support/gssapi/g_mit_krb5_mech.c

   1 /*
   2  *  g_mit_krb5_mech.c
   3  *
   4  *  Copyright (c) 2004 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Kevin Coffman <kwc@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  */
  35
  36 #include "config.h"
  37 #include <stdio.h>
  38 #include <dlfcn.h>
  39 #include "mglueP.h"
  40
  41 /*
  42  * Table of function names that we need to locate within a mechanism's
  43  * shared library if it does not support the xxx_gss_initialize function.
  44  */
  45 static char *glue_func_names[] = {
  46         "gss_acquire_cred",
  47         "gss_release_cred",
  48         "gss_init_sec_context",
  49         "gss_accept_sec_context",
  50         "gss_process_context_token",
  51         "gss_delete_sec_context",
  52         "gss_context_time",
  53         "gss_sign",
  54         "gss_verify",
  55         "gss_seal",
  56         "gss_unseal",
  57         "gss_display_status",
  58         "gss_indicate_mechs",
  59         "gss_compare_name",
  60         "gss_display_name",
  61         "gss_import_name",
  62         "gss_release_name",
  63         "gss_inquire_cred",
  64         "gss_add_cred",
  65         "gss_export_sec_context",
  66         "gss_import_sec_context",
  67         "gss_inquire_cred_by_mech",
  68         "gss_inquire_names_for_mech",
  69         "gss_inquire_context",
  70         "gss_internal_release_oid",
  71         "gss_wrap_size_limit",
  72         "pname_to_uid",
  73         "gss_duplicate_name",
  74         "gss_set_allowable_enctypes",
  75         "gss_verify_mic",
  76         NULL
  77 };
  78
  79 #ifdef HAVE_KRB5
  80 /*
  81  * The MIT code does not support the krb5_gss_initialize function, so
  82  * we need to locate the functions within the gssapi_krb5.so library
  83  * and fill in this structure.
  84  */
  85 static struct gss_config mit_krb5_mechanism = {
  86         {9, "\052\206\110\206\367\022\001\002\002"},
  87         NULL,           /* mechanism context -- we don't currently use this */
  88         NULL,           /* gss_acquire_cred */
  89         NULL,           /* gss_release_cred */
  90         NULL,           /* gss_init_sec_context */
  91         NULL,           /* gss_accept_sec_context */
  92         NULL,           /* gss_process_context_token */
  93         NULL,           /* gss_delete_sec_context */
  94         NULL,           /* gss_context_time */
  95         NULL,           /* gss_sign */
  96         NULL,           /* gss_verify */
  97         NULL,           /* gss_seal */
  98         NULL,           /* gss_unseal */
  99         NULL,           /* gss_display_status */
 100         NULL,           /* gss_indicate_mechs */
 101         NULL,           /* gss_compare_name */
 102         NULL,           /* gss_display_name */
 103         NULL,           /* gss_import_name */
 104         NULL,           /* gss_release_name */
 105         NULL,           /* gss_inquire_cred */
 106         NULL,           /* gss_add_cred */
 107         NULL,           /* gss_export_sec_context */
 108         NULL,           /* gss_import_sec_context */
 109         NULL,           /* gss_inquire_cred_by_mech */
 110         NULL,           /* gss_inquire_names_for_mech */
 111         NULL,           /* gss_inquire_context */
 112         NULL,           /* gss_internal_release_oid */
 113         NULL,           /* gss_wrap_size_limit */
 114         NULL,           /* pname_to_uid */
 115         NULL,           /* gss_duplicate_name */
 116         NULL,           /* gss_set_allowable_enctypes */
 117         NULL,           /* gss_verify_mic */
 118 };
 119 #endif
 120
 121 #ifdef HAVE_HEIMDAL
 122 /*
 123  * The heimdal code does not support the krb5_gss_initialize function, so
 124  * we need to locate the functions within the libgssapi.so library
 125  * and fill in this structure.
 126  */
 127 static struct gss_config heimdal_krb5_mechanism = {
 128         {9, "\052\206\110\206\367\022\001\002\002"},
 129         NULL,           /* mechanism context -- we don't currently use this */
 130         NULL,           /* gss_acquire_cred */
 131         NULL,           /* gss_release_cred */
 132         NULL,           /* gss_init_sec_context */
 133         NULL,           /* gss_accept_sec_context */
 134         NULL,           /* gss_process_context_token */
 135         NULL,           /* gss_delete_sec_context */
 136         NULL,           /* gss_context_time */
 137         NULL,           /* gss_sign */
 138         NULL,           /* gss_verify */
 139         NULL,           /* gss_seal */
 140         NULL,           /* gss_unseal */
 141         NULL,           /* gss_display_status */
 142         NULL,           /* gss_indicate_mechs */
 143         NULL,           /* gss_compare_name */
 144         NULL,           /* gss_display_name */
 145         NULL,           /* gss_import_name */
 146         NULL,           /* gss_release_name */
 147         NULL,           /* gss_inquire_cred */
 148         NULL,           /* gss_add_cred */
 149         NULL,           /* gss_export_sec_context */
 150         NULL,           /* gss_import_sec_context */
 151         NULL,           /* gss_inquire_cred_by_mech */
 152         NULL,           /* gss_inquire_names_for_mech */
 153         NULL,           /* gss_inquire_context */
 154         NULL,           /* gss_internal_release_oid */
 155         NULL,           /* gss_wrap_size_limit */
 156         NULL,           /* pname_to_uid */
 157         NULL,           /* gss_duplicate_name */
 158         NULL,           /* gss_set_allowable_enctypes */
 159         NULL,           /* gss_verify_mic */
 160 };
 161 #endif
 162
 163
 164 /*
 165  * Given a handle to a dynamic library (dl) and a symbol
 166  * name (symname), return its address.  Returns -1 if the
 167  * symbol cannot be located.  (Note that the value of the
 168  * symbol could be NULL, which is valid.)
 169  */
 170 void *
 171 locate_symbol(void *dl, char *symname, char *prefix)
 172 {
 173         void *sym;
 174         const char *err_string;
 175         char fullname[256];
 176
 177         snprintf(fullname, sizeof(fullname), "%s%s", prefix, symname);
 178
 179         if ((sym = dlsym(dl, fullname)) == NULL) {
 180                 if ((sym = dlsym(dl, symname)) == NULL) {
 181                         if ((err_string = dlerror()) != NULL) {
 182                                 return (void *)-1;
 183                         }
 184                         else {
 185                                 return NULL;
 186                         }
 187                 }
 188         }
 189         return sym;
 190 }
 191
 192 #ifdef HAVE_KRB5
 193 /*
 194  * Locate all the symbols in the MIT gssapi library and
 195  * fill in the gss_config (gss_mechanism) structure.
 196  */
 197 gss_mechanism
 198 internal_krb5_gss_initialize(void *dl)
 199 {
 200         char *fname;
 201         void *p;
 202         void **fptr;
 203         int i;
 204         static int mit_krb5_initialized = 0;
 205
 206         if (mit_krb5_initialized)
 207                 return (&mit_krb5_mechanism);
 208
 209         fptr = (void *) &mit_krb5_mechanism.gss_acquire_cred;
 210
 211
 212         for (i = 0, fname = glue_func_names[i];
 213              fname;
 214              i++, fname = glue_func_names[i]) {
 215                 if ((p = locate_symbol(dl, fname, "krb5_")) != (void *)-1) {
 216                         *fptr++ = p;
 217                 }
 218                 else {
 219                         *fptr++ = NULL;
 220                 }
 221         }
 222         if (mit_krb5_mechanism.gss_internal_release_oid == NULL ||
 223             mit_krb5_mechanism.gss_internal_release_oid == (void *) -1) {
 224             fprintf(stderr, "WARNING: unable to locate function "
 225                 "krb5_gss_internal_release_oid in krb5 mechanism library: "
 226                 "there will be problems if multiple mechanisms are used!\n");
 227             p = locate_symbol(dl, "krb5_gss_release_oid", "");
 228             if (p == NULL || p == (void *) -1) {
 229                 fprintf(stderr, "ERROR: Unable to locate function "
 230                         "krb5_gss_internal_release_oid or "
 231                         "krb5_gss_release_oid in krb5 mechanism library\n");
 232                 return NULL;
 233             }
 234         }
 235 #ifdef HAVE_SET_ALLOWABLE_ENCTYPES
 236         /*
 237          * Special case for set_allowable_enctypes which has a different
 238          * name format than the rest of the gss routines :-/
 239          */
 240         if ((p = locate_symbol(dl, "gss_krb5_set_allowable_enctypes", ""))
 241                                                         != (void *)-1) {
 242                 mit_krb5_mechanism.gss_set_allowable_enctypes = p;
 243         }
 244 #endif
 245         mit_krb5_initialized = 1;
 246         return (&mit_krb5_mechanism);
 247 }
 248 #endif
 249
 250 #ifdef HAVE_HEIMDAL
 251 /*
 252  * Locate all the symbols in the MIT gssapi library and
 253  * fill in the gss_config (gss_mechanism) structure.
 254  */
 255 gss_mechanism
 256 internal_heimdal_gss_initialize(void *dl)
 257 {
 258         char *fname;
 259         void *p;
 260         void **fptr;
 261         int i;
 262         static int heimdal_krb5_initialized = 0;
 263
 264         if (heimdal_krb5_initialized)
 265                 return (&heimdal_krb5_mechanism);
 266
 267         fptr = (void *) &heimdal_krb5_mechanism.gss_acquire_cred;
 268
 269
 270         for (i = 0, fname = glue_func_names[i];
 271              fname;
 272              i++, fname = glue_func_names[i]) {
 273                 if ((p = locate_symbol(dl, fname, "")) != (void *)-1) {
 274                         *fptr++ = p;
 275                 }
 276                 else {
 277 printf("Failed to locate function '%s' !!!\n", fname);
 278                         *fptr++ = NULL;
 279                 }
 280         }
 281         if (heimdal_krb5_mechanism.gss_internal_release_oid == NULL ||
 282             heimdal_krb5_mechanism.gss_internal_release_oid == (void *) -1) {
 283             fprintf(stderr, "WARNING: unable to locate function "
 284                 "gss_internal_release_oid in krb5 mechanism library: "
 285                 "there will be problems if multiple mechanisms are used!\n");
 286             p = locate_symbol(dl, "krb5_gss_release_oid", "");
 287             if (p == NULL || p == (void *) -1) {
 288                 fprintf(stderr, "ERROR: Unable to locate function "
 289                         "gss_internal_release_oid or "
 290                         "gss_release_oid in krb5 mechanism library\n");
 291                 return NULL;
 292             }
 293         }
 294         heimdal_krb5_initialized = 1;
 295         return (&heimdal_krb5_mechanism);
 296 }
 297 #endif