lustre/utils/gss/context_lucid.c

   1 /*
   2  * COPYRIGHT (c) 2006
   3  * The Regents of the University of Michigan
   4  * ALL RIGHTS RESERVED
   5  *
   6  * Permission is granted to use, copy, create derivative works
   7  * and redistribute this software and such derivative works
   8  * for any purpose, so long as the name of The University of
   9  * Michigan is not used in any advertising or publicity
  10  * pertaining to the use of distribution of this software
  11  * without specific, written prior authorization.  If the
  12  * above copyright notice or any other identification of the
  13  * University of Michigan is included in any copy of any
  14  * portion of this software, then the disclaimer below must
  15  * also be included.
  16  *
  17  * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
  18  * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
  19  * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
  20  * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
  21  * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
  22  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
  23  * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
  24  * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
  25  * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
  26  * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
  27  * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGES.
  29  */
  30
  31 #include "config.h"
  32
  33 #ifdef HAVE_LUCID_CONTEXT_SUPPORT
  34
  35 /*
  36  * Newer versions of MIT and Heimdal have lucid context support.
  37  * We can use common code if it is supported.
  38  */
  39
  40 #include <stdio.h>
  41 #include <syslog.h>
  42 #include <string.h>
  43 #include <errno.h>
  44 #include <stdint.h>
  45 #include <krb5.h>
  46 #include <gssapi/gssapi.h>
  47 #ifndef OM_uint64
  48 typedef uint64_t OM_uint64;
  49 #endif
  50 #include <gssapi/gssapi_krb5.h>
  51
  52 #ifdef _NEW_BUILD_
  53 # include "lgss_utils.h"
  54 #else
  55 # include "gss_util.h"
  56 # include "gss_oids.h"
  57 # include "err_util.h"
  58 #endif
  59 #include "write_bytes.h"
  60 #include "context.h"
  61
  62 extern OM_uint32 gss_export_lucid_sec_context(OM_uint32 *min_stat,
  63                                               gss_ctx_id_t *ctx,
  64                                               OM_uint32 version,
  65                                               void **kctx);
  66 extern OM_uint32 gss_free_lucid_sec_context(OM_uint32 *min_stat,
  67                                             gss_ctx_id_t ctx,
  68                                             void *kctx);
  69
  70 static int
  71 write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
  72 {
  73         gss_buffer_desc tmp;
  74
  75         if (WRITE_BYTES(p, end, key->type)) return -1;
  76         tmp.length = key->length;
  77         tmp.value = key->data;
  78         if (write_buffer(p, end, &tmp)) return -1;
  79         return 0;
  80 }
  81
  82 static int
  83 prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
  84         gss_buffer_desc *buf)
  85 {
  86         char *p, *end;
  87         static int constant_zero = 0;
  88         unsigned char fakeseed[16] = { 0 };
  89         uint32_t word_send_seq;
  90         gss_krb5_lucid_key_t enc_key;
  91         int i;
  92         char *skd, *dkd;
  93
  94         /*
  95          * The new Kerberos interface to get the gss context
  96          * does not include the seed or seed_init fields
  97          * because we never really use them.  But for now,
  98          * send down a fake buffer so we can use the same
  99          * interface to the kernel.
 100          */
 101         memset(&enc_key, 0, sizeof(enc_key));
 102
 103         if (!(buf->value = calloc(1, MAX_CTX_LEN)))
 104                 goto out_err;
 105         p = buf->value;
 106         end = buf->value + MAX_CTX_LEN;
 107
 108         if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
 109
 110         /* seed_init and seed not used by kernel anyway */
 111         if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
 112         if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
 113
 114         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
 115         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
 116         if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
 117         word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
 118         if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
 119         if (write_oid(&p, end, &krb5oid)) goto out_err;
 120
 121 #ifdef HAVE_HEIMDAL
 122         /*
 123          * The kernel gss code expects des-cbc-raw for all flavors of des.
 124          * The keytype from MIT has this type, but Heimdal does not.
 125          * Force the Heimdal keytype to 4 (des-cbc-raw).
 126          * Note that the rfc1964 version only supports DES enctypes.
 127          */
 128         if (lctx->rfc1964_kd.ctx_key.type != 4) {
 129                 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
 130                          __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
 131                 lctx->rfc1964_kd.ctx_key.type = 4;
 132         }
 133 #endif
 134         printerr(2, "%s: serializing keys with enctype %d and length %d\n",
 135                  __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
 136                  lctx->rfc1964_kd.ctx_key.length);
 137
 138         /* derive the encryption key and copy it into buffer */
 139         enc_key.type = lctx->rfc1964_kd.ctx_key.type;
 140         enc_key.length = lctx->rfc1964_kd.ctx_key.length;
 141         if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
 142                 goto out_err;
 143         skd = (char *) lctx->rfc1964_kd.ctx_key.data;
 144         dkd = (char *) enc_key.data;
 145         for (i = 0; i < enc_key.length; i++)
 146                 dkd[i] = skd[i] ^ 0xf0;
 147         if (write_lucid_keyblock(&p, end, &enc_key))
 148                 goto out_err;
 149         if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
 150                 goto out_err;
 151         free(enc_key.data);
 152
 153         buf->length = p - (char *)buf->value;
 154         return 0;
 155 out_err:
 156         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 157         if (buf->value) {
 158                 free(buf->value);
 159                 buf->value = NULL;
 160         }
 161         buf->length = 0;
 162         if (enc_key.data) free(enc_key.data);
 163         return -1;
 164 }
 165
 166 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 167 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 168
 169 /* for 3DES */
 170 #define KG_USAGE_SEAL 22
 171 #define KG_USAGE_SIGN 23
 172 #define KG_USAGE_SEQ  24
 173
 174 /* for rfc???? */
 175 #define KG_USAGE_ACCEPTOR_SEAL  22
 176 #define KG_USAGE_ACCEPTOR_SIGN  23
 177 #define KG_USAGE_INITIATOR_SEAL 24
 178 #define KG_USAGE_INITIATOR_SIGN 25
 179
 180 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
 181 enum seal_alg {
 182   SEAL_ALG_NONE            = 0xffff,
 183   SEAL_ALG_DES             = 0x0000,
 184   SEAL_ALG_1               = 0x0001, /* not published */
 185   SEAL_ALG_MICROSOFT_RC4   = 0x0010, /* microsoft w2k;  */
 186   SEAL_ALG_DES3KD          = 0x0002
 187 };
 188
 189 #define KEY_USAGE_SEED_ENCRYPTION       0xAA
 190 #define KEY_USAGE_SEED_INTEGRITY        0x55
 191 #define KEY_USAGE_SEED_CHECKSUM         0x99
 192 #define K5CLENGTH 5
 193
 194 /* Flags for version 2 context flags */
 195 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 196 #define KRB5_CTX_FLAG_CFX               0x00000002
 197 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 198
 199 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 200 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 201 /*
 202  * We don't have "legal" access to these MIT-only
 203  * structures located in libk5crypto
 204  */
 205 extern void *krb5int_enc_arcfour;
 206 extern void *krb5int_enc_des3;
 207 extern void *krb5int_enc_aes128;
 208 extern void *krb5int_enc_aes256;
 209
 210 static void
 211 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
 212 {
 213         memset(kout, '\0', sizeof(kout));
 214 #ifdef HAVE_KRB5
 215         kout->enctype = lin->type;
 216         kout->length = lin->length;
 217         kout->contents = lin->data;
 218 #else
 219         kout->keytype = lin->type;
 220         kout->keyvalue.length = lin->length;
 221         kout->keyvalue.data = lin->data;
 222 #endif
 223 }
 224
 225 static void
 226 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
 227 {
 228         memset(lout, '\0', sizeof(lout));
 229 #ifdef HAVE_KRB5
 230         lout->type = kin->enctype;
 231         lout->length = kin->length;
 232         lout->data = kin->contents;
 233 #else
 234         lout->type = kin->keytype;
 235         lout->length = kin->keyvalue.length;
 236         memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
 237 #endif
 238 }
 239
 240 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 241 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 242 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 243 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 244 /*
 245  * Function to derive a new key from a given key and given constant data.
 246  */
 247 static krb5_error_code
 248 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
 249                  int usage, char extra)
 250 {
 251         krb5_error_code code;
 252         unsigned char constant_data[K5CLENGTH];
 253         krb5_data datain;
 254         int keylength;
 255         void *enc;
 256         krb5_keyblock kin, kout;  /* must send krb5_keyblock, not lucid! */
 257 #if defined(HAVE_HEIMDAL) || HAVE_KRB5INT_DERIVE_KEY
 258         krb5_context kcontext;
 259 #endif
 260 #if HAVE_KRB5INT_DERIVE_KEY
 261         krb5_key key_in, key_out;
 262 #endif
 263 #ifdef HAVE_HEIMDAL
 264         krb5_keyblock *outkey;
 265 #endif
 266
 267         /*
 268          * XXX Hack alert.  We don't have "legal" access to these
 269          * values and structures located in libk5crypto
 270          */
 271         switch (in->type) {
 272         case ENCTYPE_DES3_CBC_SHA1:
 273 #ifdef HAVE_KRB5
 274         case ENCTYPE_DES3_CBC_RAW:
 275 #endif
 276                 keylength = 24;
 277 #ifdef HAVE_KRB5
 278                 enc = &krb5int_enc_des3;
 279 #endif
 280                 break;
 281         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 282                 keylength = 16;
 283 #ifdef HAVE_KRB5
 284                 enc = &krb5int_enc_aes128;
 285 #endif
 286                 break;
 287         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 288                 keylength = 32;
 289 #ifdef HAVE_KRB5
 290                 enc = &krb5int_enc_aes256;
 291 #endif
 292                 break;
 293         default:
 294                 code = KRB5_BAD_ENCTYPE;
 295                 goto out;
 296         }
 297
 298         /* allocate memory for output key */
 299         if ((out->data = malloc(keylength)) == NULL) {
 300                 code = ENOMEM;
 301                 goto out;
 302         }
 303         out->length = keylength;
 304         out->type = in->type;
 305
 306         /* Convert to correct format for call to krb5_derive_key */
 307         key_lucid_to_krb5(in, &kin);
 308         key_lucid_to_krb5(out, &kout);
 309
 310         datain.data = (char *) constant_data;
 311         datain.length = K5CLENGTH;
 312
 313         ((char *)(datain.data))[0] = (usage>>24)&0xff;
 314         ((char *)(datain.data))[1] = (usage>>16)&0xff;
 315         ((char *)(datain.data))[2] = (usage>>8)&0xff;
 316         ((char *)(datain.data))[3] = usage&0xff;
 317
 318         ((char *)(datain.data))[4] = (char) extra;
 319
 320 #ifdef HAVE_KRB5
 321 #if HAVE_KRB5INT_DERIVE_KEY
 322         code = krb5_init_context(&kcontext);
 323         if (code) {
 324                 free(out->data);
 325                 out->data = NULL;
 326                 goto out;
 327         }
 328         code = krb5_k_create_key(kcontext, &kin, &key_in);
 329         if (code) {
 330                 free(out->data);
 331                 out->data = NULL;
 332                 goto out;
 333         }
 334         code = krb5_k_create_key(kcontext, &kout, &key_out);
 335         if (code) {
 336                 free(out->data);
 337                 out->data = NULL;
 338                 goto out;
 339         }
 340         code = krb5int_derive_key(enc, key_in, &key_out, &datain,
 341                                   DERIVE_RFC3961);
 342 #else  /* !HAVE_KRB5INT_DERIVE_KEY */
 343         code = krb5_derive_key(enc, &kin, &kout, &datain);
 344 #endif  /* HAVE_KRB5INT_DERIVE_KEY */
 345 #else   /* !defined(HAVE_KRB5) */
 346         if ((code = krb5_init_context(&kcontext))) {
 347         }
 348         code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
 349 #endif  /* defined(HAVE_KRB5) */
 350         if (code) {
 351                 free(out->data);
 352                 out->data = NULL;
 353                 goto out;
 354         }
 355 #ifdef HAVE_KRB5
 356         key_krb5_to_lucid(&kout, out);
 357 #if HAVE_KRB5INT_DERIVE_KEY
 358         krb5_free_context(kcontext);
 359 #endif  /* HAVE_KRB5INT_DERIVE_KEY */
 360 #else   /* !defined(HAVE_KRB5) */
 361         key_krb5_to_lucid(outkey, out);
 362         krb5_free_keyblock(kcontext, outkey);
 363         krb5_free_context(kcontext);
 364 #endif  /* defined(HAVE_KRB5) */
 365
 366   out:
 367         if (code)
 368                 printerr(0, "ERROR: %s: returning error %d (%s)\n",
 369                          __FUNCTION__, code, error_message(code));
 370         return (code);
 371 }
 372
 373
 374 /*
 375  * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
 376  * to send to the kernel for newer encryption types -- or for DES3.
 377  *
 378  * The new format is:
 379  *
 380  *      u32 initiate;                   ( whether we are the initiator or not )
 381  *      s32 endtime;
 382  *      u32 flags;
 383  *      #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 384  *      #define KRB5_CTX_FLAG_CFX               0x00000002
 385  *      #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 386  *      u64 seq_send;
 387  *      u32  enctype;                   ( encrption type of keys )
 388  *      u32  size_of_each_key;          ( size of each key in bytes )
 389  *      u32  number_of_keys;            ( N -- should always be 3 for now )
 390  *      keydata-1;                      ( Ke )
 391  *      keydata-2;                      ( Ki )
 392  *      keydata-3;                      ( Kc )
 393  *
 394  */
 395 static int
 396 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
 397                             gss_buffer_desc *buf)
 398 {
 399         static int constant_two = 2;
 400         char *p, *end;
 401         uint32_t v2_flags = 0;
 402         gss_krb5_lucid_key_t enc_key;
 403         gss_krb5_lucid_key_t derived_key;
 404         gss_buffer_desc fakeoid;
 405         uint32_t enctype;
 406         uint32_t keysize;
 407         uint32_t numkeys;
 408
 409         memset(&enc_key, 0, sizeof(enc_key));
 410         memset(&fakeoid, 0, sizeof(fakeoid));
 411
 412         if (!(buf->value = calloc(1, MAX_CTX_LEN)))
 413                 goto out_err;
 414         p = buf->value;
 415         end = buf->value + MAX_CTX_LEN;
 416
 417         /* Version 2 */
 418         if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
 419         if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
 420
 421         if (lctx->initiate)
 422                 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
 423         if (lctx->protocol != 0)
 424                 v2_flags |= KRB5_CTX_FLAG_CFX;
 425         if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
 426                 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
 427
 428         if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
 429
 430         if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
 431
 432         /* Protocol 0 here implies DES3 or RC4 */
 433         printerr(3, "protocol %d\n", lctx->protocol);
 434         if (lctx->protocol == 0) {
 435                 enctype = lctx->rfc1964_kd.ctx_key.type;
 436 #ifdef HAVE_HEIMDAL
 437                 /*
 438                  * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
 439                  * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
 440                  * Force the Heimdal enctype to 6.
 441                  */
 442                 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
 443                         printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
 444                                  __FUNCTION__, enctype, 6);
 445
 446                         enctype = 6;
 447                 }
 448 #endif
 449                 keysize = lctx->rfc1964_kd.ctx_key.length;
 450                 numkeys = 3;    /* XXX is always gonna be three? */
 451         } else {
 452                 if (lctx->cfx_kd.have_acceptor_subkey) {
 453                         enctype = lctx->cfx_kd.acceptor_subkey.type;
 454                         keysize = lctx->cfx_kd.acceptor_subkey.length;
 455                 } else {
 456                         enctype = lctx->cfx_kd.ctx_key.type;
 457                         keysize = lctx->cfx_kd.ctx_key.length;
 458                 }
 459                 numkeys = 3;
 460         }
 461         printerr(3, "serializing %d keys with enctype %d and size %d\n",
 462                  numkeys, enctype, keysize);
 463         if (WRITE_BYTES(&p, end, enctype)) goto out_err;
 464         if (WRITE_BYTES(&p, end, keysize)) goto out_err;
 465         if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
 466
 467         if (lctx->protocol == 0) {
 468                 /* derive and send down: Ke, Ki, and Kc */
 469                 /* Ke */
 470                 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 471                                 lctx->rfc1964_kd.ctx_key.length))
 472                         goto out_err;
 473
 474                 /* Ki */
 475                 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 476                                 lctx->rfc1964_kd.ctx_key.length))
 477                         goto out_err;
 478
 479                 /* Kc */
 480                 /*
 481                  * RC4 is special, it dosen't need key derivation. Actually
 482                  * the Ke is based on plain text. Here we just let all three
 483                  * key identical, kernel will handle everything. --ericm
 484                  */
 485                 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
 486                         if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 487                                         lctx->rfc1964_kd.ctx_key.length))
 488                                 goto out_err;
 489                 } else {
 490                         if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
 491                                         &derived_key,
 492                                         KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
 493                                 goto out_err;
 494                         if (write_bytes(&p, end, derived_key.data,
 495                                         derived_key.length))
 496                                 goto out_err;
 497                         free(derived_key.data);
 498                 }
 499         } else {
 500                 gss_krb5_lucid_key_t *keyptr;
 501                 uint32_t sign_usage, seal_usage;
 502
 503                 if (lctx->cfx_kd.have_acceptor_subkey)
 504                         keyptr = &lctx->cfx_kd.acceptor_subkey;
 505                 else
 506                         keyptr = &lctx->cfx_kd.ctx_key;
 507
 508 #if 0
 509                 if (lctx->initiate == 1) {
 510                         sign_usage = KG_USAGE_INITIATOR_SIGN;
 511                         seal_usage = KG_USAGE_INITIATOR_SEAL;
 512                 } else {
 513                         sign_usage = KG_USAGE_ACCEPTOR_SIGN;
 514                         seal_usage = KG_USAGE_ACCEPTOR_SEAL;
 515                 }
 516 #else
 517                 /* FIXME
 518                  * These are from rfc4142, but I don't understand: if we supply
 519                  * different 'usage' value for client & server, then the peers
 520                  * will have different derived keys. How could this work?
 521                  *
 522                  * Here we simply use old SIGN/SEAL values until we find the
 523                  * answer.  --ericm
 524                  * FIXME
 525                  */
 526                 sign_usage = KG_USAGE_SIGN;
 527                 seal_usage = KG_USAGE_SEAL;
 528 #endif
 529
 530                 /* derive and send down: Ke, Ki, and Kc */
 531
 532                 /* Ke */
 533                 if (derive_key_lucid(keyptr, &derived_key,
 534                                seal_usage, KEY_USAGE_SEED_ENCRYPTION))
 535                         goto out_err;
 536                 if (write_bytes(&p, end, derived_key.data,
 537                                 derived_key.length))
 538                         goto out_err;
 539                 free(derived_key.data);
 540
 541                 /* Ki */
 542                 if (derive_key_lucid(keyptr, &derived_key,
 543                                seal_usage, KEY_USAGE_SEED_INTEGRITY))
 544                         goto out_err;
 545                 if (write_bytes(&p, end, derived_key.data,
 546                                 derived_key.length))
 547                         goto out_err;
 548                 free(derived_key.data);
 549
 550                 /* Kc */
 551                 if (derive_key_lucid(keyptr, &derived_key,
 552                                sign_usage, KEY_USAGE_SEED_CHECKSUM))
 553                         goto out_err;
 554                 if (write_bytes(&p, end, derived_key.data,
 555                                 derived_key.length))
 556                         goto out_err;
 557                 free(derived_key.data);
 558         }
 559
 560         buf->length = p - (char *)buf->value;
 561         return 0;
 562
 563 out_err:
 564         printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
 565                  __FUNCTION__);
 566         if (buf->value) {
 567                 free(buf->value);
 568                 buf->value = NULL;
 569         }
 570         buf->length = 0;
 571         if (enc_key.data) {
 572                 free(enc_key.data);
 573                 enc_key.data = NULL;
 574         }
 575         return -1;
 576 }
 577 int
 578 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
 579 {
 580         OM_uint32 maj_stat, min_stat;
 581         void *return_ctx = 0;
 582         OM_uint32 vers;
 583         gss_krb5_lucid_context_v1_t *lctx = 0;
 584         int retcode = 0;
 585
 586         printerr(3, "lucid version!\n");
 587         maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
 588                                                 1, &return_ctx);
 589         if (maj_stat != GSS_S_COMPLETE) {
 590                 pgsserr("gss_export_lucid_sec_context",
 591                         maj_stat, min_stat, &krb5oid);
 592                 goto out_err;
 593         }
 594
 595         /* Check the version returned, we only support v1 right now */
 596         vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
 597         switch (vers) {
 598         case 1:
 599                 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
 600                 break;
 601         default:
 602                 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
 603                         vers);
 604                 goto out_err;
 605                 break;
 606         }
 607
 608         /*
 609          * Now lctx points to a lucid context that we can send down to kernel
 610          *
 611          * Note: we send down different information to the kernel depending
 612          * on the protocol version and the enctyption type.
 613          * For protocol version 0 with all enctypes besides DES3, we use
 614          * the original format.  For protocol version != 0 or DES3, we
 615          * send down the new style information.
 616          */
 617
 618         if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
 619                 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
 620         else
 621                 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
 622
 623         maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
 624         if (maj_stat != GSS_S_COMPLETE) {
 625                 pgsserr("gss_export_lucid_sec_context",
 626                         maj_stat, min_stat, &krb5oid);
 627                 printerr(0, "WARN: failed to free lucid sec context\n");
 628         }
 629
 630         if (retcode) {
 631                 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
 632                          __FUNCTION__, retcode);
 633                 goto out_err;
 634         }
 635
 636         return 0;
 637
 638 out_err:
 639         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 640         return -1;
 641 }
 642
 643
 644
 645 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */