1 // SPDX-License-Identifier: BSD-3-Clause
3 * linux/net/sunrpc/gss_krb5_mech.c
5 * Copyright (c) 2001-2008 The Regents of the University of Michigan.
8 * Andy Adamson <andros@umich.edu>
9 * J. Bruce Fields <bfields@umich.edu>
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 <linux/sunrpc/gss_krb5_enctypes.h>
24 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
25 # define RPCDBG_FACILITY RPCDBG_AUTH
28 static struct gss_api_mech gss_kerberos_mech; /* forward declaration */
30 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
31 #ifndef CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES
33 * DES (All DES enctypes are mapped to the same gss functionality)
36 .etype = ENCTYPE_DES_CBC_RAW,
37 .ctype = CKSUMTYPE_RSA_MD5,
38 .name = "des-cbc-crc",
39 .encrypt_name = "cbc(des)",
41 .encrypt = krb5_encrypt,
42 .decrypt = krb5_decrypt,
44 .signalg = SGN_ALG_DES_MAC_MD5,
45 .sealalg = SEAL_ALG_DES,
53 #endif /* CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES */
58 .etype = ENCTYPE_ARCFOUR_HMAC,
59 .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
61 .encrypt_name = "ecb(arc4)",
62 .cksum_name = "hmac(md5)",
63 .encrypt = krb5_encrypt,
64 .decrypt = krb5_decrypt,
66 .signalg = SGN_ALG_HMAC_MD5,
67 .sealalg = SEAL_ALG_MICROSOFT_RC4,
79 .etype = ENCTYPE_DES3_CBC_RAW,
80 .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
81 .name = "des3-hmac-sha1",
82 .encrypt_name = "cbc(des3_ede)",
83 .cksum_name = "hmac(sha1)",
84 .encrypt = krb5_encrypt,
85 .decrypt = krb5_decrypt,
86 .mk_key = gss_krb5_des3_make_key,
87 .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
88 .sealalg = SEAL_ALG_DES3KD,
100 .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
101 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
102 .name = "aes128-cts",
103 .encrypt_name = "cts(cbc(aes))",
104 .cksum_name = "hmac(sha1)",
105 .encrypt = krb5_encrypt,
106 .decrypt = krb5_decrypt,
107 .mk_key = gss_krb5_aes_make_key,
108 .encrypt_v2 = gss_krb5_aes_encrypt,
109 .decrypt_v2 = gss_krb5_aes_decrypt,
123 .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
124 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
125 .name = "aes256-cts",
126 .encrypt_name = "cts(cbc(aes))",
127 .cksum_name = "hmac(sha1)",
128 .encrypt = krb5_encrypt,
129 .decrypt = krb5_decrypt,
130 .mk_key = gss_krb5_aes_make_key,
131 .encrypt_v2 = gss_krb5_aes_encrypt,
132 .decrypt_v2 = gss_krb5_aes_decrypt,
144 static const int num_supported_enctypes =
145 ARRAY_SIZE(supported_gss_krb5_enctypes);
148 supported_gss_krb5_enctype(int etype)
151 for (i = 0; i < num_supported_enctypes; i++)
152 if (supported_gss_krb5_enctypes[i].etype == etype)
157 static const struct gss_krb5_enctype *
158 get_gss_krb5_enctype(int etype)
161 for (i = 0; i < num_supported_enctypes; i++)
162 if (supported_gss_krb5_enctypes[i].etype == etype)
163 return &supported_gss_krb5_enctypes[i];
168 simple_get_bytes(const void *p, const void *end, void *res, int len)
170 const void *q = (const void *)((const char *)p + len);
171 if (unlikely(q > end || q < p))
172 return ERR_PTR(-EFAULT);
178 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
183 p = simple_get_bytes(p, end, &len, sizeof(len));
186 q = (const void *)((const char *)p + len);
187 if (unlikely(q > end || q < p))
188 return ERR_PTR(-EFAULT);
189 res->data = kmemdup(p, len, GFP_NOFS);
190 if (unlikely(res->data == NULL))
191 return ERR_PTR(-ENOMEM);
196 static inline const void *
197 get_key(const void *p, const void *end,
198 struct krb5_ctx *ctx, struct crypto_sync_skcipher **res)
200 struct xdr_netobj key;
203 p = simple_get_bytes(p, end, &alg, sizeof(alg));
208 case ENCTYPE_DES_CBC_CRC:
209 case ENCTYPE_DES_CBC_MD4:
210 case ENCTYPE_DES_CBC_MD5:
211 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
212 alg = ENCTYPE_DES_CBC_RAW;
216 if (!supported_gss_krb5_enctype(alg)) {
217 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
218 "encryption key algorithm %d\n", alg);
219 p = ERR_PTR(-EINVAL);
222 p = simple_get_netobj(p, end, &key);
226 *res = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
228 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
229 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
231 goto out_err_free_key;
233 if (crypto_sync_skcipher_setkey(*res, key.data, key.len)) {
234 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
235 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
236 goto out_err_free_tfm;
243 crypto_free_sync_skcipher(*res);
246 p = ERR_PTR(-EINVAL);
252 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
258 p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
262 /* Old format supports only DES! Any other enctype uses new format */
263 ctx->enctype = ENCTYPE_DES_CBC_RAW;
265 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
266 if (ctx->gk5e == NULL) {
267 p = ERR_PTR(-EINVAL);
271 /* The downcall format was designed before we completely understood
272 * the uses of the context fields; so it includes some stuff we
273 * just give some minimal sanity-checking, and some we ignore
274 * completely (like the next twenty bytes): */
275 if (unlikely(p + 20 > end || p + 20 < p)) {
276 p = ERR_PTR(-EFAULT);
280 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
283 if (tmp != SGN_ALG_DES_MAC_MD5) {
284 p = ERR_PTR(-ENOSYS);
287 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
290 if (tmp != SEAL_ALG_DES) {
291 p = ERR_PTR(-ENOSYS);
294 p = simple_get_bytes(p, end, &time32, sizeof(time32));
297 /* unsigned 32-bit time overflows in year 2106 */
298 ctx->endtime = (time64_t)time32;
299 p = simple_get_bytes(p, end, &seq_send, sizeof(seq_send));
302 atomic_set(&ctx->seq_send, seq_send);
303 p = simple_get_netobj(p, end, &ctx->mech_used);
306 p = get_key(p, end, ctx, &ctx->enc);
308 goto out_err_free_mech;
309 p = get_key(p, end, ctx, &ctx->seq);
311 goto out_err_free_key1;
313 p = ERR_PTR(-EFAULT);
314 goto out_err_free_key2;
320 crypto_free_sync_skcipher(ctx->seq);
322 crypto_free_sync_skcipher(ctx->enc);
324 kfree(ctx->mech_used.data);
329 static struct crypto_sync_skcipher *
330 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
332 struct crypto_sync_skcipher *cp;
334 cp = crypto_alloc_sync_skcipher(cname, 0, 0);
336 dprintk("gss_kerberos_mech: unable to initialize "
337 "crypto algorithm %s\n", cname);
340 if (crypto_sync_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
341 dprintk("gss_kerberos_mech: error setting key for "
342 "crypto algorithm %s\n", cname);
343 crypto_free_sync_skcipher(cp);
350 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
352 cdata[0] = (usage>>24)&0xff;
353 cdata[1] = (usage>>16)&0xff;
354 cdata[2] = (usage>>8)&0xff;
355 cdata[3] = usage&0xff;
360 context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
362 struct xdr_netobj c, keyin, keyout;
363 u8 cdata[GSS_KRB5_K5CLENGTH];
366 c.len = GSS_KRB5_K5CLENGTH;
369 keyin.data = ctx->Ksess;
370 keyin.len = ctx->gk5e->keylength;
371 keyout.len = ctx->gk5e->keylength;
373 /* seq uses the raw key */
374 ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
376 if (ctx->seq == NULL)
379 ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
381 if (ctx->enc == NULL)
385 set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
386 keyout.data = ctx->cksum;
387 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
389 dprintk("%s: Error %d deriving cksum key\n",
397 crypto_free_sync_skcipher(ctx->enc);
399 crypto_free_sync_skcipher(ctx->seq);
405 * Note that RC4 depends on deriving keys using the sequence
406 * number or the checksum of a token. Therefore, the final keys
407 * cannot be calculated until the token is being constructed!
410 context_derive_keys_rc4(struct krb5_ctx *ctx)
412 struct crypto_shash *hmac;
413 char sigkeyconstant[] = "signaturekey";
414 int slen = strlen(sigkeyconstant) + 1; /* include null terminator */
415 struct shash_desc *desc;
418 dprintk("RPC: %s: entered\n", __func__);
420 * derive cksum (aka Ksign) key
422 hmac = crypto_alloc_shash(ctx->gk5e->cksum_name, 0, 0);
424 dprintk("%s: error %ld allocating hash '%s'\n",
425 __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
430 err = crypto_shash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
432 goto out_err_free_hmac;
435 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac), GFP_NOFS);
437 dprintk("%s: failed to allocate hash descriptor for '%s'\n",
438 __func__, ctx->gk5e->cksum_name);
440 goto out_err_free_hmac;
445 err = crypto_shash_digest(desc, sigkeyconstant, slen, ctx->cksum);
448 goto out_err_free_hmac;
450 * allocate hash, and skciphers for data and seqnum encryption
452 ctx->enc = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
453 if (IS_ERR(ctx->enc)) {
454 err = PTR_ERR(ctx->enc);
455 goto out_err_free_hmac;
458 ctx->seq = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
459 if (IS_ERR(ctx->seq)) {
460 crypto_free_sync_skcipher(ctx->enc);
461 err = PTR_ERR(ctx->seq);
462 goto out_err_free_hmac;
465 dprintk("RPC: %s: returning success\n", __func__);
470 crypto_free_shash(hmac);
472 dprintk("RPC: %s: returning %d\n", __func__, err);
477 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
479 struct xdr_netobj c, keyin, keyout;
480 u8 cdata[GSS_KRB5_K5CLENGTH];
483 c.len = GSS_KRB5_K5CLENGTH;
486 keyin.data = ctx->Ksess;
487 keyin.len = ctx->gk5e->keylength;
488 keyout.len = ctx->gk5e->keylength;
490 /* initiator seal encryption */
491 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
492 keyout.data = ctx->initiator_seal;
493 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
495 dprintk("%s: Error %d deriving initiator_seal key\n",
499 ctx->initiator_enc = context_v2_alloc_cipher(ctx,
500 ctx->gk5e->encrypt_name,
501 ctx->initiator_seal);
502 if (ctx->initiator_enc == NULL)
505 /* acceptor seal encryption */
506 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
507 keyout.data = ctx->acceptor_seal;
508 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
510 dprintk("%s: Error %d deriving acceptor_seal key\n",
512 goto out_free_initiator_enc;
514 ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
515 ctx->gk5e->encrypt_name,
517 if (ctx->acceptor_enc == NULL)
518 goto out_free_initiator_enc;
520 /* initiator sign checksum */
521 set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
522 keyout.data = ctx->initiator_sign;
523 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
525 dprintk("%s: Error %d deriving initiator_sign key\n",
527 goto out_free_acceptor_enc;
530 /* acceptor sign checksum */
531 set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
532 keyout.data = ctx->acceptor_sign;
533 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
535 dprintk("%s: Error %d deriving acceptor_sign key\n",
537 goto out_free_acceptor_enc;
540 /* initiator seal integrity */
541 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
542 keyout.data = ctx->initiator_integ;
543 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
545 dprintk("%s: Error %d deriving initiator_integ key\n",
547 goto out_free_acceptor_enc;
550 /* acceptor seal integrity */
551 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
552 keyout.data = ctx->acceptor_integ;
553 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
555 dprintk("%s: Error %d deriving acceptor_integ key\n",
557 goto out_free_acceptor_enc;
560 switch (ctx->enctype) {
561 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
562 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
563 ctx->initiator_enc_aux =
564 context_v2_alloc_cipher(ctx, "cbc(aes)",
565 ctx->initiator_seal);
566 if (ctx->initiator_enc_aux == NULL)
567 goto out_free_acceptor_enc;
568 ctx->acceptor_enc_aux =
569 context_v2_alloc_cipher(ctx, "cbc(aes)",
571 if (ctx->acceptor_enc_aux == NULL) {
572 crypto_free_sync_skcipher(ctx->initiator_enc_aux);
573 goto out_free_acceptor_enc;
579 out_free_acceptor_enc:
580 crypto_free_sync_skcipher(ctx->acceptor_enc);
581 out_free_initiator_enc:
582 crypto_free_sync_skcipher(ctx->initiator_enc);
588 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
595 p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
598 ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
600 p = simple_get_bytes(p, end, &time32, sizeof(time32));
603 /* unsigned 32-bit time overflows in year 2106 */
604 ctx->endtime = (time64_t)time32;
605 p = simple_get_bytes(p, end, &seq_send64, sizeof(seq_send64));
608 atomic64_set(&ctx->seq_send64, seq_send64);
609 /* set seq_send for use by "older" enctypes */
610 atomic_set(&ctx->seq_send, seq_send64);
611 if (seq_send64 != atomic_read(&ctx->seq_send)) {
612 dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__,
613 seq_send64, atomic_read(&ctx->seq_send));
614 p = ERR_PTR(-EINVAL);
617 p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
620 /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
621 if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
622 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
623 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
624 if (ctx->gk5e == NULL) {
625 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
627 p = ERR_PTR(-EINVAL);
630 keylen = ctx->gk5e->keylength;
632 p = simple_get_bytes(p, end, ctx->Ksess, keylen);
637 p = ERR_PTR(-EINVAL);
641 ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
642 gss_kerberos_mech.gm_oid.len, gfp_mask);
643 if (unlikely(ctx->mech_used.data == NULL)) {
644 p = ERR_PTR(-ENOMEM);
647 ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
649 switch (ctx->enctype) {
650 case ENCTYPE_DES3_CBC_RAW:
651 return context_derive_keys_des3(ctx, gfp_mask);
652 case ENCTYPE_ARCFOUR_HMAC:
653 return context_derive_keys_rc4(ctx);
654 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
655 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
656 return context_derive_keys_new(ctx, gfp_mask);
666 gss_import_sec_context_kerberos(const void *p, size_t len,
667 struct gss_ctx *ctx_id,
671 const void *end = (const void *)((const char *)p + len);
672 struct krb5_ctx *ctx;
675 ctx = kzalloc(sizeof(*ctx), gfp_mask);
680 ret = gss_import_v1_context(p, end, ctx);
682 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
685 ctx_id->internal_ctx_id = ctx;
687 *endtime = ctx->endtime;
691 dprintk("RPC: %s: returning %d\n", __func__, ret);
696 gss_delete_sec_context_kerberos(void *internal_ctx) {
697 struct krb5_ctx *kctx = internal_ctx;
699 crypto_free_sync_skcipher(kctx->seq);
700 crypto_free_sync_skcipher(kctx->enc);
701 crypto_free_sync_skcipher(kctx->acceptor_enc);
702 crypto_free_sync_skcipher(kctx->initiator_enc);
703 crypto_free_sync_skcipher(kctx->acceptor_enc_aux);
704 crypto_free_sync_skcipher(kctx->initiator_enc_aux);
705 kfree(kctx->mech_used.data);
709 static const struct gss_api_ops gss_kerberos_ops = {
710 .gss_import_sec_context = gss_import_sec_context_kerberos,
711 .gss_get_mic = gss_get_mic_kerberos,
712 .gss_verify_mic = gss_verify_mic_kerberos,
713 .gss_wrap = gss_wrap_kerberos,
714 .gss_unwrap = gss_unwrap_kerberos,
715 .gss_delete_sec_context = gss_delete_sec_context_kerberos,
718 static struct pf_desc gss_kerberos_pfs[] = {
720 .pseudoflavor = RPC_AUTH_GSS_KRB5,
721 .qop = GSS_C_QOP_DEFAULT,
722 .service = RPC_GSS_SVC_NONE,
726 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
727 .qop = GSS_C_QOP_DEFAULT,
728 .service = RPC_GSS_SVC_INTEGRITY,
733 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
734 .qop = GSS_C_QOP_DEFAULT,
735 .service = RPC_GSS_SVC_PRIVACY,
741 MODULE_ALIAS("rpc-auth-gss-krb5");
742 MODULE_ALIAS("rpc-auth-gss-krb5i");
743 MODULE_ALIAS("rpc-auth-gss-krb5p");
744 MODULE_ALIAS("rpc-auth-gss-390003");
745 MODULE_ALIAS("rpc-auth-gss-390004");
746 MODULE_ALIAS("rpc-auth-gss-390005");
747 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
749 static struct gss_api_mech gss_kerberos_mech = {
751 .gm_owner = THIS_MODULE,
752 .gm_oid = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
753 .gm_ops = &gss_kerberos_ops,
754 .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
755 .gm_pfs = gss_kerberos_pfs,
756 .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
759 static int __init init_kerberos_module(void)
763 status = gss_mech_register(&gss_kerberos_mech);
765 printk("Failed to register kerberos gss mechanism!\n");
769 static void __exit cleanup_kerberos_module(void)
771 gss_mech_unregister(&gss_kerberos_mech);
774 MODULE_LICENSE("GPL");
775 module_init(init_kerberos_module);
776 module_exit(cleanup_kerberos_module);