lustre/utils/gss/context_lucid.c

   1 /*
   2  * COPYRIGHT (c) 2006 The Regents of the University of Michigan
   3  * ALL RIGHTS RESERVED
   4  *
   5  * Copyright (c) 2014, Intel Corporation.
   6  *
   7  * Permission is granted to use, copy, create derivative works
   8  * and redistribute this software and such derivative works
   9  * for any purpose, so long as the name of The University of
  10  * Michigan is not used in any advertising or publicity
  11  * pertaining to the use of distribution of this software
  12  * without specific, written prior authorization.  If the
  13  * above copyright notice or any other identification of the
  14  * University of Michigan is included in any copy of any
  15  * portion of this software, then the disclaimer below must
  16  * also be included.
  17  *
  18  * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
  19  * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
  20  * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
  21  * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
  22  * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
  24  * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
  25  * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
  26  * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
  27  * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
  28  * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGES.
  30  */
  31
  32 #include "config.h"
  33
  34 #ifdef HAVE_LUCID_CONTEXT_SUPPORT
  35
  36 /*
  37  * Newer versions of MIT and Heimdal have lucid context support.
  38  * We can use common code if it is supported.
  39  */
  40
  41 #include <stdio.h>
  42 #include <syslog.h>
  43 #include <string.h>
  44 #include <errno.h>
  45 #include <stdint.h>
  46 #include <krb5.h>
  47 #include <gssapi/gssapi.h>
  48 #ifndef OM_uint64
  49 typedef uint64_t OM_uint64;
  50 #endif
  51 #include <gssapi/gssapi_krb5.h>
  52
  53 #ifdef _NEW_BUILD_
  54 # include "lgss_utils.h"
  55 #else
  56 # include "gss_util.h"
  57 # include "gss_oids.h"
  58 # include "err_util.h"
  59 #endif
  60 #include "write_bytes.h"
  61 #include "context.h"
  62
  63 extern OM_uint32 gss_export_lucid_sec_context(OM_uint32 *min_stat,
  64                                               gss_ctx_id_t *ctx,
  65                                               OM_uint32 version,
  66                                               void **kctx);
  67 extern OM_uint32 gss_free_lucid_sec_context(OM_uint32 *min_stat,
  68                                             gss_ctx_id_t ctx,
  69                                             void *kctx);
  70
  71 static int
  72 write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
  73 {
  74         gss_buffer_desc tmp;
  75
  76         if (WRITE_BYTES(p, end, key->type)) return -1;
  77         tmp.length = key->length;
  78         tmp.value = key->data;
  79         if (write_buffer(p, end, &tmp)) return -1;
  80         return 0;
  81 }
  82
  83 static int
  84 prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
  85         gss_buffer_desc *buf)
  86 {
  87         char *p, *end;
  88         static int constant_zero = 0;
  89         unsigned char fakeseed[16] = { 0 };
  90         uint32_t word_send_seq;
  91         gss_krb5_lucid_key_t enc_key;
  92         int i;
  93         char *skd, *dkd;
  94
  95         /*
  96          * The new Kerberos interface to get the gss context
  97          * does not include the seed or seed_init fields
  98          * because we never really use them.  But for now,
  99          * send down a fake buffer so we can use the same
 100          * interface to the kernel.
 101          */
 102         memset(&enc_key, 0, sizeof(enc_key));
 103
 104         if (!(buf->value = calloc(1, MAX_CTX_LEN)))
 105                 goto out_err;
 106         p = buf->value;
 107         end = buf->value + MAX_CTX_LEN;
 108
 109         if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
 110
 111         /* seed_init and seed not used by kernel anyway */
 112         if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
 113         if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
 114
 115         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
 116         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
 117         if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
 118         word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
 119         if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
 120         if (write_oid(&p, end, &krb5oid)) goto out_err;
 121
 122 #ifdef HAVE_HEIMDAL
 123         /*
 124          * The kernel gss code expects des-cbc-raw for all flavors of des.
 125          * The keytype from MIT has this type, but Heimdal does not.
 126          * Force the Heimdal keytype to 4 (des-cbc-raw).
 127          * Note that the rfc1964 version only supports DES enctypes.
 128          */
 129         if (lctx->rfc1964_kd.ctx_key.type != 4) {
 130                 printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
 131                          __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
 132                 lctx->rfc1964_kd.ctx_key.type = 4;
 133         }
 134 #endif
 135         printerr(2, "%s: serializing keys with enctype %d and length %d\n",
 136                  __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
 137                  lctx->rfc1964_kd.ctx_key.length);
 138
 139         /* derive the encryption key and copy it into buffer */
 140         enc_key.type = lctx->rfc1964_kd.ctx_key.type;
 141         enc_key.length = lctx->rfc1964_kd.ctx_key.length;
 142         if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
 143                 goto out_err;
 144         skd = (char *) lctx->rfc1964_kd.ctx_key.data;
 145         dkd = (char *) enc_key.data;
 146         for (i = 0; i < enc_key.length; i++)
 147                 dkd[i] = skd[i] ^ 0xf0;
 148         if (write_lucid_keyblock(&p, end, &enc_key))
 149                 goto out_err;
 150         if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
 151                 goto out_err;
 152         free(enc_key.data);
 153
 154         buf->length = p - (char *)buf->value;
 155         return 0;
 156 out_err:
 157         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 158         if (buf->value) {
 159                 free(buf->value);
 160                 buf->value = NULL;
 161         }
 162         buf->length = 0;
 163         if (enc_key.data) free(enc_key.data);
 164         return -1;
 165 }
 166
 167 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 168 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 169
 170 /* for 3DES */
 171 #define KG_USAGE_SEAL 22
 172 #define KG_USAGE_SIGN 23
 173 #define KG_USAGE_SEQ  24
 174
 175 /* for rfc???? */
 176 #define KG_USAGE_ACCEPTOR_SEAL  22
 177 #define KG_USAGE_ACCEPTOR_SIGN  23
 178 #define KG_USAGE_INITIATOR_SEAL 24
 179 #define KG_USAGE_INITIATOR_SIGN 25
 180
 181 /* Lifted from mit src/lib/gssapi/krb5/gssapiP_krb5.h */
 182 enum seal_alg {
 183   SEAL_ALG_NONE            = 0xffff,
 184   SEAL_ALG_DES             = 0x0000,
 185   SEAL_ALG_1               = 0x0001, /* not published */
 186   SEAL_ALG_MICROSOFT_RC4   = 0x0010, /* microsoft w2k;  */
 187   SEAL_ALG_DES3KD          = 0x0002
 188 };
 189
 190 #define KEY_USAGE_SEED_ENCRYPTION       0xAA
 191 #define KEY_USAGE_SEED_INTEGRITY        0x55
 192 #define KEY_USAGE_SEED_CHECKSUM         0x99
 193 #define K5CLENGTH 5
 194
 195 /* Flags for version 2 context flags */
 196 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 197 #define KRB5_CTX_FLAG_CFX               0x00000002
 198 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 199
 200 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 201 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 202 /*
 203  * We don't have "legal" access to these MIT-only
 204  * structures located in libk5crypto
 205  */
 206 extern void *krb5int_enc_arcfour;
 207 extern void *krb5int_enc_des3;
 208 extern void *krb5int_enc_aes128;
 209 extern void *krb5int_enc_aes256;
 210
 211 static void
 212 key_lucid_to_krb5(const gss_krb5_lucid_key_t *lin, krb5_keyblock *kout)
 213 {
 214         memset(kout, 0, sizeof(*kout));
 215 #ifdef HAVE_KRB5
 216         kout->enctype = lin->type;
 217         kout->length = lin->length;
 218         kout->contents = lin->data;
 219 #else
 220         kout->keytype = lin->type;
 221         kout->keyvalue.length = lin->length;
 222         kout->keyvalue.data = lin->data;
 223 #endif
 224 }
 225
 226 static void
 227 key_krb5_to_lucid(const krb5_keyblock *kin, gss_krb5_lucid_key_t *lout)
 228 {
 229         memset(lout, 0, sizeof(*lout));
 230 #ifdef HAVE_KRB5
 231         lout->type = kin->enctype;
 232         lout->length = kin->length;
 233         lout->data = kin->contents;
 234 #else
 235         lout->type = kin->keytype;
 236         lout->length = kin->keyvalue.length;
 237         memcpy(lout->data, kin->keyvalue.data, kin->keyvalue.length);
 238 #endif
 239 }
 240
 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 /* XXX Hack alert! XXX  Do NOT submit upstream! XXX */
 245 /*
 246  * Function to derive a new key from a given key and given constant data.
 247  */
 248 static krb5_error_code
 249 derive_key_lucid(const gss_krb5_lucid_key_t *in, gss_krb5_lucid_key_t *out,
 250                  int usage, char extra)
 251 {
 252         krb5_error_code code;
 253         unsigned char constant_data[K5CLENGTH];
 254         krb5_data datain;
 255         int keylength;
 256         void *enc;
 257         krb5_keyblock kin, kout;  /* must send krb5_keyblock, not lucid! */
 258 #if defined(HAVE_HEIMDAL) || HAVE_KRB5INT_DERIVE_KEY
 259         krb5_context kcontext;
 260 #endif
 261 #if HAVE_KRB5INT_DERIVE_KEY
 262         krb5_key key_in, key_out;
 263 #endif
 264 #ifdef HAVE_HEIMDAL
 265         krb5_keyblock *outkey;
 266 #endif
 267
 268         /*
 269          * XXX Hack alert.  We don't have "legal" access to these
 270          * values and structures located in libk5crypto
 271          */
 272         switch (in->type) {
 273         case ENCTYPE_DES3_CBC_SHA1:
 274 #ifdef HAVE_KRB5
 275         case ENCTYPE_DES3_CBC_RAW:
 276 #endif
 277                 keylength = 24;
 278 #ifdef HAVE_KRB5
 279                 enc = &krb5int_enc_des3;
 280 #endif
 281                 break;
 282         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 283                 keylength = 16;
 284 #ifdef HAVE_KRB5
 285                 enc = &krb5int_enc_aes128;
 286 #endif
 287                 break;
 288         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 289                 keylength = 32;
 290 #ifdef HAVE_KRB5
 291                 enc = &krb5int_enc_aes256;
 292 #endif
 293                 break;
 294         default:
 295                 code = KRB5_BAD_ENCTYPE;
 296                 goto out;
 297         }
 298
 299         /* allocate memory for output key */
 300         if ((out->data = malloc(keylength)) == NULL) {
 301                 code = ENOMEM;
 302                 goto out;
 303         }
 304         out->length = keylength;
 305         out->type = in->type;
 306
 307         /* Convert to correct format for call to krb5_derive_key */
 308         key_lucid_to_krb5(in, &kin);
 309         key_lucid_to_krb5(out, &kout);
 310
 311         datain.data = (char *) constant_data;
 312         datain.length = K5CLENGTH;
 313
 314         ((char *)(datain.data))[0] = (usage>>24)&0xff;
 315         ((char *)(datain.data))[1] = (usage>>16)&0xff;
 316         ((char *)(datain.data))[2] = (usage>>8)&0xff;
 317         ((char *)(datain.data))[3] = usage&0xff;
 318
 319         ((char *)(datain.data))[4] = (char) extra;
 320
 321 #ifdef HAVE_KRB5
 322 #if HAVE_KRB5INT_DERIVE_KEY
 323         code = krb5_init_context(&kcontext);
 324         if (code) {
 325                 free(out->data);
 326                 out->data = NULL;
 327                 goto out;
 328         }
 329         code = krb5_k_create_key(kcontext, &kin, &key_in);
 330         if (code) {
 331                 free(out->data);
 332                 out->data = NULL;
 333                 goto out;
 334         }
 335         code = krb5_k_create_key(kcontext, &kout, &key_out);
 336         if (code) {
 337                 free(out->data);
 338                 out->data = NULL;
 339                 goto out;
 340         }
 341         code = krb5int_derive_key(enc, key_in, &key_out, &datain,
 342                                   DERIVE_RFC3961);
 343 #else  /* !HAVE_KRB5INT_DERIVE_KEY */
 344         code = krb5_derive_key(enc, &kin, &kout, &datain);
 345 #endif  /* HAVE_KRB5INT_DERIVE_KEY */
 346 #else   /* !defined(HAVE_KRB5) */
 347         if ((code = krb5_init_context(&kcontext))) {
 348         }
 349         code = krb5_derive_key(kcontext, &kin, in->type, constant_data, K5CLENGTH, &outkey);
 350 #endif  /* defined(HAVE_KRB5) */
 351         if (code) {
 352                 free(out->data);
 353                 out->data = NULL;
 354                 goto out;
 355         }
 356 #ifdef HAVE_KRB5
 357         key_krb5_to_lucid(&kout, out);
 358 #if HAVE_KRB5INT_DERIVE_KEY
 359         krb5_free_context(kcontext);
 360 #endif  /* HAVE_KRB5INT_DERIVE_KEY */
 361 #else   /* !defined(HAVE_KRB5) */
 362         key_krb5_to_lucid(outkey, out);
 363         krb5_free_keyblock(kcontext, outkey);
 364         krb5_free_context(kcontext);
 365 #endif  /* defined(HAVE_KRB5) */
 366
 367   out:
 368         if (code)
 369                 printerr(0, "ERROR: %s: returning error %d (%s)\n",
 370                          __FUNCTION__, code, error_message(code));
 371         return (code);
 372 }
 373
 374
 375 /*
 376  * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
 377  * to send to the kernel for newer encryption types -- or for DES3.
 378  *
 379  * The new format is:
 380  *
 381  *      u32 initiate;                   ( whether we are the initiator or not )
 382  *      s32 endtime;
 383  *      u32 flags;
 384  *      #define KRB5_CTX_FLAG_INITIATOR         0x00000001
 385  *      #define KRB5_CTX_FLAG_CFX               0x00000002
 386  *      #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
 387  *      u64 seq_send;
 388  *      u32  enctype;                   ( encrption type of keys )
 389  *      u32  size_of_each_key;          ( size of each key in bytes )
 390  *      u32  number_of_keys;            ( N -- should always be 3 for now )
 391  *      keydata-1;                      ( Ke )
 392  *      keydata-2;                      ( Ki )
 393  *      keydata-3;                      ( Kc )
 394  *
 395  */
 396 static int
 397 prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
 398                             gss_buffer_desc *buf)
 399 {
 400         static int constant_two = 2;
 401         char *p, *end;
 402         uint32_t v2_flags = 0;
 403         gss_krb5_lucid_key_t enc_key;
 404         gss_krb5_lucid_key_t derived_key;
 405         gss_buffer_desc fakeoid;
 406         uint32_t enctype;
 407         uint32_t keysize;
 408         uint32_t numkeys;
 409
 410         memset(&enc_key, 0, sizeof(enc_key));
 411         memset(&fakeoid, 0, sizeof(fakeoid));
 412
 413         if (!(buf->value = calloc(1, MAX_CTX_LEN)))
 414                 goto out_err;
 415         p = buf->value;
 416         end = buf->value + MAX_CTX_LEN;
 417
 418         /* Version 2 */
 419         if (WRITE_BYTES(&p, end, constant_two)) goto out_err;
 420         if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
 421
 422         if (lctx->initiate)
 423                 v2_flags |= KRB5_CTX_FLAG_INITIATOR;
 424         if (lctx->protocol != 0)
 425                 v2_flags |= KRB5_CTX_FLAG_CFX;
 426         if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
 427                 v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
 428
 429         if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
 430
 431         if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
 432
 433         /* Protocol 0 here implies DES3 or RC4 */
 434         printerr(3, "protocol %d\n", lctx->protocol);
 435         if (lctx->protocol == 0) {
 436                 enctype = lctx->rfc1964_kd.ctx_key.type;
 437 #ifdef HAVE_HEIMDAL
 438                 /*
 439                  * The kernel gss code expects ENCTYPE_DES3_CBC_RAW (6) for
 440                  * 3des keys, but Heimdal key has ENCTYPE_DES3_CBC_SHA1 (16).
 441                  * Force the Heimdal enctype to 6.
 442                  */
 443                 if (enctype == ENCTYPE_DES3_CBC_SHA1) {
 444                         printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
 445                                  __FUNCTION__, enctype, 6);
 446
 447                         enctype = 6;
 448                 }
 449 #endif
 450                 keysize = lctx->rfc1964_kd.ctx_key.length;
 451                 numkeys = 3;    /* XXX is always gonna be three? */
 452         } else {
 453                 if (lctx->cfx_kd.have_acceptor_subkey) {
 454                         enctype = lctx->cfx_kd.acceptor_subkey.type;
 455                         keysize = lctx->cfx_kd.acceptor_subkey.length;
 456                 } else {
 457                         enctype = lctx->cfx_kd.ctx_key.type;
 458                         keysize = lctx->cfx_kd.ctx_key.length;
 459                 }
 460                 numkeys = 3;
 461         }
 462         printerr(3, "serializing %d keys with enctype %d and size %d\n",
 463                  numkeys, enctype, keysize);
 464         if (WRITE_BYTES(&p, end, enctype)) goto out_err;
 465         if (WRITE_BYTES(&p, end, keysize)) goto out_err;
 466         if (WRITE_BYTES(&p, end, numkeys)) goto out_err;
 467
 468         if (lctx->protocol == 0) {
 469                 /* derive and send down: Ke, Ki, and Kc */
 470                 /* Ke */
 471                 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 472                                 lctx->rfc1964_kd.ctx_key.length))
 473                         goto out_err;
 474
 475                 /* Ki */
 476                 if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 477                                 lctx->rfc1964_kd.ctx_key.length))
 478                         goto out_err;
 479
 480                 /* Kc */
 481                 /*
 482                  * RC4 is special, it dosen't need key derivation. Actually
 483                  * the Ke is based on plain text. Here we just let all three
 484                  * key identical, kernel will handle everything. --ericm
 485                  */
 486                 if (lctx->rfc1964_kd.ctx_key.type == ENCTYPE_ARCFOUR_HMAC) {
 487                         if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
 488                                         lctx->rfc1964_kd.ctx_key.length))
 489                                 goto out_err;
 490                 } else {
 491                         if (derive_key_lucid(&lctx->rfc1964_kd.ctx_key,
 492                                         &derived_key,
 493                                         KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM))
 494                                 goto out_err;
 495                         if (write_bytes(&p, end, derived_key.data,
 496                                         derived_key.length))
 497                                 goto out_err;
 498                         free(derived_key.data);
 499                 }
 500         } else {
 501                 gss_krb5_lucid_key_t *keyptr;
 502                 uint32_t sign_usage, seal_usage;
 503
 504                 if (lctx->cfx_kd.have_acceptor_subkey)
 505                         keyptr = &lctx->cfx_kd.acceptor_subkey;
 506                 else
 507                         keyptr = &lctx->cfx_kd.ctx_key;
 508
 509 #if 0
 510                 if (lctx->initiate == 1) {
 511                         sign_usage = KG_USAGE_INITIATOR_SIGN;
 512                         seal_usage = KG_USAGE_INITIATOR_SEAL;
 513                 } else {
 514                         sign_usage = KG_USAGE_ACCEPTOR_SIGN;
 515                         seal_usage = KG_USAGE_ACCEPTOR_SEAL;
 516                 }
 517 #else
 518                 /* FIXME
 519                  * These are from rfc4142, but I don't understand: if we supply
 520                  * different 'usage' value for client & server, then the peers
 521                  * will have different derived keys. How could this work?
 522                  *
 523                  * Here we simply use old SIGN/SEAL values until we find the
 524                  * answer.  --ericm
 525                  * FIXME
 526                  */
 527                 sign_usage = KG_USAGE_SIGN;
 528                 seal_usage = KG_USAGE_SEAL;
 529 #endif
 530
 531                 /* derive and send down: Ke, Ki, and Kc */
 532
 533                 /* Ke */
 534                 if (derive_key_lucid(keyptr, &derived_key,
 535                                seal_usage, KEY_USAGE_SEED_ENCRYPTION))
 536                         goto out_err;
 537                 if (write_bytes(&p, end, derived_key.data,
 538                                 derived_key.length))
 539                         goto out_err;
 540                 free(derived_key.data);
 541
 542                 /* Ki */
 543                 if (derive_key_lucid(keyptr, &derived_key,
 544                                seal_usage, KEY_USAGE_SEED_INTEGRITY))
 545                         goto out_err;
 546                 if (write_bytes(&p, end, derived_key.data,
 547                                 derived_key.length))
 548                         goto out_err;
 549                 free(derived_key.data);
 550
 551                 /* Kc */
 552                 if (derive_key_lucid(keyptr, &derived_key,
 553                                sign_usage, KEY_USAGE_SEED_CHECKSUM))
 554                         goto out_err;
 555                 if (write_bytes(&p, end, derived_key.data,
 556                                 derived_key.length))
 557                         goto out_err;
 558                 free(derived_key.data);
 559         }
 560
 561         buf->length = p - (char *)buf->value;
 562         return 0;
 563
 564 out_err:
 565         printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
 566                  __FUNCTION__);
 567         if (buf->value) {
 568                 free(buf->value);
 569                 buf->value = NULL;
 570         }
 571         buf->length = 0;
 572         if (enc_key.data) {
 573                 free(enc_key.data);
 574                 enc_key.data = NULL;
 575         }
 576         return -1;
 577 }
 578 int
 579 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf)
 580 {
 581         OM_uint32 maj_stat, min_stat;
 582         void *return_ctx = 0;
 583         OM_uint32 vers;
 584         gss_krb5_lucid_context_v1_t *lctx = 0;
 585         int retcode = 0;
 586
 587         printerr(3, "lucid version!\n");
 588         maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
 589                                                 1, &return_ctx);
 590         if (maj_stat != GSS_S_COMPLETE) {
 591                 pgsserr("gss_export_lucid_sec_context",
 592                         maj_stat, min_stat, &krb5oid);
 593                 goto out_err;
 594         }
 595
 596         /* Check the version returned, we only support v1 right now */
 597         vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
 598         switch (vers) {
 599         case 1:
 600                 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
 601                 break;
 602         default:
 603                 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
 604                         vers);
 605                 goto out_err;
 606                 break;
 607         }
 608
 609         /*
 610          * Now lctx points to a lucid context that we can send down to kernel
 611          *
 612          * Note: we send down different information to the kernel depending
 613          * on the protocol version and the enctyption type.
 614          * For protocol version 0 with all enctypes besides DES3, we use
 615          * the original format.  For protocol version != 0 or DES3, we
 616          * send down the new style information.
 617          */
 618
 619         if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
 620                 retcode = prepare_krb5_rfc1964_buffer(lctx, buf);
 621         else
 622                 retcode = prepare_krb5_rfc4121_buffer(lctx, buf);
 623
 624         maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
 625         if (maj_stat != GSS_S_COMPLETE) {
 626                 pgsserr("gss_export_lucid_sec_context",
 627                         maj_stat, min_stat, &krb5oid);
 628                 printerr(0, "WARN: failed to free lucid sec context\n");
 629         }
 630
 631         if (retcode) {
 632                 printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
 633                          __FUNCTION__, retcode);
 634                 goto out_err;
 635         }
 636
 637         return 0;
 638
 639 out_err:
 640         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 641         return -1;
 642 }
 643
 644
 645
 646 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */