src/mod_authn_ldap.c

   1 #include "first.h"
   2
   3 #include <ldap.h>
   4
   5 #include "base.h"
   6 #include "http_auth.h"
   7 #include "log.h"
   8 #include "plugin.h"
   9
  10 #include <errno.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 typedef struct {
  15     LDAP *ldap;
  16     server *srv;
  17
  18     buffer *auth_ldap_hostname;
  19     buffer *auth_ldap_basedn;
  20     buffer *auth_ldap_binddn;
  21     buffer *auth_ldap_bindpw;
  22     buffer *auth_ldap_filter;
  23     buffer *auth_ldap_cafile;
  24     buffer *auth_ldap_groupmember;
  25     unsigned short auth_ldap_starttls;
  26     unsigned short auth_ldap_allow_empty_pw;
  27 } plugin_config;
  28
  29 typedef struct {
  30     PLUGIN_DATA;
  31     plugin_config **config_storage;
  32     plugin_config conf, *anon_conf; /* this is only used as long as no handler_ctx is setup */
  33
  34     buffer *ldap_filter;
  35 } plugin_data;
  36
  37 static handler_t mod_authn_ldap_basic(server *srv, connection *con, void *p_d, const http_auth_require_t *require, const buffer *username, const char *pw);
  38
  39 INIT_FUNC(mod_authn_ldap_init) {
  40     static http_auth_backend_t http_auth_backend_ldap =
  41       { "ldap", mod_authn_ldap_basic, NULL, NULL };
  42     plugin_data *p = calloc(1, sizeof(*p));
  43     p->ldap_filter = buffer_init();
  44
  45     /* register http_auth_backend_ldap */
  46     http_auth_backend_ldap.p_d = p;
  47     http_auth_backend_set(&http_auth_backend_ldap);
  48
  49     return p;
  50 }
  51
  52 FREE_FUNC(mod_authn_ldap_free) {
  53     plugin_data *p = p_d;
  54
  55     UNUSED(srv);
  56
  57     if (!p) return HANDLER_GO_ON;
  58
  59     buffer_free(p->ldap_filter);
  60
  61     if (p->config_storage) {
  62         size_t i;
  63         for (i = 0; i < srv->config_context->used; i++) {
  64             plugin_config *s = p->config_storage[i];
  65
  66             if (NULL == s) continue;
  67
  68             buffer_free(s->auth_ldap_hostname);
  69             buffer_free(s->auth_ldap_basedn);
  70             buffer_free(s->auth_ldap_binddn);
  71             buffer_free(s->auth_ldap_bindpw);
  72             buffer_free(s->auth_ldap_filter);
  73             buffer_free(s->auth_ldap_cafile);
  74             buffer_free(s->auth_ldap_groupmember);
  75
  76             if (NULL != s->ldap) ldap_unbind_ext_s(s->ldap, NULL, NULL);
  77             free(s);
  78         }
  79         free(p->config_storage);
  80     }
  81
  82     free(p);
  83
  84     return HANDLER_GO_ON;
  85 }
  86
  87 /*(copied from mod_vhostdb_ldap.c)*/
  88 static void mod_authn_add_scheme (server *srv, buffer *host)
  89 {
  90     if (!buffer_string_is_empty(host)) {
  91         /* reformat hostname(s) as LDAP URIs (scheme://host:port) */
  92         static const char *schemes[] = {
  93           "ldap://", "ldaps://", "ldapi://", "cldap://"
  94         };
  95         char *b, *e = host->ptr;
  96         buffer_clear(srv->tmp_buf);
  97         while (*(b = e)) {
  98             unsigned int j;
  99             while (*b==' '||*b=='\t'||*b=='\r'||*b=='\n'||*b==',') ++b;
 100             if (*b == '\0') break;
 101             e = b;
 102             while (*e!=' '&&*e!='\t'&&*e!='\r'&&*e!='\n'&&*e!=','&&*e!='\0')
 103                 ++e;
 104             if (!buffer_string_is_empty(srv->tmp_buf))
 105                 buffer_append_string_len(srv->tmp_buf, CONST_STR_LEN(","));
 106             for (j = 0; j < sizeof(schemes)/sizeof(char *); ++j) {
 107                 if (buffer_eq_icase_ssn(b, schemes[j], strlen(schemes[j]))) {
 108                     break;
 109                 }
 110             }
 111             if (j == sizeof(schemes)/sizeof(char *))
 112                 buffer_append_string_len(srv->tmp_buf,
 113                                          CONST_STR_LEN("ldap://"));
 114             buffer_append_string_len(srv->tmp_buf, b, (size_t)(e - b));
 115         }
 116         buffer_copy_buffer(host, srv->tmp_buf);
 117     }
 118 }
 119
 120 SETDEFAULTS_FUNC(mod_authn_ldap_set_defaults) {
 121     plugin_data *p = p_d;
 122     size_t i;
 123 config_values_t cv[] = {
 124         { "auth.backend.ldap.hostname",     NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 0 */
 125         { "auth.backend.ldap.base-dn",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 1 */
 126         { "auth.backend.ldap.filter",       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 2 */
 127         { "auth.backend.ldap.ca-file",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 3 */
 128         { "auth.backend.ldap.starttls",     NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION }, /* 4 */
 129         { "auth.backend.ldap.bind-dn",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 5 */
 130         { "auth.backend.ldap.bind-pw",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 6 */
 131         { "auth.backend.ldap.allow-empty-pw",     NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION }, /* 7 */
 132         { "auth.backend.ldap.groupmember",  NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 8 */
 133         { NULL,                             NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
 134     };
 135
 136     p->config_storage = calloc(srv->config_context->used, sizeof(plugin_config *));
 137
 138     for (i = 0; i < srv->config_context->used; i++) {
 139         data_config const* config = (data_config const*)srv->config_context->data[i];
 140         plugin_config *s;
 141
 142         s = calloc(1, sizeof(plugin_config));
 143
 144         s->auth_ldap_hostname = buffer_init();
 145         s->auth_ldap_basedn = buffer_init();
 146         s->auth_ldap_binddn = buffer_init();
 147         s->auth_ldap_bindpw = buffer_init();
 148         s->auth_ldap_filter = buffer_init();
 149         s->auth_ldap_cafile = buffer_init();
 150         s->auth_ldap_groupmember = buffer_init_string("memberUid");
 151         s->auth_ldap_starttls = 0;
 152         s->ldap = NULL;
 153
 154         cv[0].destination = s->auth_ldap_hostname;
 155         cv[1].destination = s->auth_ldap_basedn;
 156         cv[2].destination = s->auth_ldap_filter;
 157         cv[3].destination = s->auth_ldap_cafile;
 158         cv[4].destination = &(s->auth_ldap_starttls);
 159         cv[5].destination = s->auth_ldap_binddn;
 160         cv[6].destination = s->auth_ldap_bindpw;
 161         cv[7].destination = &(s->auth_ldap_allow_empty_pw);
 162         cv[8].destination = s->auth_ldap_groupmember;
 163
 164         p->config_storage[i] = s;
 165
 166         if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
 167             return HANDLER_ERROR;
 168         }
 169
 170         if (!buffer_string_is_empty(s->auth_ldap_filter)) {
 171             if (*s->auth_ldap_filter->ptr != ',') {
 172                 /*(translate '$' to '?' for consistency with other modules)*/
 173                 char *d = s->auth_ldap_filter->ptr;
 174                 for (; NULL != (d = strchr(d, '$')); ++d) *d = '?';
 175                 if (NULL == strchr(s->auth_ldap_filter->ptr, '?')) {
 176                     log_error_write(srv, __FILE__, __LINE__, "s", "ldap: auth.backend.ldap.filter is missing a replace-operator '?'");
 177                     return HANDLER_ERROR;
 178                 }
 179             }
 180         }
 181
 182         mod_authn_add_scheme(srv, s->auth_ldap_hostname);
 183     }
 184
 185     return HANDLER_GO_ON;
 186 }
 187
 188 #define PATCH(x) \
 189     p->conf.x = s->x;
 190 static int mod_authn_ldap_patch_connection(server *srv, connection *con, plugin_data *p) {
 191     size_t i, j;
 192     plugin_config *s = p->config_storage[0];
 193
 194     PATCH(auth_ldap_hostname);
 195     PATCH(auth_ldap_basedn);
 196     PATCH(auth_ldap_binddn);
 197     PATCH(auth_ldap_bindpw);
 198     PATCH(auth_ldap_filter);
 199     PATCH(auth_ldap_cafile);
 200     PATCH(auth_ldap_starttls);
 201     PATCH(auth_ldap_allow_empty_pw);
 202     PATCH(auth_ldap_groupmember);
 203     p->anon_conf = s;
 204
 205     /* skip the first, the global context */
 206     for (i = 1; i < srv->config_context->used; i++) {
 207         data_config *dc = (data_config *)srv->config_context->data[i];
 208         s = p->config_storage[i];
 209
 210         /* condition didn't match */
 211         if (!config_check_cond(srv, con, dc)) continue;
 212
 213         /* merge config */
 214         for (j = 0; j < dc->value->used; j++) {
 215             data_unset *du = dc->value->data[j];
 216
 217             if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.hostname"))) {
 218                 PATCH(auth_ldap_hostname);
 219                 p->anon_conf = s;
 220             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.base-dn"))) {
 221                 PATCH(auth_ldap_basedn);
 222             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.filter"))) {
 223                 PATCH(auth_ldap_filter);
 224             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.ca-file"))) {
 225                 PATCH(auth_ldap_cafile);
 226             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.starttls"))) {
 227                 PATCH(auth_ldap_starttls);
 228             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.bind-dn"))) {
 229                 PATCH(auth_ldap_binddn);
 230             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.bind-pw"))) {
 231                 PATCH(auth_ldap_bindpw);
 232             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.allow-empty-pw"))) {
 233                 PATCH(auth_ldap_allow_empty_pw);
 234             } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.groupmember"))) {
 235                 PATCH(auth_ldap_groupmember);
 236             }
 237         }
 238     }
 239
 240     return 0;
 241 }
 242 #undef PATCH
 243
 244 static void mod_authn_ldap_err(server *srv, const char *file, unsigned long line, const char *fn, int err)
 245 {
 246     log_error_write(srv,file,line,"sSss","ldap:",fn,":",ldap_err2string(err));
 247 }
 248
 249 static void mod_authn_ldap_opt_err(server *srv, const char *file, unsigned long line, const char *fn, LDAP *ld)
 250 {
 251     int err;
 252     ldap_get_option(ld, LDAP_OPT_ERROR_NUMBER, &err);
 253     mod_authn_ldap_err(srv, file, line, fn, err);
 254 }
 255
 256 static void mod_authn_append_ldap_dn_escape(buffer * const filter, const buffer * const raw) {
 257     /* [RFC4514] 2.4 Converting an AttributeValue from ASN.1 to a String
 258      *
 259      * https://www.ldap.com/ldap-dns-and-rdns
 260      * http://social.technet.microsoft.com/wiki/contents/articles/5312.active-directory-characters-to-escape.aspx
 261      */
 262     const char * const b = raw->ptr;
 263     const size_t rlen = buffer_string_length(raw);
 264     if (0 == rlen) return;
 265
 266     if (b[0] == ' ') { /* || b[0] == '#' handled below for MS Active Directory*/
 267         /* escape leading ' ' */
 268         buffer_append_string_len(filter, CONST_STR_LEN("\\"));
 269     }
 270
 271     for (size_t i = 0; i < rlen; ++i) {
 272         size_t len = i;
 273         int bs = 0;
 274         do {
 275             /* encode all UTF-8 chars with high bit set
 276              * (instead of validating UTF-8 and escaping only invalid UTF-8) */
 277             if (((unsigned char *)b)[len] > 0x7f)
 278                 break;
 279             switch (b[len]) {
 280               default:
 281                 continue;
 282               case '"': case '+': case ',': case ';': case '\\':
 283               case '<': case '>':
 284               case '=': case '#': /* (for MS Active Directory) */
 285                 bs = 1;
 286                 break;
 287               case '\0':
 288                 break;
 289             }
 290             break;
 291         } while (++len < rlen);
 292         len -= i;
 293
 294         if (len) {
 295             buffer_append_string_len(filter, b+i, len);
 296             if ((i += len) == rlen) break;
 297         }
 298
 299         if (bs) {
 300             buffer_append_string_len(filter, CONST_STR_LEN("\\"));
 301             buffer_append_string_len(filter, b+i, 1);
 302         }
 303         else {
 304             /* escape NUL ('\0') (and all UTF-8 chars with high bit set) */
 305             char *f;
 306             buffer_string_prepare_append(filter, 3);
 307             f = filter->ptr + buffer_string_length(filter);
 308             f[0] = '\\';
 309             f[1] = "0123456789abcdef"[(((unsigned char *)b)[i] >> 4) & 0xf];
 310             f[2] = "0123456789abcdef"[(((unsigned char *)b)[i]     ) & 0xf];
 311             buffer_commit(filter, 3);
 312         }
 313     }
 314
 315     if (rlen > 1 && b[rlen-1] == ' ') {
 316         /* escape trailing ' ' */
 317         filter->ptr[buffer_string_length(filter)-1] = '\\';
 318         buffer_append_string_len(filter, CONST_STR_LEN(" "));
 319     }
 320 }
 321
 322 static void mod_authn_append_ldap_filter_escape(buffer * const filter, const buffer * const raw) {
 323     /* [RFC4515] 3. String Search Filter Definition
 324      *
 325      * [...]
 326      *
 327      * The <valueencoding> rule ensures that the entire filter string is a
 328      * valid UTF-8 string and provides that the octets that represent the
 329      * ASCII characters "*" (ASCII 0x2a), "(" (ASCII 0x28), ")" (ASCII
 330      * 0x29), "\" (ASCII 0x5c), and NUL (ASCII 0x00) are represented as a
 331      * backslash "\" (ASCII 0x5c) followed by the two hexadecimal digits
 332      * representing the value of the encoded octet.
 333      *
 334      * [...]
 335      *
 336      * As indicated by the <valueencoding> rule, implementations MUST escape
 337      * all octets greater than 0x7F that are not part of a valid UTF-8
 338      * encoding sequence when they generate a string representation of a
 339      * search filter.  Implementations SHOULD accept as input strings that
 340      * are not valid UTF-8 strings.  This is necessary because RFC 2254 did
 341      * not clearly define the term "string representation" (and in
 342      * particular did not mention that the string representation of an LDAP
 343      * search filter is a string of UTF-8-encoded Unicode characters).
 344      *
 345      *
 346      * https://www.ldap.com/ldap-filters
 347      * Although not required, you may escape any other characters that you want
 348      * in the assertion value (or substring component) of a filter. This may be
 349      * accomplished by prefixing the hexadecimal representation of each byte of
 350      * the UTF-8 encoding of the character to escape with a backslash character.
 351      */
 352     const char * const b = raw->ptr;
 353     const size_t rlen = buffer_string_length(raw);
 354     for (size_t i = 0; i < rlen; ++i) {
 355         size_t len = i;
 356         char *f;
 357         do {
 358             /* encode all UTF-8 chars with high bit set
 359              * (instead of validating UTF-8 and escaping only invalid UTF-8) */
 360             if (((unsigned char *)b)[len] > 0x7f)
 361                 break;
 362             switch (b[len]) {
 363               default:
 364                 continue;
 365               case '\0': case '(': case ')': case '*': case '\\':
 366                 break;
 367             }
 368             break;
 369         } while (++len < rlen);
 370         len -= i;
 371
 372         if (len) {
 373             buffer_append_string_len(filter, b+i, len);
 374             if ((i += len) == rlen) break;
 375         }
 376
 377         /* escape * ( ) \ NUL ('\0') (and all UTF-8 chars with high bit set) */
 378         buffer_string_prepare_append(filter, 3);
 379         f = filter->ptr + buffer_string_length(filter);
 380         f[0] = '\\';
 381         f[1] = "0123456789abcdef"[(((unsigned char *)b)[i] >> 4) & 0xf];
 382         f[2] = "0123456789abcdef"[(((unsigned char *)b)[i]     ) & 0xf];
 383         buffer_commit(filter, 3);
 384     }
 385 }
 386
 387 static LDAP * mod_authn_ldap_host_init(server *srv, plugin_config *s) {
 388     LDAP *ld;
 389     int ret;
 390
 391     if (buffer_string_is_empty(s->auth_ldap_hostname)) return NULL;
 392
 393     if (LDAP_SUCCESS != ldap_initialize(&ld, s->auth_ldap_hostname->ptr)) {
 394         log_error_write(srv, __FILE__, __LINE__, "sss", "ldap:",
 395                         "ldap_initialize():", strerror(errno));
 396         return NULL;
 397     }
 398
 399     ret = LDAP_VERSION3;
 400     ret = ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &ret);
 401     if (LDAP_OPT_SUCCESS != ret) {
 402         mod_authn_ldap_err(srv, __FILE__, __LINE__, "ldap_set_option()", ret);
 403         ldap_destroy(ld);
 404         return NULL;
 405     }
 406
 407     /* restart ldap functions if interrupted by a signal, e.g. SIGCHLD */
 408     ldap_set_option(ld, LDAP_OPT_RESTART, LDAP_OPT_ON);
 409
 410     if (s->auth_ldap_starttls) {
 411         /* if no CA file is given, it is ok, as we will use encryption
 412          * if the server requires a CAfile it will tell us */
 413         if (!buffer_string_is_empty(s->auth_ldap_cafile)) {
 414             ret = ldap_set_option(NULL, LDAP_OPT_X_TLS_CACERTFILE,
 415                                   s->auth_ldap_cafile->ptr);
 416             if (LDAP_OPT_SUCCESS != ret) {
 417                 mod_authn_ldap_err(srv, __FILE__, __LINE__,
 418                                    "ldap_set_option(LDAP_OPT_X_TLS_CACERTFILE)",
 419                                    ret);
 420                 ldap_destroy(ld);
 421                 return NULL;
 422             }
 423         }
 424
 425         ret = ldap_start_tls_s(ld, NULL,  NULL);
 426         if (LDAP_OPT_SUCCESS != ret) {
 427             mod_authn_ldap_err(srv,__FILE__,__LINE__,"ldap_start_tls_s()",ret);
 428             ldap_destroy(ld);
 429             return NULL;
 430         }
 431     }
 432
 433     return ld;
 434 }
 435
 436 static int mod_authn_ldap_bind(server *srv, LDAP *ld, const char *dn, const char *pw) {
 437     struct berval creds;
 438     int ret;
 439
 440     if (NULL != pw) {
 441         *((const char **)&creds.bv_val) = pw; /*(cast away const)*/
 442         creds.bv_len = strlen(pw);
 443     } else {
 444         creds.bv_val = NULL;
 445         creds.bv_len = 0;
 446     }
 447
 448     /* RFE: add functionality: LDAP_SASL_EXTERNAL (or GSS-SPNEGO, etc.) */
 449
 450     ret = ldap_sasl_bind_s(ld,dn,LDAP_SASL_SIMPLE,&creds,NULL,NULL,NULL);
 451     if (ret != LDAP_SUCCESS) {
 452         mod_authn_ldap_err(srv, __FILE__, __LINE__, "ldap_sasl_bind_s()", ret);
 453     }
 454
 455     return ret;
 456 }
 457
 458 static int mod_authn_ldap_rebind_proc (LDAP *ld, LDAP_CONST char *url, ber_tag_t ldap_request, ber_int_t msgid, void *params) {
 459     plugin_config *s = (plugin_config *)params;
 460     UNUSED(url);
 461     UNUSED(ldap_request);
 462     UNUSED(msgid);
 463     return !buffer_string_is_empty(s->auth_ldap_binddn)
 464       ? mod_authn_ldap_bind(s->srv, ld,
 465                             s->auth_ldap_binddn->ptr,
 466                             s->auth_ldap_bindpw->ptr)
 467       : mod_authn_ldap_bind(s->srv, ld, NULL, NULL);
 468 }
 469
 470 static LDAPMessage * mod_authn_ldap_search(server *srv, plugin_config *s, char *base, char *filter) {
 471     LDAPMessage *lm = NULL;
 472     char *attrs[] = { LDAP_NO_ATTRS, NULL };
 473     int ret;
 474
 475     /*
 476      * 1. connect anonymously (if not already connected)
 477      *    (ldap connection is kept open unless connection-level error occurs)
 478      * 2. issue search using filter
 479      */
 480
 481     if (s->ldap != NULL) {
 482         ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter,
 483                                 attrs, 0, NULL, NULL, NULL, 0, &lm);
 484         if (LDAP_SUCCESS == ret) {
 485             return lm;
 486         } else if (LDAP_SERVER_DOWN != ret) {
 487             /* try again (or initial request);
 488              * ldap lib sometimes fails for the first call but reconnects */
 489             ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter,
 490                                     attrs, 0, NULL, NULL, NULL, 0, &lm);
 491             if (LDAP_SUCCESS == ret) {
 492                 return lm;
 493             }
 494         }
 495
 496         ldap_unbind_ext_s(s->ldap, NULL, NULL);
 497     }
 498
 499     s->ldap = mod_authn_ldap_host_init(srv, s);
 500     if (NULL == s->ldap) {
 501         return NULL;
 502     }
 503
 504     ldap_set_rebind_proc(s->ldap, mod_authn_ldap_rebind_proc, s);
 505     ret = mod_authn_ldap_rebind_proc(s->ldap, NULL, 0, 0, s);
 506     if (LDAP_SUCCESS != ret) {
 507         ldap_destroy(s->ldap);
 508         s->ldap = NULL;
 509         return NULL;
 510     }
 511
 512     ret = ldap_search_ext_s(s->ldap, base, LDAP_SCOPE_SUBTREE, filter,
 513                             attrs, 0, NULL, NULL, NULL, 0, &lm);
 514     if (LDAP_SUCCESS != ret) {
 515         log_error_write(srv, __FILE__, __LINE__, "sSss",
 516                         "ldap:", ldap_err2string(ret), "; filter:", filter);
 517         ldap_unbind_ext_s(s->ldap, NULL, NULL);
 518         s->ldap = NULL;
 519         return NULL;
 520     }
 521
 522     return lm;
 523 }
 524
 525 static char * mod_authn_ldap_get_dn(server *srv, plugin_config *s, char *base, char *filter) {
 526     LDAP *ld;
 527     LDAPMessage *lm, *first;
 528     char *dn;
 529     int count;
 530
 531     lm = mod_authn_ldap_search(srv, s, base, filter);
 532     if (NULL == lm) {
 533         return NULL;
 534     }
 535
 536     ld = s->ldap; /*(must be after mod_authn_ldap_search(); might reconnect)*/
 537
 538     count = ldap_count_entries(ld, lm);
 539     if (0 == count) { /*(no entires found)*/
 540         ldap_msgfree(lm);
 541         return NULL;
 542     } else if (count > 1) {
 543         log_error_write(srv, __FILE__, __LINE__, "sss",
 544                         "ldap:", "more than one record returned.  "
 545                         "you might have to refine the filter:", filter);
 546     }
 547
 548     if (NULL == (first = ldap_first_entry(ld, lm))) {
 549         mod_authn_ldap_opt_err(srv,__FILE__,__LINE__,"ldap_first_entry()",ld);
 550         ldap_msgfree(lm);
 551         return NULL;
 552     }
 553
 554     if (NULL == (dn = ldap_get_dn(ld, first))) {
 555         mod_authn_ldap_opt_err(srv,__FILE__,__LINE__,"ldap_get_dn()",ld);
 556         ldap_msgfree(lm);
 557         return NULL;
 558     }
 559
 560     ldap_msgfree(lm);
 561     return dn;
 562 }
 563
 564 static handler_t mod_authn_ldap_memberOf(server *srv, plugin_config *s, const http_auth_require_t *require, const buffer *username, const char *userdn) {
 565     array *groups = require->group;
 566     buffer *filter = buffer_init();
 567     handler_t rc = HANDLER_ERROR;
 568
 569     buffer_copy_string_len(filter, CONST_STR_LEN("("));
 570     buffer_append_string_buffer(filter, s->auth_ldap_groupmember);
 571     buffer_append_string_len(filter, CONST_STR_LEN("="));
 572     if (buffer_is_equal_string(s->auth_ldap_groupmember,
 573                                CONST_STR_LEN("member"))) {
 574         buffer_append_string(filter, userdn);
 575     } else { /*(assume "memberUid"; consider validating in SETDEFAULTS_FUNC)*/
 576         mod_authn_append_ldap_filter_escape(filter, username);
 577     }
 578     buffer_append_string_len(filter, CONST_STR_LEN(")"));
 579
 580     for (size_t i = 0; i < groups->used; ++i) {
 581         char *base = groups->data[i]->key->ptr;
 582         LDAPMessage *lm = mod_authn_ldap_search(srv, s, base, filter->ptr);
 583         if (NULL != lm) {
 584             int count = ldap_count_entries(s->ldap, lm);
 585             ldap_msgfree(lm);
 586             if (count > 0) {
 587                 rc = HANDLER_GO_ON;
 588                 break;
 589             }
 590         }
 591     }
 592
 593     buffer_free(filter);
 594     return rc;
 595 }
 596
 597 static handler_t mod_authn_ldap_basic(server *srv, connection *con, void *p_d, const http_auth_require_t *require, const buffer *username, const char *pw) {
 598     plugin_data *p = (plugin_data *)p_d;
 599     LDAP *ld;
 600     char *dn;
 601     buffer *template;
 602     handler_t rc;
 603
 604     mod_authn_ldap_patch_connection(srv, con, p);
 605     p->anon_conf->srv = srv;
 606     p->conf.srv = srv;
 607
 608     if (pw[0] == '\0' && !p->conf.auth_ldap_allow_empty_pw)
 609         return HANDLER_ERROR;
 610
 611     template = p->conf.auth_ldap_filter;
 612     if (buffer_string_is_empty(template)) {
 613         return HANDLER_ERROR;
 614     }
 615
 616     /* build filter to get DN for uid = username */
 617     buffer_clear(p->ldap_filter);
 618     if (*template->ptr == ',') {
 619         /* special-case filter template beginning with ',' to be explicit DN */
 620         buffer_append_string_len(p->ldap_filter, CONST_STR_LEN("uid="));
 621         mod_authn_append_ldap_dn_escape(p->ldap_filter, username);
 622         buffer_append_string_buffer(p->ldap_filter, template);
 623         dn = p->ldap_filter->ptr;
 624     } else {
 625         for (char *b = template->ptr, *d; *b; b = d+1) {
 626             if (NULL != (d = strchr(b, '?'))) {
 627                 buffer_append_string_len(p->ldap_filter, b, (size_t)(d - b));
 628                 mod_authn_append_ldap_filter_escape(p->ldap_filter, username);
 629             } else {
 630                 d = template->ptr + buffer_string_length(template);
 631                 buffer_append_string_len(p->ldap_filter, b, (size_t)(d - b));
 632                 break;
 633             }
 634         }
 635
 636         /* ldap_search for DN (synchronous; blocking) */
 637         dn = mod_authn_ldap_get_dn(srv, p->anon_conf,
 638                                    p->conf.auth_ldap_basedn->ptr,
 639                                    p->ldap_filter->ptr);
 640         if (NULL == dn) {
 641             return HANDLER_ERROR;
 642         }
 643     }
 644
 645     /* auth against LDAP server (synchronous; blocking) */
 646
 647     ld = mod_authn_ldap_host_init(srv, &p->conf);
 648     if (NULL == ld) {
 649         if (dn != p->ldap_filter->ptr) ldap_memfree(dn);
 650         return HANDLER_ERROR;
 651     }
 652
 653     /* Disable referral tracking.  Target user should be in provided scope */
 654     {
 655         int ret = ldap_set_option(ld, LDAP_OPT_REFERRALS, LDAP_OPT_OFF);
 656         if (LDAP_OPT_SUCCESS != ret) {
 657             mod_authn_ldap_err(srv,__FILE__,__LINE__,"ldap_set_option()",ret);
 658             ldap_destroy(ld);
 659             if (dn != p->ldap_filter->ptr) ldap_memfree(dn);
 660             return HANDLER_ERROR;
 661         }
 662     }
 663
 664     if (LDAP_SUCCESS != mod_authn_ldap_bind(srv, ld, dn, pw)) {
 665         ldap_destroy(ld);
 666         if (dn != p->ldap_filter->ptr) ldap_memfree(dn);
 667         return HANDLER_ERROR;
 668     }
 669
 670     ldap_unbind_ext_s(ld, NULL, NULL); /* disconnect */
 671
 672     if (http_auth_match_rules(require, username->ptr, NULL, NULL)) {
 673         rc = HANDLER_GO_ON; /* access granted */
 674     } else {
 675         rc = HANDLER_ERROR;
 676         if (require->group->used) {
 677             /*(must not re-use p->ldap_filter, since it might be used for dn)*/
 678             rc = mod_authn_ldap_memberOf(srv, &p->conf, require, username, dn);
 679         }
 680     }
 681
 682     if (dn != p->ldap_filter->ptr) ldap_memfree(dn);
 683     return rc;
 684 }
 685
 686 int mod_authn_ldap_plugin_init(plugin *p);
 687 int mod_authn_ldap_plugin_init(plugin *p) {
 688     p->version     = LIGHTTPD_VERSION_ID;
 689     p->name        = buffer_init_string("authn_ldap");
 690     p->init        = mod_authn_ldap_init;
 691     p->set_defaults = mod_authn_ldap_set_defaults;
 692     p->cleanup     = mod_authn_ldap_free;
 693
 694     p->data        = NULL;
 695
 696     return 0;
 697 }