1// SPDX-License-Identifier: BSD-3-Clause
2/*
3 * linux/net/sunrpc/gss_krb5_mech.c
4 *
5 * Copyright (c) 2001-2008 The Regents of the University of Michigan.
6 * All rights reserved.
7 *
8 * Andy Adamson <andros@umich.edu>
9 * J. Bruce Fields <bfields@umich.edu>
10 */
11
12#include <crypto/hash.h>
13#include <crypto/skcipher.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/types.h>
18#include <linux/slab.h>
19#include <linux/sunrpc/auth.h>
20#include <linux/sunrpc/gss_krb5.h>
21#include <linux/sunrpc/xdr.h>
22#include <kunit/visibility.h>
23
24#include "auth_gss_internal.h"
25#include "gss_krb5_internal.h"
26
27#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
28# define RPCDBG_FACILITY RPCDBG_AUTH
29#endif
30
31static struct gss_api_mech gss_kerberos_mech;
32
33static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
34#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA1)
35 /*
36 * AES-128 with SHA-1 (RFC 3962)
37 */
38 {
39 .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
40 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
41 .name = "aes128-cts",
42 .encrypt_name = "cts(cbc(aes))",
43 .aux_cipher = "cbc(aes)",
44 .cksum_name = "hmac(sha1)",
45 .derive_key = krb5_derive_key_v2,
46 .encrypt = gss_krb5_aes_encrypt,
47 .decrypt = gss_krb5_aes_decrypt,
48
49 .get_mic = gss_krb5_get_mic_v2,
50 .verify_mic = gss_krb5_verify_mic_v2,
51 .wrap = gss_krb5_wrap_v2,
52 .unwrap = gss_krb5_unwrap_v2,
53
54 .signalg = -1,
55 .sealalg = -1,
56 .keybytes = 16,
57 .keylength = BITS2OCTETS(128),
58 .Kc_length = BITS2OCTETS(128),
59 .Ke_length = BITS2OCTETS(128),
60 .Ki_length = BITS2OCTETS(128),
61 .cksumlength = BITS2OCTETS(96),
62 .keyed_cksum = 1,
63 },
64 /*
65 * AES-256 with SHA-1 (RFC 3962)
66 */
67 {
68 .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
69 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
70 .name = "aes256-cts",
71 .encrypt_name = "cts(cbc(aes))",
72 .aux_cipher = "cbc(aes)",
73 .cksum_name = "hmac(sha1)",
74 .derive_key = krb5_derive_key_v2,
75 .encrypt = gss_krb5_aes_encrypt,
76 .decrypt = gss_krb5_aes_decrypt,
77
78 .get_mic = gss_krb5_get_mic_v2,
79 .verify_mic = gss_krb5_verify_mic_v2,
80 .wrap = gss_krb5_wrap_v2,
81 .unwrap = gss_krb5_unwrap_v2,
82
83 .signalg = -1,
84 .sealalg = -1,
85 .keybytes = 32,
86 .keylength = BITS2OCTETS(256),
87 .Kc_length = BITS2OCTETS(256),
88 .Ke_length = BITS2OCTETS(256),
89 .Ki_length = BITS2OCTETS(256),
90 .cksumlength = BITS2OCTETS(96),
91 .keyed_cksum = 1,
92 },
93#endif
94
95#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_CAMELLIA)
96 /*
97 * Camellia-128 with CMAC (RFC 6803)
98 */
99 {
100 .etype = ENCTYPE_CAMELLIA128_CTS_CMAC,
101 .ctype = CKSUMTYPE_CMAC_CAMELLIA128,
102 .name = "camellia128-cts-cmac",
103 .encrypt_name = "cts(cbc(camellia))",
104 .aux_cipher = "cbc(camellia)",
105 .cksum_name = "cmac(camellia)",
106 .cksumlength = BITS2OCTETS(128),
107 .keyed_cksum = 1,
108 .keylength = BITS2OCTETS(128),
109 .Kc_length = BITS2OCTETS(128),
110 .Ke_length = BITS2OCTETS(128),
111 .Ki_length = BITS2OCTETS(128),
112
113 .derive_key = krb5_kdf_feedback_cmac,
114 .encrypt = gss_krb5_aes_encrypt,
115 .decrypt = gss_krb5_aes_decrypt,
116
117 .get_mic = gss_krb5_get_mic_v2,
118 .verify_mic = gss_krb5_verify_mic_v2,
119 .wrap = gss_krb5_wrap_v2,
120 .unwrap = gss_krb5_unwrap_v2,
121 },
122 /*
123 * Camellia-256 with CMAC (RFC 6803)
124 */
125 {
126 .etype = ENCTYPE_CAMELLIA256_CTS_CMAC,
127 .ctype = CKSUMTYPE_CMAC_CAMELLIA256,
128 .name = "camellia256-cts-cmac",
129 .encrypt_name = "cts(cbc(camellia))",
130 .aux_cipher = "cbc(camellia)",
131 .cksum_name = "cmac(camellia)",
132 .cksumlength = BITS2OCTETS(128),
133 .keyed_cksum = 1,
134 .keylength = BITS2OCTETS(256),
135 .Kc_length = BITS2OCTETS(256),
136 .Ke_length = BITS2OCTETS(256),
137 .Ki_length = BITS2OCTETS(256),
138
139 .derive_key = krb5_kdf_feedback_cmac,
140 .encrypt = gss_krb5_aes_encrypt,
141 .decrypt = gss_krb5_aes_decrypt,
142
143 .get_mic = gss_krb5_get_mic_v2,
144 .verify_mic = gss_krb5_verify_mic_v2,
145 .wrap = gss_krb5_wrap_v2,
146 .unwrap = gss_krb5_unwrap_v2,
147 },
148#endif
149
150#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA2)
151 /*
152 * AES-128 with SHA-256 (RFC 8009)
153 */
154 {
155 .etype = ENCTYPE_AES128_CTS_HMAC_SHA256_128,
156 .ctype = CKSUMTYPE_HMAC_SHA256_128_AES128,
157 .name = "aes128-cts-hmac-sha256-128",
158 .encrypt_name = "cts(cbc(aes))",
159 .aux_cipher = "cbc(aes)",
160 .cksum_name = "hmac(sha256)",
161 .cksumlength = BITS2OCTETS(128),
162 .keyed_cksum = 1,
163 .keylength = BITS2OCTETS(128),
164 .Kc_length = BITS2OCTETS(128),
165 .Ke_length = BITS2OCTETS(128),
166 .Ki_length = BITS2OCTETS(128),
167
168 .derive_key = krb5_kdf_hmac_sha2,
169 .encrypt = krb5_etm_encrypt,
170 .decrypt = krb5_etm_decrypt,
171
172 .get_mic = gss_krb5_get_mic_v2,
173 .verify_mic = gss_krb5_verify_mic_v2,
174 .wrap = gss_krb5_wrap_v2,
175 .unwrap = gss_krb5_unwrap_v2,
176 },
177 /*
178 * AES-256 with SHA-384 (RFC 8009)
179 */
180 {
181 .etype = ENCTYPE_AES256_CTS_HMAC_SHA384_192,
182 .ctype = CKSUMTYPE_HMAC_SHA384_192_AES256,
183 .name = "aes256-cts-hmac-sha384-192",
184 .encrypt_name = "cts(cbc(aes))",
185 .aux_cipher = "cbc(aes)",
186 .cksum_name = "hmac(sha384)",
187 .cksumlength = BITS2OCTETS(192),
188 .keyed_cksum = 1,
189 .keylength = BITS2OCTETS(256),
190 .Kc_length = BITS2OCTETS(192),
191 .Ke_length = BITS2OCTETS(256),
192 .Ki_length = BITS2OCTETS(192),
193
194 .derive_key = krb5_kdf_hmac_sha2,
195 .encrypt = krb5_etm_encrypt,
196 .decrypt = krb5_etm_decrypt,
197
198 .get_mic = gss_krb5_get_mic_v2,
199 .verify_mic = gss_krb5_verify_mic_v2,
200 .wrap = gss_krb5_wrap_v2,
201 .unwrap = gss_krb5_unwrap_v2,
202 },
203#endif
204};
205
206/*
207 * The list of advertised enctypes is specified in order of most
208 * preferred to least.
209 */
210static char gss_krb5_enctype_priority_list[64];
211
212static void gss_krb5_prepare_enctype_priority_list(void)
213{
214 static const u32 gss_krb5_enctypes[] = {
215#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA2)
216 ENCTYPE_AES256_CTS_HMAC_SHA384_192,
217 ENCTYPE_AES128_CTS_HMAC_SHA256_128,
218#endif
219#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_CAMELLIA)
220 ENCTYPE_CAMELLIA256_CTS_CMAC,
221 ENCTYPE_CAMELLIA128_CTS_CMAC,
222#endif
223#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA1)
224 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
225 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
226#endif
227 };
228 size_t total, i;
229 char buf[16];
230 char *sep;
231 int n;
232
233 sep = "";
234 gss_krb5_enctype_priority_list[0] = '\0';
235 for (total = 0, i = 0; i < ARRAY_SIZE(gss_krb5_enctypes); i++) {
236 n = sprintf(buf, fmt: "%s%u", sep, gss_krb5_enctypes[i]);
237 if (n < 0)
238 break;
239 if (total + n >= sizeof(gss_krb5_enctype_priority_list))
240 break;
241 strcat(p: gss_krb5_enctype_priority_list, q: buf);
242 sep = ",";
243 total += n;
244 }
245}
246
247/**
248 * gss_krb5_lookup_enctype - Retrieve profile information for a given enctype
249 * @etype: ENCTYPE value
250 *
251 * Returns a pointer to a gss_krb5_enctype structure, or NULL if no
252 * matching etype is found.
253 */
254VISIBLE_IF_KUNIT
255const struct gss_krb5_enctype *gss_krb5_lookup_enctype(u32 etype)
256{
257 size_t i;
258
259 for (i = 0; i < ARRAY_SIZE(supported_gss_krb5_enctypes); i++)
260 if (supported_gss_krb5_enctypes[i].etype == etype)
261 return &supported_gss_krb5_enctypes[i];
262 return NULL;
263}
264EXPORT_SYMBOL_IF_KUNIT(gss_krb5_lookup_enctype);
265
266static struct crypto_sync_skcipher *
267gss_krb5_alloc_cipher_v2(const char *cname, const struct xdr_netobj *key)
268{
269 struct crypto_sync_skcipher *tfm;
270
271 tfm = crypto_alloc_sync_skcipher(alg_name: cname, type: 0, mask: 0);
272 if (IS_ERR(ptr: tfm))
273 return NULL;
274 if (crypto_sync_skcipher_setkey(tfm, key: key->data, keylen: key->len)) {
275 crypto_free_sync_skcipher(tfm);
276 return NULL;
277 }
278 return tfm;
279}
280
281static struct crypto_ahash *
282gss_krb5_alloc_hash_v2(struct krb5_ctx *kctx, const struct xdr_netobj *key)
283{
284 struct crypto_ahash *tfm;
285
286 tfm = crypto_alloc_ahash(alg_name: kctx->gk5e->cksum_name, type: 0, CRYPTO_ALG_ASYNC);
287 if (IS_ERR(ptr: tfm))
288 return NULL;
289 if (crypto_ahash_setkey(tfm, key: key->data, keylen: key->len)) {
290 crypto_free_ahash(tfm);
291 return NULL;
292 }
293 return tfm;
294}
295
296static int
297gss_krb5_import_ctx_v2(struct krb5_ctx *ctx, gfp_t gfp_mask)
298{
299 struct xdr_netobj keyin = {
300 .len = ctx->gk5e->keylength,
301 .data = ctx->Ksess,
302 };
303 struct xdr_netobj keyout;
304 int ret = -EINVAL;
305
306 keyout.data = kmalloc(GSS_KRB5_MAX_KEYLEN, flags: gfp_mask);
307 if (!keyout.data)
308 return -ENOMEM;
309
310 /* initiator seal encryption */
311 keyout.len = ctx->gk5e->Ke_length;
312 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_INITIATOR_SEAL,
313 KEY_USAGE_SEED_ENCRYPTION, gfp_mask))
314 goto out;
315 ctx->initiator_enc = gss_krb5_alloc_cipher_v2(cname: ctx->gk5e->encrypt_name,
316 key: &keyout);
317 if (ctx->initiator_enc == NULL)
318 goto out;
319 if (ctx->gk5e->aux_cipher) {
320 ctx->initiator_enc_aux =
321 gss_krb5_alloc_cipher_v2(cname: ctx->gk5e->aux_cipher,
322 key: &keyout);
323 if (ctx->initiator_enc_aux == NULL)
324 goto out_free;
325 }
326
327 /* acceptor seal encryption */
328 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_ACCEPTOR_SEAL,
329 KEY_USAGE_SEED_ENCRYPTION, gfp_mask))
330 goto out_free;
331 ctx->acceptor_enc = gss_krb5_alloc_cipher_v2(cname: ctx->gk5e->encrypt_name,
332 key: &keyout);
333 if (ctx->acceptor_enc == NULL)
334 goto out_free;
335 if (ctx->gk5e->aux_cipher) {
336 ctx->acceptor_enc_aux =
337 gss_krb5_alloc_cipher_v2(cname: ctx->gk5e->aux_cipher,
338 key: &keyout);
339 if (ctx->acceptor_enc_aux == NULL)
340 goto out_free;
341 }
342
343 /* initiator sign checksum */
344 keyout.len = ctx->gk5e->Kc_length;
345 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_INITIATOR_SIGN,
346 KEY_USAGE_SEED_CHECKSUM, gfp_mask))
347 goto out_free;
348 ctx->initiator_sign = gss_krb5_alloc_hash_v2(kctx: ctx, key: &keyout);
349 if (ctx->initiator_sign == NULL)
350 goto out_free;
351
352 /* acceptor sign checksum */
353 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_ACCEPTOR_SIGN,
354 KEY_USAGE_SEED_CHECKSUM, gfp_mask))
355 goto out_free;
356 ctx->acceptor_sign = gss_krb5_alloc_hash_v2(kctx: ctx, key: &keyout);
357 if (ctx->acceptor_sign == NULL)
358 goto out_free;
359
360 /* initiator seal integrity */
361 keyout.len = ctx->gk5e->Ki_length;
362 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_INITIATOR_SEAL,
363 KEY_USAGE_SEED_INTEGRITY, gfp_mask))
364 goto out_free;
365 ctx->initiator_integ = gss_krb5_alloc_hash_v2(kctx: ctx, key: &keyout);
366 if (ctx->initiator_integ == NULL)
367 goto out_free;
368
369 /* acceptor seal integrity */
370 if (krb5_derive_key(kctx: ctx, inkey: &keyin, outkey: &keyout, KG_USAGE_ACCEPTOR_SEAL,
371 KEY_USAGE_SEED_INTEGRITY, gfp_mask))
372 goto out_free;
373 ctx->acceptor_integ = gss_krb5_alloc_hash_v2(kctx: ctx, key: &keyout);
374 if (ctx->acceptor_integ == NULL)
375 goto out_free;
376
377 ret = 0;
378out:
379 kfree_sensitive(objp: keyout.data);
380 return ret;
381
382out_free:
383 crypto_free_ahash(tfm: ctx->acceptor_integ);
384 crypto_free_ahash(tfm: ctx->initiator_integ);
385 crypto_free_ahash(tfm: ctx->acceptor_sign);
386 crypto_free_ahash(tfm: ctx->initiator_sign);
387 crypto_free_sync_skcipher(tfm: ctx->acceptor_enc_aux);
388 crypto_free_sync_skcipher(tfm: ctx->acceptor_enc);
389 crypto_free_sync_skcipher(tfm: ctx->initiator_enc_aux);
390 crypto_free_sync_skcipher(tfm: ctx->initiator_enc);
391 goto out;
392}
393
394static int
395gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
396 gfp_t gfp_mask)
397{
398 u64 seq_send64;
399 int keylen;
400 u32 time32;
401 int ret;
402
403 p = simple_get_bytes(p, end, res: &ctx->flags, len: sizeof(ctx->flags));
404 if (IS_ERR(ptr: p))
405 goto out_err;
406 ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
407
408 p = simple_get_bytes(p, end, res: &time32, len: sizeof(time32));
409 if (IS_ERR(ptr: p))
410 goto out_err;
411 /* unsigned 32-bit time overflows in year 2106 */
412 ctx->endtime = (time64_t)time32;
413 p = simple_get_bytes(p, end, res: &seq_send64, len: sizeof(seq_send64));
414 if (IS_ERR(ptr: p))
415 goto out_err;
416 atomic64_set(v: &ctx->seq_send64, i: seq_send64);
417 /* set seq_send for use by "older" enctypes */
418 atomic_set(v: &ctx->seq_send, i: seq_send64);
419 if (seq_send64 != atomic_read(v: &ctx->seq_send)) {
420 dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__,
421 seq_send64, atomic_read(&ctx->seq_send));
422 p = ERR_PTR(error: -EINVAL);
423 goto out_err;
424 }
425 p = simple_get_bytes(p, end, res: &ctx->enctype, len: sizeof(ctx->enctype));
426 if (IS_ERR(ptr: p))
427 goto out_err;
428 ctx->gk5e = gss_krb5_lookup_enctype(ctx->enctype);
429 if (ctx->gk5e == NULL) {
430 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
431 ctx->enctype);
432 p = ERR_PTR(error: -EINVAL);
433 goto out_err;
434 }
435 keylen = ctx->gk5e->keylength;
436
437 p = simple_get_bytes(p, end, res: ctx->Ksess, len: keylen);
438 if (IS_ERR(ptr: p))
439 goto out_err;
440
441 if (p != end) {
442 p = ERR_PTR(error: -EINVAL);
443 goto out_err;
444 }
445
446 ctx->mech_used.data = kmemdup(p: gss_kerberos_mech.gm_oid.data,
447 size: gss_kerberos_mech.gm_oid.len, gfp: gfp_mask);
448 if (unlikely(ctx->mech_used.data == NULL)) {
449 p = ERR_PTR(error: -ENOMEM);
450 goto out_err;
451 }
452 ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
453
454 ret = gss_krb5_import_ctx_v2(ctx, gfp_mask);
455 if (ret) {
456 p = ERR_PTR(error: ret);
457 goto out_free;
458 }
459
460 return 0;
461
462out_free:
463 kfree(objp: ctx->mech_used.data);
464out_err:
465 return PTR_ERR(ptr: p);
466}
467
468static int
469gss_krb5_import_sec_context(const void *p, size_t len, struct gss_ctx *ctx_id,
470 time64_t *endtime, gfp_t gfp_mask)
471{
472 const void *end = (const void *)((const char *)p + len);
473 struct krb5_ctx *ctx;
474 int ret;
475
476 ctx = kzalloc(size: sizeof(*ctx), flags: gfp_mask);
477 if (ctx == NULL)
478 return -ENOMEM;
479
480 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
481 memzero_explicit(s: &ctx->Ksess, count: sizeof(ctx->Ksess));
482 if (ret) {
483 kfree(objp: ctx);
484 return ret;
485 }
486
487 ctx_id->internal_ctx_id = ctx;
488 if (endtime)
489 *endtime = ctx->endtime;
490 return 0;
491}
492
493static void
494gss_krb5_delete_sec_context(void *internal_ctx)
495{
496 struct krb5_ctx *kctx = internal_ctx;
497
498 crypto_free_sync_skcipher(tfm: kctx->seq);
499 crypto_free_sync_skcipher(tfm: kctx->enc);
500 crypto_free_sync_skcipher(tfm: kctx->acceptor_enc);
501 crypto_free_sync_skcipher(tfm: kctx->initiator_enc);
502 crypto_free_sync_skcipher(tfm: kctx->acceptor_enc_aux);
503 crypto_free_sync_skcipher(tfm: kctx->initiator_enc_aux);
504 crypto_free_ahash(tfm: kctx->acceptor_sign);
505 crypto_free_ahash(tfm: kctx->initiator_sign);
506 crypto_free_ahash(tfm: kctx->acceptor_integ);
507 crypto_free_ahash(tfm: kctx->initiator_integ);
508 kfree(objp: kctx->mech_used.data);
509 kfree(objp: kctx);
510}
511
512/**
513 * gss_krb5_get_mic - get_mic for the Kerberos GSS mechanism
514 * @gctx: GSS context
515 * @text: plaintext to checksum
516 * @token: buffer into which to write the computed checksum
517 *
518 * Return values:
519 * %GSS_S_COMPLETE - success, and @token is filled in
520 * %GSS_S_FAILURE - checksum could not be generated
521 * %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
522 */
523static u32 gss_krb5_get_mic(struct gss_ctx *gctx, struct xdr_buf *text,
524 struct xdr_netobj *token)
525{
526 struct krb5_ctx *kctx = gctx->internal_ctx_id;
527
528 return kctx->gk5e->get_mic(kctx, text, token);
529}
530
531/**
532 * gss_krb5_verify_mic - verify_mic for the Kerberos GSS mechanism
533 * @gctx: GSS context
534 * @message_buffer: plaintext to check
535 * @read_token: received checksum to check
536 *
537 * Return values:
538 * %GSS_S_COMPLETE - computed and received checksums match
539 * %GSS_S_DEFECTIVE_TOKEN - received checksum is not valid
540 * %GSS_S_BAD_SIG - computed and received checksums do not match
541 * %GSS_S_FAILURE - received checksum could not be checked
542 * %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
543 */
544static u32 gss_krb5_verify_mic(struct gss_ctx *gctx,
545 struct xdr_buf *message_buffer,
546 struct xdr_netobj *read_token)
547{
548 struct krb5_ctx *kctx = gctx->internal_ctx_id;
549
550 return kctx->gk5e->verify_mic(kctx, message_buffer, read_token);
551}
552
553/**
554 * gss_krb5_wrap - gss_wrap for the Kerberos GSS mechanism
555 * @gctx: initialized GSS context
556 * @offset: byte offset in @buf to start writing the cipher text
557 * @buf: OUT: send buffer
558 * @pages: plaintext to wrap
559 *
560 * Return values:
561 * %GSS_S_COMPLETE - success, @buf has been updated
562 * %GSS_S_FAILURE - @buf could not be wrapped
563 * %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
564 */
565static u32 gss_krb5_wrap(struct gss_ctx *gctx, int offset,
566 struct xdr_buf *buf, struct page **pages)
567{
568 struct krb5_ctx *kctx = gctx->internal_ctx_id;
569
570 return kctx->gk5e->wrap(kctx, offset, buf, pages);
571}
572
573/**
574 * gss_krb5_unwrap - gss_unwrap for the Kerberos GSS mechanism
575 * @gctx: initialized GSS context
576 * @offset: starting byte offset into @buf
577 * @len: size of ciphertext to unwrap
578 * @buf: ciphertext to unwrap
579 *
580 * Return values:
581 * %GSS_S_COMPLETE - success, @buf has been updated
582 * %GSS_S_DEFECTIVE_TOKEN - received blob is not valid
583 * %GSS_S_BAD_SIG - computed and received checksums do not match
584 * %GSS_S_FAILURE - @buf could not be unwrapped
585 * %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
586 */
587static u32 gss_krb5_unwrap(struct gss_ctx *gctx, int offset,
588 int len, struct xdr_buf *buf)
589{
590 struct krb5_ctx *kctx = gctx->internal_ctx_id;
591
592 return kctx->gk5e->unwrap(kctx, offset, len, buf,
593 &gctx->slack, &gctx->align);
594}
595
596static const struct gss_api_ops gss_kerberos_ops = {
597 .gss_import_sec_context = gss_krb5_import_sec_context,
598 .gss_get_mic = gss_krb5_get_mic,
599 .gss_verify_mic = gss_krb5_verify_mic,
600 .gss_wrap = gss_krb5_wrap,
601 .gss_unwrap = gss_krb5_unwrap,
602 .gss_delete_sec_context = gss_krb5_delete_sec_context,
603};
604
605static struct pf_desc gss_kerberos_pfs[] = {
606 [0] = {
607 .pseudoflavor = RPC_AUTH_GSS_KRB5,
608 .qop = GSS_C_QOP_DEFAULT,
609 .service = RPC_GSS_SVC_NONE,
610 .name = "krb5",
611 },
612 [1] = {
613 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
614 .qop = GSS_C_QOP_DEFAULT,
615 .service = RPC_GSS_SVC_INTEGRITY,
616 .name = "krb5i",
617 .datatouch = true,
618 },
619 [2] = {
620 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
621 .qop = GSS_C_QOP_DEFAULT,
622 .service = RPC_GSS_SVC_PRIVACY,
623 .name = "krb5p",
624 .datatouch = true,
625 },
626};
627
628MODULE_ALIAS("rpc-auth-gss-krb5");
629MODULE_ALIAS("rpc-auth-gss-krb5i");
630MODULE_ALIAS("rpc-auth-gss-krb5p");
631MODULE_ALIAS("rpc-auth-gss-390003");
632MODULE_ALIAS("rpc-auth-gss-390004");
633MODULE_ALIAS("rpc-auth-gss-390005");
634MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
635
636static struct gss_api_mech gss_kerberos_mech = {
637 .gm_name = "krb5",
638 .gm_owner = THIS_MODULE,
639 .gm_oid = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
640 .gm_ops = &gss_kerberos_ops,
641 .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
642 .gm_pfs = gss_kerberos_pfs,
643 .gm_upcall_enctypes = gss_krb5_enctype_priority_list,
644};
645
646static int __init init_kerberos_module(void)
647{
648 int status;
649
650 gss_krb5_prepare_enctype_priority_list();
651 status = gss_mech_register(&gss_kerberos_mech);
652 if (status)
653 printk("Failed to register kerberos gss mechanism!\n");
654 return status;
655}
656
657static void __exit cleanup_kerberos_module(void)
658{
659 gss_mech_unregister(&gss_kerberos_mech);
660}
661
662MODULE_DESCRIPTION("Sun RPC Kerberos 5 module");
663MODULE_LICENSE("GPL");
664module_init(init_kerberos_module);
665module_exit(cleanup_kerberos_module);
666

source code of linux/net/sunrpc/auth_gss/gss_krb5_mech.c