net/rxrpc/rxkad.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Kerberos-based RxRPC security
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <crypto/skcipher.h>
  11 #include <linux/module.h>
  12 #include <linux/net.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/udp.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/ctype.h>
  17 #include <linux/slab.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include <keys/rxrpc-type.h>
  21 #include "ar-internal.h"
  22
  23 #define RXKAD_VERSION                   2
  24 #define MAXKRB5TICKETLEN                1024
  25 #define RXKAD_TKT_TYPE_KERBEROS_V5      256
  26 #define ANAME_SZ                        40      /* size of authentication name */
  27 #define INST_SZ                         40      /* size of principal's instance */
  28 #define REALM_SZ                        40      /* size of principal's auth domain */
  29 #define SNAME_SZ                        40      /* size of service name */
  30
  31 struct rxkad_level1_hdr {
  32         __be32  data_size;      /* true data size (excluding padding) */
  33 };
  34
  35 struct rxkad_level2_hdr {
  36         __be32  data_size;      /* true data size (excluding padding) */
  37         __be32  checksum;       /* decrypted data checksum */
  38 };
  39
  40 /*
  41  * this holds a pinned cipher so that keventd doesn't get called by the cipher
  42  * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
  43  * packets
  44  */
  45 static struct crypto_sync_skcipher *rxkad_ci;
  46 static struct skcipher_request *rxkad_ci_req;
  47 static DEFINE_MUTEX(rxkad_ci_mutex);
  48
  49 /*
  50  * initialise connection security
  51  */
  52 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
  53 {
  54         struct crypto_sync_skcipher *ci;
  55         struct rxrpc_key_token *token;
  56         int ret;
  57
  58         _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
  59
  60         token = conn->params.key->payload.data[0];
  61         conn->security_ix = token->security_index;
  62
  63         ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
  64         if (IS_ERR(ci)) {
  65                 _debug("no cipher");
  66                 ret = PTR_ERR(ci);
  67                 goto error;
  68         }
  69
  70         if (crypto_sync_skcipher_setkey(ci, token->kad->session_key,
  71                                    sizeof(token->kad->session_key)) < 0)
  72                 BUG();
  73
  74         switch (conn->params.security_level) {
  75         case RXRPC_SECURITY_PLAIN:
  76                 break;
  77         case RXRPC_SECURITY_AUTH:
  78                 conn->size_align = 8;
  79                 conn->security_size = sizeof(struct rxkad_level1_hdr);
  80                 break;
  81         case RXRPC_SECURITY_ENCRYPT:
  82                 conn->size_align = 8;
  83                 conn->security_size = sizeof(struct rxkad_level2_hdr);
  84                 break;
  85         default:
  86                 ret = -EKEYREJECTED;
  87                 goto error;
  88         }
  89
  90         conn->cipher = ci;
  91         ret = 0;
  92 error:
  93         _leave(" = %d", ret);
  94         return ret;
  95 }
  96
  97 /*
  98  * prime the encryption state with the invariant parts of a connection's
  99  * description
 100  */
 101 static int rxkad_prime_packet_security(struct rxrpc_connection *conn)
 102 {
 103         struct skcipher_request *req;
 104         struct rxrpc_key_token *token;
 105         struct scatterlist sg;
 106         struct rxrpc_crypt iv;
 107         __be32 *tmpbuf;
 108         size_t tmpsize = 4 * sizeof(__be32);
 109
 110         _enter("");
 111
 112         if (!conn->params.key)
 113                 return 0;
 114
 115         tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
 116         if (!tmpbuf)
 117                 return -ENOMEM;
 118
 119         req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS);
 120         if (!req) {
 121                 kfree(tmpbuf);
 122                 return -ENOMEM;
 123         }
 124
 125         token = conn->params.key->payload.data[0];
 126         memcpy(&iv, token->kad->session_key, sizeof(iv));
 127
 128         tmpbuf[0] = htonl(conn->proto.epoch);
 129         tmpbuf[1] = htonl(conn->proto.cid);
 130         tmpbuf[2] = 0;
 131         tmpbuf[3] = htonl(conn->security_ix);
 132
 133         sg_init_one(&sg, tmpbuf, tmpsize);
 134         skcipher_request_set_sync_tfm(req, conn->cipher);
 135         skcipher_request_set_callback(req, 0, NULL, NULL);
 136         skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
 137         crypto_skcipher_encrypt(req);
 138         skcipher_request_free(req);
 139
 140         memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv));
 141         kfree(tmpbuf);
 142         _leave(" = 0");
 143         return 0;
 144 }
 145
 146 /*
 147  * Allocate and prepare the crypto request on a call.  For any particular call,
 148  * this is called serially for the packets, so no lock should be necessary.
 149  */
 150 static struct skcipher_request *rxkad_get_call_crypto(struct rxrpc_call *call)
 151 {
 152         struct crypto_skcipher *tfm = &call->conn->cipher->base;
 153         struct skcipher_request *cipher_req = call->cipher_req;
 154
 155         if (!cipher_req) {
 156                 cipher_req = skcipher_request_alloc(tfm, GFP_NOFS);
 157                 if (!cipher_req)
 158                         return NULL;
 159                 call->cipher_req = cipher_req;
 160         }
 161
 162         return cipher_req;
 163 }
 164
 165 /*
 166  * Clean up the crypto on a call.
 167  */
 168 static void rxkad_free_call_crypto(struct rxrpc_call *call)
 169 {
 170         if (call->cipher_req)
 171                 skcipher_request_free(call->cipher_req);
 172         call->cipher_req = NULL;
 173 }
 174
 175 /*
 176  * partially encrypt a packet (level 1 security)
 177  */
 178 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
 179                                     struct sk_buff *skb,
 180                                     u32 data_size,
 181                                     void *sechdr,
 182                                     struct skcipher_request *req)
 183 {
 184         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 185         struct rxkad_level1_hdr hdr;
 186         struct rxrpc_crypt iv;
 187         struct scatterlist sg;
 188         u16 check;
 189
 190         _enter("");
 191
 192         check = sp->hdr.seq ^ call->call_id;
 193         data_size |= (u32)check << 16;
 194
 195         hdr.data_size = htonl(data_size);
 196         memcpy(sechdr, &hdr, sizeof(hdr));
 197
 198         /* start the encryption afresh */
 199         memset(&iv, 0, sizeof(iv));
 200
 201         sg_init_one(&sg, sechdr, 8);
 202         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 203         skcipher_request_set_callback(req, 0, NULL, NULL);
 204         skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
 205         crypto_skcipher_encrypt(req);
 206         skcipher_request_zero(req);
 207
 208         _leave(" = 0");
 209         return 0;
 210 }
 211
 212 /*
 213  * wholly encrypt a packet (level 2 security)
 214  */
 215 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
 216                                        struct sk_buff *skb,
 217                                        u32 data_size,
 218                                        void *sechdr,
 219                                        struct skcipher_request *req)
 220 {
 221         const struct rxrpc_key_token *token;
 222         struct rxkad_level2_hdr rxkhdr;
 223         struct rxrpc_skb_priv *sp;
 224         struct rxrpc_crypt iv;
 225         struct scatterlist sg[16];
 226         unsigned int len;
 227         u16 check;
 228         int err;
 229
 230         sp = rxrpc_skb(skb);
 231
 232         _enter("");
 233
 234         check = sp->hdr.seq ^ call->call_id;
 235
 236         rxkhdr.data_size = htonl(data_size | (u32)check << 16);
 237         rxkhdr.checksum = 0;
 238         memcpy(sechdr, &rxkhdr, sizeof(rxkhdr));
 239
 240         /* encrypt from the session key */
 241         token = call->conn->params.key->payload.data[0];
 242         memcpy(&iv, token->kad->session_key, sizeof(iv));
 243
 244         sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
 245         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 246         skcipher_request_set_callback(req, 0, NULL, NULL);
 247         skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
 248         crypto_skcipher_encrypt(req);
 249
 250         /* we want to encrypt the skbuff in-place */
 251         err = -EMSGSIZE;
 252         if (skb_shinfo(skb)->nr_frags > 16)
 253                 goto out;
 254
 255         len = data_size + call->conn->size_align - 1;
 256         len &= ~(call->conn->size_align - 1);
 257
 258         sg_init_table(sg, ARRAY_SIZE(sg));
 259         err = skb_to_sgvec(skb, sg, 0, len);
 260         if (unlikely(err < 0))
 261                 goto out;
 262         skcipher_request_set_crypt(req, sg, sg, len, iv.x);
 263         crypto_skcipher_encrypt(req);
 264
 265         _leave(" = 0");
 266         err = 0;
 267
 268 out:
 269         skcipher_request_zero(req);
 270         return err;
 271 }
 272
 273 /*
 274  * checksum an RxRPC packet header
 275  */
 276 static int rxkad_secure_packet(struct rxrpc_call *call,
 277                                struct sk_buff *skb,
 278                                size_t data_size,
 279                                void *sechdr)
 280 {
 281         struct rxrpc_skb_priv *sp;
 282         struct skcipher_request *req;
 283         struct rxrpc_crypt iv;
 284         struct scatterlist sg;
 285         u32 x, y;
 286         int ret;
 287
 288         sp = rxrpc_skb(skb);
 289
 290         _enter("{%d{%x}},{#%u},%zu,",
 291                call->debug_id, key_serial(call->conn->params.key),
 292                sp->hdr.seq, data_size);
 293
 294         if (!call->conn->cipher)
 295                 return 0;
 296
 297         ret = key_validate(call->conn->params.key);
 298         if (ret < 0)
 299                 return ret;
 300
 301         req = rxkad_get_call_crypto(call);
 302         if (!req)
 303                 return -ENOMEM;
 304
 305         /* continue encrypting from where we left off */
 306         memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
 307
 308         /* calculate the security checksum */
 309         x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
 310         x |= sp->hdr.seq & 0x3fffffff;
 311         call->crypto_buf[0] = htonl(call->call_id);
 312         call->crypto_buf[1] = htonl(x);
 313
 314         sg_init_one(&sg, call->crypto_buf, 8);
 315         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 316         skcipher_request_set_callback(req, 0, NULL, NULL);
 317         skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
 318         crypto_skcipher_encrypt(req);
 319         skcipher_request_zero(req);
 320
 321         y = ntohl(call->crypto_buf[1]);
 322         y = (y >> 16) & 0xffff;
 323         if (y == 0)
 324                 y = 1; /* zero checksums are not permitted */
 325         sp->hdr.cksum = y;
 326
 327         switch (call->conn->params.security_level) {
 328         case RXRPC_SECURITY_PLAIN:
 329                 ret = 0;
 330                 break;
 331         case RXRPC_SECURITY_AUTH:
 332                 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr,
 333                                                req);
 334                 break;
 335         case RXRPC_SECURITY_ENCRYPT:
 336                 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
 337                                                   sechdr, req);
 338                 break;
 339         default:
 340                 ret = -EPERM;
 341                 break;
 342         }
 343
 344         _leave(" = %d [set %hx]", ret, y);
 345         return ret;
 346 }
 347
 348 /*
 349  * decrypt partial encryption on a packet (level 1 security)
 350  */
 351 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 352                                  unsigned int offset, unsigned int len,
 353                                  rxrpc_seq_t seq,
 354                                  struct skcipher_request *req)
 355 {
 356         struct rxkad_level1_hdr sechdr;
 357         struct rxrpc_crypt iv;
 358         struct scatterlist sg[16];
 359         bool aborted;
 360         u32 data_size, buf;
 361         u16 check;
 362         int ret;
 363
 364         _enter("");
 365
 366         if (len < 8) {
 367                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
 368                                            RXKADSEALEDINCON);
 369                 goto protocol_error;
 370         }
 371
 372         /* Decrypt the skbuff in-place.  TODO: We really want to decrypt
 373          * directly into the target buffer.
 374          */
 375         sg_init_table(sg, ARRAY_SIZE(sg));
 376         ret = skb_to_sgvec(skb, sg, offset, 8);
 377         if (unlikely(ret < 0))
 378                 return ret;
 379
 380         /* start the decryption afresh */
 381         memset(&iv, 0, sizeof(iv));
 382
 383         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 384         skcipher_request_set_callback(req, 0, NULL, NULL);
 385         skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
 386         crypto_skcipher_decrypt(req);
 387         skcipher_request_zero(req);
 388
 389         /* Extract the decrypted packet length */
 390         if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
 391                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
 392                                              RXKADDATALEN);
 393                 goto protocol_error;
 394         }
 395         offset += sizeof(sechdr);
 396         len -= sizeof(sechdr);
 397
 398         buf = ntohl(sechdr.data_size);
 399         data_size = buf & 0xffff;
 400
 401         check = buf >> 16;
 402         check ^= seq ^ call->call_id;
 403         check &= 0xffff;
 404         if (check != 0) {
 405                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
 406                                              RXKADSEALEDINCON);
 407                 goto protocol_error;
 408         }
 409
 410         if (data_size > len) {
 411                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
 412                                              RXKADDATALEN);
 413                 goto protocol_error;
 414         }
 415
 416         _leave(" = 0 [dlen=%x]", data_size);
 417         return 0;
 418
 419 protocol_error:
 420         if (aborted)
 421                 rxrpc_send_abort_packet(call);
 422         return -EPROTO;
 423 }
 424
 425 /*
 426  * wholly decrypt a packet (level 2 security)
 427  */
 428 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 429                                  unsigned int offset, unsigned int len,
 430                                  rxrpc_seq_t seq,
 431                                  struct skcipher_request *req)
 432 {
 433         const struct rxrpc_key_token *token;
 434         struct rxkad_level2_hdr sechdr;
 435         struct rxrpc_crypt iv;
 436         struct scatterlist _sg[4], *sg;
 437         bool aborted;
 438         u32 data_size, buf;
 439         u16 check;
 440         int nsg, ret;
 441
 442         _enter(",{%d}", skb->len);
 443
 444         if (len < 8) {
 445                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
 446                                              RXKADSEALEDINCON);
 447                 goto protocol_error;
 448         }
 449
 450         /* Decrypt the skbuff in-place.  TODO: We really want to decrypt
 451          * directly into the target buffer.
 452          */
 453         sg = _sg;
 454         nsg = skb_shinfo(skb)->nr_frags;
 455         if (nsg <= 4) {
 456                 nsg = 4;
 457         } else {
 458                 sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO);
 459                 if (!sg)
 460                         goto nomem;
 461         }
 462
 463         sg_init_table(sg, nsg);
 464         ret = skb_to_sgvec(skb, sg, offset, len);
 465         if (unlikely(ret < 0)) {
 466                 if (sg != _sg)
 467                         kfree(sg);
 468                 return ret;
 469         }
 470
 471         /* decrypt from the session key */
 472         token = call->conn->params.key->payload.data[0];
 473         memcpy(&iv, token->kad->session_key, sizeof(iv));
 474
 475         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 476         skcipher_request_set_callback(req, 0, NULL, NULL);
 477         skcipher_request_set_crypt(req, sg, sg, len, iv.x);
 478         crypto_skcipher_decrypt(req);
 479         skcipher_request_zero(req);
 480         if (sg != _sg)
 481                 kfree(sg);
 482
 483         /* Extract the decrypted packet length */
 484         if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
 485                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
 486                                              RXKADDATALEN);
 487                 goto protocol_error;
 488         }
 489         offset += sizeof(sechdr);
 490         len -= sizeof(sechdr);
 491
 492         buf = ntohl(sechdr.data_size);
 493         data_size = buf & 0xffff;
 494
 495         check = buf >> 16;
 496         check ^= seq ^ call->call_id;
 497         check &= 0xffff;
 498         if (check != 0) {
 499                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
 500                                              RXKADSEALEDINCON);
 501                 goto protocol_error;
 502         }
 503
 504         if (data_size > len) {
 505                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
 506                                              RXKADDATALEN);
 507                 goto protocol_error;
 508         }
 509
 510         _leave(" = 0 [dlen=%x]", data_size);
 511         return 0;
 512
 513 protocol_error:
 514         if (aborted)
 515                 rxrpc_send_abort_packet(call);
 516         return -EPROTO;
 517
 518 nomem:
 519         _leave(" = -ENOMEM");
 520         return -ENOMEM;
 521 }
 522
 523 /*
 524  * Verify the security on a received packet or subpacket (if part of a
 525  * jumbo packet).
 526  */
 527 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
 528                                unsigned int offset, unsigned int len,
 529                                rxrpc_seq_t seq, u16 expected_cksum)
 530 {
 531         struct skcipher_request *req;
 532         struct rxrpc_crypt iv;
 533         struct scatterlist sg;
 534         bool aborted;
 535         u16 cksum;
 536         u32 x, y;
 537
 538         _enter("{%d{%x}},{#%u}",
 539                call->debug_id, key_serial(call->conn->params.key), seq);
 540
 541         if (!call->conn->cipher)
 542                 return 0;
 543
 544         req = rxkad_get_call_crypto(call);
 545         if (!req)
 546                 return -ENOMEM;
 547
 548         /* continue encrypting from where we left off */
 549         memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
 550
 551         /* validate the security checksum */
 552         x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
 553         x |= seq & 0x3fffffff;
 554         call->crypto_buf[0] = htonl(call->call_id);
 555         call->crypto_buf[1] = htonl(x);
 556
 557         sg_init_one(&sg, call->crypto_buf, 8);
 558         skcipher_request_set_sync_tfm(req, call->conn->cipher);
 559         skcipher_request_set_callback(req, 0, NULL, NULL);
 560         skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
 561         crypto_skcipher_encrypt(req);
 562         skcipher_request_zero(req);
 563
 564         y = ntohl(call->crypto_buf[1]);
 565         cksum = (y >> 16) & 0xffff;
 566         if (cksum == 0)
 567                 cksum = 1; /* zero checksums are not permitted */
 568
 569         if (cksum != expected_cksum) {
 570                 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
 571                                              RXKADSEALEDINCON);
 572                 goto protocol_error;
 573         }
 574
 575         switch (call->conn->params.security_level) {
 576         case RXRPC_SECURITY_PLAIN:
 577                 return 0;
 578         case RXRPC_SECURITY_AUTH:
 579                 return rxkad_verify_packet_1(call, skb, offset, len, seq, req);
 580         case RXRPC_SECURITY_ENCRYPT:
 581                 return rxkad_verify_packet_2(call, skb, offset, len, seq, req);
 582         default:
 583                 return -ENOANO;
 584         }
 585
 586 protocol_error:
 587         if (aborted)
 588                 rxrpc_send_abort_packet(call);
 589         return -EPROTO;
 590 }
 591
 592 /*
 593  * Locate the data contained in a packet that was partially encrypted.
 594  */
 595 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
 596                                 unsigned int *_offset, unsigned int *_len)
 597 {
 598         struct rxkad_level1_hdr sechdr;
 599
 600         if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
 601                 BUG();
 602         *_offset += sizeof(sechdr);
 603         *_len = ntohl(sechdr.data_size) & 0xffff;
 604 }
 605
 606 /*
 607  * Locate the data contained in a packet that was completely encrypted.
 608  */
 609 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
 610                                 unsigned int *_offset, unsigned int *_len)
 611 {
 612         struct rxkad_level2_hdr sechdr;
 613
 614         if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
 615                 BUG();
 616         *_offset += sizeof(sechdr);
 617         *_len = ntohl(sechdr.data_size) & 0xffff;
 618 }
 619
 620 /*
 621  * Locate the data contained in an already decrypted packet.
 622  */
 623 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
 624                               unsigned int *_offset, unsigned int *_len)
 625 {
 626         switch (call->conn->params.security_level) {
 627         case RXRPC_SECURITY_AUTH:
 628                 rxkad_locate_data_1(call, skb, _offset, _len);
 629                 return;
 630         case RXRPC_SECURITY_ENCRYPT:
 631                 rxkad_locate_data_2(call, skb, _offset, _len);
 632                 return;
 633         default:
 634                 return;
 635         }
 636 }
 637
 638 /*
 639  * issue a challenge
 640  */
 641 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
 642 {
 643         struct rxkad_challenge challenge;
 644         struct rxrpc_wire_header whdr;
 645         struct msghdr msg;
 646         struct kvec iov[2];
 647         size_t len;
 648         u32 serial;
 649         int ret;
 650
 651         _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
 652
 653         ret = key_validate(conn->server_key);
 654         if (ret < 0)
 655                 return ret;
 656
 657         get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
 658
 659         challenge.version       = htonl(2);
 660         challenge.nonce         = htonl(conn->security_nonce);
 661         challenge.min_level     = htonl(0);
 662         challenge.__padding     = 0;
 663
 664         msg.msg_name    = &conn->params.peer->srx.transport;
 665         msg.msg_namelen = conn->params.peer->srx.transport_len;
 666         msg.msg_control = NULL;
 667         msg.msg_controllen = 0;
 668         msg.msg_flags   = 0;
 669
 670         whdr.epoch      = htonl(conn->proto.epoch);
 671         whdr.cid        = htonl(conn->proto.cid);
 672         whdr.callNumber = 0;
 673         whdr.seq        = 0;
 674         whdr.type       = RXRPC_PACKET_TYPE_CHALLENGE;
 675         whdr.flags      = conn->out_clientflag;
 676         whdr.userStatus = 0;
 677         whdr.securityIndex = conn->security_ix;
 678         whdr._rsvd      = 0;
 679         whdr.serviceId  = htons(conn->service_id);
 680
 681         iov[0].iov_base = &whdr;
 682         iov[0].iov_len  = sizeof(whdr);
 683         iov[1].iov_base = &challenge;
 684         iov[1].iov_len  = sizeof(challenge);
 685
 686         len = iov[0].iov_len + iov[1].iov_len;
 687
 688         serial = atomic_inc_return(&conn->serial);
 689         whdr.serial = htonl(serial);
 690         _proto("Tx CHALLENGE %%%u", serial);
 691
 692         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 693         if (ret < 0) {
 694                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 695                                     rxrpc_tx_point_rxkad_challenge);
 696                 return -EAGAIN;
 697         }
 698
 699         conn->params.peer->last_tx_at = ktime_get_seconds();
 700         trace_rxrpc_tx_packet(conn->debug_id, &whdr,
 701                               rxrpc_tx_point_rxkad_challenge);
 702         _leave(" = 0");
 703         return 0;
 704 }
 705
 706 /*
 707  * send a Kerberos security response
 708  */
 709 static int rxkad_send_response(struct rxrpc_connection *conn,
 710                                struct rxrpc_host_header *hdr,
 711                                struct rxkad_response *resp,
 712                                const struct rxkad_key *s2)
 713 {
 714         struct rxrpc_wire_header whdr;
 715         struct msghdr msg;
 716         struct kvec iov[3];
 717         size_t len;
 718         u32 serial;
 719         int ret;
 720
 721         _enter("");
 722
 723         msg.msg_name    = &conn->params.peer->srx.transport;
 724         msg.msg_namelen = conn->params.peer->srx.transport_len;
 725         msg.msg_control = NULL;
 726         msg.msg_controllen = 0;
 727         msg.msg_flags   = 0;
 728
 729         memset(&whdr, 0, sizeof(whdr));
 730         whdr.epoch      = htonl(hdr->epoch);
 731         whdr.cid        = htonl(hdr->cid);
 732         whdr.type       = RXRPC_PACKET_TYPE_RESPONSE;
 733         whdr.flags      = conn->out_clientflag;
 734         whdr.securityIndex = hdr->securityIndex;
 735         whdr.serviceId  = htons(hdr->serviceId);
 736
 737         iov[0].iov_base = &whdr;
 738         iov[0].iov_len  = sizeof(whdr);
 739         iov[1].iov_base = resp;
 740         iov[1].iov_len  = sizeof(*resp);
 741         iov[2].iov_base = (void *)s2->ticket;
 742         iov[2].iov_len  = s2->ticket_len;
 743
 744         len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
 745
 746         serial = atomic_inc_return(&conn->serial);
 747         whdr.serial = htonl(serial);
 748         _proto("Tx RESPONSE %%%u", serial);
 749
 750         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
 751         if (ret < 0) {
 752                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 753                                     rxrpc_tx_point_rxkad_response);
 754                 return -EAGAIN;
 755         }
 756
 757         conn->params.peer->last_tx_at = ktime_get_seconds();
 758         _leave(" = 0");
 759         return 0;
 760 }
 761
 762 /*
 763  * calculate the response checksum
 764  */
 765 static void rxkad_calc_response_checksum(struct rxkad_response *response)
 766 {
 767         u32 csum = 1000003;
 768         int loop;
 769         u8 *p = (u8 *) response;
 770
 771         for (loop = sizeof(*response); loop > 0; loop--)
 772                 csum = csum * 0x10204081 + *p++;
 773
 774         response->encrypted.checksum = htonl(csum);
 775 }
 776
 777 /*
 778  * encrypt the response packet
 779  */
 780 static int rxkad_encrypt_response(struct rxrpc_connection *conn,
 781                                   struct rxkad_response *resp,
 782                                   const struct rxkad_key *s2)
 783 {
 784         struct skcipher_request *req;
 785         struct rxrpc_crypt iv;
 786         struct scatterlist sg[1];
 787
 788         req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS);
 789         if (!req)
 790                 return -ENOMEM;
 791
 792         /* continue encrypting from where we left off */
 793         memcpy(&iv, s2->session_key, sizeof(iv));
 794
 795         sg_init_table(sg, 1);
 796         sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
 797         skcipher_request_set_sync_tfm(req, conn->cipher);
 798         skcipher_request_set_callback(req, 0, NULL, NULL);
 799         skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
 800         crypto_skcipher_encrypt(req);
 801         skcipher_request_free(req);
 802         return 0;
 803 }
 804
 805 /*
 806  * respond to a challenge packet
 807  */
 808 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 809                                       struct sk_buff *skb,
 810                                       u32 *_abort_code)
 811 {
 812         const struct rxrpc_key_token *token;
 813         struct rxkad_challenge challenge;
 814         struct rxkad_response *resp;
 815         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 816         const char *eproto;
 817         u32 version, nonce, min_level, abort_code;
 818         int ret;
 819
 820         _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
 821
 822         eproto = tracepoint_string("chall_no_key");
 823         abort_code = RX_PROTOCOL_ERROR;
 824         if (!conn->params.key)
 825                 goto protocol_error;
 826
 827         abort_code = RXKADEXPIRED;
 828         ret = key_validate(conn->params.key);
 829         if (ret < 0)
 830                 goto other_error;
 831
 832         eproto = tracepoint_string("chall_short");
 833         abort_code = RXKADPACKETSHORT;
 834         if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 835                           &challenge, sizeof(challenge)) < 0)
 836                 goto protocol_error;
 837
 838         version = ntohl(challenge.version);
 839         nonce = ntohl(challenge.nonce);
 840         min_level = ntohl(challenge.min_level);
 841
 842         _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
 843                sp->hdr.serial, version, nonce, min_level);
 844
 845         eproto = tracepoint_string("chall_ver");
 846         abort_code = RXKADINCONSISTENCY;
 847         if (version != RXKAD_VERSION)
 848                 goto protocol_error;
 849
 850         abort_code = RXKADLEVELFAIL;
 851         ret = -EACCES;
 852         if (conn->params.security_level < min_level)
 853                 goto other_error;
 854
 855         token = conn->params.key->payload.data[0];
 856
 857         /* build the response packet */
 858         resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
 859         if (!resp)
 860                 return -ENOMEM;
 861
 862         resp->version                   = htonl(RXKAD_VERSION);
 863         resp->encrypted.epoch           = htonl(conn->proto.epoch);
 864         resp->encrypted.cid             = htonl(conn->proto.cid);
 865         resp->encrypted.securityIndex   = htonl(conn->security_ix);
 866         resp->encrypted.inc_nonce       = htonl(nonce + 1);
 867         resp->encrypted.level           = htonl(conn->params.security_level);
 868         resp->kvno                      = htonl(token->kad->kvno);
 869         resp->ticket_len                = htonl(token->kad->ticket_len);
 870         resp->encrypted.call_id[0]      = htonl(conn->channels[0].call_counter);
 871         resp->encrypted.call_id[1]      = htonl(conn->channels[1].call_counter);
 872         resp->encrypted.call_id[2]      = htonl(conn->channels[2].call_counter);
 873         resp->encrypted.call_id[3]      = htonl(conn->channels[3].call_counter);
 874
 875         /* calculate the response checksum and then do the encryption */
 876         rxkad_calc_response_checksum(resp);
 877         ret = rxkad_encrypt_response(conn, resp, token->kad);
 878         if (ret == 0)
 879                 ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
 880         kfree(resp);
 881         return ret;
 882
 883 protocol_error:
 884         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
 885         ret = -EPROTO;
 886 other_error:
 887         *_abort_code = abort_code;
 888         return ret;
 889 }
 890
 891 /*
 892  * decrypt the kerberos IV ticket in the response
 893  */
 894 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
 895                                 struct sk_buff *skb,
 896                                 void *ticket, size_t ticket_len,
 897                                 struct rxrpc_crypt *_session_key,
 898                                 time64_t *_expiry,
 899                                 u32 *_abort_code)
 900 {
 901         struct skcipher_request *req;
 902         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 903         struct rxrpc_crypt iv, key;
 904         struct scatterlist sg[1];
 905         struct in_addr addr;
 906         unsigned int life;
 907         const char *eproto;
 908         time64_t issue, now;
 909         bool little_endian;
 910         int ret;
 911         u32 abort_code;
 912         u8 *p, *q, *name, *end;
 913
 914         _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
 915
 916         *_expiry = 0;
 917
 918         ret = key_validate(conn->server_key);
 919         if (ret < 0) {
 920                 switch (ret) {
 921                 case -EKEYEXPIRED:
 922                         abort_code = RXKADEXPIRED;
 923                         goto other_error;
 924                 default:
 925                         abort_code = RXKADNOAUTH;
 926                         goto other_error;
 927                 }
 928         }
 929
 930         ASSERT(conn->server_key->payload.data[0] != NULL);
 931         ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
 932
 933         memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
 934
 935         ret = -ENOMEM;
 936         req = skcipher_request_alloc(conn->server_key->payload.data[0],
 937                                      GFP_NOFS);
 938         if (!req)
 939                 goto temporary_error;
 940
 941         sg_init_one(&sg[0], ticket, ticket_len);
 942         skcipher_request_set_callback(req, 0, NULL, NULL);
 943         skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
 944         crypto_skcipher_decrypt(req);
 945         skcipher_request_free(req);
 946
 947         p = ticket;
 948         end = p + ticket_len;
 949
 950 #define Z(field)                                        \
 951         ({                                              \
 952                 u8 *__str = p;                          \
 953                 eproto = tracepoint_string("rxkad_bad_"#field); \
 954                 q = memchr(p, 0, end - p);              \
 955                 if (!q || q - p > (field##_SZ))         \
 956                         goto bad_ticket;                \
 957                 for (; p < q; p++)                      \
 958                         if (!isprint(*p))               \
 959                                 goto bad_ticket;        \
 960                 p++;                                    \
 961                 __str;                                  \
 962         })
 963
 964         /* extract the ticket flags */
 965         _debug("KIV FLAGS: %x", *p);
 966         little_endian = *p & 1;
 967         p++;
 968
 969         /* extract the authentication name */
 970         name = Z(ANAME);
 971         _debug("KIV ANAME: %s", name);
 972
 973         /* extract the principal's instance */
 974         name = Z(INST);
 975         _debug("KIV INST : %s", name);
 976
 977         /* extract the principal's authentication domain */
 978         name = Z(REALM);
 979         _debug("KIV REALM: %s", name);
 980
 981         eproto = tracepoint_string("rxkad_bad_len");
 982         if (end - p < 4 + 8 + 4 + 2)
 983                 goto bad_ticket;
 984
 985         /* get the IPv4 address of the entity that requested the ticket */
 986         memcpy(&addr, p, sizeof(addr));
 987         p += 4;
 988         _debug("KIV ADDR : %pI4", &addr);
 989
 990         /* get the session key from the ticket */
 991         memcpy(&key, p, sizeof(key));
 992         p += 8;
 993         _debug("KIV KEY  : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
 994         memcpy(_session_key, &key, sizeof(key));
 995
 996         /* get the ticket's lifetime */
 997         life = *p++ * 5 * 60;
 998         _debug("KIV LIFE : %u", life);
 999
1000         /* get the issue time of the ticket */
1001         if (little_endian) {
1002                 __le32 stamp;
1003                 memcpy(&stamp, p, 4);
1004                 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
1005         } else {
1006                 __be32 stamp;
1007                 memcpy(&stamp, p, 4);
1008                 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
1009         }
1010         p += 4;
1011         now = ktime_get_real_seconds();
1012         _debug("KIV ISSUE: %llx [%llx]", issue, now);
1013
1014         /* check the ticket is in date */
1015         if (issue > now) {
1016                 abort_code = RXKADNOAUTH;
1017                 ret = -EKEYREJECTED;
1018                 goto other_error;
1019         }
1020
1021         if (issue < now - life) {
1022                 abort_code = RXKADEXPIRED;
1023                 ret = -EKEYEXPIRED;
1024                 goto other_error;
1025         }
1026
1027         *_expiry = issue + life;
1028
1029         /* get the service name */
1030         name = Z(SNAME);
1031         _debug("KIV SNAME: %s", name);
1032
1033         /* get the service instance name */
1034         name = Z(INST);
1035         _debug("KIV SINST: %s", name);
1036         return 0;
1037
1038 bad_ticket:
1039         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1040         abort_code = RXKADBADTICKET;
1041         ret = -EPROTO;
1042 other_error:
1043         *_abort_code = abort_code;
1044         return ret;
1045 temporary_error:
1046         return ret;
1047 }
1048
1049 /*
1050  * decrypt the response packet
1051  */
1052 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1053                                    struct rxkad_response *resp,
1054                                    const struct rxrpc_crypt *session_key)
1055 {
1056         struct skcipher_request *req = rxkad_ci_req;
1057         struct scatterlist sg[1];
1058         struct rxrpc_crypt iv;
1059
1060         _enter(",,%08x%08x",
1061                ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1062
1063         mutex_lock(&rxkad_ci_mutex);
1064         if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
1065                                         sizeof(*session_key)) < 0)
1066                 BUG();
1067
1068         memcpy(&iv, session_key, sizeof(iv));
1069
1070         sg_init_table(sg, 1);
1071         sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1072         skcipher_request_set_sync_tfm(req, rxkad_ci);
1073         skcipher_request_set_callback(req, 0, NULL, NULL);
1074         skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1075         crypto_skcipher_decrypt(req);
1076         skcipher_request_zero(req);
1077
1078         mutex_unlock(&rxkad_ci_mutex);
1079
1080         _leave("");
1081 }
1082
1083 /*
1084  * verify a response
1085  */
1086 static int rxkad_verify_response(struct rxrpc_connection *conn,
1087                                  struct sk_buff *skb,
1088                                  u32 *_abort_code)
1089 {
1090         struct rxkad_response *response;
1091         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1092         struct rxrpc_crypt session_key;
1093         const char *eproto;
1094         time64_t expiry;
1095         void *ticket;
1096         u32 abort_code, version, kvno, ticket_len, level;
1097         __be32 csum;
1098         int ret, i;
1099
1100         _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1101
1102         ret = -ENOMEM;
1103         response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
1104         if (!response)
1105                 goto temporary_error;
1106
1107         eproto = tracepoint_string("rxkad_rsp_short");
1108         abort_code = RXKADPACKETSHORT;
1109         if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1110                           response, sizeof(*response)) < 0)
1111                 goto protocol_error;
1112         if (!pskb_pull(skb, sizeof(*response)))
1113                 BUG();
1114
1115         version = ntohl(response->version);
1116         ticket_len = ntohl(response->ticket_len);
1117         kvno = ntohl(response->kvno);
1118         _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1119                sp->hdr.serial, version, kvno, ticket_len);
1120
1121         eproto = tracepoint_string("rxkad_rsp_ver");
1122         abort_code = RXKADINCONSISTENCY;
1123         if (version != RXKAD_VERSION)
1124                 goto protocol_error;
1125
1126         eproto = tracepoint_string("rxkad_rsp_tktlen");
1127         abort_code = RXKADTICKETLEN;
1128         if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1129                 goto protocol_error;
1130
1131         eproto = tracepoint_string("rxkad_rsp_unkkey");
1132         abort_code = RXKADUNKNOWNKEY;
1133         if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1134                 goto protocol_error;
1135
1136         /* extract the kerberos ticket and decrypt and decode it */
1137         ret = -ENOMEM;
1138         ticket = kmalloc(ticket_len, GFP_NOFS);
1139         if (!ticket)
1140                 goto temporary_error_free_resp;
1141
1142         eproto = tracepoint_string("rxkad_tkt_short");
1143         abort_code = RXKADPACKETSHORT;
1144         if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1145                           ticket, ticket_len) < 0)
1146                 goto protocol_error_free;
1147
1148         ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1149                                    &expiry, _abort_code);
1150         if (ret < 0)
1151                 goto temporary_error_free_ticket;
1152
1153         /* use the session key from inside the ticket to decrypt the
1154          * response */
1155         rxkad_decrypt_response(conn, response, &session_key);
1156
1157         eproto = tracepoint_string("rxkad_rsp_param");
1158         abort_code = RXKADSEALEDINCON;
1159         if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
1160                 goto protocol_error_free;
1161         if (ntohl(response->encrypted.cid) != conn->proto.cid)
1162                 goto protocol_error_free;
1163         if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
1164                 goto protocol_error_free;
1165         csum = response->encrypted.checksum;
1166         response->encrypted.checksum = 0;
1167         rxkad_calc_response_checksum(response);
1168         eproto = tracepoint_string("rxkad_rsp_csum");
1169         if (response->encrypted.checksum != csum)
1170                 goto protocol_error_free;
1171
1172         spin_lock(&conn->bundle->channel_lock);
1173         for (i = 0; i < RXRPC_MAXCALLS; i++) {
1174                 struct rxrpc_call *call;
1175                 u32 call_id = ntohl(response->encrypted.call_id[i]);
1176
1177                 eproto = tracepoint_string("rxkad_rsp_callid");
1178                 if (call_id > INT_MAX)
1179                         goto protocol_error_unlock;
1180
1181                 eproto = tracepoint_string("rxkad_rsp_callctr");
1182                 if (call_id < conn->channels[i].call_counter)
1183                         goto protocol_error_unlock;
1184
1185                 eproto = tracepoint_string("rxkad_rsp_callst");
1186                 if (call_id > conn->channels[i].call_counter) {
1187                         call = rcu_dereference_protected(
1188                                 conn->channels[i].call,
1189                                 lockdep_is_held(&conn->bundle->channel_lock));
1190                         if (call && call->state < RXRPC_CALL_COMPLETE)
1191                                 goto protocol_error_unlock;
1192                         conn->channels[i].call_counter = call_id;
1193                 }
1194         }
1195         spin_unlock(&conn->bundle->channel_lock);
1196
1197         eproto = tracepoint_string("rxkad_rsp_seq");
1198         abort_code = RXKADOUTOFSEQUENCE;
1199         if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1)
1200                 goto protocol_error_free;
1201
1202         eproto = tracepoint_string("rxkad_rsp_level");
1203         abort_code = RXKADLEVELFAIL;
1204         level = ntohl(response->encrypted.level);
1205         if (level > RXRPC_SECURITY_ENCRYPT)
1206                 goto protocol_error_free;
1207         conn->params.security_level = level;
1208
1209         /* create a key to hold the security data and expiration time - after
1210          * this the connection security can be handled in exactly the same way
1211          * as for a client connection */
1212         ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1213         if (ret < 0)
1214                 goto temporary_error_free_ticket;
1215
1216         kfree(ticket);
1217         kfree(response);
1218         _leave(" = 0");
1219         return 0;
1220
1221 protocol_error_unlock:
1222         spin_unlock(&conn->bundle->channel_lock);
1223 protocol_error_free:
1224         kfree(ticket);
1225 protocol_error:
1226         kfree(response);
1227         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1228         *_abort_code = abort_code;
1229         return -EPROTO;
1230
1231 temporary_error_free_ticket:
1232         kfree(ticket);
1233 temporary_error_free_resp:
1234         kfree(response);
1235 temporary_error:
1236         /* Ignore the response packet if we got a temporary error such as
1237          * ENOMEM.  We just want to send the challenge again.  Note that we
1238          * also come out this way if the ticket decryption fails.
1239          */
1240         return ret;
1241 }
1242
1243 /*
1244  * clear the connection security
1245  */
1246 static void rxkad_clear(struct rxrpc_connection *conn)
1247 {
1248         _enter("");
1249
1250         if (conn->cipher)
1251                 crypto_free_sync_skcipher(conn->cipher);
1252 }
1253
1254 /*
1255  * Initialise the rxkad security service.
1256  */
1257 static int rxkad_init(void)
1258 {
1259         struct crypto_sync_skcipher *tfm;
1260         struct skcipher_request *req;
1261
1262         /* pin the cipher we need so that the crypto layer doesn't invoke
1263          * keventd to go get it */
1264         tfm = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
1265         if (IS_ERR(tfm))
1266                 return PTR_ERR(tfm);
1267
1268         req = skcipher_request_alloc(&tfm->base, GFP_KERNEL);
1269         if (!req)
1270                 goto nomem_tfm;
1271
1272         rxkad_ci_req = req;
1273         rxkad_ci = tfm;
1274         return 0;
1275
1276 nomem_tfm:
1277         crypto_free_sync_skcipher(tfm);
1278         return -ENOMEM;
1279 }
1280
1281 /*
1282  * Clean up the rxkad security service.
1283  */
1284 static void rxkad_exit(void)
1285 {
1286         crypto_free_sync_skcipher(rxkad_ci);
1287         skcipher_request_free(rxkad_ci_req);
1288 }
1289
1290 /*
1291  * RxRPC Kerberos-based security
1292  */
1293 const struct rxrpc_security rxkad = {
1294         .name                           = "rxkad",
1295         .security_index                 = RXRPC_SECURITY_RXKAD,
1296         .no_key_abort                   = RXKADUNKNOWNKEY,
1297         .init                           = rxkad_init,
1298         .exit                           = rxkad_exit,
1299         .init_connection_security       = rxkad_init_connection_security,
1300         .prime_packet_security          = rxkad_prime_packet_security,
1301         .secure_packet                  = rxkad_secure_packet,
1302         .verify_packet                  = rxkad_verify_packet,
1303         .free_call_crypto               = rxkad_free_call_crypto,
1304         .locate_data                    = rxkad_locate_data,
1305         .issue_challenge                = rxkad_issue_challenge,
1306         .respond_to_challenge           = rxkad_respond_to_challenge,
1307         .verify_response                = rxkad_verify_response,
1308         .clear                          = rxkad_clear,
1309 };