net/sunrpc/auth_gss/gss_krb5_mech.c

   1 /*
   2  *  linux/net/sunrpc/gss_krb5_mech.c
   3  *
   4  *  Copyright (c) 2001-2008 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Andy Adamson <andros@umich.edu>
   8  *  J. Bruce Fields <bfields@umich.edu>
   9  *
  10  *  Redistribution and use in source and binary forms, with or without
  11  *  modification, are permitted provided that the following conditions
  12  *  are met:
  13  *
  14  *  1. Redistributions of source code must retain the above copyright
  15  *     notice, this list of conditions and the following disclaimer.
  16  *  2. Redistributions in binary form must reproduce the above copyright
  17  *     notice, this list of conditions and the following disclaimer in the
  18  *     documentation and/or other materials provided with the distribution.
  19  *  3. Neither the name of the University nor the names of its
  20  *     contributors may be used to endorse or promote products derived
  21  *     from this software without specific prior written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  */
  36
  37 #include <crypto/hash.h>
  38 #include <crypto/skcipher.h>
  39 #include <linux/err.h>
  40 #include <linux/module.h>
  41 #include <linux/init.h>
  42 #include <linux/types.h>
  43 #include <linux/slab.h>
  44 #include <linux/sunrpc/auth.h>
  45 #include <linux/sunrpc/gss_krb5.h>
  46 #include <linux/sunrpc/xdr.h>
  47 #include <linux/sunrpc/gss_krb5_enctypes.h>
  48
  49 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  50 # define RPCDBG_FACILITY        RPCDBG_AUTH
  51 #endif
  52
  53 static struct gss_api_mech gss_kerberos_mech;   /* forward declaration */
  54
  55 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
  56         /*
  57          * DES (All DES enctypes are mapped to the same gss functionality)
  58          */
  59         {
  60           .etype = ENCTYPE_DES_CBC_RAW,
  61           .ctype = CKSUMTYPE_RSA_MD5,
  62           .name = "des-cbc-crc",
  63           .encrypt_name = "cbc(des)",
  64           .cksum_name = "md5",
  65           .encrypt = krb5_encrypt,
  66           .decrypt = krb5_decrypt,
  67           .mk_key = NULL,
  68           .signalg = SGN_ALG_DES_MAC_MD5,
  69           .sealalg = SEAL_ALG_DES,
  70           .keybytes = 7,
  71           .keylength = 8,
  72           .blocksize = 8,
  73           .conflen = 8,
  74           .cksumlength = 8,
  75           .keyed_cksum = 0,
  76         },
  77         /*
  78          * RC4-HMAC
  79          */
  80         {
  81           .etype = ENCTYPE_ARCFOUR_HMAC,
  82           .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
  83           .name = "rc4-hmac",
  84           .encrypt_name = "ecb(arc4)",
  85           .cksum_name = "hmac(md5)",
  86           .encrypt = krb5_encrypt,
  87           .decrypt = krb5_decrypt,
  88           .mk_key = NULL,
  89           .signalg = SGN_ALG_HMAC_MD5,
  90           .sealalg = SEAL_ALG_MICROSOFT_RC4,
  91           .keybytes = 16,
  92           .keylength = 16,
  93           .blocksize = 1,
  94           .conflen = 8,
  95           .cksumlength = 8,
  96           .keyed_cksum = 1,
  97         },
  98         /*
  99          * 3DES
 100          */
 101         {
 102           .etype = ENCTYPE_DES3_CBC_RAW,
 103           .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
 104           .name = "des3-hmac-sha1",
 105           .encrypt_name = "cbc(des3_ede)",
 106           .cksum_name = "hmac(sha1)",
 107           .encrypt = krb5_encrypt,
 108           .decrypt = krb5_decrypt,
 109           .mk_key = gss_krb5_des3_make_key,
 110           .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
 111           .sealalg = SEAL_ALG_DES3KD,
 112           .keybytes = 21,
 113           .keylength = 24,
 114           .blocksize = 8,
 115           .conflen = 8,
 116           .cksumlength = 20,
 117           .keyed_cksum = 1,
 118         },
 119         /*
 120          * AES128
 121          */
 122         {
 123           .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
 124           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
 125           .name = "aes128-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,
 133           .signalg = -1,
 134           .sealalg = -1,
 135           .keybytes = 16,
 136           .keylength = 16,
 137           .blocksize = 16,
 138           .conflen = 16,
 139           .cksumlength = 12,
 140           .keyed_cksum = 1,
 141         },
 142         /*
 143          * AES256
 144          */
 145         {
 146           .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
 147           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
 148           .name = "aes256-cts",
 149           .encrypt_name = "cts(cbc(aes))",
 150           .cksum_name = "hmac(sha1)",
 151           .encrypt = krb5_encrypt,
 152           .decrypt = krb5_decrypt,
 153           .mk_key = gss_krb5_aes_make_key,
 154           .encrypt_v2 = gss_krb5_aes_encrypt,
 155           .decrypt_v2 = gss_krb5_aes_decrypt,
 156           .signalg = -1,
 157           .sealalg = -1,
 158           .keybytes = 32,
 159           .keylength = 32,
 160           .blocksize = 16,
 161           .conflen = 16,
 162           .cksumlength = 12,
 163           .keyed_cksum = 1,
 164         },
 165 };
 166
 167 static const int num_supported_enctypes =
 168         ARRAY_SIZE(supported_gss_krb5_enctypes);
 169
 170 static int
 171 supported_gss_krb5_enctype(int etype)
 172 {
 173         int i;
 174         for (i = 0; i < num_supported_enctypes; i++)
 175                 if (supported_gss_krb5_enctypes[i].etype == etype)
 176                         return 1;
 177         return 0;
 178 }
 179
 180 static const struct gss_krb5_enctype *
 181 get_gss_krb5_enctype(int etype)
 182 {
 183         int i;
 184         for (i = 0; i < num_supported_enctypes; i++)
 185                 if (supported_gss_krb5_enctypes[i].etype == etype)
 186                         return &supported_gss_krb5_enctypes[i];
 187         return NULL;
 188 }
 189
 190 static const void *
 191 simple_get_bytes(const void *p, const void *end, void *res, int len)
 192 {
 193         const void *q = (const void *)((const char *)p + len);
 194         if (unlikely(q > end || q < p))
 195                 return ERR_PTR(-EFAULT);
 196         memcpy(res, p, len);
 197         return q;
 198 }
 199
 200 static const void *
 201 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
 202 {
 203         const void *q;
 204         unsigned int len;
 205
 206         p = simple_get_bytes(p, end, &len, sizeof(len));
 207         if (IS_ERR(p))
 208                 return p;
 209         q = (const void *)((const char *)p + len);
 210         if (unlikely(q > end || q < p))
 211                 return ERR_PTR(-EFAULT);
 212         res->data = kmemdup(p, len, GFP_NOFS);
 213         if (unlikely(res->data == NULL))
 214                 return ERR_PTR(-ENOMEM);
 215         res->len = len;
 216         return q;
 217 }
 218
 219 static inline const void *
 220 get_key(const void *p, const void *end,
 221         struct krb5_ctx *ctx, struct crypto_skcipher **res)
 222 {
 223         struct xdr_netobj       key;
 224         int                     alg;
 225
 226         p = simple_get_bytes(p, end, &alg, sizeof(alg));
 227         if (IS_ERR(p))
 228                 goto out_err;
 229
 230         switch (alg) {
 231         case ENCTYPE_DES_CBC_CRC:
 232         case ENCTYPE_DES_CBC_MD4:
 233         case ENCTYPE_DES_CBC_MD5:
 234                 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
 235                 alg = ENCTYPE_DES_CBC_RAW;
 236                 break;
 237         }
 238
 239         if (!supported_gss_krb5_enctype(alg)) {
 240                 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
 241                         "encryption key algorithm %d\n", alg);
 242                 p = ERR_PTR(-EINVAL);
 243                 goto out_err;
 244         }
 245         p = simple_get_netobj(p, end, &key);
 246         if (IS_ERR(p))
 247                 goto out_err;
 248
 249         *res = crypto_alloc_skcipher(ctx->gk5e->encrypt_name, 0,
 250                                                         CRYPTO_ALG_ASYNC);
 251         if (IS_ERR(*res)) {
 252                 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
 253                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 254                 *res = NULL;
 255                 goto out_err_free_key;
 256         }
 257         if (crypto_skcipher_setkey(*res, key.data, key.len)) {
 258                 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
 259                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 260                 goto out_err_free_tfm;
 261         }
 262
 263         kfree(key.data);
 264         return p;
 265
 266 out_err_free_tfm:
 267         crypto_free_skcipher(*res);
 268 out_err_free_key:
 269         kfree(key.data);
 270         p = ERR_PTR(-EINVAL);
 271 out_err:
 272         return p;
 273 }
 274
 275 static int
 276 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 277 {
 278         int tmp;
 279
 280         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 281         if (IS_ERR(p))
 282                 goto out_err;
 283
 284         /* Old format supports only DES!  Any other enctype uses new format */
 285         ctx->enctype = ENCTYPE_DES_CBC_RAW;
 286
 287         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 288         if (ctx->gk5e == NULL) {
 289                 p = ERR_PTR(-EINVAL);
 290                 goto out_err;
 291         }
 292
 293         /* The downcall format was designed before we completely understood
 294          * the uses of the context fields; so it includes some stuff we
 295          * just give some minimal sanity-checking, and some we ignore
 296          * completely (like the next twenty bytes): */
 297         if (unlikely(p + 20 > end || p + 20 < p)) {
 298                 p = ERR_PTR(-EFAULT);
 299                 goto out_err;
 300         }
 301         p += 20;
 302         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 303         if (IS_ERR(p))
 304                 goto out_err;
 305         if (tmp != SGN_ALG_DES_MAC_MD5) {
 306                 p = ERR_PTR(-ENOSYS);
 307                 goto out_err;
 308         }
 309         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 310         if (IS_ERR(p))
 311                 goto out_err;
 312         if (tmp != SEAL_ALG_DES) {
 313                 p = ERR_PTR(-ENOSYS);
 314                 goto out_err;
 315         }
 316         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 317         if (IS_ERR(p))
 318                 goto out_err;
 319         p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 320         if (IS_ERR(p))
 321                 goto out_err;
 322         p = simple_get_netobj(p, end, &ctx->mech_used);
 323         if (IS_ERR(p))
 324                 goto out_err;
 325         p = get_key(p, end, ctx, &ctx->enc);
 326         if (IS_ERR(p))
 327                 goto out_err_free_mech;
 328         p = get_key(p, end, ctx, &ctx->seq);
 329         if (IS_ERR(p))
 330                 goto out_err_free_key1;
 331         if (p != end) {
 332                 p = ERR_PTR(-EFAULT);
 333                 goto out_err_free_key2;
 334         }
 335
 336         return 0;
 337
 338 out_err_free_key2:
 339         crypto_free_skcipher(ctx->seq);
 340 out_err_free_key1:
 341         crypto_free_skcipher(ctx->enc);
 342 out_err_free_mech:
 343         kfree(ctx->mech_used.data);
 344 out_err:
 345         return PTR_ERR(p);
 346 }
 347
 348 static struct crypto_skcipher *
 349 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
 350 {
 351         struct crypto_skcipher *cp;
 352
 353         cp = crypto_alloc_skcipher(cname, 0, CRYPTO_ALG_ASYNC);
 354         if (IS_ERR(cp)) {
 355                 dprintk("gss_kerberos_mech: unable to initialize "
 356                         "crypto algorithm %s\n", cname);
 357                 return NULL;
 358         }
 359         if (crypto_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
 360                 dprintk("gss_kerberos_mech: error setting key for "
 361                         "crypto algorithm %s\n", cname);
 362                 crypto_free_skcipher(cp);
 363                 return NULL;
 364         }
 365         return cp;
 366 }
 367
 368 static inline void
 369 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
 370 {
 371         cdata[0] = (usage>>24)&0xff;
 372         cdata[1] = (usage>>16)&0xff;
 373         cdata[2] = (usage>>8)&0xff;
 374         cdata[3] = usage&0xff;
 375         cdata[4] = seed;
 376 }
 377
 378 static int
 379 context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
 380 {
 381         struct xdr_netobj c, keyin, keyout;
 382         u8 cdata[GSS_KRB5_K5CLENGTH];
 383         u32 err;
 384
 385         c.len = GSS_KRB5_K5CLENGTH;
 386         c.data = cdata;
 387
 388         keyin.data = ctx->Ksess;
 389         keyin.len = ctx->gk5e->keylength;
 390         keyout.len = ctx->gk5e->keylength;
 391
 392         /* seq uses the raw key */
 393         ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 394                                            ctx->Ksess);
 395         if (ctx->seq == NULL)
 396                 goto out_err;
 397
 398         ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 399                                            ctx->Ksess);
 400         if (ctx->enc == NULL)
 401                 goto out_free_seq;
 402
 403         /* derive cksum */
 404         set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
 405         keyout.data = ctx->cksum;
 406         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 407         if (err) {
 408                 dprintk("%s: Error %d deriving cksum key\n",
 409                         __func__, err);
 410                 goto out_free_enc;
 411         }
 412
 413         return 0;
 414
 415 out_free_enc:
 416         crypto_free_skcipher(ctx->enc);
 417 out_free_seq:
 418         crypto_free_skcipher(ctx->seq);
 419 out_err:
 420         return -EINVAL;
 421 }
 422
 423 /*
 424  * Note that RC4 depends on deriving keys using the sequence
 425  * number or the checksum of a token.  Therefore, the final keys
 426  * cannot be calculated until the token is being constructed!
 427  */
 428 static int
 429 context_derive_keys_rc4(struct krb5_ctx *ctx)
 430 {
 431         struct crypto_shash *hmac;
 432         char sigkeyconstant[] = "signaturekey";
 433         int slen = strlen(sigkeyconstant) + 1;  /* include null terminator */
 434         struct shash_desc *desc;
 435         int err;
 436
 437         dprintk("RPC:       %s: entered\n", __func__);
 438         /*
 439          * derive cksum (aka Ksign) key
 440          */
 441         hmac = crypto_alloc_shash(ctx->gk5e->cksum_name, 0, 0);
 442         if (IS_ERR(hmac)) {
 443                 dprintk("%s: error %ld allocating hash '%s'\n",
 444                         __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
 445                 err = PTR_ERR(hmac);
 446                 goto out_err;
 447         }
 448
 449         err = crypto_shash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
 450         if (err)
 451                 goto out_err_free_hmac;
 452
 453
 454         desc = kmalloc(sizeof(*desc), GFP_KERNEL);
 455         if (!desc) {
 456                 dprintk("%s: failed to allocate hash descriptor for '%s'\n",
 457                         __func__, ctx->gk5e->cksum_name);
 458                 err = -ENOMEM;
 459                 goto out_err_free_hmac;
 460         }
 461
 462         desc->tfm = hmac;
 463         desc->flags = 0;
 464
 465         err = crypto_shash_digest(desc, sigkeyconstant, slen, ctx->cksum);
 466         kzfree(desc);
 467         if (err)
 468                 goto out_err_free_hmac;
 469         /*
 470          * allocate hash, and skciphers for data and seqnum encryption
 471          */
 472         ctx->enc = crypto_alloc_skcipher(ctx->gk5e->encrypt_name, 0,
 473                                          CRYPTO_ALG_ASYNC);
 474         if (IS_ERR(ctx->enc)) {
 475                 err = PTR_ERR(ctx->enc);
 476                 goto out_err_free_hmac;
 477         }
 478
 479         ctx->seq = crypto_alloc_skcipher(ctx->gk5e->encrypt_name, 0,
 480                                          CRYPTO_ALG_ASYNC);
 481         if (IS_ERR(ctx->seq)) {
 482                 crypto_free_skcipher(ctx->enc);
 483                 err = PTR_ERR(ctx->seq);
 484                 goto out_err_free_hmac;
 485         }
 486
 487         dprintk("RPC:       %s: returning success\n", __func__);
 488
 489         err = 0;
 490
 491 out_err_free_hmac:
 492         crypto_free_shash(hmac);
 493 out_err:
 494         dprintk("RPC:       %s: returning %d\n", __func__, err);
 495         return err;
 496 }
 497
 498 static int
 499 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
 500 {
 501         struct xdr_netobj c, keyin, keyout;
 502         u8 cdata[GSS_KRB5_K5CLENGTH];
 503         u32 err;
 504
 505         c.len = GSS_KRB5_K5CLENGTH;
 506         c.data = cdata;
 507
 508         keyin.data = ctx->Ksess;
 509         keyin.len = ctx->gk5e->keylength;
 510         keyout.len = ctx->gk5e->keylength;
 511
 512         /* initiator seal encryption */
 513         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 514         keyout.data = ctx->initiator_seal;
 515         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 516         if (err) {
 517                 dprintk("%s: Error %d deriving initiator_seal key\n",
 518                         __func__, err);
 519                 goto out_err;
 520         }
 521         ctx->initiator_enc = context_v2_alloc_cipher(ctx,
 522                                                      ctx->gk5e->encrypt_name,
 523                                                      ctx->initiator_seal);
 524         if (ctx->initiator_enc == NULL)
 525                 goto out_err;
 526
 527         /* acceptor seal encryption */
 528         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 529         keyout.data = ctx->acceptor_seal;
 530         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 531         if (err) {
 532                 dprintk("%s: Error %d deriving acceptor_seal key\n",
 533                         __func__, err);
 534                 goto out_free_initiator_enc;
 535         }
 536         ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
 537                                                     ctx->gk5e->encrypt_name,
 538                                                     ctx->acceptor_seal);
 539         if (ctx->acceptor_enc == NULL)
 540                 goto out_free_initiator_enc;
 541
 542         /* initiator sign checksum */
 543         set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 544         keyout.data = ctx->initiator_sign;
 545         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 546         if (err) {
 547                 dprintk("%s: Error %d deriving initiator_sign key\n",
 548                         __func__, err);
 549                 goto out_free_acceptor_enc;
 550         }
 551
 552         /* acceptor sign checksum */
 553         set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 554         keyout.data = ctx->acceptor_sign;
 555         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 556         if (err) {
 557                 dprintk("%s: Error %d deriving acceptor_sign key\n",
 558                         __func__, err);
 559                 goto out_free_acceptor_enc;
 560         }
 561
 562         /* initiator seal integrity */
 563         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 564         keyout.data = ctx->initiator_integ;
 565         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 566         if (err) {
 567                 dprintk("%s: Error %d deriving initiator_integ key\n",
 568                         __func__, err);
 569                 goto out_free_acceptor_enc;
 570         }
 571
 572         /* acceptor seal integrity */
 573         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 574         keyout.data = ctx->acceptor_integ;
 575         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 576         if (err) {
 577                 dprintk("%s: Error %d deriving acceptor_integ key\n",
 578                         __func__, err);
 579                 goto out_free_acceptor_enc;
 580         }
 581
 582         switch (ctx->enctype) {
 583         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 584         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 585                 ctx->initiator_enc_aux =
 586                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 587                                                 ctx->initiator_seal);
 588                 if (ctx->initiator_enc_aux == NULL)
 589                         goto out_free_acceptor_enc;
 590                 ctx->acceptor_enc_aux =
 591                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 592                                                 ctx->acceptor_seal);
 593                 if (ctx->acceptor_enc_aux == NULL) {
 594                         crypto_free_skcipher(ctx->initiator_enc_aux);
 595                         goto out_free_acceptor_enc;
 596                 }
 597         }
 598
 599         return 0;
 600
 601 out_free_acceptor_enc:
 602         crypto_free_skcipher(ctx->acceptor_enc);
 603 out_free_initiator_enc:
 604         crypto_free_skcipher(ctx->initiator_enc);
 605 out_err:
 606         return -EINVAL;
 607 }
 608
 609 static int
 610 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 611                 gfp_t gfp_mask)
 612 {
 613         int keylen;
 614
 615         p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
 616         if (IS_ERR(p))
 617                 goto out_err;
 618         ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
 619
 620         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 621         if (IS_ERR(p))
 622                 goto out_err;
 623         p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
 624         if (IS_ERR(p))
 625                 goto out_err;
 626         /* set seq_send for use by "older" enctypes */
 627         ctx->seq_send = ctx->seq_send64;
 628         if (ctx->seq_send64 != ctx->seq_send) {
 629                 dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__,
 630                         (unsigned long)ctx->seq_send64, ctx->seq_send);
 631                 p = ERR_PTR(-EINVAL);
 632                 goto out_err;
 633         }
 634         p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
 635         if (IS_ERR(p))
 636                 goto out_err;
 637         /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
 638         if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
 639                 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
 640         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 641         if (ctx->gk5e == NULL) {
 642                 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
 643                         ctx->enctype);
 644                 p = ERR_PTR(-EINVAL);
 645                 goto out_err;
 646         }
 647         keylen = ctx->gk5e->keylength;
 648
 649         p = simple_get_bytes(p, end, ctx->Ksess, keylen);
 650         if (IS_ERR(p))
 651                 goto out_err;
 652
 653         if (p != end) {
 654                 p = ERR_PTR(-EINVAL);
 655                 goto out_err;
 656         }
 657
 658         ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
 659                                       gss_kerberos_mech.gm_oid.len, gfp_mask);
 660         if (unlikely(ctx->mech_used.data == NULL)) {
 661                 p = ERR_PTR(-ENOMEM);
 662                 goto out_err;
 663         }
 664         ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
 665
 666         switch (ctx->enctype) {
 667         case ENCTYPE_DES3_CBC_RAW:
 668                 return context_derive_keys_des3(ctx, gfp_mask);
 669         case ENCTYPE_ARCFOUR_HMAC:
 670                 return context_derive_keys_rc4(ctx);
 671         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 672         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 673                 return context_derive_keys_new(ctx, gfp_mask);
 674         default:
 675                 return -EINVAL;
 676         }
 677
 678 out_err:
 679         return PTR_ERR(p);
 680 }
 681
 682 static int
 683 gss_import_sec_context_kerberos(const void *p, size_t len,
 684                                 struct gss_ctx *ctx_id,
 685                                 time_t *endtime,
 686                                 gfp_t gfp_mask)
 687 {
 688         const void *end = (const void *)((const char *)p + len);
 689         struct  krb5_ctx *ctx;
 690         int ret;
 691
 692         ctx = kzalloc(sizeof(*ctx), gfp_mask);
 693         if (ctx == NULL)
 694                 return -ENOMEM;
 695
 696         if (len == 85)
 697                 ret = gss_import_v1_context(p, end, ctx);
 698         else
 699                 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
 700
 701         if (ret == 0) {
 702                 ctx_id->internal_ctx_id = ctx;
 703                 if (endtime)
 704                         *endtime = ctx->endtime;
 705         } else
 706                 kfree(ctx);
 707
 708         dprintk("RPC:       %s: returning %d\n", __func__, ret);
 709         return ret;
 710 }
 711
 712 static void
 713 gss_delete_sec_context_kerberos(void *internal_ctx) {
 714         struct krb5_ctx *kctx = internal_ctx;
 715
 716         crypto_free_skcipher(kctx->seq);
 717         crypto_free_skcipher(kctx->enc);
 718         crypto_free_skcipher(kctx->acceptor_enc);
 719         crypto_free_skcipher(kctx->initiator_enc);
 720         crypto_free_skcipher(kctx->acceptor_enc_aux);
 721         crypto_free_skcipher(kctx->initiator_enc_aux);
 722         kfree(kctx->mech_used.data);
 723         kfree(kctx);
 724 }
 725
 726 static const struct gss_api_ops gss_kerberos_ops = {
 727         .gss_import_sec_context = gss_import_sec_context_kerberos,
 728         .gss_get_mic            = gss_get_mic_kerberos,
 729         .gss_verify_mic         = gss_verify_mic_kerberos,
 730         .gss_wrap               = gss_wrap_kerberos,
 731         .gss_unwrap             = gss_unwrap_kerberos,
 732         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 733 };
 734
 735 static struct pf_desc gss_kerberos_pfs[] = {
 736         [0] = {
 737                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 738                 .qop = GSS_C_QOP_DEFAULT,
 739                 .service = RPC_GSS_SVC_NONE,
 740                 .name = "krb5",
 741         },
 742         [1] = {
 743                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 744                 .qop = GSS_C_QOP_DEFAULT,
 745                 .service = RPC_GSS_SVC_INTEGRITY,
 746                 .name = "krb5i",
 747         },
 748         [2] = {
 749                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 750                 .qop = GSS_C_QOP_DEFAULT,
 751                 .service = RPC_GSS_SVC_PRIVACY,
 752                 .name = "krb5p",
 753         },
 754 };
 755
 756 MODULE_ALIAS("rpc-auth-gss-krb5");
 757 MODULE_ALIAS("rpc-auth-gss-krb5i");
 758 MODULE_ALIAS("rpc-auth-gss-krb5p");
 759 MODULE_ALIAS("rpc-auth-gss-390003");
 760 MODULE_ALIAS("rpc-auth-gss-390004");
 761 MODULE_ALIAS("rpc-auth-gss-390005");
 762 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
 763
 764 static struct gss_api_mech gss_kerberos_mech = {
 765         .gm_name        = "krb5",
 766         .gm_owner       = THIS_MODULE,
 767         .gm_oid         = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
 768         .gm_ops         = &gss_kerberos_ops,
 769         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 770         .gm_pfs         = gss_kerberos_pfs,
 771         .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
 772 };
 773
 774 static int __init init_kerberos_module(void)
 775 {
 776         int status;
 777
 778         status = gss_mech_register(&gss_kerberos_mech);
 779         if (status)
 780                 printk("Failed to register kerberos gss mechanism!\n");
 781         return status;
 782 }
 783
 784 static void __exit cleanup_kerberos_module(void)
 785 {
 786         gss_mech_unregister(&gss_kerberos_mech);
 787 }
 788
 789 MODULE_LICENSE("GPL");
 790 module_init(init_kerberos_module);
 791 module_exit(cleanup_kerberos_module);