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 RCSID("$Id$");
  32
  33 #ifndef _PATH_GSS_MECH
  34 #define _PATH_GSS_MECH  "/etc/gss/mech"
  35 #endif
  36
  37 struct _gss_mech_switch_list _gss_mechs = { NULL } ;
  38 gss_OID_set _gss_mech_oids;
  39 static HEIMDAL_MUTEX _gss_mech_mutex = HEIMDAL_MUTEX_INITIALIZER;
  40
  41 /*
  42  * Convert a string containing an OID in 'dot' form
  43  * (e.g. 1.2.840.113554.1.2.2) to a gss_OID.
  44  */
  45 static int
  46 _gss_string_to_oid(const char* s, gss_OID oid)
  47 {
  48         int                     number_count, i, j;
  49         int                     byte_count;
  50         const char              *p, *q;
  51         char                    *res;
  52
  53         oid->length = 0;
  54         oid->elements = NULL;
  55
  56         /*
  57          * First figure out how many numbers in the oid, then
  58          * calculate the compiled oid size.
  59          */
  60         number_count = 0;
  61         for (p = s; p; p = q) {
  62                 q = strchr(p, '.');
  63                 if (q) q = q + 1;
  64                 number_count++;
  65         }
  66
  67         /*
  68          * The first two numbers are in the first byte and each
  69          * subsequent number is encoded in a variable byte sequence.
  70          */
  71         if (number_count < 2)
  72                 return (EINVAL);
  73
  74         /*
  75          * We do this in two passes. The first pass, we just figure
  76          * out the size. Second time around, we actually encode the
  77          * number.
  78          */
  79         res = 0;
  80         for (i = 0; i < 2; i++) {
  81                 byte_count = 0;
  82                 for (p = s, j = 0; p; p = q, j++) {
  83                         unsigned int number = 0;
  84
  85                         /*
  86                          * Find the end of this number.
  87                          */
  88                         q = strchr(p, '.');
  89                         if (q) q = q + 1;
  90
  91                         /*
  92                          * Read the number of of the string. Don't
  93                          * bother with anything except base ten.
  94                          */
  95                         while (*p && *p != '.') {
  96                                 number = 10 * number + (*p - '0');
  97                                 p++;
  98                         }
  99
 100                         /*
 101                          * Encode the number. The first two numbers
 102                          * are packed into the first byte. Subsequent
 103                          * numbers are encoded in bytes seven bits at
 104                          * a time with the last byte having the high
 105                          * bit set.
 106                          */
 107                         if (j == 0) {
 108                                 if (res)
 109                                         *res = number * 40;
 110                         } else if (j == 1) {
 111                                 if (res) {
 112                                         *res += number;
 113                                         res++;
 114                                 }
 115                                 byte_count++;
 116                         } else if (j >= 2) {
 117                                 /*
 118                                  * The number is encoded in seven bit chunks.
 119                                  */
 120                                 unsigned int t;
 121                                 int bytes;
 122
 123                                 bytes = 0;
 124                                 for (t = number; t; t >>= 7)
 125                                         bytes++;
 126                                 if (bytes == 0) bytes = 1;
 127                                 while (bytes) {
 128                                         if (res) {
 129                                                 int bit = 7*(bytes-1);
 130
 131                                                 *res = (number >> bit) & 0x7f;
 132                                                 if (bytes != 1)
 133                                                         *res |= 0x80;
 134                                                 res++;
 135                                         }
 136                                         byte_count++;
 137                                         bytes--;
 138                                 }
 139                         }
 140                 }
 141                 if (!res) {
 142                         res = malloc(byte_count);
 143                         if (!res)
 144                                 return (ENOMEM);
 145                         oid->length = byte_count;
 146                         oid->elements = res;
 147                 }
 148         }
 149
 150         return (0);
 151 }
 152
 153 #define SYM(name)                                                       \
 154 do {                                                                    \
 155         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);               \
 156         if (!m->gm_mech.gm_ ## name) {                                  \
 157                 fprintf(stderr, "can't find symbol gss_" #name "\n");   \
 158                 goto bad;                                               \
 159         }                                                               \
 160 } while (0)
 161
 162 #define OPTSYM(name)                                                    \
 163 do {                                                                    \
 164         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);                       \
 165 } while (0)
 166
 167 /*
 168  *
 169  */
 170 static int
 171 add_builtin(gssapi_mech_interface mech)
 172 {
 173     struct _gss_mech_switch *m;
 174     OM_uint32 minor_status;
 175
 176     /* not registering any mech is ok */
 177     if (mech == NULL)
 178         return 0;
 179
 180     m = malloc(sizeof(*m));
 181     if (m == NULL)
 182         return 1;
 183     m->gm_so = NULL;
 184     m->gm_mech = *mech;
 185     m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
 186     gss_add_oid_set_member(&minor_status,
 187                            &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 188
 189     SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 190     return 0;
 191 }
 192
 193 /*
 194  * Load the mechanisms file (/etc/gss/mech).
 195  */
 196 void
 197 _gss_load_mech(void)
 198 {
 199         OM_uint32       major_status, minor_status;
 200         FILE            *fp;
 201         char            buf[256];
 202         char            *p;
 203         char            *name, *oid, *lib, *kobj;
 204         struct _gss_mech_switch *m;
 205         void            *so;
 206
 207
 208         HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
 209
 210         if (SLIST_FIRST(&_gss_mechs)) {
 211                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 212                 return;
 213         }
 214
 215         major_status = gss_create_empty_oid_set(&minor_status,
 216             &_gss_mech_oids);
 217         if (major_status) {
 218                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 219                 return;
 220         }
 221
 222         add_builtin(__gss_krb5_initialize());
 223         add_builtin(__gss_spnego_initialize());
 224         add_builtin(__gss_ntlm_initialize());
 225
 226 #ifdef HAVE_DLOPEN
 227         fp = fopen(_PATH_GSS_MECH, "r");
 228         if (!fp) {
 229                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 230                 return;
 231         }
 232
 233         while (fgets(buf, sizeof(buf), fp)) {
 234                 if (*buf == '#')
 235                         continue;
 236                 p = buf;
 237                 name = strsep(&p, "\t\n ");
 238                 if (p) while (isspace((unsigned char)*p)) p++;
 239                 oid = strsep(&p, "\t\n ");
 240                 if (p) while (isspace((unsigned char)*p)) p++;
 241                 lib = strsep(&p, "\t\n ");
 242                 if (p) while (isspace((unsigned char)*p)) p++;
 243                 kobj = strsep(&p, "\t\n ");
 244                 if (!name || !oid || !lib || !kobj)
 245                         continue;
 246
 247 #ifndef RTLD_LOCAL
 248 #define RTLD_LOCAL 0
 249 #endif
 250
 251                 so = dlopen(lib, RTLD_LOCAL);
 252                 if (!so) {
 253 /*                      fprintf(stderr, "dlopen: %s\n", dlerror()); */
 254                         continue;
 255                 }
 256
 257                 m = malloc(sizeof(*m));
 258                 if (!m)
 259                         break;
 260                 m->gm_so = so;
 261                 if (_gss_string_to_oid(oid, &m->gm_mech.gm_mech_oid)) {
 262                         free(m);
 263                         continue;
 264                 }
 265
 266                 major_status = gss_add_oid_set_member(&minor_status,
 267                     &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 268                 if (major_status) {
 269                         free(m->gm_mech.gm_mech_oid.elements);
 270                         free(m);
 271                         continue;
 272                 }
 273
 274                 SYM(acquire_cred);
 275                 SYM(release_cred);
 276                 SYM(init_sec_context);
 277                 SYM(accept_sec_context);
 278                 SYM(process_context_token);
 279                 SYM(delete_sec_context);
 280                 SYM(context_time);
 281                 SYM(get_mic);
 282                 SYM(verify_mic);
 283                 SYM(wrap);
 284                 SYM(unwrap);
 285                 SYM(display_status);
 286                 SYM(indicate_mechs);
 287                 SYM(compare_name);
 288                 SYM(display_name);
 289                 SYM(import_name);
 290                 SYM(export_name);
 291                 SYM(release_name);
 292                 SYM(inquire_cred);
 293                 SYM(inquire_context);
 294                 SYM(wrap_size_limit);
 295                 SYM(add_cred);
 296                 SYM(inquire_cred_by_mech);
 297                 SYM(export_sec_context);
 298                 SYM(import_sec_context);
 299                 SYM(inquire_names_for_mech);
 300                 SYM(inquire_mechs_for_name);
 301                 SYM(canonicalize_name);
 302                 SYM(duplicate_name);
 303                 OPTSYM(inquire_cred_by_oid);
 304                 OPTSYM(inquire_sec_context_by_oid);
 305                 OPTSYM(set_sec_context_option);
 306                 OPTSYM(set_cred_option);
 307                 OPTSYM(pseudo_random);
 308
 309                 SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 310                 continue;
 311
 312         bad:
 313                 free(m->gm_mech.gm_mech_oid.elements);
 314                 free(m);
 315                 dlclose(so);
 316                 continue;
 317         }
 318         fclose(fp);
 319 #endif
 320         HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 321 }
 322
 323 gssapi_mech_interface
 324 __gss_get_mechanism(gss_OID mech)
 325 {
 326         struct _gss_mech_switch *m;
 327
 328         _gss_load_mech();
 329         SLIST_FOREACH(m, &_gss_mechs, gm_link) {
 330                 if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
 331                         return &m->gm_mech;
 332         }
 333         return NULL;
 334 }