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  * 1.3.6.1.4.1.5322(padl)
  41  *      gssEap(22)
  42  *       mechanisms(1)
  43  *        eap-aes128-cts-hmac-sha1-96(17)
  44  *        eap-aes256-cts-hmac-sha1-96(18)
  45  *       nameTypes(2)
  46  *       apiExtensions(3)
  47  *        inquireSecContextByOid(1)
  48  *        inquireCredByOid(2)
  49  *        setSecContextOption(3)
  50  *        setCredOption(4)
  51  *        mechInvoke(5)
  52  */
  53
  54 /*
  55  * Note: the enctype-less OID is used as the mechanism OID in non-
  56  * canonicalized exported names.
  57  */
  58 static gss_OID_desc gssEapMechOids[] = {
  59     /* 1.3.6.1.4.1.5322.22.1  */
  60     { 9, "\x2B\x06\x01\x04\x01\xA9\x4A\x16\x01" },
  61     /* 1.3.6.1.4.1.5322.22.1.17 */
  62     { 10, "\x2B\x06\x01\x04\x01\xA9\x4A\x16\x01\x11" },
  63     /* 1.3.6.1.4.1.5322.22.1.18 */
  64     { 10, "\x2B\x06\x01\x04\x01\xA9\x4A\x16\x01\x12" }
  65 };
  66
  67 gss_OID GSS_EAP_MECHANISM                            = &gssEapMechOids[0];
  68 gss_OID GSS_EAP_AES128_CTS_HMAC_SHA1_96_MECHANISM    = &gssEapMechOids[1];
  69 gss_OID GSS_EAP_AES256_CTS_HMAC_SHA1_96_MECHANISM    = &gssEapMechOids[2];
  70
  71 static int
  72 internalizeOid(const gss_OID oid,
  73                gss_OID *const pInternalizedOid);
  74
  75 /*
  76  * Returns TRUE is the OID is a concrete mechanism OID, that is, one
  77  * with a Kerberos enctype as the last element.
  78  */
  79 int
  80 gssEapIsConcreteMechanismOid(const gss_OID oid)
  81 {
  82     return oid->length > GSS_EAP_MECHANISM->length &&
  83            memcmp(oid->elements, GSS_EAP_MECHANISM->elements,
  84                   GSS_EAP_MECHANISM->length) == 0;
  85 }
  86
  87 int
  88 gssEapIsMechanismOid(const gss_OID oid)
  89 {
  90     return oid == GSS_C_NO_OID ||
  91            oidEqual(oid, GSS_EAP_MECHANISM) ||
  92            gssEapIsConcreteMechanismOid(oid);
  93 }
  94
  95 /*
  96  * Validate that all elements are concrete mechanism OIDs.
  97  */
  98 OM_uint32
  99 gssEapValidateMechs(OM_uint32 *minor,
 100                     const gss_OID_set mechs)
 101 {
 102     int i;
 103
 104     *minor = 0;
 105
 106     if (mechs == GSS_C_NO_OID_SET) {
 107         return GSS_S_COMPLETE;
 108     }
 109
 110     for (i = 0; i < mechs->count; i++) {
 111         gss_OID oid = &mechs->elements[i];
 112
 113         if (!gssEapIsConcreteMechanismOid(oid)) {
 114             *minor = GSSEAP_WRONG_MECH;
 115             return GSS_S_BAD_MECH;
 116         }
 117     }
 118
 119     return GSS_S_COMPLETE;
 120 }
 121
 122 OM_uint32
 123 gssEapOidToEnctype(OM_uint32 *minor,
 124                    const gss_OID oid,
 125                    krb5_enctype *enctype)
 126 {
 127     OM_uint32 major;
 128     int suffix;
 129
 130     major = decomposeOid(minor,
 131                          GSS_EAP_MECHANISM->elements,
 132                          GSS_EAP_MECHANISM->length,
 133                          oid,
 134                          &suffix);
 135     if (major == GSS_S_COMPLETE)
 136         *enctype = suffix;
 137
 138     return major;
 139 }
 140
 141 OM_uint32
 142 gssEapEnctypeToOid(OM_uint32 *minor,
 143                    krb5_enctype enctype,
 144                    gss_OID *pOid)
 145 {
 146     OM_uint32 major;
 147     gss_OID oid;
 148
 149     *pOid = NULL;
 150
 151     oid = (gss_OID)GSSEAP_MALLOC(sizeof(*oid));
 152     if (oid == NULL) {
 153         *minor = ENOMEM;
 154         return GSS_S_FAILURE;
 155     }
 156
 157     oid->length = GSS_EAP_MECHANISM->length + 1;
 158     oid->elements = GSSEAP_MALLOC(oid->length);
 159     if (oid->elements == NULL) {
 160         *minor = ENOMEM;
 161         GSSEAP_FREE(oid);
 162         return GSS_S_FAILURE;
 163     }
 164
 165     major = composeOid(minor,
 166                        GSS_EAP_MECHANISM->elements,
 167                        GSS_EAP_MECHANISM->length,
 168                        enctype,
 169                        oid);
 170     if (major == GSS_S_COMPLETE) {
 171         internalizeOid(oid, pOid);
 172         *pOid = oid;
 173     } else {
 174         GSSEAP_FREE(oid->elements);
 175         GSSEAP_FREE(oid);
 176     }
 177
 178     return major;
 179 }
 180
 181 OM_uint32
 182 gssEapIndicateMechs(OM_uint32 *minor,
 183                     gss_OID_set *mechs)
 184 {
 185     krb5_context krbContext;
 186     OM_uint32 major, tmpMinor;
 187     krb5_enctype *etypes;
 188     int i;
 189
 190     GSSEAP_KRB_INIT(&krbContext);
 191
 192     *minor = krb5_get_permitted_enctypes(krbContext, &etypes);
 193     if (*minor != 0) {
 194         return GSS_S_FAILURE;
 195     }
 196
 197     major = gss_create_empty_oid_set(minor, mechs);
 198     if (GSS_ERROR(major)) {
 199         GSSEAP_FREE(etypes);
 200         return major;
 201     }
 202
 203     for (i = 0; etypes[i] != ENCTYPE_NULL; i++) {
 204         gss_OID mechOid;
 205
 206         /* XXX currently we aren't equipped to encode these enctypes */
 207         if (etypes[i] < 0 || etypes[i] > 127)
 208             continue;
 209
 210         major = gssEapEnctypeToOid(minor, etypes[i], &mechOid);
 211         if (GSS_ERROR(major))
 212             break;
 213
 214         major = gss_add_oid_set_member(minor, mechOid, mechs);
 215         if (GSS_ERROR(major))
 216             break;
 217
 218         gss_release_oid(&tmpMinor, &mechOid);
 219     }
 220
 221     GSSEAP_FREE(etypes);
 222
 223     *minor = 0;
 224     return major;
 225 }
 226
 227 OM_uint32
 228 gssEapDefaultMech(OM_uint32 *minor,
 229                   gss_OID *oid)
 230 {
 231     gss_OID_set mechs;
 232     OM_uint32 major, tmpMinor;
 233
 234     major = gssEapIndicateMechs(minor, &mechs);
 235     if (GSS_ERROR(major)) {
 236         return major;
 237     }
 238
 239     if (mechs->count == 0) {
 240         gss_release_oid_set(&tmpMinor, &mechs);
 241         return GSS_S_BAD_MECH;
 242     }
 243
 244     if (!internalizeOid(&mechs->elements[0], oid)) {
 245         /* don't double-free if we didn't internalize it */
 246         mechs->elements[0].length = 0;
 247         mechs->elements[0].elements = NULL;
 248     }
 249
 250     gss_release_oid_set(&tmpMinor, &mechs);
 251
 252     *minor = 0;
 253     return GSS_S_COMPLETE;
 254 }
 255
 256 static int
 257 internalizeOid(const gss_OID oid,
 258                gss_OID *const pInternalizedOid)
 259 {
 260     int i;
 261
 262     *pInternalizedOid = GSS_C_NO_OID;
 263
 264     for (i = 0;
 265          i < sizeof(gssEapMechOids) / sizeof(gssEapMechOids[0]);
 266          i++) {
 267         if (oidEqual(oid, &gssEapMechOids[i])) {
 268             *pInternalizedOid = (const gss_OID)&gssEapMechOids[i];
 269             break;
 270         }
 271     }
 272
 273     if (*pInternalizedOid == GSS_C_NO_OID) {
 274         if (oidEqual(oid, GSS_EAP_NT_EAP_NAME))
 275             *pInternalizedOid = (const gss_OID)GSS_EAP_NT_EAP_NAME;
 276     }
 277
 278     if (*pInternalizedOid == GSS_C_NO_OID) {
 279         *pInternalizedOid = oid;
 280         return 0;
 281     }
 282
 283     return 1;
 284 }
 285
 286 OM_uint32
 287 gssEapReleaseOid(OM_uint32 *minor, gss_OID *oid)
 288 {
 289     gss_OID internalizedOid = GSS_C_NO_OID;
 290
 291     *minor = 0;
 292
 293     if (internalizeOid(*oid, &internalizedOid)) {
 294         /* OID was internalized, so we can mark it as "freed" */
 295         *oid = GSS_C_NO_OID;
 296         return GSS_S_COMPLETE;
 297     }
 298
 299     /* we don't know about this OID */
 300     return GSS_S_CONTINUE_NEEDED;
 301 }
 302
 303 OM_uint32
 304 gssEapCanonicalizeOid(OM_uint32 *minor,
 305                       const gss_OID oid,
 306                       OM_uint32 flags,
 307                       gss_OID *pOid)
 308 {
 309     OM_uint32 major;
 310     int mapToNull = 0;
 311
 312     major = GSS_S_COMPLETE;
 313     *minor = 0;
 314     *pOid = GSS_C_NULL_OID;
 315
 316     if (oid == GSS_C_NULL_OID) {
 317         if ((flags & OID_FLAG_NULL_VALID) == 0) {
 318             *minor = GSSEAP_WRONG_MECH;
 319             return GSS_S_BAD_MECH;
 320         } else if (flags & OID_FLAG_MAP_NULL_TO_DEFAULT_MECH) {
 321             return gssEapDefaultMech(minor, pOid);
 322         } else {
 323             mapToNull = 1;
 324         }
 325     } else if (oidEqual(oid, GSS_EAP_MECHANISM)) {
 326         if ((flags & OID_FLAG_FAMILY_MECH_VALID) == 0) {
 327             *minor = GSSEAP_WRONG_MECH;
 328             return GSS_S_BAD_MECH;
 329         } else if (flags & OID_FLAG_MAP_FAMILY_MECH_TO_NULL) {
 330             mapToNull = 1;
 331         }
 332     } else if (!gssEapIsConcreteMechanismOid(oid)) {
 333         *minor = GSSEAP_WRONG_MECH;
 334         return GSS_S_BAD_MECH;
 335     }
 336
 337     if (!mapToNull) {
 338         if (!internalizeOid(oid, pOid))
 339             major = duplicateOid(minor, oid, pOid);
 340     }
 341
 342     return major;
 343 }
 344
 345 static gss_buffer_desc gssEapSaslMechs[] = {
 346     { sizeof("EAP") - 1,        "EAP",       }, /* not used */
 347     { sizeof("EAP-AES128") - 1, "EAP-AES128" },
 348     { sizeof("EAP-AES256") - 1, "EAP-AES256" },
 349 };
 350
 351 gss_buffer_t
 352 gssEapOidToSaslName(const gss_OID oid)
 353 {
 354     size_t i;
 355
 356     for (i = 1; i < sizeof(gssEapMechOids)/sizeof(gssEapMechOids[0]); i++) {
 357         if (oidEqual(&gssEapMechOids[i], oid))
 358             return &gssEapSaslMechs[i];
 359     }
 360
 361     return GSS_C_NO_BUFFER;
 362 }
 363
 364 gss_OID
 365 gssEapSaslNameToOid(const gss_buffer_t name)
 366 {
 367     size_t i;
 368
 369     for (i = 1; i < sizeof(gssEapSaslMechs)/sizeof(gssEapSaslMechs[0]); i++) {
 370         if (bufferEqual(&gssEapSaslMechs[i], name))
 371             return &gssEapMechOids[i];
 372     }
 373
 374     return GSS_C_NO_OID;
 375 }