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 #include "auth_gss_internal.h"
  49
  50 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  51 # define RPCDBG_FACILITY        RPCDBG_AUTH
  52 #endif
  53
  54 static struct gss_api_mech gss_kerberos_mech;   /* forward declaration */
  55
  56 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
  57         /*
  58          * DES (All DES enctypes are mapped to the same gss functionality)
  59          */
  60         {
  61           .etype = ENCTYPE_DES_CBC_RAW,
  62           .ctype = CKSUMTYPE_RSA_MD5,
  63           .name = "des-cbc-crc",
  64           .encrypt_name = "cbc(des)",
  65           .cksum_name = "md5",
  66           .encrypt = krb5_encrypt,
  67           .decrypt = krb5_decrypt,
  68           .mk_key = NULL,
  69           .signalg = SGN_ALG_DES_MAC_MD5,
  70           .sealalg = SEAL_ALG_DES,
  71           .keybytes = 7,
  72           .keylength = 8,
  73           .blocksize = 8,
  74           .conflen = 8,
  75           .cksumlength = 8,
  76           .keyed_cksum = 0,
  77         },
  78         /*
  79          * RC4-HMAC
  80          */
  81         {
  82           .etype = ENCTYPE_ARCFOUR_HMAC,
  83           .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
  84           .name = "rc4-hmac",
  85           .encrypt_name = "ecb(arc4)",
  86           .cksum_name = "hmac(md5)",
  87           .encrypt = krb5_encrypt,
  88           .decrypt = krb5_decrypt,
  89           .mk_key = NULL,
  90           .signalg = SGN_ALG_HMAC_MD5,
  91           .sealalg = SEAL_ALG_MICROSOFT_RC4,
  92           .keybytes = 16,
  93           .keylength = 16,
  94           .blocksize = 1,
  95           .conflen = 8,
  96           .cksumlength = 8,
  97           .keyed_cksum = 1,
  98         },
  99         /*
 100          * 3DES
 101          */
 102         {
 103           .etype = ENCTYPE_DES3_CBC_RAW,
 104           .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
 105           .name = "des3-hmac-sha1",
 106           .encrypt_name = "cbc(des3_ede)",
 107           .cksum_name = "hmac(sha1)",
 108           .encrypt = krb5_encrypt,
 109           .decrypt = krb5_decrypt,
 110           .mk_key = gss_krb5_des3_make_key,
 111           .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
 112           .sealalg = SEAL_ALG_DES3KD,
 113           .keybytes = 21,
 114           .keylength = 24,
 115           .blocksize = 8,
 116           .conflen = 8,
 117           .cksumlength = 20,
 118           .keyed_cksum = 1,
 119         },
 120         /*
 121          * AES128
 122          */
 123         {
 124           .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
 125           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
 126           .name = "aes128-cts",
 127           .encrypt_name = "cts(cbc(aes))",
 128           .cksum_name = "hmac(sha1)",
 129           .encrypt = krb5_encrypt,
 130           .decrypt = krb5_decrypt,
 131           .mk_key = gss_krb5_aes_make_key,
 132           .encrypt_v2 = gss_krb5_aes_encrypt,
 133           .decrypt_v2 = gss_krb5_aes_decrypt,
 134           .signalg = -1,
 135           .sealalg = -1,
 136           .keybytes = 16,
 137           .keylength = 16,
 138           .blocksize = 16,
 139           .conflen = 16,
 140           .cksumlength = 12,
 141           .keyed_cksum = 1,
 142         },
 143         /*
 144          * AES256
 145          */
 146         {
 147           .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
 148           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
 149           .name = "aes256-cts",
 150           .encrypt_name = "cts(cbc(aes))",
 151           .cksum_name = "hmac(sha1)",
 152           .encrypt = krb5_encrypt,
 153           .decrypt = krb5_decrypt,
 154           .mk_key = gss_krb5_aes_make_key,
 155           .encrypt_v2 = gss_krb5_aes_encrypt,
 156           .decrypt_v2 = gss_krb5_aes_decrypt,
 157           .signalg = -1,
 158           .sealalg = -1,
 159           .keybytes = 32,
 160           .keylength = 32,
 161           .blocksize = 16,
 162           .conflen = 16,
 163           .cksumlength = 12,
 164           .keyed_cksum = 1,
 165         },
 166 };
 167
 168 static const int num_supported_enctypes =
 169         ARRAY_SIZE(supported_gss_krb5_enctypes);
 170
 171 static int
 172 supported_gss_krb5_enctype(int etype)
 173 {
 174         int i;
 175         for (i = 0; i < num_supported_enctypes; i++)
 176                 if (supported_gss_krb5_enctypes[i].etype == etype)
 177                         return 1;
 178         return 0;
 179 }
 180
 181 static const struct gss_krb5_enctype *
 182 get_gss_krb5_enctype(int etype)
 183 {
 184         int i;
 185         for (i = 0; i < num_supported_enctypes; i++)
 186                 if (supported_gss_krb5_enctypes[i].etype == etype)
 187                         return &supported_gss_krb5_enctypes[i];
 188         return NULL;
 189 }
 190
 191 static inline const void *
 192 get_key(const void *p, const void *end,
 193         struct krb5_ctx *ctx, struct crypto_blkcipher **res)
 194 {
 195         struct xdr_netobj       key;
 196         int                     alg;
 197
 198         p = simple_get_bytes(p, end, &alg, sizeof(alg));
 199         if (IS_ERR(p))
 200                 goto out_err;
 201
 202         switch (alg) {
 203         case ENCTYPE_DES_CBC_CRC:
 204         case ENCTYPE_DES_CBC_MD4:
 205         case ENCTYPE_DES_CBC_MD5:
 206                 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
 207                 alg = ENCTYPE_DES_CBC_RAW;
 208                 break;
 209         }
 210
 211         if (!supported_gss_krb5_enctype(alg)) {
 212                 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
 213                         "encryption key algorithm %d\n", alg);
 214                 p = ERR_PTR(-EINVAL);
 215                 goto out_err;
 216         }
 217         p = simple_get_netobj(p, end, &key);
 218         if (IS_ERR(p))
 219                 goto out_err;
 220
 221         *res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
 222                                                         CRYPTO_ALG_ASYNC);
 223         if (IS_ERR(*res)) {
 224                 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
 225                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 226                 *res = NULL;
 227                 goto out_err_free_key;
 228         }
 229         if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
 230                 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
 231                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 232                 goto out_err_free_tfm;
 233         }
 234
 235         kfree(key.data);
 236         return p;
 237
 238 out_err_free_tfm:
 239         crypto_free_blkcipher(*res);
 240 out_err_free_key:
 241         kfree(key.data);
 242         p = ERR_PTR(-EINVAL);
 243 out_err:
 244         return p;
 245 }
 246
 247 static int
 248 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 249 {
 250         int tmp;
 251
 252         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 253         if (IS_ERR(p))
 254                 goto out_err;
 255
 256         /* Old format supports only DES!  Any other enctype uses new format */
 257         ctx->enctype = ENCTYPE_DES_CBC_RAW;
 258
 259         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 260         if (ctx->gk5e == NULL) {
 261                 p = ERR_PTR(-EINVAL);
 262                 goto out_err;
 263         }
 264
 265         /* The downcall format was designed before we completely understood
 266          * the uses of the context fields; so it includes some stuff we
 267          * just give some minimal sanity-checking, and some we ignore
 268          * completely (like the next twenty bytes): */
 269         if (unlikely(p + 20 > end || p + 20 < p)) {
 270                 p = ERR_PTR(-EFAULT);
 271                 goto out_err;
 272         }
 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 static 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, gfp_t gfp_mask)
 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, gfp_mask);
 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 /*
 396  * Note that RC4 depends on deriving keys using the sequence
 397  * number or the checksum of a token.  Therefore, the final keys
 398  * cannot be calculated until the token is being constructed!
 399  */
 400 static int
 401 context_derive_keys_rc4(struct krb5_ctx *ctx)
 402 {
 403         struct crypto_hash *hmac;
 404         char sigkeyconstant[] = "signaturekey";
 405         int slen = strlen(sigkeyconstant) + 1;  /* include null terminator */
 406         struct hash_desc desc;
 407         struct scatterlist sg[1];
 408         int err;
 409
 410         dprintk("RPC:       %s: entered\n", __func__);
 411         /*
 412          * derive cksum (aka Ksign) key
 413          */
 414         hmac = crypto_alloc_hash(ctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
 415         if (IS_ERR(hmac)) {
 416                 dprintk("%s: error %ld allocating hash '%s'\n",
 417                         __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
 418                 err = PTR_ERR(hmac);
 419                 goto out_err;
 420         }
 421
 422         err = crypto_hash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
 423         if (err)
 424                 goto out_err_free_hmac;
 425
 426         sg_init_table(sg, 1);
 427         sg_set_buf(sg, sigkeyconstant, slen);
 428
 429         desc.tfm = hmac;
 430         desc.flags = 0;
 431
 432         err = crypto_hash_init(&desc);
 433         if (err)
 434                 goto out_err_free_hmac;
 435
 436         err = crypto_hash_digest(&desc, sg, slen, ctx->cksum);
 437         if (err)
 438                 goto out_err_free_hmac;
 439         /*
 440          * allocate hash, and blkciphers for data and seqnum encryption
 441          */
 442         ctx->enc = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
 443                                           CRYPTO_ALG_ASYNC);
 444         if (IS_ERR(ctx->enc)) {
 445                 err = PTR_ERR(ctx->enc);
 446                 goto out_err_free_hmac;
 447         }
 448
 449         ctx->seq = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
 450                                           CRYPTO_ALG_ASYNC);
 451         if (IS_ERR(ctx->seq)) {
 452                 crypto_free_blkcipher(ctx->enc);
 453                 err = PTR_ERR(ctx->seq);
 454                 goto out_err_free_hmac;
 455         }
 456
 457         dprintk("RPC:       %s: returning success\n", __func__);
 458
 459         err = 0;
 460
 461 out_err_free_hmac:
 462         crypto_free_hash(hmac);
 463 out_err:
 464         dprintk("RPC:       %s: returning %d\n", __func__, err);
 465         return err;
 466 }
 467
 468 static int
 469 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
 470 {
 471         struct xdr_netobj c, keyin, keyout;
 472         u8 cdata[GSS_KRB5_K5CLENGTH];
 473         u32 err;
 474
 475         c.len = GSS_KRB5_K5CLENGTH;
 476         c.data = cdata;
 477
 478         keyin.data = ctx->Ksess;
 479         keyin.len = ctx->gk5e->keylength;
 480         keyout.len = ctx->gk5e->keylength;
 481
 482         /* initiator seal encryption */
 483         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 484         keyout.data = ctx->initiator_seal;
 485         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 486         if (err) {
 487                 dprintk("%s: Error %d deriving initiator_seal key\n",
 488                         __func__, err);
 489                 goto out_err;
 490         }
 491         ctx->initiator_enc = context_v2_alloc_cipher(ctx,
 492                                                      ctx->gk5e->encrypt_name,
 493                                                      ctx->initiator_seal);
 494         if (ctx->initiator_enc == NULL)
 495                 goto out_err;
 496
 497         /* acceptor seal encryption */
 498         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 499         keyout.data = ctx->acceptor_seal;
 500         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 501         if (err) {
 502                 dprintk("%s: Error %d deriving acceptor_seal key\n",
 503                         __func__, err);
 504                 goto out_free_initiator_enc;
 505         }
 506         ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
 507                                                     ctx->gk5e->encrypt_name,
 508                                                     ctx->acceptor_seal);
 509         if (ctx->acceptor_enc == NULL)
 510                 goto out_free_initiator_enc;
 511
 512         /* initiator sign checksum */
 513         set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 514         keyout.data = ctx->initiator_sign;
 515         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 516         if (err) {
 517                 dprintk("%s: Error %d deriving initiator_sign key\n",
 518                         __func__, err);
 519                 goto out_free_acceptor_enc;
 520         }
 521
 522         /* acceptor sign checksum */
 523         set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 524         keyout.data = ctx->acceptor_sign;
 525         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 526         if (err) {
 527                 dprintk("%s: Error %d deriving acceptor_sign key\n",
 528                         __func__, err);
 529                 goto out_free_acceptor_enc;
 530         }
 531
 532         /* initiator seal integrity */
 533         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 534         keyout.data = ctx->initiator_integ;
 535         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 536         if (err) {
 537                 dprintk("%s: Error %d deriving initiator_integ key\n",
 538                         __func__, err);
 539                 goto out_free_acceptor_enc;
 540         }
 541
 542         /* acceptor seal integrity */
 543         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 544         keyout.data = ctx->acceptor_integ;
 545         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 546         if (err) {
 547                 dprintk("%s: Error %d deriving acceptor_integ key\n",
 548                         __func__, err);
 549                 goto out_free_acceptor_enc;
 550         }
 551
 552         switch (ctx->enctype) {
 553         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 554         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 555                 ctx->initiator_enc_aux =
 556                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 557                                                 ctx->initiator_seal);
 558                 if (ctx->initiator_enc_aux == NULL)
 559                         goto out_free_acceptor_enc;
 560                 ctx->acceptor_enc_aux =
 561                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 562                                                 ctx->acceptor_seal);
 563                 if (ctx->acceptor_enc_aux == NULL) {
 564                         crypto_free_blkcipher(ctx->initiator_enc_aux);
 565                         goto out_free_acceptor_enc;
 566                 }
 567         }
 568
 569         return 0;
 570
 571 out_free_acceptor_enc:
 572         crypto_free_blkcipher(ctx->acceptor_enc);
 573 out_free_initiator_enc:
 574         crypto_free_blkcipher(ctx->initiator_enc);
 575 out_err:
 576         return -EINVAL;
 577 }
 578
 579 static int
 580 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 581                 gfp_t gfp_mask)
 582 {
 583         int keylen;
 584
 585         p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
 586         if (IS_ERR(p))
 587                 goto out_err;
 588         ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
 589
 590         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 591         if (IS_ERR(p))
 592                 goto out_err;
 593         p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
 594         if (IS_ERR(p))
 595                 goto out_err;
 596         /* set seq_send for use by "older" enctypes */
 597         ctx->seq_send = ctx->seq_send64;
 598         if (ctx->seq_send64 != ctx->seq_send) {
 599                 dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__,
 600                         (unsigned long)ctx->seq_send64, ctx->seq_send);
 601                 p = ERR_PTR(-EINVAL);
 602                 goto out_err;
 603         }
 604         p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
 605         if (IS_ERR(p))
 606                 goto out_err;
 607         /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
 608         if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
 609                 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
 610         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 611         if (ctx->gk5e == NULL) {
 612                 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
 613                         ctx->enctype);
 614                 p = ERR_PTR(-EINVAL);
 615                 goto out_err;
 616         }
 617         keylen = ctx->gk5e->keylength;
 618
 619         p = simple_get_bytes(p, end, ctx->Ksess, keylen);
 620         if (IS_ERR(p))
 621                 goto out_err;
 622
 623         if (p != end) {
 624                 p = ERR_PTR(-EINVAL);
 625                 goto out_err;
 626         }
 627
 628         ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
 629                                       gss_kerberos_mech.gm_oid.len, gfp_mask);
 630         if (unlikely(ctx->mech_used.data == NULL)) {
 631                 p = ERR_PTR(-ENOMEM);
 632                 goto out_err;
 633         }
 634         ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
 635
 636         switch (ctx->enctype) {
 637         case ENCTYPE_DES3_CBC_RAW:
 638                 return context_derive_keys_des3(ctx, gfp_mask);
 639         case ENCTYPE_ARCFOUR_HMAC:
 640                 return context_derive_keys_rc4(ctx);
 641         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 642         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 643                 return context_derive_keys_new(ctx, gfp_mask);
 644         default:
 645                 return -EINVAL;
 646         }
 647
 648 out_err:
 649         return PTR_ERR(p);
 650 }
 651
 652 static int
 653 gss_import_sec_context_kerberos(const void *p, size_t len,
 654                                 struct gss_ctx *ctx_id,
 655                                 time_t *endtime,
 656                                 gfp_t gfp_mask)
 657 {
 658         const void *end = (const void *)((const char *)p + len);
 659         struct  krb5_ctx *ctx;
 660         int ret;
 661
 662         ctx = kzalloc(sizeof(*ctx), gfp_mask);
 663         if (ctx == NULL)
 664                 return -ENOMEM;
 665
 666         if (len == 85)
 667                 ret = gss_import_v1_context(p, end, ctx);
 668         else
 669                 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
 670
 671         if (ret == 0) {
 672                 ctx_id->internal_ctx_id = ctx;
 673                 if (endtime)
 674                         *endtime = ctx->endtime;
 675         } else
 676                 kfree(ctx);
 677
 678         dprintk("RPC:       %s: returning %d\n", __func__, ret);
 679         return ret;
 680 }
 681
 682 static void
 683 gss_delete_sec_context_kerberos(void *internal_ctx) {
 684         struct krb5_ctx *kctx = internal_ctx;
 685
 686         crypto_free_blkcipher(kctx->seq);
 687         crypto_free_blkcipher(kctx->enc);
 688         crypto_free_blkcipher(kctx->acceptor_enc);
 689         crypto_free_blkcipher(kctx->initiator_enc);
 690         crypto_free_blkcipher(kctx->acceptor_enc_aux);
 691         crypto_free_blkcipher(kctx->initiator_enc_aux);
 692         kfree(kctx->mech_used.data);
 693         kfree(kctx);
 694 }
 695
 696 static const struct gss_api_ops gss_kerberos_ops = {
 697         .gss_import_sec_context = gss_import_sec_context_kerberos,
 698         .gss_get_mic            = gss_get_mic_kerberos,
 699         .gss_verify_mic         = gss_verify_mic_kerberos,
 700         .gss_wrap               = gss_wrap_kerberos,
 701         .gss_unwrap             = gss_unwrap_kerberos,
 702         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 703 };
 704
 705 static struct pf_desc gss_kerberos_pfs[] = {
 706         [0] = {
 707                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 708                 .qop = GSS_C_QOP_DEFAULT,
 709                 .service = RPC_GSS_SVC_NONE,
 710                 .name = "krb5",
 711         },
 712         [1] = {
 713                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 714                 .qop = GSS_C_QOP_DEFAULT,
 715                 .service = RPC_GSS_SVC_INTEGRITY,
 716                 .name = "krb5i",
 717         },
 718         [2] = {
 719                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 720                 .qop = GSS_C_QOP_DEFAULT,
 721                 .service = RPC_GSS_SVC_PRIVACY,
 722                 .name = "krb5p",
 723         },
 724 };
 725
 726 MODULE_ALIAS("rpc-auth-gss-krb5");
 727 MODULE_ALIAS("rpc-auth-gss-krb5i");
 728 MODULE_ALIAS("rpc-auth-gss-krb5p");
 729 MODULE_ALIAS("rpc-auth-gss-390003");
 730 MODULE_ALIAS("rpc-auth-gss-390004");
 731 MODULE_ALIAS("rpc-auth-gss-390005");
 732 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
 733
 734 static struct gss_api_mech gss_kerberos_mech = {
 735         .gm_name        = "krb5",
 736         .gm_owner       = THIS_MODULE,
 737         .gm_oid         = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
 738         .gm_ops         = &gss_kerberos_ops,
 739         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 740         .gm_pfs         = gss_kerberos_pfs,
 741         .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
 742 };
 743
 744 static int __init init_kerberos_module(void)
 745 {
 746         int status;
 747
 748         status = gss_mech_register(&gss_kerberos_mech);
 749         if (status)
 750                 printk("Failed to register kerberos gss mechanism!\n");
 751         return status;
 752 }
 753
 754 static void __exit cleanup_kerberos_module(void)
 755 {
 756         gss_mech_unregister(&gss_kerberos_mech);
 757 }
 758
 759 MODULE_LICENSE("GPL");
 760 module_init(init_kerberos_module);
 761 module_exit(cleanup_kerberos_module);