lib/gssapi/mech/gss_mech_switch.c

   1 /*-
   2  * Copyright (c) 2005 Doug Rabson
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  *      $FreeBSD: src/lib/libgssapi/gss_mech_switch.c,v 1.2 2006/02/04 09:40:21 dfr Exp $
  27  */
  28
  29 #include "mech_locl.h"
  30 #include <heim_threads.h>
  31
  32 #ifndef _PATH_GSS_MECH
  33 #define _PATH_GSS_MECH  "/etc/gss/mech"
  34 #endif
  35
  36 struct _gss_mech_switch_list _gss_mechs = { NULL } ;
  37 gss_OID_set _gss_mech_oids;
  38 static HEIMDAL_MUTEX _gss_mech_mutex = HEIMDAL_MUTEX_INITIALIZER;
  39
  40 /*
  41  * Convert a string containing an OID in 'dot' form
  42  * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
  43  */
  44 static int
  45 _gss_string_to_oid(const char* s, gss_OID oid)
  46 {
  47         int                     number_count, i, j;
  48         size_t                  byte_count;
  49         const char              *p, *q;
  50         char                    *res;
  51
  52         oid->length = 0;
  53         oid->elements = NULL;
  54
  55         /*
  56          * First figure out how many numbers in the oid, then
  57          * calculate the compiled oid size.
  58          */
  59         number_count = 0;
  60         for (p = s; p; p = q) {
  61                 q = strchr(p, '.');
  62                 if (q) q = q + 1;
  63                 number_count++;
  64         }
  65
  66         /*
  67          * The first two numbers are in the first byte and each
  68          * subsequent number is encoded in a variable byte sequence.
  69          */
  70         if (number_count < 2)
  71                 return (EINVAL);
  72
  73         /*
  74          * We do this in two passes. The first pass, we just figure
  75          * out the size. Second time around, we actually encode the
  76          * number.
  77          */
  78         res = 0;
  79         for (i = 0; i < 2; i++) {
  80                 byte_count = 0;
  81                 for (p = s, j = 0; p; p = q, j++) {
  82                         unsigned int number = 0;
  83
  84                         /*
  85                          * Find the end of this number.
  86                          */
  87                         q = strchr(p, '.');
  88                         if (q) q = q + 1;
  89
  90                         /*
  91                          * Read the number of of the string. Don't
  92                          * bother with anything except base ten.
  93                          */
  94                         while (*p && *p != '.') {
  95                                 number = 10 * number + (*p - '0');
  96                                 p++;
  97                         }
  98
  99                         /*
 100                          * Encode the number. The first two numbers
 101                          * are packed into the first byte. Subsequent
 102                          * numbers are encoded in bytes seven bits at
 103                          * a time with the last byte having the high
 104                          * bit set.
 105                          */
 106                         if (j == 0) {
 107                                 if (res)
 108                                         *res = number * 40;
 109                         } else if (j == 1) {
 110                                 if (res) {
 111                                         *res += number;
 112                                         res++;
 113                                 }
 114                                 byte_count++;
 115                         } else if (j >= 2) {
 116                                 /*
 117                                  * The number is encoded in seven bit chunks.
 118                                  */
 119                                 unsigned int t;
 120                                 unsigned int bytes;
 121
 122                                 bytes = 0;
 123                                 for (t = number; t; t >>= 7)
 124                                         bytes++;
 125                                 if (bytes == 0) bytes = 1;
 126                                 while (bytes) {
 127                                         if (res) {
 128                                                 int bit = 7*(bytes-1);
 129
 130                                                 *res = (number >> bit) & 0x7f;
 131                                                 if (bytes != 1)
 132                                                         *res |= 0x80;
 133                                                 res++;
 134                                         }
 135                                         byte_count++;
 136                                         bytes--;
 137                                 }
 138                         }
 139                 }
 140                 if (!res) {
 141                         res = malloc(byte_count);
 142                         if (!res)
 143                                 return (ENOMEM);
 144                         oid->length = byte_count;
 145                         oid->elements = res;
 146                 }
 147         }
 148
 149         return (0);
 150 }
 151
 152 #define SYM(name)                                                       \
 153 do {                                                                    \
 154         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);               \
 155         if (!m->gm_mech.gm_ ## name) {                                  \
 156                 fprintf(stderr, "can't find symbol gss_" #name "\n");   \
 157                 goto bad;                                               \
 158         }                                                               \
 159 } while (0)
 160
 161 #define OPTSYM(name)                                                    \
 162 do {                                                                    \
 163         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);                       \
 164 } while (0)
 165
 166 /*
 167  *
 168  */
 169 static int
 170 add_builtin(gssapi_mech_interface mech)
 171 {
 172     struct _gss_mech_switch *m;
 173     OM_uint32 minor_status;
 174
 175     /* not registering any mech is ok */
 176     if (mech == NULL)
 177         return 0;
 178
 179     m = calloc(1, sizeof(*m));
 180     if (m == NULL)
 181         return 1;
 182     m->gm_so = NULL;
 183     m->gm_mech = *mech;
 184     m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
 185     gss_add_oid_set_member(&minor_status,
 186                            &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 187
 188     /* pick up the oid sets of names */
 189
 190     if (m->gm_mech.gm_inquire_names_for_mech) {
 191         (*m->gm_mech.gm_inquire_names_for_mech)(&minor_status,
 192             &m->gm_mech.gm_mech_oid, &m->gm_name_types);
 193     }
 194     if (m->gm_name_types == NULL) {
 195         gss_create_empty_oid_set(&minor_status, &m->gm_name_types);
 196     }
 197
 198     SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 199     return 0;
 200 }
 201
 202 /*
 203  * Load the mechanisms file (/etc/gss/mech).
 204  */
 205 void
 206 _gss_load_mech(void)
 207 {
 208         OM_uint32       major_status, minor_status;
 209         FILE            *fp;
 210         char            buf[256];
 211         char            *p;
 212         char            *name, *oid, *lib, *kobj;
 213         struct _gss_mech_switch *m;
 214         void            *so;
 215         gss_OID_desc    mech_oid;
 216         int             found;
 217
 218
 219         HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
 220
 221         if (SLIST_FIRST(&_gss_mechs)) {
 222                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 223                 return;
 224         }
 225
 226         major_status = gss_create_empty_oid_set(&minor_status,
 227             &_gss_mech_oids);
 228         if (major_status) {
 229                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 230                 return;
 231         }
 232
 233         add_builtin(__gss_krb5_initialize());
 234         add_builtin(__gss_spnego_initialize());
 235         add_builtin(__gss_ntlm_initialize());
 236
 237 #ifdef HAVE_DLOPEN
 238         fp = fopen(_PATH_GSS_MECH, "r");
 239         if (!fp) {
 240                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 241                 return;
 242         }
 243         rk_cloexec_file(fp);
 244
 245         while (fgets(buf, sizeof(buf), fp)) {
 246                 if (*buf == '#')
 247                         continue;
 248                 p = buf;
 249                 name = strsep(&p, "\t\n ");
 250                 if (p) while (isspace((unsigned char)*p)) p++;
 251                 oid = strsep(&p, "\t\n ");
 252                 if (p) while (isspace((unsigned char)*p)) p++;
 253                 lib = strsep(&p, "\t\n ");
 254                 if (p) while (isspace((unsigned char)*p)) p++;
 255                 kobj = strsep(&p, "\t\n ");
 256                 if (!name || !oid || !lib || !kobj)
 257                         continue;
 258
 259                 if (_gss_string_to_oid(oid, &mech_oid))
 260                         continue;
 261
 262                 /*
 263                  * Check for duplicates, already loaded mechs.
 264                  */
 265                 found = 0;
 266                 SLIST_FOREACH(m, &_gss_mechs, gm_link) {
 267                         if (gss_oid_equal(&m->gm_mech.gm_mech_oid, &mech_oid)) {
 268                                 found = 1;
 269                                 free(mech_oid.elements);
 270                                 break;
 271                         }
 272                 }
 273                 if (found)
 274                         continue;
 275
 276 #ifndef RTLD_LOCAL
 277 #define RTLD_LOCAL 0
 278 #endif
 279
 280                 so = dlopen(lib, RTLD_LAZY | RTLD_LOCAL);
 281                 if (!so) {
 282 /*                      fprintf(stderr, "dlopen: %s\n", dlerror()); */
 283                         free(mech_oid.elements);
 284                         continue;
 285                 }
 286
 287                 m = malloc(sizeof(*m));
 288                 if (!m) {
 289                         free(mech_oid.elements);
 290                         break;
 291                 }
 292                 m->gm_so = so;
 293                 m->gm_mech.gm_mech_oid = mech_oid;
 294                 m->gm_mech.gm_flags = 0;
 295
 296                 major_status = gss_add_oid_set_member(&minor_status,
 297                     &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 298                 if (major_status) {
 299                         free(m->gm_mech.gm_mech_oid.elements);
 300                         free(m);
 301                         continue;
 302                 }
 303
 304                 SYM(acquire_cred);
 305                 SYM(release_cred);
 306                 SYM(init_sec_context);
 307                 SYM(accept_sec_context);
 308                 SYM(process_context_token);
 309                 SYM(delete_sec_context);
 310                 SYM(context_time);
 311                 SYM(get_mic);
 312                 SYM(verify_mic);
 313                 SYM(wrap);
 314                 SYM(unwrap);
 315                 SYM(display_status);
 316                 SYM(indicate_mechs);
 317                 SYM(compare_name);
 318                 SYM(display_name);
 319                 SYM(import_name);
 320                 SYM(export_name);
 321                 SYM(release_name);
 322                 SYM(inquire_cred);
 323                 SYM(inquire_context);
 324                 SYM(wrap_size_limit);
 325                 SYM(add_cred);
 326                 SYM(inquire_cred_by_mech);
 327                 SYM(export_sec_context);
 328                 SYM(import_sec_context);
 329                 SYM(inquire_names_for_mech);
 330                 SYM(inquire_mechs_for_name);
 331                 SYM(canonicalize_name);
 332                 SYM(duplicate_name);
 333                 OPTSYM(inquire_cred_by_oid);
 334                 OPTSYM(inquire_sec_context_by_oid);
 335                 OPTSYM(set_sec_context_option);
 336                 OPTSYM(set_cred_option);
 337                 OPTSYM(pseudo_random);
 338                 OPTSYM(wrap_iov);
 339                 OPTSYM(unwrap_iov);
 340                 OPTSYM(wrap_iov_length);
 341
 342                 SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 343                 continue;
 344
 345         bad:
 346                 free(m->gm_mech.gm_mech_oid.elements);
 347                 free(m);
 348                 dlclose(so);
 349                 continue;
 350         }
 351         fclose(fp);
 352 #endif
 353         HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 354 }
 355
 356 gssapi_mech_interface
 357 __gss_get_mechanism(gss_OID mech)
 358 {
 359         struct _gss_mech_switch *m;
 360
 361         _gss_load_mech();
 362         SLIST_FOREACH(m, &_gss_mechs, gm_link) {
 363                 if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
 364                         return &m->gm_mech;
 365         }
 366         return NULL;
 367 }