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
  47 #ifdef RPC_DEBUG
  48 # define RPCDBG_FACILITY        RPCDBG_AUTH
  49 #endif
  50
  51 static struct gss_api_mech gss_kerberos_mech;   /* forward declaration */
  52
  53 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
  54         /*
  55          * DES (All DES enctypes are mapped to the same gss functionality)
  56          */
  57         {
  58           .etype = ENCTYPE_DES_CBC_RAW,
  59           .ctype = CKSUMTYPE_RSA_MD5,
  60           .name = "des-cbc-crc",
  61           .encrypt_name = "cbc(des)",
  62           .cksum_name = "md5",
  63           .encrypt = krb5_encrypt,
  64           .decrypt = krb5_decrypt,
  65           .mk_key = NULL,
  66           .signalg = SGN_ALG_DES_MAC_MD5,
  67           .sealalg = SEAL_ALG_DES,
  68           .keybytes = 7,
  69           .keylength = 8,
  70           .blocksize = 8,
  71           .conflen = 8,
  72           .cksumlength = 8,
  73           .keyed_cksum = 0,
  74         },
  75         /*
  76          * 3DES
  77          */
  78         {
  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,
  89           .keybytes = 21,
  90           .keylength = 24,
  91           .blocksize = 8,
  92           .conflen = 8,
  93           .cksumlength = 20,
  94           .keyed_cksum = 1,
  95         },
  96         /*
  97          * AES128
  98          */
  99         {
 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,
 110           .signalg = -1,
 111           .sealalg = -1,
 112           .keybytes = 16,
 113           .keylength = 16,
 114           .blocksize = 16,
 115           .conflen = 16,
 116           .cksumlength = 12,
 117           .keyed_cksum = 1,
 118         },
 119         /*
 120          * AES256
 121          */
 122         {
 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,
 133           .signalg = -1,
 134           .sealalg = -1,
 135           .keybytes = 32,
 136           .keylength = 32,
 137           .blocksize = 16,
 138           .conflen = 16,
 139           .cksumlength = 12,
 140           .keyed_cksum = 1,
 141         },
 142 };
 143
 144 static const int num_supported_enctypes =
 145         ARRAY_SIZE(supported_gss_krb5_enctypes);
 146
 147 static int
 148 supported_gss_krb5_enctype(int etype)
 149 {
 150         int i;
 151         for (i = 0; i < num_supported_enctypes; i++)
 152                 if (supported_gss_krb5_enctypes[i].etype == etype)
 153                         return 1;
 154         return 0;
 155 }
 156
 157 static const struct gss_krb5_enctype *
 158 get_gss_krb5_enctype(int etype)
 159 {
 160         int i;
 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];
 164         return NULL;
 165 }
 166
 167 static const void *
 168 simple_get_bytes(const void *p, const void *end, void *res, int len)
 169 {
 170         const void *q = (const void *)((const char *)p + len);
 171         if (unlikely(q > end || q < p))
 172                 return ERR_PTR(-EFAULT);
 173         memcpy(res, p, len);
 174         return q;
 175 }
 176
 177 static const void *
 178 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
 179 {
 180         const void *q;
 181         unsigned int len;
 182
 183         p = simple_get_bytes(p, end, &len, sizeof(len));
 184         if (IS_ERR(p))
 185                 return p;
 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);
 192         res->len = len;
 193         return q;
 194 }
 195
 196 static inline const void *
 197 get_key(const void *p, const void *end,
 198         struct krb5_ctx *ctx, struct crypto_blkcipher **res)
 199 {
 200         struct xdr_netobj       key;
 201         int                     alg;
 202
 203         p = simple_get_bytes(p, end, &alg, sizeof(alg));
 204         if (IS_ERR(p))
 205                 goto out_err;
 206
 207         switch (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;
 213                 break;
 214         }
 215
 216         if (!supported_gss_krb5_enctype(alg)) {
 217                 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
 218                         "encryption key algorithm %d\n", alg);
 219                 goto out_err;
 220         }
 221         p = simple_get_netobj(p, end, &key);
 222         if (IS_ERR(p))
 223                 goto out_err;
 224
 225         *res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
 226                                                         CRYPTO_ALG_ASYNC);
 227         if (IS_ERR(*res)) {
 228                 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
 229                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 230                 *res = NULL;
 231                 goto out_err_free_key;
 232         }
 233         if (crypto_blkcipher_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;
 237         }
 238
 239         kfree(key.data);
 240         return p;
 241
 242 out_err_free_tfm:
 243         crypto_free_blkcipher(*res);
 244 out_err_free_key:
 245         kfree(key.data);
 246         p = ERR_PTR(-EINVAL);
 247 out_err:
 248         return p;
 249 }
 250
 251 static int
 252 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 253 {
 254         int tmp;
 255
 256         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 257         if (IS_ERR(p))
 258                 goto out_err;
 259
 260         /* Old format supports only DES!  Any other enctype uses new format */
 261         ctx->enctype = ENCTYPE_DES_CBC_RAW;
 262
 263         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 264         if (ctx->gk5e == NULL)
 265                 goto out_err;
 266
 267         /* The downcall format was designed before we completely understood
 268          * the uses of the context fields; so it includes some stuff we
 269          * just give some minimal sanity-checking, and some we ignore
 270          * completely (like the next twenty bytes): */
 271         if (unlikely(p + 20 > end || p + 20 < p))
 272                 goto out_err;
 273         p += 20;
 274         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 275         if (IS_ERR(p))
 276                 goto out_err;
 277         if (tmp != SGN_ALG_DES_MAC_MD5) {
 278                 p = ERR_PTR(-ENOSYS);
 279                 goto out_err;
 280         }
 281         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 282         if (IS_ERR(p))
 283                 goto out_err;
 284         if (tmp != SEAL_ALG_DES) {
 285                 p = ERR_PTR(-ENOSYS);
 286                 goto out_err;
 287         }
 288         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 289         if (IS_ERR(p))
 290                 goto out_err;
 291         p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 292         if (IS_ERR(p))
 293                 goto out_err;
 294         p = simple_get_netobj(p, end, &ctx->mech_used);
 295         if (IS_ERR(p))
 296                 goto out_err;
 297         p = get_key(p, end, ctx, &ctx->enc);
 298         if (IS_ERR(p))
 299                 goto out_err_free_mech;
 300         p = get_key(p, end, ctx, &ctx->seq);
 301         if (IS_ERR(p))
 302                 goto out_err_free_key1;
 303         if (p != end) {
 304                 p = ERR_PTR(-EFAULT);
 305                 goto out_err_free_key2;
 306         }
 307
 308         return 0;
 309
 310 out_err_free_key2:
 311         crypto_free_blkcipher(ctx->seq);
 312 out_err_free_key1:
 313         crypto_free_blkcipher(ctx->enc);
 314 out_err_free_mech:
 315         kfree(ctx->mech_used.data);
 316 out_err:
 317         return PTR_ERR(p);
 318 }
 319
 320 struct crypto_blkcipher *
 321 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
 322 {
 323         struct crypto_blkcipher *cp;
 324
 325         cp = crypto_alloc_blkcipher(cname, 0, CRYPTO_ALG_ASYNC);
 326         if (IS_ERR(cp)) {
 327                 dprintk("gss_kerberos_mech: unable to initialize "
 328                         "crypto algorithm %s\n", cname);
 329                 return NULL;
 330         }
 331         if (crypto_blkcipher_setkey(cp, key, ctx->gk5e->keylength)) {
 332                 dprintk("gss_kerberos_mech: error setting key for "
 333                         "crypto algorithm %s\n", cname);
 334                 crypto_free_blkcipher(cp);
 335                 return NULL;
 336         }
 337         return cp;
 338 }
 339
 340 static inline void
 341 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
 342 {
 343         cdata[0] = (usage>>24)&0xff;
 344         cdata[1] = (usage>>16)&0xff;
 345         cdata[2] = (usage>>8)&0xff;
 346         cdata[3] = usage&0xff;
 347         cdata[4] = seed;
 348 }
 349
 350 static int
 351 context_derive_keys_des3(struct krb5_ctx *ctx)
 352 {
 353         struct xdr_netobj c, keyin, keyout;
 354         u8 cdata[GSS_KRB5_K5CLENGTH];
 355         u32 err;
 356
 357         c.len = GSS_KRB5_K5CLENGTH;
 358         c.data = cdata;
 359
 360         keyin.data = ctx->Ksess;
 361         keyin.len = ctx->gk5e->keylength;
 362         keyout.len = ctx->gk5e->keylength;
 363
 364         /* seq uses the raw key */
 365         ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 366                                            ctx->Ksess);
 367         if (ctx->seq == NULL)
 368                 goto out_err;
 369
 370         ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 371                                            ctx->Ksess);
 372         if (ctx->enc == NULL)
 373                 goto out_free_seq;
 374
 375         /* derive cksum */
 376         set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
 377         keyout.data = ctx->cksum;
 378         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 379         if (err) {
 380                 dprintk("%s: Error %d deriving cksum key\n",
 381                         __func__, err);
 382                 goto out_free_enc;
 383         }
 384
 385         return 0;
 386
 387 out_free_enc:
 388         crypto_free_blkcipher(ctx->enc);
 389 out_free_seq:
 390         crypto_free_blkcipher(ctx->seq);
 391 out_err:
 392         return -EINVAL;
 393 }
 394
 395 static int
 396 context_derive_keys_new(struct krb5_ctx *ctx)
 397 {
 398         struct xdr_netobj c, keyin, keyout;
 399         u8 cdata[GSS_KRB5_K5CLENGTH];
 400         u32 err;
 401
 402         c.len = GSS_KRB5_K5CLENGTH;
 403         c.data = cdata;
 404
 405         keyin.data = ctx->Ksess;
 406         keyin.len = ctx->gk5e->keylength;
 407         keyout.len = ctx->gk5e->keylength;
 408
 409         /* initiator seal encryption */
 410         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 411         keyout.data = ctx->initiator_seal;
 412         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 413         if (err) {
 414                 dprintk("%s: Error %d deriving initiator_seal key\n",
 415                         __func__, err);
 416                 goto out_err;
 417         }
 418         ctx->initiator_enc = context_v2_alloc_cipher(ctx,
 419                                                      ctx->gk5e->encrypt_name,
 420                                                      ctx->initiator_seal);
 421         if (ctx->initiator_enc == NULL)
 422                 goto out_err;
 423
 424         /* acceptor seal encryption */
 425         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 426         keyout.data = ctx->acceptor_seal;
 427         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 428         if (err) {
 429                 dprintk("%s: Error %d deriving acceptor_seal key\n",
 430                         __func__, err);
 431                 goto out_free_initiator_enc;
 432         }
 433         ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
 434                                                     ctx->gk5e->encrypt_name,
 435                                                     ctx->acceptor_seal);
 436         if (ctx->acceptor_enc == NULL)
 437                 goto out_free_initiator_enc;
 438
 439         /* initiator sign checksum */
 440         set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 441         keyout.data = ctx->initiator_sign;
 442         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 443         if (err) {
 444                 dprintk("%s: Error %d deriving initiator_sign key\n",
 445                         __func__, err);
 446                 goto out_free_acceptor_enc;
 447         }
 448
 449         /* acceptor sign checksum */
 450         set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 451         keyout.data = ctx->acceptor_sign;
 452         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 453         if (err) {
 454                 dprintk("%s: Error %d deriving acceptor_sign key\n",
 455                         __func__, err);
 456                 goto out_free_acceptor_enc;
 457         }
 458
 459         /* initiator seal integrity */
 460         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 461         keyout.data = ctx->initiator_integ;
 462         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 463         if (err) {
 464                 dprintk("%s: Error %d deriving initiator_integ key\n",
 465                         __func__, err);
 466                 goto out_free_acceptor_enc;
 467         }
 468
 469         /* acceptor seal integrity */
 470         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 471         keyout.data = ctx->acceptor_integ;
 472         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
 473         if (err) {
 474                 dprintk("%s: Error %d deriving acceptor_integ key\n",
 475                         __func__, err);
 476                 goto out_free_acceptor_enc;
 477         }
 478
 479         switch (ctx->enctype) {
 480         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 481         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 482                 ctx->initiator_enc_aux =
 483                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 484                                                 ctx->initiator_seal);
 485                 if (ctx->initiator_enc_aux == NULL)
 486                         goto out_free_acceptor_enc;
 487                 ctx->acceptor_enc_aux =
 488                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 489                                                 ctx->acceptor_seal);
 490                 if (ctx->acceptor_enc_aux == NULL) {
 491                         crypto_free_blkcipher(ctx->initiator_enc_aux);
 492                         goto out_free_acceptor_enc;
 493                 }
 494         }
 495
 496         return 0;
 497
 498 out_free_acceptor_enc:
 499         crypto_free_blkcipher(ctx->acceptor_enc);
 500 out_free_initiator_enc:
 501         crypto_free_blkcipher(ctx->initiator_enc);
 502 out_err:
 503         return -EINVAL;
 504 }
 505
 506 static int
 507 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx)
 508 {
 509         int keylen;
 510
 511         p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
 512         if (IS_ERR(p))
 513                 goto out_err;
 514         ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
 515
 516         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 517         if (IS_ERR(p))
 518                 goto out_err;
 519         p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
 520         if (IS_ERR(p))
 521                 goto out_err;
 522         /* set seq_send for use by "older" enctypes */
 523         ctx->seq_send = ctx->seq_send64;
 524         if (ctx->seq_send64 != ctx->seq_send) {
 525                 dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__,
 526                         (long unsigned)ctx->seq_send64, ctx->seq_send);
 527                 goto out_err;
 528         }
 529         p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
 530         if (IS_ERR(p))
 531                 goto out_err;
 532         /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
 533         if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
 534                 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
 535         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 536         if (ctx->gk5e == NULL) {
 537                 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
 538                         ctx->enctype);
 539                 p = ERR_PTR(-EINVAL);
 540                 goto out_err;
 541         }
 542         keylen = ctx->gk5e->keylength;
 543
 544         p = simple_get_bytes(p, end, ctx->Ksess, keylen);
 545         if (IS_ERR(p))
 546                 goto out_err;
 547
 548         if (p != end) {
 549                 p = ERR_PTR(-EINVAL);
 550                 goto out_err;
 551         }
 552
 553         ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
 554                                       gss_kerberos_mech.gm_oid.len, GFP_KERNEL);
 555         if (unlikely(ctx->mech_used.data == NULL)) {
 556                 p = ERR_PTR(-ENOMEM);
 557                 goto out_err;
 558         }
 559         ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
 560
 561         switch (ctx->enctype) {
 562         case ENCTYPE_DES3_CBC_RAW:
 563                 return context_derive_keys_des3(ctx);
 564         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 565         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 566                 return context_derive_keys_new(ctx);
 567         default:
 568                 return -EINVAL;
 569         }
 570
 571 out_err:
 572         return PTR_ERR(p);
 573 }
 574
 575 static int
 576 gss_import_sec_context_kerberos(const void *p, size_t len,
 577                                 struct gss_ctx *ctx_id)
 578 {
 579         const void *end = (const void *)((const char *)p + len);
 580         struct  krb5_ctx *ctx;
 581         int ret;
 582
 583         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 584         if (ctx == NULL)
 585                 return -ENOMEM;
 586
 587         if (len == 85)
 588                 ret = gss_import_v1_context(p, end, ctx);
 589         else
 590                 ret = gss_import_v2_context(p, end, ctx);
 591
 592         if (ret == 0)
 593                 ctx_id->internal_ctx_id = ctx;
 594         else
 595                 kfree(ctx);
 596
 597         dprintk("RPC:       %s: returning %d\n", __func__, ret);
 598         return ret;
 599 }
 600
 601 static void
 602 gss_delete_sec_context_kerberos(void *internal_ctx) {
 603         struct krb5_ctx *kctx = internal_ctx;
 604
 605         crypto_free_blkcipher(kctx->seq);
 606         crypto_free_blkcipher(kctx->enc);
 607         crypto_free_blkcipher(kctx->acceptor_enc);
 608         crypto_free_blkcipher(kctx->initiator_enc);
 609         crypto_free_blkcipher(kctx->acceptor_enc_aux);
 610         crypto_free_blkcipher(kctx->initiator_enc_aux);
 611         kfree(kctx->mech_used.data);
 612         kfree(kctx);
 613 }
 614
 615 static const struct gss_api_ops gss_kerberos_ops = {
 616         .gss_import_sec_context = gss_import_sec_context_kerberos,
 617         .gss_get_mic            = gss_get_mic_kerberos,
 618         .gss_verify_mic         = gss_verify_mic_kerberos,
 619         .gss_wrap               = gss_wrap_kerberos,
 620         .gss_unwrap             = gss_unwrap_kerberos,
 621         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 622 };
 623
 624 static struct pf_desc gss_kerberos_pfs[] = {
 625         [0] = {
 626                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 627                 .service = RPC_GSS_SVC_NONE,
 628                 .name = "krb5",
 629         },
 630         [1] = {
 631                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 632                 .service = RPC_GSS_SVC_INTEGRITY,
 633                 .name = "krb5i",
 634         },
 635         [2] = {
 636                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 637                 .service = RPC_GSS_SVC_PRIVACY,
 638                 .name = "krb5p",
 639         },
 640 };
 641
 642 static struct gss_api_mech gss_kerberos_mech = {
 643         .gm_name        = "krb5",
 644         .gm_owner       = THIS_MODULE,
 645         .gm_oid         = {9, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"},
 646         .gm_ops         = &gss_kerberos_ops,
 647         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 648         .gm_pfs         = gss_kerberos_pfs,
 649         .gm_upcall_enctypes = "enctypes=18,17,16,3,1,2 ",
 650 };
 651
 652 static int __init init_kerberos_module(void)
 653 {
 654         int status;
 655
 656         status = gss_mech_register(&gss_kerberos_mech);
 657         if (status)
 658                 printk("Failed to register kerberos gss mechanism!\n");
 659         return status;
 660 }
 661
 662 static void __exit cleanup_kerberos_module(void)
 663 {
 664         gss_mech_unregister(&gss_kerberos_mech);
 665 }
 666
 667 MODULE_LICENSE("GPL");
 668 module_init(init_kerberos_module);
 669 module_exit(cleanup_kerberos_module);