source4/heimdal/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: gss_mech_switch.c,v 1.7 2006/10/09 11:13:30 lha Exp $");
  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         /*
  54          * First figure out how many numbers in the oid, then
  55          * calculate the compiled oid size.
  56          */
  57         number_count = 0;
  58         for (p = s; p; p = q) {
  59                 q = strchr(p, '.');
  60                 if (q) q = q + 1;
  61                 number_count++;
  62         }
  63
  64         /*
  65          * The first two numbers are in the first byte and each
  66          * subsequent number is encoded in a variable byte sequence.
  67          */
  68         if (number_count < 2)
  69                 return (EINVAL);
  70
  71         /*
  72          * We do this in two passes. The first pass, we just figure
  73          * out the size. Second time around, we actually encode the
  74          * number.
  75          */
  76         res = 0;
  77         for (i = 0; i < 2; i++) {
  78                 byte_count = 0;
  79                 for (p = s, j = 0; p; p = q, j++) {
  80                         unsigned int number = 0;
  81
  82                         /*
  83                          * Find the end of this number.
  84                          */
  85                         q = strchr(p, '.');
  86                         if (q) q = q + 1;
  87
  88                         /*
  89                          * Read the number of of the string. Don't
  90                          * bother with anything except base ten.
  91                          */
  92                         while (*p && *p != '.') {
  93                                 number = 10 * number + (*p - '0');
  94                                 p++;
  95                         }
  96
  97                         /*
  98                          * Encode the number. The first two numbers
  99                          * are packed into the first byte. Subsequent
 100                          * numbers are encoded in bytes seven bits at
 101                          * a time with the last byte having the high
 102                          * bit set.
 103                          */
 104                         if (j == 0) {
 105                                 if (res)
 106                                         *res = number * 40;
 107                         } else if (j == 1) {
 108                                 if (res) {
 109                                         *res += number;
 110                                         res++;
 111                                 }
 112                                 byte_count++;
 113                         } else if (j >= 2) {
 114                                 /*
 115                                  * The number is encoded in seven bit chunks.
 116                                  */
 117                                 unsigned int t;
 118                                 int bytes;
 119
 120                                 bytes = 0;
 121                                 for (t = number; t; t >>= 7)
 122                                         bytes++;
 123                                 if (bytes == 0) bytes = 1;
 124                                 while (bytes) {
 125                                         if (res) {
 126                                                 int bit = 7*(bytes-1);
 127
 128                                                 *res = (number >> bit) & 0x7f;
 129                                                 if (bytes != 1)
 130                                                         *res |= 0x80;
 131                                                 res++;
 132                                         }
 133                                         byte_count++;
 134                                         bytes--;
 135                                 }
 136                         }
 137                 }
 138                 if (!res) {
 139                         res = malloc(byte_count);
 140                         if (!res)
 141                                 return (ENOMEM);
 142                         oid->length = byte_count;
 143                         oid->elements = res;
 144                 }
 145         }
 146
 147         return (0);
 148 }
 149
 150 #define SYM(name)                                                       \
 151 do {                                                                    \
 152         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);               \
 153         if (!m->gm_mech.gm_ ## name) {                                  \
 154                 fprintf(stderr, "can't find symbol gss_" #name "\n");   \
 155                 goto bad;                                               \
 156         }                                                               \
 157 } while (0)
 158
 159 #define OPTSYM(name)                                                    \
 160 do {                                                                    \
 161         m->gm_mech.gm_ ## name = dlsym(so, "gss_" #name);                       \
 162 } while (0)
 163
 164 /*
 165  *
 166  */
 167 static int
 168 add_builtin(gssapi_mech_interface mech)
 169 {
 170     struct _gss_mech_switch *m;
 171     OM_uint32 minor_status;
 172
 173     m = malloc(sizeof(*m));
 174     if (m == NULL)
 175         return 1;
 176     m->gm_so = NULL;
 177     m->gm_mech = *mech;
 178     m->gm_mech_oid = mech->gm_mech_oid; /* XXX */
 179     gss_add_oid_set_member(&minor_status,
 180                            &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 181
 182     SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 183     return 0;
 184 }
 185
 186 /*
 187  * Load the mechanisms file (/etc/gss/mech).
 188  */
 189 void
 190 _gss_load_mech(void)
 191 {
 192         OM_uint32       major_status, minor_status;
 193         FILE            *fp;
 194         char            buf[256];
 195         char            *p;
 196         char            *name, *oid, *lib, *kobj;
 197         struct _gss_mech_switch *m;
 198         void            *so;
 199
 200
 201         HEIMDAL_MUTEX_lock(&_gss_mech_mutex);
 202
 203         if (SLIST_FIRST(&_gss_mechs)) {
 204                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 205                 return;
 206         }
 207
 208         major_status = gss_create_empty_oid_set(&minor_status,
 209             &_gss_mech_oids);
 210         if (major_status) {
 211                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 212                 return;
 213         }
 214
 215         add_builtin(__gss_krb5_initialize());
 216         add_builtin(__gss_spnego_initialize());
 217
 218         fp = fopen(_PATH_GSS_MECH, "r");
 219         if (!fp) {
 220 /*              perror(_PATH_GSS_MECH); */
 221                 HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 222                 return;
 223         }
 224
 225         while (fgets(buf, sizeof(buf), fp)) {
 226                 if (*buf == '#')
 227                         continue;
 228                 p = buf;
 229                 name = strsep(&p, "\t\n ");
 230                 if (p) while (isspace((unsigned char)*p)) p++;
 231                 oid = strsep(&p, "\t\n ");
 232                 if (p) while (isspace((unsigned char)*p)) p++;
 233                 lib = strsep(&p, "\t\n ");
 234                 if (p) while (isspace((unsigned char)*p)) p++;
 235                 kobj = strsep(&p, "\t\n ");
 236                 if (!name || !oid || !lib || !kobj)
 237                         continue;
 238
 239 #ifndef RTLD_LOCAL
 240 #define RTLD_LOCAL 0
 241 #endif
 242
 243                 so = dlopen(lib, RTLD_LOCAL);
 244                 if (!so) {
 245 /*                      fprintf(stderr, "dlopen: %s\n", dlerror()); */
 246                         continue;
 247                 }
 248
 249                 m = malloc(sizeof(*m));
 250                 if (!m)
 251                         break;
 252                 m->gm_so = so;
 253                 if (_gss_string_to_oid(oid, &m->gm_mech.gm_mech_oid)) {
 254                         free(m);
 255                         continue;
 256                 }
 257
 258                 major_status = gss_add_oid_set_member(&minor_status,
 259                     &m->gm_mech.gm_mech_oid, &_gss_mech_oids);
 260                 if (major_status) {
 261                         free(m->gm_mech.gm_mech_oid.elements);
 262                         free(m);
 263                         continue;
 264                 }
 265
 266                 SYM(acquire_cred);
 267                 SYM(release_cred);
 268                 SYM(init_sec_context);
 269                 SYM(accept_sec_context);
 270                 SYM(process_context_token);
 271                 SYM(delete_sec_context);
 272                 SYM(context_time);
 273                 SYM(get_mic);
 274                 SYM(verify_mic);
 275                 SYM(wrap);
 276                 SYM(unwrap);
 277                 SYM(display_status);
 278                 SYM(indicate_mechs);
 279                 SYM(compare_name);
 280                 SYM(display_name);
 281                 SYM(import_name);
 282                 SYM(export_name);
 283                 SYM(release_name);
 284                 SYM(inquire_cred);
 285                 SYM(inquire_context);
 286                 SYM(wrap_size_limit);
 287                 SYM(add_cred);
 288                 SYM(inquire_cred_by_mech);
 289                 SYM(export_sec_context);
 290                 SYM(import_sec_context);
 291                 SYM(inquire_names_for_mech);
 292                 SYM(inquire_mechs_for_name);
 293                 SYM(canonicalize_name);
 294                 SYM(duplicate_name);
 295                 OPTSYM(inquire_cred_by_oid);
 296                 OPTSYM(inquire_sec_context_by_oid);
 297                 OPTSYM(set_sec_context_option);
 298                 OPTSYM(set_cred_option);
 299
 300                 SLIST_INSERT_HEAD(&_gss_mechs, m, gm_link);
 301                 continue;
 302
 303         bad:
 304                 free(m->gm_mech.gm_mech_oid.elements);
 305                 free(m);
 306                 dlclose(so);
 307                 continue;
 308         }
 309         fclose(fp);
 310         HEIMDAL_MUTEX_unlock(&_gss_mech_mutex);
 311 }
 312
 313 gssapi_mech_interface
 314 __gss_get_mechanism(gss_OID mech)
 315 {
 316         struct _gss_mech_switch *m;
 317
 318         _gss_load_mech();
 319         SLIST_FOREACH(m, &_gss_mechs, gm_link) {
 320                 if (gss_oid_equal(&m->gm_mech.gm_mech_oid, mech))
 321                         return &m->gm_mech;
 322         }
 323         return NULL;
 324 }