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 #include "auth_gss_internal.h"
26 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
27 # define RPCDBG_FACILITY RPCDBG_AUTH
30 static struct gss_api_mech gss_kerberos_mech; /* forward declaration */
32 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
33 #ifndef CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES
35 * DES (All DES enctypes are mapped to the same gss functionality)
38 .etype = ENCTYPE_DES_CBC_RAW,
39 .ctype = CKSUMTYPE_RSA_MD5,
40 .name = "des-cbc-crc",
41 .encrypt_name = "cbc(des)",
43 .encrypt = krb5_encrypt,
44 .decrypt = krb5_decrypt,
46 .signalg = SGN_ALG_DES_MAC_MD5,
47 .sealalg = SEAL_ALG_DES,
55 #endif /* CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES */
60 .etype = ENCTYPE_ARCFOUR_HMAC,
61 .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
63 .encrypt_name = "ecb(arc4)",
64 .cksum_name = "hmac(md5)",
65 .encrypt = krb5_encrypt,
66 .decrypt = krb5_decrypt,
68 .signalg = SGN_ALG_HMAC_MD5,
69 .sealalg = SEAL_ALG_MICROSOFT_RC4,
81 .etype = ENCTYPE_DES3_CBC_RAW,
82 .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
83 .name = "des3-hmac-sha1",
84 .encrypt_name = "cbc(des3_ede)",
85 .cksum_name = "hmac(sha1)",
86 .encrypt = krb5_encrypt,
87 .decrypt = krb5_decrypt,
88 .mk_key = gss_krb5_des3_make_key,
89 .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
90 .sealalg = SEAL_ALG_DES3KD,
102 .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
103 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
104 .name = "aes128-cts",
105 .encrypt_name = "cts(cbc(aes))",
106 .cksum_name = "hmac(sha1)",
107 .encrypt = krb5_encrypt,
108 .decrypt = krb5_decrypt,
109 .mk_key = gss_krb5_aes_make_key,
110 .encrypt_v2 = gss_krb5_aes_encrypt,
111 .decrypt_v2 = gss_krb5_aes_decrypt,
125 .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
126 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
127 .name = "aes256-cts",
128 .encrypt_name = "cts(cbc(aes))",
129 .cksum_name = "hmac(sha1)",
130 .encrypt = krb5_encrypt,
131 .decrypt = krb5_decrypt,
132 .mk_key = gss_krb5_aes_make_key,
133 .encrypt_v2 = gss_krb5_aes_encrypt,
134 .decrypt_v2 = gss_krb5_aes_decrypt,
146 static const int num_supported_enctypes =
147 ARRAY_SIZE(supported_gss_krb5_enctypes);
150 supported_gss_krb5_enctype(int etype)
153 for (i = 0; i < num_supported_enctypes; i++)
154 if (supported_gss_krb5_enctypes[i].etype == etype)
159 static const struct gss_krb5_enctype *
160 get_gss_krb5_enctype(int etype)
163 for (i = 0; i < num_supported_enctypes; i++)
164 if (supported_gss_krb5_enctypes[i].etype == etype)
165 return &supported_gss_krb5_enctypes[i];
169 static inline const void *
170 get_key(const void *p, const void *end,
171 struct krb5_ctx *ctx, struct crypto_sync_skcipher **res)
173 struct xdr_netobj key;
176 p = simple_get_bytes(p, end, &alg, sizeof(alg));
181 case ENCTYPE_DES_CBC_CRC:
182 case ENCTYPE_DES_CBC_MD4:
183 case ENCTYPE_DES_CBC_MD5:
184 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
185 alg = ENCTYPE_DES_CBC_RAW;
189 if (!supported_gss_krb5_enctype(alg)) {
190 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
191 "encryption key algorithm %d\n", alg);
192 p = ERR_PTR(-EINVAL);
195 p = simple_get_netobj(p, end, &key);
199 *res = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
201 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
202 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
204 goto out_err_free_key;
206 if (crypto_sync_skcipher_setkey(*res, key.data, key.len)) {
207 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
208 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
209 goto out_err_free_tfm;
216 crypto_free_sync_skcipher(*res);
219 p = ERR_PTR(-EINVAL);
225 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
230 p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
234 /* Old format supports only DES! Any other enctype uses new format */
235 ctx->enctype = ENCTYPE_DES_CBC_RAW;
237 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
238 if (ctx->gk5e == NULL) {
239 p = ERR_PTR(-EINVAL);
243 /* The downcall format was designed before we completely understood
244 * the uses of the context fields; so it includes some stuff we
245 * just give some minimal sanity-checking, and some we ignore
246 * completely (like the next twenty bytes): */
247 if (unlikely(p + 20 > end || p + 20 < p)) {
248 p = ERR_PTR(-EFAULT);
252 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
255 if (tmp != SGN_ALG_DES_MAC_MD5) {
256 p = ERR_PTR(-ENOSYS);
259 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
262 if (tmp != SEAL_ALG_DES) {
263 p = ERR_PTR(-ENOSYS);
266 p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
269 p = simple_get_bytes(p, end, &seq_send, sizeof(seq_send));
272 atomic_set(&ctx->seq_send, seq_send);
273 p = simple_get_netobj(p, end, &ctx->mech_used);
276 p = get_key(p, end, ctx, &ctx->enc);
278 goto out_err_free_mech;
279 p = get_key(p, end, ctx, &ctx->seq);
281 goto out_err_free_key1;
283 p = ERR_PTR(-EFAULT);
284 goto out_err_free_key2;
290 crypto_free_sync_skcipher(ctx->seq);
292 crypto_free_sync_skcipher(ctx->enc);
294 kfree(ctx->mech_used.data);
299 static struct crypto_sync_skcipher *
300 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
302 struct crypto_sync_skcipher *cp;
304 cp = crypto_alloc_sync_skcipher(cname, 0, 0);
306 dprintk("gss_kerberos_mech: unable to initialize "
307 "crypto algorithm %s\n", cname);
310 if (crypto_sync_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
311 dprintk("gss_kerberos_mech: error setting key for "
312 "crypto algorithm %s\n", cname);
313 crypto_free_sync_skcipher(cp);
320 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
322 cdata[0] = (usage>>24)&0xff;
323 cdata[1] = (usage>>16)&0xff;
324 cdata[2] = (usage>>8)&0xff;
325 cdata[3] = usage&0xff;
330 context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
332 struct xdr_netobj c, keyin, keyout;
333 u8 cdata[GSS_KRB5_K5CLENGTH];
336 c.len = GSS_KRB5_K5CLENGTH;
339 keyin.data = ctx->Ksess;
340 keyin.len = ctx->gk5e->keylength;
341 keyout.len = ctx->gk5e->keylength;
343 /* seq uses the raw key */
344 ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
346 if (ctx->seq == NULL)
349 ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
351 if (ctx->enc == NULL)
355 set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
356 keyout.data = ctx->cksum;
357 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
359 dprintk("%s: Error %d deriving cksum key\n",
367 crypto_free_sync_skcipher(ctx->enc);
369 crypto_free_sync_skcipher(ctx->seq);
375 * Note that RC4 depends on deriving keys using the sequence
376 * number or the checksum of a token. Therefore, the final keys
377 * cannot be calculated until the token is being constructed!
380 context_derive_keys_rc4(struct krb5_ctx *ctx)
382 struct crypto_shash *hmac;
383 char sigkeyconstant[] = "signaturekey";
384 int slen = strlen(sigkeyconstant) + 1; /* include null terminator */
385 struct shash_desc *desc;
388 dprintk("RPC: %s: entered\n", __func__);
390 * derive cksum (aka Ksign) key
392 hmac = crypto_alloc_shash(ctx->gk5e->cksum_name, 0, 0);
394 dprintk("%s: error %ld allocating hash '%s'\n",
395 __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
400 err = crypto_shash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
402 goto out_err_free_hmac;
405 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac), GFP_NOFS);
407 dprintk("%s: failed to allocate hash descriptor for '%s'\n",
408 __func__, ctx->gk5e->cksum_name);
410 goto out_err_free_hmac;
415 err = crypto_shash_digest(desc, sigkeyconstant, slen, ctx->cksum);
418 goto out_err_free_hmac;
420 * allocate hash, and skciphers for data and seqnum encryption
422 ctx->enc = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
423 if (IS_ERR(ctx->enc)) {
424 err = PTR_ERR(ctx->enc);
425 goto out_err_free_hmac;
428 ctx->seq = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
429 if (IS_ERR(ctx->seq)) {
430 crypto_free_sync_skcipher(ctx->enc);
431 err = PTR_ERR(ctx->seq);
432 goto out_err_free_hmac;
435 dprintk("RPC: %s: returning success\n", __func__);
440 crypto_free_shash(hmac);
442 dprintk("RPC: %s: returning %d\n", __func__, err);
447 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
449 struct xdr_netobj c, keyin, keyout;
450 u8 cdata[GSS_KRB5_K5CLENGTH];
453 c.len = GSS_KRB5_K5CLENGTH;
456 keyin.data = ctx->Ksess;
457 keyin.len = ctx->gk5e->keylength;
458 keyout.len = ctx->gk5e->keylength;
460 /* initiator seal encryption */
461 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
462 keyout.data = ctx->initiator_seal;
463 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
465 dprintk("%s: Error %d deriving initiator_seal key\n",
469 ctx->initiator_enc = context_v2_alloc_cipher(ctx,
470 ctx->gk5e->encrypt_name,
471 ctx->initiator_seal);
472 if (ctx->initiator_enc == NULL)
475 /* acceptor seal encryption */
476 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
477 keyout.data = ctx->acceptor_seal;
478 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
480 dprintk("%s: Error %d deriving acceptor_seal key\n",
482 goto out_free_initiator_enc;
484 ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
485 ctx->gk5e->encrypt_name,
487 if (ctx->acceptor_enc == NULL)
488 goto out_free_initiator_enc;
490 /* initiator sign checksum */
491 set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
492 keyout.data = ctx->initiator_sign;
493 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
495 dprintk("%s: Error %d deriving initiator_sign key\n",
497 goto out_free_acceptor_enc;
500 /* acceptor sign checksum */
501 set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
502 keyout.data = ctx->acceptor_sign;
503 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
505 dprintk("%s: Error %d deriving acceptor_sign key\n",
507 goto out_free_acceptor_enc;
510 /* initiator seal integrity */
511 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
512 keyout.data = ctx->initiator_integ;
513 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
515 dprintk("%s: Error %d deriving initiator_integ key\n",
517 goto out_free_acceptor_enc;
520 /* acceptor seal integrity */
521 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
522 keyout.data = ctx->acceptor_integ;
523 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
525 dprintk("%s: Error %d deriving acceptor_integ key\n",
527 goto out_free_acceptor_enc;
530 switch (ctx->enctype) {
531 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
532 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
533 ctx->initiator_enc_aux =
534 context_v2_alloc_cipher(ctx, "cbc(aes)",
535 ctx->initiator_seal);
536 if (ctx->initiator_enc_aux == NULL)
537 goto out_free_acceptor_enc;
538 ctx->acceptor_enc_aux =
539 context_v2_alloc_cipher(ctx, "cbc(aes)",
541 if (ctx->acceptor_enc_aux == NULL) {
542 crypto_free_sync_skcipher(ctx->initiator_enc_aux);
543 goto out_free_acceptor_enc;
549 out_free_acceptor_enc:
550 crypto_free_sync_skcipher(ctx->acceptor_enc);
551 out_free_initiator_enc:
552 crypto_free_sync_skcipher(ctx->initiator_enc);
558 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
564 p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
567 ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
569 p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
572 p = simple_get_bytes(p, end, &seq_send64, sizeof(seq_send64));
575 atomic64_set(&ctx->seq_send64, seq_send64);
576 /* set seq_send for use by "older" enctypes */
577 atomic_set(&ctx->seq_send, seq_send64);
578 if (seq_send64 != atomic_read(&ctx->seq_send)) {
579 dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__,
580 seq_send64, atomic_read(&ctx->seq_send));
581 p = ERR_PTR(-EINVAL);
584 p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
587 /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
588 if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
589 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
590 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
591 if (ctx->gk5e == NULL) {
592 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
594 p = ERR_PTR(-EINVAL);
597 keylen = ctx->gk5e->keylength;
599 p = simple_get_bytes(p, end, ctx->Ksess, keylen);
604 p = ERR_PTR(-EINVAL);
608 ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
609 gss_kerberos_mech.gm_oid.len, gfp_mask);
610 if (unlikely(ctx->mech_used.data == NULL)) {
611 p = ERR_PTR(-ENOMEM);
614 ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
616 switch (ctx->enctype) {
617 case ENCTYPE_DES3_CBC_RAW:
618 return context_derive_keys_des3(ctx, gfp_mask);
619 case ENCTYPE_ARCFOUR_HMAC:
620 return context_derive_keys_rc4(ctx);
621 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
622 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
623 return context_derive_keys_new(ctx, gfp_mask);
633 gss_import_sec_context_kerberos(const void *p, size_t len,
634 struct gss_ctx *ctx_id,
638 const void *end = (const void *)((const char *)p + len);
639 struct krb5_ctx *ctx;
642 ctx = kzalloc(sizeof(*ctx), gfp_mask);
647 ret = gss_import_v1_context(p, end, ctx);
649 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
652 ctx_id->internal_ctx_id = ctx;
654 *endtime = ctx->endtime;
658 dprintk("RPC: %s: returning %d\n", __func__, ret);
663 gss_delete_sec_context_kerberos(void *internal_ctx) {
664 struct krb5_ctx *kctx = internal_ctx;
666 crypto_free_sync_skcipher(kctx->seq);
667 crypto_free_sync_skcipher(kctx->enc);
668 crypto_free_sync_skcipher(kctx->acceptor_enc);
669 crypto_free_sync_skcipher(kctx->initiator_enc);
670 crypto_free_sync_skcipher(kctx->acceptor_enc_aux);
671 crypto_free_sync_skcipher(kctx->initiator_enc_aux);
672 kfree(kctx->mech_used.data);
676 static const struct gss_api_ops gss_kerberos_ops = {
677 .gss_import_sec_context = gss_import_sec_context_kerberos,
678 .gss_get_mic = gss_get_mic_kerberos,
679 .gss_verify_mic = gss_verify_mic_kerberos,
680 .gss_wrap = gss_wrap_kerberos,
681 .gss_unwrap = gss_unwrap_kerberos,
682 .gss_delete_sec_context = gss_delete_sec_context_kerberos,
685 static struct pf_desc gss_kerberos_pfs[] = {
687 .pseudoflavor = RPC_AUTH_GSS_KRB5,
688 .qop = GSS_C_QOP_DEFAULT,
689 .service = RPC_GSS_SVC_NONE,
693 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
694 .qop = GSS_C_QOP_DEFAULT,
695 .service = RPC_GSS_SVC_INTEGRITY,
700 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
701 .qop = GSS_C_QOP_DEFAULT,
702 .service = RPC_GSS_SVC_PRIVACY,
708 MODULE_ALIAS("rpc-auth-gss-krb5");
709 MODULE_ALIAS("rpc-auth-gss-krb5i");
710 MODULE_ALIAS("rpc-auth-gss-krb5p");
711 MODULE_ALIAS("rpc-auth-gss-390003");
712 MODULE_ALIAS("rpc-auth-gss-390004");
713 MODULE_ALIAS("rpc-auth-gss-390005");
714 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
716 static struct gss_api_mech gss_kerberos_mech = {
718 .gm_owner = THIS_MODULE,
719 .gm_oid = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
720 .gm_ops = &gss_kerberos_ops,
721 .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
722 .gm_pfs = gss_kerberos_pfs,
723 .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
726 static int __init init_kerberos_module(void)
730 status = gss_mech_register(&gss_kerberos_mech);
732 printk("Failed to register kerberos gss mechanism!\n");
736 static void __exit cleanup_kerberos_module(void)
738 gss_mech_unregister(&gss_kerberos_mech);
741 MODULE_LICENSE("GPL");
742 module_init(init_kerberos_module);
743 module_exit(cleanup_kerberos_module);