mech_eap/util_mech.c

   1 /*
   2  * Copyright (c) 2011, JANET(UK)
   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  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * General mechanism utility routines.
  35  */
  36
  37 #include "gssapiP_eap.h"
  38
  39 /*
  40  * Mechanism and name types are taken from 1.3.6.1.5.5(mechanisms)
  41  * assigned at http://www.iana.org/assignments/smi-numbers
  42  *
  43  *      abfab(15)
  44  *       mechanisms(1)
  45  *        gss-eap-v1(1)
  46  *         eap-aes128-cts-hmac-sha1-96(17)
  47  *         eap-aes256-cts-hmac-sha1-96(18)
  48  *       nametypes(2)
  49  *        GSS_EAP_NT_EAP_NAME(1)
  50  *
  51  * Implementation-internal OIDs are taken from 1.3.6.1.4.1.5322(padl)
  52  *      gssEap(22)
  53  *       apiExtensions(3)
  54  *        inquireSecContextByOid(1)
  55  *        inquireCredByOid(2)
  56  *        setSecContextOption(3)
  57  *        setCredOption(4)
  58  *        mechInvoke(5)
  59  */
  60
  61 /*
  62  * Note: the enctype-less OID is used as the mechanism OID in non-
  63  * canonicalized exported names.
  64  */
  65 static gss_OID_desc gssEapMechOids[] = {
  66     /* 1.3.6.1.5.5.15.1.1  */
  67     { 8, "\x2B\x06\x01\x05\x05\x0f\x01\x01" },
  68     /* 1.3.6.1.5.5.15.1.1.17  */
  69     { 9, "\x2B\x06\x01\x05\x05\x0f\x01\x01\x11" },
  70     /* 1.3.6.1.5.5.15.1.1.18  */
  71     { 9, "\x2B\x06\x01\x05\x05\x0f\x01\x01\x12" },
  72 };
  73
  74 gss_OID GSS_EAP_MECHANISM                            = &gssEapMechOids[0];
  75 gss_OID GSS_EAP_AES128_CTS_HMAC_SHA1_96_MECHANISM    = &gssEapMechOids[1];
  76 gss_OID GSS_EAP_AES256_CTS_HMAC_SHA1_96_MECHANISM    = &gssEapMechOids[2];
  77
  78 static int
  79 internalizeOid(const gss_OID oid,
  80                gss_OID *const pInternalizedOid);
  81
  82 /*
  83  * Returns TRUE is the OID is a concrete mechanism OID, that is, one
  84  * with a Kerberos enctype as the last element.
  85  */
  86 int
  87 gssEapIsConcreteMechanismOid(const gss_OID oid)
  88 {
  89     return oid->length > GSS_EAP_MECHANISM->length &&
  90            memcmp(oid->elements, GSS_EAP_MECHANISM->elements,
  91                   GSS_EAP_MECHANISM->length) == 0;
  92 }
  93
  94 int
  95 gssEapIsMechanismOid(const gss_OID oid)
  96 {
  97     return oid == GSS_C_NO_OID ||
  98            oidEqual(oid, GSS_EAP_MECHANISM) ||
  99            gssEapIsConcreteMechanismOid(oid);
 100 }
 101
 102 /*
 103  * Validate that all elements are concrete mechanism OIDs.
 104  */
 105 OM_uint32
 106 gssEapValidateMechs(OM_uint32 *minor,
 107                     const gss_OID_set mechs)
 108 {
 109     int i;
 110
 111     *minor = 0;
 112
 113     if (mechs == GSS_C_NO_OID_SET) {
 114         return GSS_S_COMPLETE;
 115     }
 116
 117     for (i = 0; i < mechs->count; i++) {
 118         gss_OID oid = &mechs->elements[i];
 119
 120         if (!gssEapIsConcreteMechanismOid(oid)) {
 121             *minor = GSSEAP_WRONG_MECH;
 122             return GSS_S_BAD_MECH;
 123         }
 124     }
 125
 126     return GSS_S_COMPLETE;
 127 }
 128
 129 OM_uint32
 130 gssEapOidToEnctype(OM_uint32 *minor,
 131                    const gss_OID oid,
 132                    krb5_enctype *enctype)
 133 {
 134     OM_uint32 major;
 135     int suffix;
 136
 137     major = decomposeOid(minor,
 138                          GSS_EAP_MECHANISM->elements,
 139                          GSS_EAP_MECHANISM->length,
 140                          oid,
 141                          &suffix);
 142     if (major == GSS_S_COMPLETE)
 143         *enctype = suffix;
 144
 145     return major;
 146 }
 147
 148 OM_uint32
 149 gssEapEnctypeToOid(OM_uint32 *minor,
 150                    krb5_enctype enctype,
 151                    gss_OID *pOid)
 152 {
 153     OM_uint32 major;
 154     gss_OID oid;
 155
 156     *pOid = NULL;
 157
 158     oid = (gss_OID)GSSEAP_MALLOC(sizeof(*oid));
 159     if (oid == NULL) {
 160         *minor = ENOMEM;
 161         return GSS_S_FAILURE;
 162     }
 163
 164     oid->length = GSS_EAP_MECHANISM->length + 1;
 165     oid->elements = GSSEAP_MALLOC(oid->length);
 166     if (oid->elements == NULL) {
 167         *minor = ENOMEM;
 168         GSSEAP_FREE(oid);
 169         return GSS_S_FAILURE;
 170     }
 171
 172     major = composeOid(minor,
 173                        GSS_EAP_MECHANISM->elements,
 174                        GSS_EAP_MECHANISM->length,
 175                        enctype,
 176                        oid);
 177     if (major == GSS_S_COMPLETE) {
 178         internalizeOid(oid, pOid);
 179         *pOid = oid;
 180     } else {
 181         GSSEAP_FREE(oid->elements);
 182         GSSEAP_FREE(oid);
 183     }
 184
 185     return major;
 186 }
 187
 188 OM_uint32
 189 gssEapIndicateMechs(OM_uint32 *minor,
 190                     gss_OID_set *mechs)
 191 {
 192     krb5_context krbContext;
 193     OM_uint32 major;
 194     krb5_enctype *etypes;
 195     int i;
 196
 197     GSSEAP_KRB_INIT(&krbContext);
 198
 199 #ifdef HAVE_HEIMDAL_VERSION
 200     *minor = krb5_get_default_in_tkt_etypes(krbContext, KRB5_PDU_NONE, &etypes);
 201 #else
 202     *minor = krb5_get_permitted_enctypes(krbContext, &etypes);
 203 #endif
 204     if (*minor != 0) {
 205         return GSS_S_FAILURE;
 206     }
 207
 208     major = gss_create_empty_oid_set(minor, mechs);
 209     if (GSS_ERROR(major)) {
 210         GSSEAP_FREE(etypes);
 211         return major;
 212     }
 213
 214     for (i = 0; etypes[i] != ENCTYPE_NULL; i++) {
 215         gss_OID mechOid;
 216 #ifndef HAVE_HEIMDAL_VERSION
 217         OM_uint32 tmpMinor;
 218 #endif
 219
 220         /* XXX currently we aren't equipped to encode these enctypes */
 221         if (etypes[i] < 0 || etypes[i] > 127)
 222             continue;
 223
 224         major = gssEapEnctypeToOid(minor, etypes[i], &mechOid);
 225         if (GSS_ERROR(major))
 226             break;
 227
 228         major = gss_add_oid_set_member(minor, mechOid, mechs);
 229         if (GSS_ERROR(major))
 230             break;
 231
 232 #ifndef HAVE_HEIMDAL_VERSION
 233         gss_release_oid(&tmpMinor, &mechOid);
 234 #endif
 235     }
 236
 237     GSSEAP_FREE(etypes);
 238
 239     *minor = 0;
 240     return major;
 241 }
 242
 243 OM_uint32
 244 gssEapDefaultMech(OM_uint32 *minor,
 245                   gss_OID *oid)
 246 {
 247     gss_OID_set mechs;
 248     OM_uint32 major, tmpMinor;
 249
 250     major = gssEapIndicateMechs(minor, &mechs);
 251     if (GSS_ERROR(major)) {
 252         return major;
 253     }
 254
 255     if (mechs->count == 0) {
 256         gss_release_oid_set(&tmpMinor, &mechs);
 257         return GSS_S_BAD_MECH;
 258     }
 259
 260     if (!internalizeOid(&mechs->elements[0], oid)) {
 261         /* don't double-free if we didn't internalize it */
 262         mechs->elements[0].length = 0;
 263         mechs->elements[0].elements = NULL;
 264     }
 265
 266     gss_release_oid_set(&tmpMinor, &mechs);
 267
 268     *minor = 0;
 269     return GSS_S_COMPLETE;
 270 }
 271
 272 static int
 273 internalizeOid(const gss_OID oid,
 274                gss_OID *const pInternalizedOid)
 275 {
 276     int i;
 277
 278     *pInternalizedOid = GSS_C_NO_OID;
 279
 280     for (i = 0;
 281          i < sizeof(gssEapMechOids) / sizeof(gssEapMechOids[0]);
 282          i++) {
 283         if (oidEqual(oid, &gssEapMechOids[i])) {
 284             *pInternalizedOid = (const gss_OID)&gssEapMechOids[i];
 285             break;
 286         }
 287     }
 288
 289     if (*pInternalizedOid == GSS_C_NO_OID) {
 290         if (oidEqual(oid, GSS_EAP_NT_EAP_NAME))
 291             *pInternalizedOid = (const gss_OID)GSS_EAP_NT_EAP_NAME;
 292     }
 293
 294     if (*pInternalizedOid == GSS_C_NO_OID) {
 295         *pInternalizedOid = oid;
 296         return 0;
 297     }
 298
 299     return 1;
 300 }
 301
 302 OM_uint32
 303 gssEapReleaseOid(OM_uint32 *minor, gss_OID *oid)
 304 {
 305     gss_OID internalizedOid = GSS_C_NO_OID;
 306
 307     *minor = 0;
 308
 309     if (internalizeOid(*oid, &internalizedOid)) {
 310         /* OID was internalized, so we can mark it as "freed" */
 311         *oid = GSS_C_NO_OID;
 312         return GSS_S_COMPLETE;
 313     }
 314
 315     /* we don't know about this OID */
 316     return GSS_S_CONTINUE_NEEDED;
 317 }
 318
 319 OM_uint32
 320 gssEapCanonicalizeOid(OM_uint32 *minor,
 321                       const gss_OID oid,
 322                       OM_uint32 flags,
 323                       gss_OID *pOid)
 324 {
 325     OM_uint32 major;
 326     int mapToNull = 0;
 327
 328     major = GSS_S_COMPLETE;
 329     *minor = 0;
 330     *pOid = GSS_C_NULL_OID;
 331
 332     if (oid == GSS_C_NULL_OID) {
 333         if ((flags & OID_FLAG_NULL_VALID) == 0) {
 334             *minor = GSSEAP_WRONG_MECH;
 335             return GSS_S_BAD_MECH;
 336         } else if (flags & OID_FLAG_MAP_NULL_TO_DEFAULT_MECH) {
 337             return gssEapDefaultMech(minor, pOid);
 338         } else {
 339             mapToNull = 1;
 340         }
 341     } else if (oidEqual(oid, GSS_EAP_MECHANISM)) {
 342         if ((flags & OID_FLAG_FAMILY_MECH_VALID) == 0) {
 343             *minor = GSSEAP_WRONG_MECH;
 344             return GSS_S_BAD_MECH;
 345         } else if (flags & OID_FLAG_MAP_FAMILY_MECH_TO_NULL) {
 346             mapToNull = 1;
 347         }
 348     } else if (!gssEapIsConcreteMechanismOid(oid)) {
 349         *minor = GSSEAP_WRONG_MECH;
 350         return GSS_S_BAD_MECH;
 351     }
 352
 353     if (!mapToNull) {
 354         if (!internalizeOid(oid, pOid))
 355             major = duplicateOid(minor, oid, pOid);
 356     }
 357
 358     return major;
 359 }
 360
 361 static gss_buffer_desc gssEapSaslMechs[] = {
 362     { sizeof("EAP") - 1,        "EAP",       }, /* not used */
 363     { sizeof("EAP-AES128") - 1, "EAP-AES128" },
 364     { sizeof("EAP-AES256") - 1, "EAP-AES256" },
 365 };
 366
 367 gss_buffer_t
 368 gssEapOidToSaslName(const gss_OID oid)
 369 {
 370     size_t i;
 371
 372     for (i = 1; i < sizeof(gssEapMechOids)/sizeof(gssEapMechOids[0]); i++) {
 373         if (oidEqual(&gssEapMechOids[i], oid))
 374             return &gssEapSaslMechs[i];
 375     }
 376
 377     return GSS_C_NO_BUFFER;
 378 }
 379
 380 gss_OID
 381 gssEapSaslNameToOid(const gss_buffer_t name)
 382 {
 383     size_t i;
 384
 385     for (i = 1; i < sizeof(gssEapSaslMechs)/sizeof(gssEapSaslMechs[0]); i++) {
 386         if (bufferEqual(&gssEapSaslMechs[i], name))
 387             return &gssEapMechOids[i];
 388     }
 389
 390     return GSS_C_NO_OID;
 391 }