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_DES3_CBC_RAW,
61 .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
62 .name = "des3-hmac-sha1",
63 .encrypt_name = "cbc(des3_ede)",
64 .cksum_name = "hmac(sha1)",
65 .encrypt = krb5_encrypt,
66 .decrypt = krb5_decrypt,
67 .mk_key = gss_krb5_des3_make_key,
68 .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
69 .sealalg = SEAL_ALG_DES3KD,
81 .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
82 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
84 .encrypt_name = "cts(cbc(aes))",
85 .cksum_name = "hmac(sha1)",
86 .encrypt = krb5_encrypt,
87 .decrypt = krb5_decrypt,
88 .mk_key = gss_krb5_aes_make_key,
89 .encrypt_v2 = gss_krb5_aes_encrypt,
90 .decrypt_v2 = gss_krb5_aes_decrypt,
104 .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
105 .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
106 .name = "aes256-cts",
107 .encrypt_name = "cts(cbc(aes))",
108 .cksum_name = "hmac(sha1)",
109 .encrypt = krb5_encrypt,
110 .decrypt = krb5_decrypt,
111 .mk_key = gss_krb5_aes_make_key,
112 .encrypt_v2 = gss_krb5_aes_encrypt,
113 .decrypt_v2 = gss_krb5_aes_decrypt,
125 static const int num_supported_enctypes =
126 ARRAY_SIZE(supported_gss_krb5_enctypes);
129 supported_gss_krb5_enctype(int etype)
132 for (i = 0; i < num_supported_enctypes; i++)
133 if (supported_gss_krb5_enctypes[i].etype == etype)
138 static const struct gss_krb5_enctype *
139 get_gss_krb5_enctype(int etype)
142 for (i = 0; i < num_supported_enctypes; i++)
143 if (supported_gss_krb5_enctypes[i].etype == etype)
144 return &supported_gss_krb5_enctypes[i];
148 static inline const void *
149 get_key(const void *p, const void *end,
150 struct krb5_ctx *ctx, struct crypto_sync_skcipher **res)
152 struct xdr_netobj key;
155 p = simple_get_bytes(p, end, &alg, sizeof(alg));
160 case ENCTYPE_DES_CBC_CRC:
161 case ENCTYPE_DES_CBC_MD4:
162 case ENCTYPE_DES_CBC_MD5:
163 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
164 alg = ENCTYPE_DES_CBC_RAW;
168 if (!supported_gss_krb5_enctype(alg)) {
169 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
170 "encryption key algorithm %d\n", alg);
171 p = ERR_PTR(-EINVAL);
174 p = simple_get_netobj(p, end, &key);
178 *res = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
180 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
181 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
183 goto out_err_free_key;
185 if (crypto_sync_skcipher_setkey(*res, key.data, key.len)) {
186 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
187 "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
188 goto out_err_free_tfm;
195 crypto_free_sync_skcipher(*res);
198 p = ERR_PTR(-EINVAL);
204 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
210 p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
214 /* Old format supports only DES! Any other enctype uses new format */
215 ctx->enctype = ENCTYPE_DES_CBC_RAW;
217 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
218 if (ctx->gk5e == NULL) {
219 p = ERR_PTR(-EINVAL);
223 /* The downcall format was designed before we completely understood
224 * the uses of the context fields; so it includes some stuff we
225 * just give some minimal sanity-checking, and some we ignore
226 * completely (like the next twenty bytes): */
227 if (unlikely(p + 20 > end || p + 20 < p)) {
228 p = ERR_PTR(-EFAULT);
232 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
235 if (tmp != SGN_ALG_DES_MAC_MD5) {
236 p = ERR_PTR(-ENOSYS);
239 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
242 if (tmp != SEAL_ALG_DES) {
243 p = ERR_PTR(-ENOSYS);
246 p = simple_get_bytes(p, end, &time32, sizeof(time32));
249 /* unsigned 32-bit time overflows in year 2106 */
250 ctx->endtime = (time64_t)time32;
251 p = simple_get_bytes(p, end, &seq_send, sizeof(seq_send));
254 atomic_set(&ctx->seq_send, seq_send);
255 p = simple_get_netobj(p, end, &ctx->mech_used);
258 p = get_key(p, end, ctx, &ctx->enc);
260 goto out_err_free_mech;
261 p = get_key(p, end, ctx, &ctx->seq);
263 goto out_err_free_key1;
265 p = ERR_PTR(-EFAULT);
266 goto out_err_free_key2;
272 crypto_free_sync_skcipher(ctx->seq);
274 crypto_free_sync_skcipher(ctx->enc);
276 kfree(ctx->mech_used.data);
281 static struct crypto_sync_skcipher *
282 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
284 struct crypto_sync_skcipher *cp;
286 cp = crypto_alloc_sync_skcipher(cname, 0, 0);
288 dprintk("gss_kerberos_mech: unable to initialize "
289 "crypto algorithm %s\n", cname);
292 if (crypto_sync_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
293 dprintk("gss_kerberos_mech: error setting key for "
294 "crypto algorithm %s\n", cname);
295 crypto_free_sync_skcipher(cp);
302 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
304 cdata[0] = (usage>>24)&0xff;
305 cdata[1] = (usage>>16)&0xff;
306 cdata[2] = (usage>>8)&0xff;
307 cdata[3] = usage&0xff;
312 context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
314 struct xdr_netobj c, keyin, keyout;
315 u8 cdata[GSS_KRB5_K5CLENGTH];
318 c.len = GSS_KRB5_K5CLENGTH;
321 keyin.data = ctx->Ksess;
322 keyin.len = ctx->gk5e->keylength;
323 keyout.len = ctx->gk5e->keylength;
325 /* seq uses the raw key */
326 ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
328 if (ctx->seq == NULL)
331 ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
333 if (ctx->enc == NULL)
337 set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
338 keyout.data = ctx->cksum;
339 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
341 dprintk("%s: Error %d deriving cksum key\n",
349 crypto_free_sync_skcipher(ctx->enc);
351 crypto_free_sync_skcipher(ctx->seq);
357 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
359 struct xdr_netobj c, keyin, keyout;
360 u8 cdata[GSS_KRB5_K5CLENGTH];
363 c.len = GSS_KRB5_K5CLENGTH;
366 keyin.data = ctx->Ksess;
367 keyin.len = ctx->gk5e->keylength;
368 keyout.len = ctx->gk5e->keylength;
370 /* initiator seal encryption */
371 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
372 keyout.data = ctx->initiator_seal;
373 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
375 dprintk("%s: Error %d deriving initiator_seal key\n",
379 ctx->initiator_enc = context_v2_alloc_cipher(ctx,
380 ctx->gk5e->encrypt_name,
381 ctx->initiator_seal);
382 if (ctx->initiator_enc == NULL)
385 /* acceptor seal encryption */
386 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
387 keyout.data = ctx->acceptor_seal;
388 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
390 dprintk("%s: Error %d deriving acceptor_seal key\n",
392 goto out_free_initiator_enc;
394 ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
395 ctx->gk5e->encrypt_name,
397 if (ctx->acceptor_enc == NULL)
398 goto out_free_initiator_enc;
400 /* initiator sign checksum */
401 set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
402 keyout.data = ctx->initiator_sign;
403 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
405 dprintk("%s: Error %d deriving initiator_sign key\n",
407 goto out_free_acceptor_enc;
410 /* acceptor sign checksum */
411 set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
412 keyout.data = ctx->acceptor_sign;
413 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
415 dprintk("%s: Error %d deriving acceptor_sign key\n",
417 goto out_free_acceptor_enc;
420 /* initiator seal integrity */
421 set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
422 keyout.data = ctx->initiator_integ;
423 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
425 dprintk("%s: Error %d deriving initiator_integ key\n",
427 goto out_free_acceptor_enc;
430 /* acceptor seal integrity */
431 set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
432 keyout.data = ctx->acceptor_integ;
433 err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
435 dprintk("%s: Error %d deriving acceptor_integ key\n",
437 goto out_free_acceptor_enc;
440 switch (ctx->enctype) {
441 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
442 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
443 ctx->initiator_enc_aux =
444 context_v2_alloc_cipher(ctx, "cbc(aes)",
445 ctx->initiator_seal);
446 if (ctx->initiator_enc_aux == NULL)
447 goto out_free_acceptor_enc;
448 ctx->acceptor_enc_aux =
449 context_v2_alloc_cipher(ctx, "cbc(aes)",
451 if (ctx->acceptor_enc_aux == NULL) {
452 crypto_free_sync_skcipher(ctx->initiator_enc_aux);
453 goto out_free_acceptor_enc;
459 out_free_acceptor_enc:
460 crypto_free_sync_skcipher(ctx->acceptor_enc);
461 out_free_initiator_enc:
462 crypto_free_sync_skcipher(ctx->initiator_enc);
468 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
475 p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
478 ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
480 p = simple_get_bytes(p, end, &time32, sizeof(time32));
483 /* unsigned 32-bit time overflows in year 2106 */
484 ctx->endtime = (time64_t)time32;
485 p = simple_get_bytes(p, end, &seq_send64, sizeof(seq_send64));
488 atomic64_set(&ctx->seq_send64, seq_send64);
489 /* set seq_send for use by "older" enctypes */
490 atomic_set(&ctx->seq_send, seq_send64);
491 if (seq_send64 != atomic_read(&ctx->seq_send)) {
492 dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__,
493 seq_send64, atomic_read(&ctx->seq_send));
494 p = ERR_PTR(-EINVAL);
497 p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
500 /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
501 if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
502 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
503 ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
504 if (ctx->gk5e == NULL) {
505 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
507 p = ERR_PTR(-EINVAL);
510 keylen = ctx->gk5e->keylength;
512 p = simple_get_bytes(p, end, ctx->Ksess, keylen);
517 p = ERR_PTR(-EINVAL);
521 ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
522 gss_kerberos_mech.gm_oid.len, gfp_mask);
523 if (unlikely(ctx->mech_used.data == NULL)) {
524 p = ERR_PTR(-ENOMEM);
527 ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
529 switch (ctx->enctype) {
530 case ENCTYPE_DES3_CBC_RAW:
531 return context_derive_keys_des3(ctx, gfp_mask);
532 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
533 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
534 return context_derive_keys_new(ctx, gfp_mask);
544 gss_import_sec_context_kerberos(const void *p, size_t len,
545 struct gss_ctx *ctx_id,
549 const void *end = (const void *)((const char *)p + len);
550 struct krb5_ctx *ctx;
553 ctx = kzalloc(sizeof(*ctx), gfp_mask);
558 ret = gss_import_v1_context(p, end, ctx);
560 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
563 ctx_id->internal_ctx_id = ctx;
565 *endtime = ctx->endtime;
569 dprintk("RPC: %s: returning %d\n", __func__, ret);
574 gss_delete_sec_context_kerberos(void *internal_ctx) {
575 struct krb5_ctx *kctx = internal_ctx;
577 crypto_free_sync_skcipher(kctx->seq);
578 crypto_free_sync_skcipher(kctx->enc);
579 crypto_free_sync_skcipher(kctx->acceptor_enc);
580 crypto_free_sync_skcipher(kctx->initiator_enc);
581 crypto_free_sync_skcipher(kctx->acceptor_enc_aux);
582 crypto_free_sync_skcipher(kctx->initiator_enc_aux);
583 kfree(kctx->mech_used.data);
587 static const struct gss_api_ops gss_kerberos_ops = {
588 .gss_import_sec_context = gss_import_sec_context_kerberos,
589 .gss_get_mic = gss_get_mic_kerberos,
590 .gss_verify_mic = gss_verify_mic_kerberos,
591 .gss_wrap = gss_wrap_kerberos,
592 .gss_unwrap = gss_unwrap_kerberos,
593 .gss_delete_sec_context = gss_delete_sec_context_kerberos,
596 static struct pf_desc gss_kerberos_pfs[] = {
598 .pseudoflavor = RPC_AUTH_GSS_KRB5,
599 .qop = GSS_C_QOP_DEFAULT,
600 .service = RPC_GSS_SVC_NONE,
604 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
605 .qop = GSS_C_QOP_DEFAULT,
606 .service = RPC_GSS_SVC_INTEGRITY,
611 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
612 .qop = GSS_C_QOP_DEFAULT,
613 .service = RPC_GSS_SVC_PRIVACY,
619 MODULE_ALIAS("rpc-auth-gss-krb5");
620 MODULE_ALIAS("rpc-auth-gss-krb5i");
621 MODULE_ALIAS("rpc-auth-gss-krb5p");
622 MODULE_ALIAS("rpc-auth-gss-390003");
623 MODULE_ALIAS("rpc-auth-gss-390004");
624 MODULE_ALIAS("rpc-auth-gss-390005");
625 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
627 static struct gss_api_mech gss_kerberos_mech = {
629 .gm_owner = THIS_MODULE,
630 .gm_oid = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
631 .gm_ops = &gss_kerberos_ops,
632 .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
633 .gm_pfs = gss_kerberos_pfs,
634 .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
637 static int __init init_kerberos_module(void)
641 status = gss_mech_register(&gss_kerberos_mech);
643 printk("Failed to register kerberos gss mechanism!\n");
647 static void __exit cleanup_kerberos_module(void)
649 gss_mech_unregister(&gss_kerberos_mech);
652 MODULE_LICENSE("GPL");
653 module_init(init_kerberos_module);
654 module_exit(cleanup_kerberos_module);