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