net/sunrpc/auth_gss/gss_krb5_mech.c

   1 // SPDX-License-Identifier: BSD-3-Clause
   2 /*
   3  *  linux/net/sunrpc/gss_krb5_mech.c
   4  *
   5  *  Copyright (c) 2001-2008 The Regents of the University of Michigan.
   6  *  All rights reserved.
   7  *
   8  *  Andy Adamson <andros@umich.edu>
   9  *  J. Bruce Fields <bfields@umich.edu>
  10  */
  11
  12 #include <crypto/hash.h>
  13 #include <crypto/skcipher.h>
  14 #include <linux/err.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/types.h>
  18 #include <linux/slab.h>
  19 #include <linux/sunrpc/auth.h>
  20 #include <linux/sunrpc/gss_krb5.h>
  21 #include <linux/sunrpc/xdr.h>
  22 #include <linux/sunrpc/gss_krb5_enctypes.h>
  23
  24 #include "auth_gss_internal.h"
  25
  26 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  27 # define RPCDBG_FACILITY        RPCDBG_AUTH
  28 #endif
  29
  30 static struct gss_api_mech gss_kerberos_mech;   /* forward declaration */
  31
  32 static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
  33 #ifndef CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES
  34         /*
  35          * DES (All DES enctypes are mapped to the same gss functionality)
  36          */
  37         {
  38           .etype = ENCTYPE_DES_CBC_RAW,
  39           .ctype = CKSUMTYPE_RSA_MD5,
  40           .name = "des-cbc-crc",
  41           .encrypt_name = "cbc(des)",
  42           .cksum_name = "md5",
  43           .encrypt = krb5_encrypt,
  44           .decrypt = krb5_decrypt,
  45           .mk_key = NULL,
  46           .signalg = SGN_ALG_DES_MAC_MD5,
  47           .sealalg = SEAL_ALG_DES,
  48           .keybytes = 7,
  49           .keylength = 8,
  50           .blocksize = 8,
  51           .conflen = 8,
  52           .cksumlength = 8,
  53           .keyed_cksum = 0,
  54         },
  55 #endif  /* CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES */
  56         /*
  57          * RC4-HMAC
  58          */
  59         {
  60           .etype = ENCTYPE_ARCFOUR_HMAC,
  61           .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
  62           .name = "rc4-hmac",
  63           .encrypt_name = "ecb(arc4)",
  64           .cksum_name = "hmac(md5)",
  65           .encrypt = krb5_encrypt,
  66           .decrypt = krb5_decrypt,
  67           .mk_key = NULL,
  68           .signalg = SGN_ALG_HMAC_MD5,
  69           .sealalg = SEAL_ALG_MICROSOFT_RC4,
  70           .keybytes = 16,
  71           .keylength = 16,
  72           .blocksize = 1,
  73           .conflen = 8,
  74           .cksumlength = 8,
  75           .keyed_cksum = 1,
  76         },
  77         /*
  78          * 3DES
  79          */
  80         {
  81           .etype = ENCTYPE_DES3_CBC_RAW,
  82           .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
  83           .name = "des3-hmac-sha1",
  84           .encrypt_name = "cbc(des3_ede)",
  85           .cksum_name = "hmac(sha1)",
  86           .encrypt = krb5_encrypt,
  87           .decrypt = krb5_decrypt,
  88           .mk_key = gss_krb5_des3_make_key,
  89           .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
  90           .sealalg = SEAL_ALG_DES3KD,
  91           .keybytes = 21,
  92           .keylength = 24,
  93           .blocksize = 8,
  94           .conflen = 8,
  95           .cksumlength = 20,
  96           .keyed_cksum = 1,
  97         },
  98         /*
  99          * AES128
 100          */
 101         {
 102           .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
 103           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
 104           .name = "aes128-cts",
 105           .encrypt_name = "cts(cbc(aes))",
 106           .cksum_name = "hmac(sha1)",
 107           .encrypt = krb5_encrypt,
 108           .decrypt = krb5_decrypt,
 109           .mk_key = gss_krb5_aes_make_key,
 110           .encrypt_v2 = gss_krb5_aes_encrypt,
 111           .decrypt_v2 = gss_krb5_aes_decrypt,
 112           .signalg = -1,
 113           .sealalg = -1,
 114           .keybytes = 16,
 115           .keylength = 16,
 116           .blocksize = 16,
 117           .conflen = 16,
 118           .cksumlength = 12,
 119           .keyed_cksum = 1,
 120         },
 121         /*
 122          * AES256
 123          */
 124         {
 125           .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
 126           .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
 127           .name = "aes256-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 = 32,
 138           .keylength = 32,
 139           .blocksize = 16,
 140           .conflen = 16,
 141           .cksumlength = 12,
 142           .keyed_cksum = 1,
 143         },
 144 };
 145
 146 static const int num_supported_enctypes =
 147         ARRAY_SIZE(supported_gss_krb5_enctypes);
 148
 149 static int
 150 supported_gss_krb5_enctype(int etype)
 151 {
 152         int i;
 153         for (i = 0; i < num_supported_enctypes; i++)
 154                 if (supported_gss_krb5_enctypes[i].etype == etype)
 155                         return 1;
 156         return 0;
 157 }
 158
 159 static const struct gss_krb5_enctype *
 160 get_gss_krb5_enctype(int etype)
 161 {
 162         int i;
 163         for (i = 0; i < num_supported_enctypes; i++)
 164                 if (supported_gss_krb5_enctypes[i].etype == etype)
 165                         return &supported_gss_krb5_enctypes[i];
 166         return NULL;
 167 }
 168
 169 static inline const void *
 170 get_key(const void *p, const void *end,
 171         struct krb5_ctx *ctx, struct crypto_sync_skcipher **res)
 172 {
 173         struct xdr_netobj       key;
 174         int                     alg;
 175
 176         p = simple_get_bytes(p, end, &alg, sizeof(alg));
 177         if (IS_ERR(p))
 178                 goto out_err;
 179
 180         switch (alg) {
 181         case ENCTYPE_DES_CBC_CRC:
 182         case ENCTYPE_DES_CBC_MD4:
 183         case ENCTYPE_DES_CBC_MD5:
 184                 /* Map all these key types to ENCTYPE_DES_CBC_RAW */
 185                 alg = ENCTYPE_DES_CBC_RAW;
 186                 break;
 187         }
 188
 189         if (!supported_gss_krb5_enctype(alg)) {
 190                 printk(KERN_WARNING "gss_kerberos_mech: unsupported "
 191                         "encryption key algorithm %d\n", alg);
 192                 p = ERR_PTR(-EINVAL);
 193                 goto out_err;
 194         }
 195         p = simple_get_netobj(p, end, &key);
 196         if (IS_ERR(p))
 197                 goto out_err;
 198
 199         *res = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
 200         if (IS_ERR(*res)) {
 201                 printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
 202                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 203                 *res = NULL;
 204                 goto out_err_free_key;
 205         }
 206         if (crypto_sync_skcipher_setkey(*res, key.data, key.len)) {
 207                 printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
 208                         "crypto algorithm %s\n", ctx->gk5e->encrypt_name);
 209                 goto out_err_free_tfm;
 210         }
 211
 212         kfree(key.data);
 213         return p;
 214
 215 out_err_free_tfm:
 216         crypto_free_sync_skcipher(*res);
 217 out_err_free_key:
 218         kfree(key.data);
 219         p = ERR_PTR(-EINVAL);
 220 out_err:
 221         return p;
 222 }
 223
 224 static int
 225 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 226 {
 227         u32 seq_send;
 228         int tmp;
 229
 230         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 231         if (IS_ERR(p))
 232                 goto out_err;
 233
 234         /* Old format supports only DES!  Any other enctype uses new format */
 235         ctx->enctype = ENCTYPE_DES_CBC_RAW;
 236
 237         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 238         if (ctx->gk5e == NULL) {
 239                 p = ERR_PTR(-EINVAL);
 240                 goto out_err;
 241         }
 242
 243         /* The downcall format was designed before we completely understood
 244          * the uses of the context fields; so it includes some stuff we
 245          * just give some minimal sanity-checking, and some we ignore
 246          * completely (like the next twenty bytes): */
 247         if (unlikely(p + 20 > end || p + 20 < p)) {
 248                 p = ERR_PTR(-EFAULT);
 249                 goto out_err;
 250         }
 251         p += 20;
 252         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 253         if (IS_ERR(p))
 254                 goto out_err;
 255         if (tmp != SGN_ALG_DES_MAC_MD5) {
 256                 p = ERR_PTR(-ENOSYS);
 257                 goto out_err;
 258         }
 259         p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
 260         if (IS_ERR(p))
 261                 goto out_err;
 262         if (tmp != SEAL_ALG_DES) {
 263                 p = ERR_PTR(-ENOSYS);
 264                 goto out_err;
 265         }
 266         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 267         if (IS_ERR(p))
 268                 goto out_err;
 269         p = simple_get_bytes(p, end, &seq_send, sizeof(seq_send));
 270         if (IS_ERR(p))
 271                 goto out_err;
 272         atomic_set(&ctx->seq_send, seq_send);
 273         p = simple_get_netobj(p, end, &ctx->mech_used);
 274         if (IS_ERR(p))
 275                 goto out_err;
 276         p = get_key(p, end, ctx, &ctx->enc);
 277         if (IS_ERR(p))
 278                 goto out_err_free_mech;
 279         p = get_key(p, end, ctx, &ctx->seq);
 280         if (IS_ERR(p))
 281                 goto out_err_free_key1;
 282         if (p != end) {
 283                 p = ERR_PTR(-EFAULT);
 284                 goto out_err_free_key2;
 285         }
 286
 287         return 0;
 288
 289 out_err_free_key2:
 290         crypto_free_sync_skcipher(ctx->seq);
 291 out_err_free_key1:
 292         crypto_free_sync_skcipher(ctx->enc);
 293 out_err_free_mech:
 294         kfree(ctx->mech_used.data);
 295 out_err:
 296         return PTR_ERR(p);
 297 }
 298
 299 static struct crypto_sync_skcipher *
 300 context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
 301 {
 302         struct crypto_sync_skcipher *cp;
 303
 304         cp = crypto_alloc_sync_skcipher(cname, 0, 0);
 305         if (IS_ERR(cp)) {
 306                 dprintk("gss_kerberos_mech: unable to initialize "
 307                         "crypto algorithm %s\n", cname);
 308                 return NULL;
 309         }
 310         if (crypto_sync_skcipher_setkey(cp, key, ctx->gk5e->keylength)) {
 311                 dprintk("gss_kerberos_mech: error setting key for "
 312                         "crypto algorithm %s\n", cname);
 313                 crypto_free_sync_skcipher(cp);
 314                 return NULL;
 315         }
 316         return cp;
 317 }
 318
 319 static inline void
 320 set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
 321 {
 322         cdata[0] = (usage>>24)&0xff;
 323         cdata[1] = (usage>>16)&0xff;
 324         cdata[2] = (usage>>8)&0xff;
 325         cdata[3] = usage&0xff;
 326         cdata[4] = seed;
 327 }
 328
 329 static int
 330 context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
 331 {
 332         struct xdr_netobj c, keyin, keyout;
 333         u8 cdata[GSS_KRB5_K5CLENGTH];
 334         u32 err;
 335
 336         c.len = GSS_KRB5_K5CLENGTH;
 337         c.data = cdata;
 338
 339         keyin.data = ctx->Ksess;
 340         keyin.len = ctx->gk5e->keylength;
 341         keyout.len = ctx->gk5e->keylength;
 342
 343         /* seq uses the raw key */
 344         ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 345                                            ctx->Ksess);
 346         if (ctx->seq == NULL)
 347                 goto out_err;
 348
 349         ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
 350                                            ctx->Ksess);
 351         if (ctx->enc == NULL)
 352                 goto out_free_seq;
 353
 354         /* derive cksum */
 355         set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
 356         keyout.data = ctx->cksum;
 357         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 358         if (err) {
 359                 dprintk("%s: Error %d deriving cksum key\n",
 360                         __func__, err);
 361                 goto out_free_enc;
 362         }
 363
 364         return 0;
 365
 366 out_free_enc:
 367         crypto_free_sync_skcipher(ctx->enc);
 368 out_free_seq:
 369         crypto_free_sync_skcipher(ctx->seq);
 370 out_err:
 371         return -EINVAL;
 372 }
 373
 374 /*
 375  * Note that RC4 depends on deriving keys using the sequence
 376  * number or the checksum of a token.  Therefore, the final keys
 377  * cannot be calculated until the token is being constructed!
 378  */
 379 static int
 380 context_derive_keys_rc4(struct krb5_ctx *ctx)
 381 {
 382         struct crypto_shash *hmac;
 383         char sigkeyconstant[] = "signaturekey";
 384         int slen = strlen(sigkeyconstant) + 1;  /* include null terminator */
 385         struct shash_desc *desc;
 386         int err;
 387
 388         dprintk("RPC:       %s: entered\n", __func__);
 389         /*
 390          * derive cksum (aka Ksign) key
 391          */
 392         hmac = crypto_alloc_shash(ctx->gk5e->cksum_name, 0, 0);
 393         if (IS_ERR(hmac)) {
 394                 dprintk("%s: error %ld allocating hash '%s'\n",
 395                         __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
 396                 err = PTR_ERR(hmac);
 397                 goto out_err;
 398         }
 399
 400         err = crypto_shash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
 401         if (err)
 402                 goto out_err_free_hmac;
 403
 404
 405         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac), GFP_NOFS);
 406         if (!desc) {
 407                 dprintk("%s: failed to allocate hash descriptor for '%s'\n",
 408                         __func__, ctx->gk5e->cksum_name);
 409                 err = -ENOMEM;
 410                 goto out_err_free_hmac;
 411         }
 412
 413         desc->tfm = hmac;
 414
 415         err = crypto_shash_digest(desc, sigkeyconstant, slen, ctx->cksum);
 416         kzfree(desc);
 417         if (err)
 418                 goto out_err_free_hmac;
 419         /*
 420          * allocate hash, and skciphers for data and seqnum encryption
 421          */
 422         ctx->enc = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
 423         if (IS_ERR(ctx->enc)) {
 424                 err = PTR_ERR(ctx->enc);
 425                 goto out_err_free_hmac;
 426         }
 427
 428         ctx->seq = crypto_alloc_sync_skcipher(ctx->gk5e->encrypt_name, 0, 0);
 429         if (IS_ERR(ctx->seq)) {
 430                 crypto_free_sync_skcipher(ctx->enc);
 431                 err = PTR_ERR(ctx->seq);
 432                 goto out_err_free_hmac;
 433         }
 434
 435         dprintk("RPC:       %s: returning success\n", __func__);
 436
 437         err = 0;
 438
 439 out_err_free_hmac:
 440         crypto_free_shash(hmac);
 441 out_err:
 442         dprintk("RPC:       %s: returning %d\n", __func__, err);
 443         return err;
 444 }
 445
 446 static int
 447 context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
 448 {
 449         struct xdr_netobj c, keyin, keyout;
 450         u8 cdata[GSS_KRB5_K5CLENGTH];
 451         u32 err;
 452
 453         c.len = GSS_KRB5_K5CLENGTH;
 454         c.data = cdata;
 455
 456         keyin.data = ctx->Ksess;
 457         keyin.len = ctx->gk5e->keylength;
 458         keyout.len = ctx->gk5e->keylength;
 459
 460         /* initiator seal encryption */
 461         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 462         keyout.data = ctx->initiator_seal;
 463         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 464         if (err) {
 465                 dprintk("%s: Error %d deriving initiator_seal key\n",
 466                         __func__, err);
 467                 goto out_err;
 468         }
 469         ctx->initiator_enc = context_v2_alloc_cipher(ctx,
 470                                                      ctx->gk5e->encrypt_name,
 471                                                      ctx->initiator_seal);
 472         if (ctx->initiator_enc == NULL)
 473                 goto out_err;
 474
 475         /* acceptor seal encryption */
 476         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
 477         keyout.data = ctx->acceptor_seal;
 478         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 479         if (err) {
 480                 dprintk("%s: Error %d deriving acceptor_seal key\n",
 481                         __func__, err);
 482                 goto out_free_initiator_enc;
 483         }
 484         ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
 485                                                     ctx->gk5e->encrypt_name,
 486                                                     ctx->acceptor_seal);
 487         if (ctx->acceptor_enc == NULL)
 488                 goto out_free_initiator_enc;
 489
 490         /* initiator sign checksum */
 491         set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 492         keyout.data = ctx->initiator_sign;
 493         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 494         if (err) {
 495                 dprintk("%s: Error %d deriving initiator_sign key\n",
 496                         __func__, err);
 497                 goto out_free_acceptor_enc;
 498         }
 499
 500         /* acceptor sign checksum */
 501         set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
 502         keyout.data = ctx->acceptor_sign;
 503         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 504         if (err) {
 505                 dprintk("%s: Error %d deriving acceptor_sign key\n",
 506                         __func__, err);
 507                 goto out_free_acceptor_enc;
 508         }
 509
 510         /* initiator seal integrity */
 511         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 512         keyout.data = ctx->initiator_integ;
 513         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 514         if (err) {
 515                 dprintk("%s: Error %d deriving initiator_integ key\n",
 516                         __func__, err);
 517                 goto out_free_acceptor_enc;
 518         }
 519
 520         /* acceptor seal integrity */
 521         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
 522         keyout.data = ctx->acceptor_integ;
 523         err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
 524         if (err) {
 525                 dprintk("%s: Error %d deriving acceptor_integ key\n",
 526                         __func__, err);
 527                 goto out_free_acceptor_enc;
 528         }
 529
 530         switch (ctx->enctype) {
 531         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 532         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 533                 ctx->initiator_enc_aux =
 534                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 535                                                 ctx->initiator_seal);
 536                 if (ctx->initiator_enc_aux == NULL)
 537                         goto out_free_acceptor_enc;
 538                 ctx->acceptor_enc_aux =
 539                         context_v2_alloc_cipher(ctx, "cbc(aes)",
 540                                                 ctx->acceptor_seal);
 541                 if (ctx->acceptor_enc_aux == NULL) {
 542                         crypto_free_sync_skcipher(ctx->initiator_enc_aux);
 543                         goto out_free_acceptor_enc;
 544                 }
 545         }
 546
 547         return 0;
 548
 549 out_free_acceptor_enc:
 550         crypto_free_sync_skcipher(ctx->acceptor_enc);
 551 out_free_initiator_enc:
 552         crypto_free_sync_skcipher(ctx->initiator_enc);
 553 out_err:
 554         return -EINVAL;
 555 }
 556
 557 static int
 558 gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 559                 gfp_t gfp_mask)
 560 {
 561         u64 seq_send64;
 562         int keylen;
 563
 564         p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
 565         if (IS_ERR(p))
 566                 goto out_err;
 567         ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
 568
 569         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 570         if (IS_ERR(p))
 571                 goto out_err;
 572         p = simple_get_bytes(p, end, &seq_send64, sizeof(seq_send64));
 573         if (IS_ERR(p))
 574                 goto out_err;
 575         atomic64_set(&ctx->seq_send64, seq_send64);
 576         /* set seq_send for use by "older" enctypes */
 577         atomic_set(&ctx->seq_send, seq_send64);
 578         if (seq_send64 != atomic_read(&ctx->seq_send)) {
 579                 dprintk("%s: seq_send64 %llx, seq_send %x overflow?\n", __func__,
 580                         seq_send64, atomic_read(&ctx->seq_send));
 581                 p = ERR_PTR(-EINVAL);
 582                 goto out_err;
 583         }
 584         p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
 585         if (IS_ERR(p))
 586                 goto out_err;
 587         /* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
 588         if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
 589                 ctx->enctype = ENCTYPE_DES3_CBC_RAW;
 590         ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
 591         if (ctx->gk5e == NULL) {
 592                 dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
 593                         ctx->enctype);
 594                 p = ERR_PTR(-EINVAL);
 595                 goto out_err;
 596         }
 597         keylen = ctx->gk5e->keylength;
 598
 599         p = simple_get_bytes(p, end, ctx->Ksess, keylen);
 600         if (IS_ERR(p))
 601                 goto out_err;
 602
 603         if (p != end) {
 604                 p = ERR_PTR(-EINVAL);
 605                 goto out_err;
 606         }
 607
 608         ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
 609                                       gss_kerberos_mech.gm_oid.len, gfp_mask);
 610         if (unlikely(ctx->mech_used.data == NULL)) {
 611                 p = ERR_PTR(-ENOMEM);
 612                 goto out_err;
 613         }
 614         ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
 615
 616         switch (ctx->enctype) {
 617         case ENCTYPE_DES3_CBC_RAW:
 618                 return context_derive_keys_des3(ctx, gfp_mask);
 619         case ENCTYPE_ARCFOUR_HMAC:
 620                 return context_derive_keys_rc4(ctx);
 621         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
 622         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
 623                 return context_derive_keys_new(ctx, gfp_mask);
 624         default:
 625                 return -EINVAL;
 626         }
 627
 628 out_err:
 629         return PTR_ERR(p);
 630 }
 631
 632 static int
 633 gss_import_sec_context_kerberos(const void *p, size_t len,
 634                                 struct gss_ctx *ctx_id,
 635                                 time_t *endtime,
 636                                 gfp_t gfp_mask)
 637 {
 638         const void *end = (const void *)((const char *)p + len);
 639         struct  krb5_ctx *ctx;
 640         int ret;
 641
 642         ctx = kzalloc(sizeof(*ctx), gfp_mask);
 643         if (ctx == NULL)
 644                 return -ENOMEM;
 645
 646         if (len == 85)
 647                 ret = gss_import_v1_context(p, end, ctx);
 648         else
 649                 ret = gss_import_v2_context(p, end, ctx, gfp_mask);
 650
 651         if (ret == 0) {
 652                 ctx_id->internal_ctx_id = ctx;
 653                 if (endtime)
 654                         *endtime = ctx->endtime;
 655         } else
 656                 kfree(ctx);
 657
 658         dprintk("RPC:       %s: returning %d\n", __func__, ret);
 659         return ret;
 660 }
 661
 662 static void
 663 gss_delete_sec_context_kerberos(void *internal_ctx) {
 664         struct krb5_ctx *kctx = internal_ctx;
 665
 666         crypto_free_sync_skcipher(kctx->seq);
 667         crypto_free_sync_skcipher(kctx->enc);
 668         crypto_free_sync_skcipher(kctx->acceptor_enc);
 669         crypto_free_sync_skcipher(kctx->initiator_enc);
 670         crypto_free_sync_skcipher(kctx->acceptor_enc_aux);
 671         crypto_free_sync_skcipher(kctx->initiator_enc_aux);
 672         kfree(kctx->mech_used.data);
 673         kfree(kctx);
 674 }
 675
 676 static const struct gss_api_ops gss_kerberos_ops = {
 677         .gss_import_sec_context = gss_import_sec_context_kerberos,
 678         .gss_get_mic            = gss_get_mic_kerberos,
 679         .gss_verify_mic         = gss_verify_mic_kerberos,
 680         .gss_wrap               = gss_wrap_kerberos,
 681         .gss_unwrap             = gss_unwrap_kerberos,
 682         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 683 };
 684
 685 static struct pf_desc gss_kerberos_pfs[] = {
 686         [0] = {
 687                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 688                 .qop = GSS_C_QOP_DEFAULT,
 689                 .service = RPC_GSS_SVC_NONE,
 690                 .name = "krb5",
 691         },
 692         [1] = {
 693                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 694                 .qop = GSS_C_QOP_DEFAULT,
 695                 .service = RPC_GSS_SVC_INTEGRITY,
 696                 .name = "krb5i",
 697                 .datatouch = true,
 698         },
 699         [2] = {
 700                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 701                 .qop = GSS_C_QOP_DEFAULT,
 702                 .service = RPC_GSS_SVC_PRIVACY,
 703                 .name = "krb5p",
 704                 .datatouch = true,
 705         },
 706 };
 707
 708 MODULE_ALIAS("rpc-auth-gss-krb5");
 709 MODULE_ALIAS("rpc-auth-gss-krb5i");
 710 MODULE_ALIAS("rpc-auth-gss-krb5p");
 711 MODULE_ALIAS("rpc-auth-gss-390003");
 712 MODULE_ALIAS("rpc-auth-gss-390004");
 713 MODULE_ALIAS("rpc-auth-gss-390005");
 714 MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
 715
 716 static struct gss_api_mech gss_kerberos_mech = {
 717         .gm_name        = "krb5",
 718         .gm_owner       = THIS_MODULE,
 719         .gm_oid         = { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
 720         .gm_ops         = &gss_kerberos_ops,
 721         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 722         .gm_pfs         = gss_kerberos_pfs,
 723         .gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
 724 };
 725
 726 static int __init init_kerberos_module(void)
 727 {
 728         int status;
 729
 730         status = gss_mech_register(&gss_kerberos_mech);
 731         if (status)
 732                 printk("Failed to register kerberos gss mechanism!\n");
 733         return status;
 734 }
 735
 736 static void __exit cleanup_kerberos_module(void)
 737 {
 738         gss_mech_unregister(&gss_kerberos_mech);
 739 }
 740
 741 MODULE_LICENSE("GPL");
 742 module_init(init_kerberos_module);
 743 module_exit(cleanup_kerberos_module);