_destroy(ld); 267 return NULL; 268 } 269 270 /* restart ldap functions if interrupted by a signal, e.g. SIGCHLD */ 271 ldap_set_option(ld, LDAP_OPT_RESTART, LDAP_OPT_ON); 272 273 #ifdef LDAP_OPT_NETWORK_TIMEOUT /* OpenLDAP-specific */ 274 ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, &s->timeout); 275 #endif 276 277 #ifdef LDAP_OPT_TIMEOUT /* OpenLDAP-specific; OpenLDAP 2.4+ */ 278 ldap_set_option(ld, LDAP_OPT_TIMEOUT, &s->timeout); 279 #endif 280 281 if (s->starttls) { 282 /* if no CA file is given, it is ok, as we will use encryption 283 * if the server requires a CAfile it will tell us */ 284 if (s->cafile) { 285 ret = ldap_set_option(NULL, LDAP_OPT_X_TLS_CACERTFILE, s->cafile); 286 if (LDAP_OPT_SUCCESS != ret) { 287 mod_authn_ldap_err(errh, __FILE__, __LINE__, 288 "ldap_set_option(LDAP_OPT_X_TLS_CACERTFILE)", ret); 289 ldap_destroy(ld); 290 return NULL; 291 } 292 } 293 294 ret = ldap_start_tls_s(ld, NULL, NULL); 295 if (LDAP_OPT_SUCCESS != ret) { 296 mod_authn_ldap_err(errh,__FILE__,__LINE__,"ldap_start_tls_s()",ret); 297 ldap_destroy(ld); 298 return NULL; 299 } 300 } 301 302 return ld; 303 } 304 305 static int mod_authn_ldap_bind(log_error_st *errh, LDAP *ld, const char *dn, const char *pw) { 306 struct berval creds; 307 int ret; 308 309 if (NULL != pw) { 310 *((const char **)&creds.bv_val) = pw; /*(cast away const)*/ 311 creds.bv_len = strlen(pw); 312 } else { 313 creds.bv_val = NULL; 314 creds.bv_len = 0; 315 } 316 317 /* RFE: add functionality: LDAP_SASL_EXTERNAL (or GSS-SPNEGO, etc.) */ 318 319 ret = ldap_sasl_bind_s(ld,dn,LDAP_SASL_SIMPLE,&creds,NULL,NULL,NULL); 320 if (ret != LDAP_SUCCESS) { 321 mod_authn_ldap_err(errh, __FILE__, __LINE__, "ldap_sasl_bind_s()", ret); 322 } 323 324 return ret; 325 } 326 327 static int mod_authn_ldap_rebind_proc (LDAP *ld, LDAP_CONST char *url, ber_tag_t ldap_request, ber_int_t msgid, void *params) { 328 vhostdb_config *s = (vhostdb_config *)params; 329 UNUSED(url); 330 UNUSED(ldap_request); 331 UNUSED(msgid); 332 return mod_authn_ldap_bind(s->errh, ld, s->binddn, s->bindpw); 333 } 334 335 static LDAPMessage * mod_authn_ldap_search(log_error_st *errh, vhostdb_config *s, char *base, char *filter) { 336 LDAPMessage *lm = NULL; 337 char *attrs[] = { LDAP_NO_ATTRS, NULL }; 338 int ret; 339 340 /* 341 * 1. connect anonymously (if not already connected) 342 * (ldap connection is kept open unless connection-level error occurs) 343 * 2. issue search using filter 344 */ 345 346 if (s->ldap != NULL) { 347 ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter, 348 attrs, 0, NULL, NULL, NULL, 0, &lm); 349 if (LDAP_SUCCESS == ret) { 350 return lm; 351 } else if (LDAP_SERVER_DOWN != ret) { 352 /* try again (or initial request); 353 * ldap lib sometimes fails for the first call but reconnects */ 354 ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter, 355 attrs, 0, NULL, NULL, NULL, 0, &lm); 356 if (LDAP_SUCCESS == ret) { 357 return lm; 358 } 359 } 360 361 ldap_unbind_ext_s(s->ldap, NULL, NULL); 362 } 363 364 s->ldap = mod_authn_ldap_host_init(errh, s); 365 if (NULL == s->ldap) { 366 return NULL; 367 } 368 369 ldap_set_rebind_proc(s->ldap, mod_authn_ldap_rebind_proc, s); 370 ret = mod_authn_ldap_bind(errh, s->ldap, s->binddn, s->bindpw); 371 if (LDAP_SUCCESS != ret) { 372 ldap_destroy(s->ldap); 373 s->ldap = NULL; 374 return NULL; 375 } 376 377 ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter, 378 attrs, 0, NULL, NULL, NULL, 0, &lm); 379 if (LDAP_SUCCESS != ret) { 380 log_error(errh, __FILE__, __LINE__, 381 "ldap: %s; filter: %s", ldap_err2string(ret), filter); 382 ldap_unbind_ext_s(s->ldap, NULL, NULL); 383 s->ldap = NULL; 384 return NULL; 385 } 386 387 return lm; 388 } 389 390 static void mod_vhostdb_patch_config (request_st * const r, plugin_data * const p); 391 392 static int mod_vhostdb_ldap_query(request_st * const r, void *p_d, buffer *docroot) 393 { 394 plugin_data *p = (plugin_data *)p_d; 395 vhostdb_config *dbconf; 396 LDAP *ld; 397 LDAPMessage *lm, *first; 398 struct berval **vals; 399 int count; 400 char *basedn; 401 const buffer *template; 402 403 /*(reuse buffer for ldap query before generating docroot result)*/ 404 buffer *filter = docroot; 405 buffer_clear(filter); /*(also resets docroot (alias))*/ 406 407 mod_vhostdb_patch_config(r, p); 408 if (NULL == p->conf.vdata) return 0; /*(after resetting docroot)*/ 409 dbconf = (vhostdb_config *)p->conf.vdata; 410 log_error_st * const errh = r->conf.errh; 411 dbconf->errh = errh; 412 413 template = dbconf->filter; 414 for (char *b = template->ptr, *d; *b; b = d+1) { 415 if (NULL != (d = strchr(b, '?'))) { 416 buffer_append_string_len(filter, b, (size_t)(d - b)); 417 mod_authn_append_ldap_filter_escape(filter, &r->uri.authority); 418 } else { 419 d = template->ptr + buffer_string_length(template); 420 buffer_append_string_len(filter, b, (size_t)(d - b)); 421 break; 422 } 423 } 424 425 /* (cast away const for poor LDAP ldap_search_ext_s() prototype) */ 426 *(const char **)&basedn = dbconf->basedn; 427 428 /* ldap_search (synchronous; blocking) */ 429 lm = mod_authn_ldap_search(errh, dbconf, basedn, filter->ptr); 430 if (NULL == lm) { 431 return -1; 432 } 433 434 /*(must be after mod_authn_ldap_search(); might reconnect)*/ 435 ld = dbconf->ldap; 436 437 count = ldap_count_entries(ld, lm); 438 if (count > 1) { 439 log_error(errh, __FILE__, __LINE__, 440 "ldap: more than one record returned. " 441 "you might have to refine the filter: %s", filter->ptr); 442 } 443 444 buffer_clear(docroot); /*(reset buffer to store result)*/ 445 446 if (0 == count) { /*(no entries found)*/ 447 ldap_msgfree(lm); 448 return 0; 449 } 450 451 if (NULL == (first = ldap_first_entry(ld, lm))) { 452 mod_authn_ldap_opt_err(errh,__FILE__,__LINE__,"ldap_first_entry()",ld); 453 ldap_msgfree(lm); 454 return -1; 455 } 456 457 if (NULL != (vals = ldap_get_values_len(ld, first, dbconf->attr))) { 458 buffer_copy_string_len(docroot, vals[0]->bv_val, vals[0]->bv_len); 459 ldap_value_free_len(vals); 460 } 461 462 ldap_msgfree(lm); 463 return 0; 464 } 465 466 467 468 469 INIT_FUNC(mod_vhostdb_init) { 470 static http_vhostdb_backend_t http_vhostdb_backend_ldap = 471 { "ldap", mod_vhostdb_ldap_query, NULL }; 472 plugin_data *p = calloc(1, sizeof(*p)); 473 474 /* register http_vhostdb_backend_ldap */ 475 http_vhostdb_backend_ldap.p_d = p; 476 http_vhostdb_backend_set(&http_vhostdb_backend_ldap); 477 478 return p; 479 } 480 481 FREE_FUNC(mod_vhostdb_cleanup) { 482 plugin_data * const p = p_d; 483 if (NULL == p->cvlist) return; 484 /* (init i to 0 if global context; to 1 to skip empty global context) */ 485 for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) { 486 config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0]; 487 for (; -1 != cpv->k_id; ++cpv) { 488 if (cpv->vtype != T_CONFIG_LOCAL || NULL == cpv->v.v) continue; 489 switch (cpv->k_id) { 490 case 0: /* vhostdb.<db> */ 491 mod_vhostdb_dbconf_free(cpv->v.v); 492 break; 493 default: 494 break; 495 } 496 } 497 } 498 } 499 500 static void mod_vhostdb_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) { 501 switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */ 502 case 0: /* vhostdb.<db> */ 503 if (cpv->vtype == T_CONFIG_LOCAL) 504 pconf->vdata = cpv->v.v; 505 break; 506 default:/* should not happen */ 507 return; 508 } 509 } 510 511 static void mod_vhostdb_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) { 512 do { 513 mod_vhostdb_merge_config_cpv(pconf, cpv); 514 } while ((++cpv)->k_id != -1); 515 } 516 517 static void mod_vhostdb_patch_config(request_st * const r, plugin_data * const p) { 518 p->conf = p->defaults; /* copy small struct instead of memcpy() */ 519 /*memcpy(&p->conf, &p->defaults, sizeof(plugin_config));*/ 520 for (int i = 1, used = p->nconfig; i < used; ++i) { 521 if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id)) 522 mod_vhostdb_merge_config(&p->conf,p->cvlist + p->cvlist[i].v.u2[0]); 523 } 524 } 525 526 SETDEFAULTS_FUNC(mod_vhostdb_set_defaults) { 527 static const config_plugin_keys_t cpk[] = { 528 { CONST_STR_LEN("vhostdb.ldap"), 529 T_CONFIG_ARRAY_KVSTRING, 530 T_CONFIG_SCOPE_CONNECTION } 531 ,{ NULL, 0, 532 T_CONFIG_UNSET, 533 T_CONFIG_SCOPE_UNSET } 534 }; 535 536 plugin_data * const p = p_d; 537 if (!config_plugin_values_init(srv, p, cpk, "mod_vhostdb_ldap")) 538 return HANDLER_ERROR; 539 540 /* process and validate config directives 541 * (init i to 0 if global context; to 1 to skip empty global context) */ 542 for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) { 543 config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0]; 544 for (; -1 != cpv->k_id; ++cpv) { 545 switch (cpv->k_id) { 546 case 0: /* vhostdb.<db> */ 547 if (cpv->v.a->used) { 548 if (0 != mod_vhostdb_dbconf_setup(srv, cpv->v.a, &cpv->v.v)) 549 return HANDLER_ERROR; 550 if (NULL != cpv->v.v) 551 cpv->vtype = T_CONFIG_LOCAL; 552 } 553 break; 554 default:/* should not happen */ 555 break; 556 } 557 } 558 } 559 560 /* initialize p->defaults from global config context */ 561 if (p->nconfig > 0 && p->cvlist->v.u2[1]) { 562 const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0]; 563 if (-1 != cpv->k_id) 564 mod_vhostdb_merge_config(&p->defaults, cpv); 565 } 566 567 return HANDLER_GO_ON; 568 } 569 570 571 int mod_vhostdb_ldap_plugin_init (plugin *p); 572 int mod_vhostdb_ldap_plugin_init (plugin *p) 573 { 574 p->version = LIGHTTPD_VERSION_ID; 575 p->name = "vhostdb_ldap"; 576 577 p->init = mod_vhostdb_init; 578 p->cleanup = mod_vhostdb_cleanup; 579 p->set_defaults = mod_vhostdb_set_defaults; 580 581 return 0; 582 } 583