1/* 2 * COPYRIGHT (c) 2008 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 <linux/types.h> 32#include <linux/jiffies.h> 33#include <linux/sunrpc/gss_krb5.h> 34#include <linux/random.h> 35#include <linux/pagemap.h> 36#include <linux/crypto.h> 37 38#ifdef RPC_DEBUG 39# define RPCDBG_FACILITY RPCDBG_AUTH 40#endif 41 42static inline int 43gss_krb5_padding(int blocksize, int length) 44{ 45 return blocksize - (length % blocksize); 46} 47 48static inline void 49gss_krb5_add_padding(struct xdr_buf *buf, int offset, int blocksize) 50{ 51 int padding = gss_krb5_padding(blocksize, buf->len - offset); 52 char *p; 53 struct kvec *iov; 54 55 if (buf->page_len || buf->tail[0].iov_len) 56 iov = &buf->tail[0]; 57 else 58 iov = &buf->head[0]; 59 p = iov->iov_base + iov->iov_len; 60 iov->iov_len += padding; 61 buf->len += padding; 62 memset(p, padding, padding); 63} 64 65static inline int 66gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize) 67{ 68 u8 *ptr; 69 u8 pad; 70 size_t len = buf->len; 71 72 if (len <= buf->head[0].iov_len) { 73 pad = *(u8 *)(buf->head[0].iov_base + len - 1); 74 if (pad > buf->head[0].iov_len) 75 return -EINVAL; 76 buf->head[0].iov_len -= pad; 77 goto out; 78 } else 79 len -= buf->head[0].iov_len; 80 if (len <= buf->page_len) { 81 unsigned int last = (buf->page_base + len - 1) 82 >>PAGE_CACHE_SHIFT; 83 unsigned int offset = (buf->page_base + len - 1) 84 & (PAGE_CACHE_SIZE - 1); 85 ptr = kmap_atomic(buf->pages[last]); 86 pad = *(ptr + offset); 87 kunmap_atomic(ptr); 88 goto out; 89 } else 90 len -= buf->page_len; 91 BUG_ON(len > buf->tail[0].iov_len); 92 pad = *(u8 *)(buf->tail[0].iov_base + len - 1); 93out: 94 /* XXX: NOTE: we do not adjust the page lengths--they represent 95 * a range of data in the real filesystem page cache, and we need 96 * to know that range so the xdr code can properly place read data. 97 * However adjusting the head length, as we do above, is harmless. 98 * In the case of a request that fits into a single page, the server 99 * also uses length and head length together to determine the original 100 * start of the request to copy the request for deferal; so it's 101 * easier on the server if we adjust head and tail length in tandem. 102 * It's not really a problem that we don't fool with the page and 103 * tail lengths, though--at worst badly formed xdr might lead the 104 * server to attempt to parse the padding. 105 * XXX: Document all these weird requirements for gss mechanism 106 * wrap/unwrap functions. */ 107 if (pad > blocksize) 108 return -EINVAL; 109 if (buf->len > pad) 110 buf->len -= pad; 111 else 112 return -EINVAL; 113 return 0; 114} 115 116void 117gss_krb5_make_confounder(char *p, u32 conflen) 118{ 119 static u64 i = 0; 120 u64 *q = (u64 *)p; 121 122 /* rfc1964 claims this should be "random". But all that's really 123 * necessary is that it be unique. And not even that is necessary in 124 * our case since our "gssapi" implementation exists only to support 125 * rpcsec_gss, so we know that the only buffers we will ever encrypt 126 * already begin with a unique sequence number. Just to hedge my bets 127 * I'll make a half-hearted attempt at something unique, but ensuring 128 * uniqueness would mean worrying about atomicity and rollover, and I 129 * don't care enough. */ 130 131 /* initialize to random value */ 132 if (i == 0) { 133 i = prandom_u32(); 134 i = (i << 32) | prandom_u32(); 135 } 136 137 switch (conflen) { 138 case 16: 139 *q++ = i++; 140 /* fall through */ 141 case 8: 142 *q++ = i++; 143 break; 144 default: 145 BUG(); 146 } 147} 148 149/* Assumptions: the head and tail of inbuf are ours to play with. 150 * The pages, however, may be real pages in the page cache and we replace 151 * them with scratch pages from **pages before writing to them. */ 152/* XXX: obviously the above should be documentation of wrap interface, 153 * and shouldn't be in this kerberos-specific file. */ 154 155/* XXX factor out common code with seal/unseal. */ 156 157static u32 158gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, 159 struct xdr_buf *buf, struct page **pages) 160{ 161 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 162 struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), 163 .data = cksumdata}; 164 int blocksize = 0, plainlen; 165 unsigned char *ptr, *msg_start; 166 s32 now; 167 int headlen; 168 struct page **tmp_pages; 169 u32 seq_send; 170 u8 *cksumkey; 171 u32 conflen = kctx->gk5e->conflen; 172 173 dprintk("RPC: %s\n", __func__); 174 175 now = get_seconds(); 176 177 blocksize = crypto_blkcipher_blocksize(kctx->enc); 178 gss_krb5_add_padding(buf, offset, blocksize); 179 BUG_ON((buf->len - offset) % blocksize); 180 plainlen = conflen + buf->len - offset; 181 182 headlen = g_token_size(&kctx->mech_used, 183 GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) - 184 (buf->len - offset); 185 186 ptr = buf->head[0].iov_base + offset; 187 /* shift data to make room for header. */ 188 xdr_extend_head(buf, offset, headlen); 189 190 /* XXX Would be cleverer to encrypt while copying. */ 191 BUG_ON((buf->len - offset - headlen) % blocksize); 192 193 g_make_token_header(&kctx->mech_used, 194 GSS_KRB5_TOK_HDR_LEN + 195 kctx->gk5e->cksumlength + plainlen, &ptr); 196 197 198 /* ptr now at header described in rfc 1964, section 1.2.1: */ 199 ptr[0] = (unsigned char) ((KG_TOK_WRAP_MSG >> 8) & 0xff); 200 ptr[1] = (unsigned char) (KG_TOK_WRAP_MSG & 0xff); 201 202 msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength; 203 204 *(__be16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg); 205 memset(ptr + 4, 0xff, 4); 206 *(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg); 207 208 gss_krb5_make_confounder(msg_start, conflen); 209 210 if (kctx->gk5e->keyed_cksum) 211 cksumkey = kctx->cksum; 212 else 213 cksumkey = NULL; 214 215 /* XXXJBF: UGH!: */ 216 tmp_pages = buf->pages; 217 buf->pages = pages; 218 if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen, 219 cksumkey, KG_USAGE_SEAL, &md5cksum)) 220 return GSS_S_FAILURE; 221 buf->pages = tmp_pages; 222 223 memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len); 224 225 spin_lock(&krb5_seq_lock); 226 seq_send = kctx->seq_send++; 227 spin_unlock(&krb5_seq_lock); 228 229 /* XXX would probably be more efficient to compute checksum 230 * and encrypt at the same time: */ 231 if ((krb5_make_seq_num(kctx, kctx->seq, kctx->initiate ? 0 : 0xff, 232 seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))) 233 return GSS_S_FAILURE; 234 235 if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { 236 struct crypto_blkcipher *cipher; 237 int err; 238 cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, 239 CRYPTO_ALG_ASYNC); 240 if (IS_ERR(cipher)) 241 return GSS_S_FAILURE; 242 243 krb5_rc4_setup_enc_key(kctx, cipher, seq_send); 244 245 err = gss_encrypt_xdr_buf(cipher, buf, 246 offset + headlen - conflen, pages); 247 crypto_free_blkcipher(cipher); 248 if (err) 249 return GSS_S_FAILURE; 250 } else { 251 if (gss_encrypt_xdr_buf(kctx->enc, buf, 252 offset + headlen - conflen, pages)) 253 return GSS_S_FAILURE; 254 } 255 256 return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 257} 258 259static u32 260gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) 261{ 262 int signalg; 263 int sealalg; 264 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; 265 struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), 266 .data = cksumdata}; 267 s32 now; 268 int direction; 269 s32 seqnum; 270 unsigned char *ptr; 271 int bodysize; 272 void *data_start, *orig_start; 273 int data_len; 274 int blocksize; 275 u32 conflen = kctx->gk5e->conflen; 276 int crypt_offset; 277 u8 *cksumkey; 278 279 dprintk("RPC: gss_unwrap_kerberos\n"); 280 281 ptr = (u8 *)buf->head[0].iov_base + offset; 282 if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr, 283 buf->len - offset)) 284 return GSS_S_DEFECTIVE_TOKEN; 285 286 if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) || 287 (ptr[1] != (KG_TOK_WRAP_MSG & 0xff))) 288 return GSS_S_DEFECTIVE_TOKEN; 289 290 /* XXX sanity-check bodysize?? */ 291 292 /* get the sign and seal algorithms */ 293 294 signalg = ptr[2] + (ptr[3] << 8); 295 if (signalg != kctx->gk5e->signalg) 296 return GSS_S_DEFECTIVE_TOKEN; 297 298 sealalg = ptr[4] + (ptr[5] << 8); 299 if (sealalg != kctx->gk5e->sealalg) 300 return GSS_S_DEFECTIVE_TOKEN; 301 302 if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) 303 return GSS_S_DEFECTIVE_TOKEN; 304 305 /* 306 * Data starts after token header and checksum. ptr points 307 * to the beginning of the token header 308 */ 309 crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) - 310 (unsigned char *)buf->head[0].iov_base; 311 312 /* 313 * Need plaintext seqnum to derive encryption key for arcfour-hmac 314 */ 315 if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN, 316 ptr + 8, &direction, &seqnum)) 317 return GSS_S_BAD_SIG; 318 319 if ((kctx->initiate && direction != 0xff) || 320 (!kctx->initiate && direction != 0)) 321 return GSS_S_BAD_SIG; 322 323 if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) { 324 struct crypto_blkcipher *cipher; 325 int err; 326 327 cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0, 328 CRYPTO_ALG_ASYNC); 329 if (IS_ERR(cipher)) 330 return GSS_S_FAILURE; 331 332 krb5_rc4_setup_enc_key(kctx, cipher, seqnum); 333 334 err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset); 335 crypto_free_blkcipher(cipher); 336 if (err) 337 return GSS_S_DEFECTIVE_TOKEN; 338 } else { 339 if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) 340 return GSS_S_DEFECTIVE_TOKEN; 341 } 342 343 if (kctx->gk5e->keyed_cksum) 344 cksumkey = kctx->cksum; 345 else 346 cksumkey = NULL; 347 348 if (make_checksum(kctx, ptr, 8, buf, crypt_offset, 349 cksumkey, KG_USAGE_SEAL, &md5cksum)) 350 return GSS_S_FAILURE; 351 352 if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN, 353 kctx->gk5e->cksumlength)) 354 return GSS_S_BAD_SIG; 355 356 /* it got through unscathed. Make sure the context is unexpired */ 357 358 now = get_seconds(); 359 360 if (now > kctx->endtime) 361 return GSS_S_CONTEXT_EXPIRED; 362 363 /* do sequencing checks */ 364 365 /* Copy the data back to the right position. XXX: Would probably be 366 * better to copy and encrypt at the same time. */ 367 368 blocksize = crypto_blkcipher_blocksize(kctx->enc); 369 data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) + 370 conflen; 371 orig_start = buf->head[0].iov_base + offset; 372 data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start; 373 memmove(orig_start, data_start, data_len); 374 buf->head[0].iov_len -= (data_start - orig_start); 375 buf->len -= (data_start - orig_start); 376 377 if (gss_krb5_remove_padding(buf, blocksize)) 378 return GSS_S_DEFECTIVE_TOKEN; 379 380 return GSS_S_COMPLETE; 381} 382 383/* 384 * We can shift data by up to LOCAL_BUF_LEN bytes in a pass. If we need 385 * to do more than that, we shift repeatedly. Kevin Coffman reports 386 * seeing 28 bytes as the value used by Microsoft clients and servers 387 * with AES, so this constant is chosen to allow handling 28 in one pass 388 * without using too much stack space. 389 * 390 * If that proves to a problem perhaps we could use a more clever 391 * algorithm. 392 */ 393#define LOCAL_BUF_LEN 32u 394 395static void rotate_buf_a_little(struct xdr_buf *buf, unsigned int shift) 396{ 397 char head[LOCAL_BUF_LEN]; 398 char tmp[LOCAL_BUF_LEN]; 399 unsigned int this_len, i; 400 401 BUG_ON(shift > LOCAL_BUF_LEN); 402 403 read_bytes_from_xdr_buf(buf, 0, head, shift); 404 for (i = 0; i + shift < buf->len; i += LOCAL_BUF_LEN) { 405 this_len = min(LOCAL_BUF_LEN, buf->len - (i + shift)); 406 read_bytes_from_xdr_buf(buf, i+shift, tmp, this_len); 407 write_bytes_to_xdr_buf(buf, i, tmp, this_len); 408 } 409 write_bytes_to_xdr_buf(buf, buf->len - shift, head, shift); 410} 411 412static void _rotate_left(struct xdr_buf *buf, unsigned int shift) 413{ 414 int shifted = 0; 415 int this_shift; 416 417 shift %= buf->len; 418 while (shifted < shift) { 419 this_shift = min(shift - shifted, LOCAL_BUF_LEN); 420 rotate_buf_a_little(buf, this_shift); 421 shifted += this_shift; 422 } 423} 424 425static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift) 426{ 427 struct xdr_buf subbuf; 428 429 xdr_buf_subsegment(buf, &subbuf, base, buf->len - base); 430 _rotate_left(&subbuf, shift); 431} 432 433static u32 434gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset, 435 struct xdr_buf *buf, struct page **pages) 436{ 437 int blocksize; 438 u8 *ptr, *plainhdr; 439 s32 now; 440 u8 flags = 0x00; 441 __be16 *be16ptr, ec = 0; 442 __be64 *be64ptr; 443 u32 err; 444 445 dprintk("RPC: %s\n", __func__); 446 447 if (kctx->gk5e->encrypt_v2 == NULL) 448 return GSS_S_FAILURE; 449 450 /* make room for gss token header */ 451 if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN)) 452 return GSS_S_FAILURE; 453 454 /* construct gss token header */ 455 ptr = plainhdr = buf->head[0].iov_base + offset; 456 *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff); 457 *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff); 458 459 if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) 460 flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR; 461 if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0) 462 flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY; 463 /* We always do confidentiality in wrap tokens */ 464 flags |= KG2_TOKEN_FLAG_SEALED; 465 466 *ptr++ = flags; 467 *ptr++ = 0xff; 468 be16ptr = (__be16 *)ptr; 469 470 blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc); 471 *be16ptr++ = cpu_to_be16(ec); 472 /* "inner" token header always uses 0 for RRC */ 473 *be16ptr++ = cpu_to_be16(0); 474 475 be64ptr = (__be64 *)be16ptr; 476 spin_lock(&krb5_seq_lock); 477 *be64ptr = cpu_to_be64(kctx->seq_send64++); 478 spin_unlock(&krb5_seq_lock); 479 480 err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages); 481 if (err) 482 return err; 483 484 now = get_seconds(); 485 return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; 486} 487 488static u32 489gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) 490{ 491 s32 now; 492 u64 seqnum; 493 u8 *ptr; 494 u8 flags = 0x00; 495 u16 ec, rrc; 496 int err; 497 u32 headskip, tailskip; 498 u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN]; 499 unsigned int movelen; 500 501 502 dprintk("RPC: %s\n", __func__); 503 504 if (kctx->gk5e->decrypt_v2 == NULL) 505 return GSS_S_FAILURE; 506 507 ptr = buf->head[0].iov_base + offset; 508 509 if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP) 510 return GSS_S_DEFECTIVE_TOKEN; 511 512 flags = ptr[2]; 513 if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) || 514 (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR))) 515 return GSS_S_BAD_SIG; 516 517 if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) { 518 dprintk("%s: token missing expected sealed flag\n", __func__); 519 return GSS_S_DEFECTIVE_TOKEN; 520 } 521 522 if (ptr[3] != 0xff) 523 return GSS_S_DEFECTIVE_TOKEN; 524 525 ec = be16_to_cpup((__be16 *)(ptr + 4)); 526 rrc = be16_to_cpup((__be16 *)(ptr + 6)); 527 528 seqnum = be64_to_cpup((__be64 *)(ptr + 8)); 529 530 if (rrc != 0) 531 rotate_left(offset + 16, buf, rrc); 532 533 err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf, 534 &headskip, &tailskip); 535 if (err) 536 return GSS_S_FAILURE; 537 538 /* 539 * Retrieve the decrypted gss token header and verify 540 * it against the original 541 */ 542 err = read_bytes_from_xdr_buf(buf, 543 buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip, 544 decrypted_hdr, GSS_KRB5_TOK_HDR_LEN); 545 if (err) { 546 dprintk("%s: error %u getting decrypted_hdr\n", __func__, err); 547 return GSS_S_FAILURE; 548 } 549 if (memcmp(ptr, decrypted_hdr, 6) 550 || memcmp(ptr + 8, decrypted_hdr + 8, 8)) { 551 dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__); 552 return GSS_S_FAILURE; 553 } 554 555 /* do sequencing checks */ 556 557 /* it got through unscathed. Make sure the context is unexpired */ 558 now = get_seconds(); 559 if (now > kctx->endtime) 560 return GSS_S_CONTEXT_EXPIRED; 561 562 /* 563 * Move the head data back to the right position in xdr_buf. 564 * We ignore any "ec" data since it might be in the head or 565 * the tail, and we really don't need to deal with it. 566 * Note that buf->head[0].iov_len may indicate the available 567 * head buffer space rather than that actually occupied. 568 */ 569 movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len); 570 movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip; 571 BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > 572 buf->head[0].iov_len); 573 memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen); 574 buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; 575 buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip; 576 577 /* Trim off the checksum blob */ 578 xdr_buf_trim(buf, GSS_KRB5_TOK_HDR_LEN + tailskip); 579 return GSS_S_COMPLETE; 580} 581 582u32 583gss_wrap_kerberos(struct gss_ctx *gctx, int offset, 584 struct xdr_buf *buf, struct page **pages) 585{ 586 struct krb5_ctx *kctx = gctx->internal_ctx_id; 587 588 switch (kctx->enctype) { 589 default: 590 BUG(); 591 case ENCTYPE_DES_CBC_RAW: 592 case ENCTYPE_DES3_CBC_RAW: 593 case ENCTYPE_ARCFOUR_HMAC: 594 return gss_wrap_kerberos_v1(kctx, offset, buf, pages); 595 case ENCTYPE_AES128_CTS_HMAC_SHA1_96: 596 case ENCTYPE_AES256_CTS_HMAC_SHA1_96: 597 return gss_wrap_kerberos_v2(kctx, offset, buf, pages); 598 } 599} 600 601u32 602gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf) 603{ 604 struct krb5_ctx *kctx = gctx->internal_ctx_id; 605 606 switch (kctx->enctype) { 607 default: 608 BUG(); 609 case ENCTYPE_DES_CBC_RAW: 610 case ENCTYPE_DES3_CBC_RAW: 611 case ENCTYPE_ARCFOUR_HMAC: 612 return gss_unwrap_kerberos_v1(kctx, offset, buf); 613 case ENCTYPE_AES128_CTS_HMAC_SHA1_96: 614 case ENCTYPE_AES256_CTS_HMAC_SHA1_96: 615 return gss_unwrap_kerberos_v2(kctx, offset, buf); 616 } 617} 618 619