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