linux/net/rxrpc/ar-key.c
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   1/* RxRPC key management
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 *
  11 * RxRPC keys should have a description of describing their purpose:
  12 *      "afs@CAMBRIDGE.REDHAT.COM>
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/net.h>
  17#include <linux/skbuff.h>
  18#include <linux/key-type.h>
  19#include <linux/crypto.h>
  20#include <linux/ctype.h>
  21#include <linux/slab.h>
  22#include <net/sock.h>
  23#include <net/af_rxrpc.h>
  24#include <keys/rxrpc-type.h>
  25#include <keys/user-type.h>
  26#include "ar-internal.h"
  27
  28static int rxrpc_vet_description_s(const char *);
  29static int rxrpc_preparse(struct key_preparsed_payload *);
  30static int rxrpc_preparse_s(struct key_preparsed_payload *);
  31static void rxrpc_free_preparse(struct key_preparsed_payload *);
  32static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
  33static void rxrpc_destroy(struct key *);
  34static void rxrpc_destroy_s(struct key *);
  35static void rxrpc_describe(const struct key *, struct seq_file *);
  36static long rxrpc_read(const struct key *, char __user *, size_t);
  37
  38/*
  39 * rxrpc defined keys take an arbitrary string as the description and an
  40 * arbitrary blob of data as the payload
  41 */
  42struct key_type key_type_rxrpc = {
  43        .name           = "rxrpc",
  44        .preparse       = rxrpc_preparse,
  45        .free_preparse  = rxrpc_free_preparse,
  46        .instantiate    = generic_key_instantiate,
  47        .destroy        = rxrpc_destroy,
  48        .describe       = rxrpc_describe,
  49        .read           = rxrpc_read,
  50};
  51EXPORT_SYMBOL(key_type_rxrpc);
  52
  53/*
  54 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
  55 * description and an 8-byte decryption key as the payload
  56 */
  57struct key_type key_type_rxrpc_s = {
  58        .name           = "rxrpc_s",
  59        .vet_description = rxrpc_vet_description_s,
  60        .preparse       = rxrpc_preparse_s,
  61        .free_preparse  = rxrpc_free_preparse_s,
  62        .instantiate    = generic_key_instantiate,
  63        .destroy        = rxrpc_destroy_s,
  64        .describe       = rxrpc_describe,
  65};
  66
  67/*
  68 * Vet the description for an RxRPC server key
  69 */
  70static int rxrpc_vet_description_s(const char *desc)
  71{
  72        unsigned long num;
  73        char *p;
  74
  75        num = simple_strtoul(desc, &p, 10);
  76        if (*p != ':' || num > 65535)
  77                return -EINVAL;
  78        num = simple_strtoul(p + 1, &p, 10);
  79        if (*p || num < 1 || num > 255)
  80                return -EINVAL;
  81        return 0;
  82}
  83
  84/*
  85 * parse an RxKAD type XDR format token
  86 * - the caller guarantees we have at least 4 words
  87 */
  88static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
  89                                    size_t datalen,
  90                                    const __be32 *xdr, unsigned int toklen)
  91{
  92        struct rxrpc_key_token *token, **pptoken;
  93        size_t plen;
  94        u32 tktlen;
  95
  96        _enter(",{%x,%x,%x,%x},%u",
  97               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
  98               toklen);
  99
 100        if (toklen <= 8 * 4)
 101                return -EKEYREJECTED;
 102        tktlen = ntohl(xdr[7]);
 103        _debug("tktlen: %x", tktlen);
 104        if (tktlen > AFSTOKEN_RK_TIX_MAX)
 105                return -EKEYREJECTED;
 106        if (toklen < 8 * 4 + tktlen)
 107                return -EKEYREJECTED;
 108
 109        plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
 110        prep->quotalen = datalen + plen;
 111
 112        plen -= sizeof(*token);
 113        token = kzalloc(sizeof(*token), GFP_KERNEL);
 114        if (!token)
 115                return -ENOMEM;
 116
 117        token->kad = kzalloc(plen, GFP_KERNEL);
 118        if (!token->kad) {
 119                kfree(token);
 120                return -ENOMEM;
 121        }
 122
 123        token->security_index   = RXRPC_SECURITY_RXKAD;
 124        token->kad->ticket_len  = tktlen;
 125        token->kad->vice_id     = ntohl(xdr[0]);
 126        token->kad->kvno        = ntohl(xdr[1]);
 127        token->kad->start       = ntohl(xdr[4]);
 128        token->kad->expiry      = ntohl(xdr[5]);
 129        token->kad->primary_flag = ntohl(xdr[6]);
 130        memcpy(&token->kad->session_key, &xdr[2], 8);
 131        memcpy(&token->kad->ticket, &xdr[8], tktlen);
 132
 133        _debug("SCIX: %u", token->security_index);
 134        _debug("TLEN: %u", token->kad->ticket_len);
 135        _debug("EXPY: %x", token->kad->expiry);
 136        _debug("KVNO: %u", token->kad->kvno);
 137        _debug("PRIM: %u", token->kad->primary_flag);
 138        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 139               token->kad->session_key[0], token->kad->session_key[1],
 140               token->kad->session_key[2], token->kad->session_key[3],
 141               token->kad->session_key[4], token->kad->session_key[5],
 142               token->kad->session_key[6], token->kad->session_key[7]);
 143        if (token->kad->ticket_len >= 8)
 144                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 145                       token->kad->ticket[0], token->kad->ticket[1],
 146                       token->kad->ticket[2], token->kad->ticket[3],
 147                       token->kad->ticket[4], token->kad->ticket[5],
 148                       token->kad->ticket[6], token->kad->ticket[7]);
 149
 150        /* count the number of tokens attached */
 151        prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
 152
 153        /* attach the data */
 154        for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
 155             *pptoken;
 156             pptoken = &(*pptoken)->next)
 157                continue;
 158        *pptoken = token;
 159        if (token->kad->expiry < prep->expiry)
 160                prep->expiry = token->kad->expiry;
 161
 162        _leave(" = 0");
 163        return 0;
 164}
 165
 166static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
 167{
 168        int loop;
 169
 170        if (princ->name_parts) {
 171                for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
 172                        kfree(princ->name_parts[loop]);
 173                kfree(princ->name_parts);
 174        }
 175        kfree(princ->realm);
 176}
 177
 178static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
 179{
 180        kfree(td->data);
 181}
 182
 183/*
 184 * free up an RxK5 token
 185 */
 186static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
 187{
 188        int loop;
 189
 190        rxrpc_free_krb5_principal(&rxk5->client);
 191        rxrpc_free_krb5_principal(&rxk5->server);
 192        rxrpc_free_krb5_tagged(&rxk5->session);
 193
 194        if (rxk5->addresses) {
 195                for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
 196                        rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
 197                kfree(rxk5->addresses);
 198        }
 199        if (rxk5->authdata) {
 200                for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
 201                        rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
 202                kfree(rxk5->authdata);
 203        }
 204
 205        kfree(rxk5->ticket);
 206        kfree(rxk5->ticket2);
 207        kfree(rxk5);
 208}
 209
 210/*
 211 * extract a krb5 principal
 212 */
 213static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
 214                                       const __be32 **_xdr,
 215                                       unsigned int *_toklen)
 216{
 217        const __be32 *xdr = *_xdr;
 218        unsigned int toklen = *_toklen, n_parts, loop, tmp;
 219
 220        /* there must be at least one name, and at least #names+1 length
 221         * words */
 222        if (toklen <= 12)
 223                return -EINVAL;
 224
 225        _enter(",{%x,%x,%x},%u",
 226               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
 227
 228        n_parts = ntohl(*xdr++);
 229        toklen -= 4;
 230        if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
 231                return -EINVAL;
 232        princ->n_name_parts = n_parts;
 233
 234        if (toklen <= (n_parts + 1) * 4)
 235                return -EINVAL;
 236
 237        princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
 238        if (!princ->name_parts)
 239                return -ENOMEM;
 240
 241        for (loop = 0; loop < n_parts; loop++) {
 242                if (toklen < 4)
 243                        return -EINVAL;
 244                tmp = ntohl(*xdr++);
 245                toklen -= 4;
 246                if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
 247                        return -EINVAL;
 248                if (tmp > toklen)
 249                        return -EINVAL;
 250                princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
 251                if (!princ->name_parts[loop])
 252                        return -ENOMEM;
 253                memcpy(princ->name_parts[loop], xdr, tmp);
 254                princ->name_parts[loop][tmp] = 0;
 255                tmp = (tmp + 3) & ~3;
 256                toklen -= tmp;
 257                xdr += tmp >> 2;
 258        }
 259
 260        if (toklen < 4)
 261                return -EINVAL;
 262        tmp = ntohl(*xdr++);
 263        toklen -= 4;
 264        if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
 265                return -EINVAL;
 266        if (tmp > toklen)
 267                return -EINVAL;
 268        princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
 269        if (!princ->realm)
 270                return -ENOMEM;
 271        memcpy(princ->realm, xdr, tmp);
 272        princ->realm[tmp] = 0;
 273        tmp = (tmp + 3) & ~3;
 274        toklen -= tmp;
 275        xdr += tmp >> 2;
 276
 277        _debug("%s/...@%s", princ->name_parts[0], princ->realm);
 278
 279        *_xdr = xdr;
 280        *_toklen = toklen;
 281        _leave(" = 0 [toklen=%u]", toklen);
 282        return 0;
 283}
 284
 285/*
 286 * extract a piece of krb5 tagged data
 287 */
 288static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
 289                                         size_t max_data_size,
 290                                         const __be32 **_xdr,
 291                                         unsigned int *_toklen)
 292{
 293        const __be32 *xdr = *_xdr;
 294        unsigned int toklen = *_toklen, len;
 295
 296        /* there must be at least one tag and one length word */
 297        if (toklen <= 8)
 298                return -EINVAL;
 299
 300        _enter(",%zu,{%x,%x},%u",
 301               max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
 302
 303        td->tag = ntohl(*xdr++);
 304        len = ntohl(*xdr++);
 305        toklen -= 8;
 306        if (len > max_data_size)
 307                return -EINVAL;
 308        td->data_len = len;
 309
 310        if (len > 0) {
 311                td->data = kmemdup(xdr, len, GFP_KERNEL);
 312                if (!td->data)
 313                        return -ENOMEM;
 314                len = (len + 3) & ~3;
 315                toklen -= len;
 316                xdr += len >> 2;
 317        }
 318
 319        _debug("tag %x len %x", td->tag, td->data_len);
 320
 321        *_xdr = xdr;
 322        *_toklen = toklen;
 323        _leave(" = 0 [toklen=%u]", toklen);
 324        return 0;
 325}
 326
 327/*
 328 * extract an array of tagged data
 329 */
 330static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
 331                                          u8 *_n_elem,
 332                                          u8 max_n_elem,
 333                                          size_t max_elem_size,
 334                                          const __be32 **_xdr,
 335                                          unsigned int *_toklen)
 336{
 337        struct krb5_tagged_data *td;
 338        const __be32 *xdr = *_xdr;
 339        unsigned int toklen = *_toklen, n_elem, loop;
 340        int ret;
 341
 342        /* there must be at least one count */
 343        if (toklen < 4)
 344                return -EINVAL;
 345
 346        _enter(",,%u,%zu,{%x},%u",
 347               max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
 348
 349        n_elem = ntohl(*xdr++);
 350        toklen -= 4;
 351        if (n_elem > max_n_elem)
 352                return -EINVAL;
 353        *_n_elem = n_elem;
 354        if (n_elem > 0) {
 355                if (toklen <= (n_elem + 1) * 4)
 356                        return -EINVAL;
 357
 358                _debug("n_elem %d", n_elem);
 359
 360                td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
 361                             GFP_KERNEL);
 362                if (!td)
 363                        return -ENOMEM;
 364                *_td = td;
 365
 366                for (loop = 0; loop < n_elem; loop++) {
 367                        ret = rxrpc_krb5_decode_tagged_data(&td[loop],
 368                                                            max_elem_size,
 369                                                            &xdr, &toklen);
 370                        if (ret < 0)
 371                                return ret;
 372                }
 373        }
 374
 375        *_xdr = xdr;
 376        *_toklen = toklen;
 377        _leave(" = 0 [toklen=%u]", toklen);
 378        return 0;
 379}
 380
 381/*
 382 * extract a krb5 ticket
 383 */
 384static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
 385                                    const __be32 **_xdr, unsigned int *_toklen)
 386{
 387        const __be32 *xdr = *_xdr;
 388        unsigned int toklen = *_toklen, len;
 389
 390        /* there must be at least one length word */
 391        if (toklen <= 4)
 392                return -EINVAL;
 393
 394        _enter(",{%x},%u", ntohl(xdr[0]), toklen);
 395
 396        len = ntohl(*xdr++);
 397        toklen -= 4;
 398        if (len > AFSTOKEN_K5_TIX_MAX)
 399                return -EINVAL;
 400        *_tktlen = len;
 401
 402        _debug("ticket len %u", len);
 403
 404        if (len > 0) {
 405                *_ticket = kmemdup(xdr, len, GFP_KERNEL);
 406                if (!*_ticket)
 407                        return -ENOMEM;
 408                len = (len + 3) & ~3;
 409                toklen -= len;
 410                xdr += len >> 2;
 411        }
 412
 413        *_xdr = xdr;
 414        *_toklen = toklen;
 415        _leave(" = 0 [toklen=%u]", toklen);
 416        return 0;
 417}
 418
 419/*
 420 * parse an RxK5 type XDR format token
 421 * - the caller guarantees we have at least 4 words
 422 */
 423static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
 424                                   size_t datalen,
 425                                   const __be32 *xdr, unsigned int toklen)
 426{
 427        struct rxrpc_key_token *token, **pptoken;
 428        struct rxk5_key *rxk5;
 429        const __be32 *end_xdr = xdr + (toklen >> 2);
 430        int ret;
 431
 432        _enter(",{%x,%x,%x,%x},%u",
 433               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 434               toklen);
 435
 436        /* reserve some payload space for this subkey - the length of the token
 437         * is a reasonable approximation */
 438        prep->quotalen = datalen + toklen;
 439
 440        token = kzalloc(sizeof(*token), GFP_KERNEL);
 441        if (!token)
 442                return -ENOMEM;
 443
 444        rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
 445        if (!rxk5) {
 446                kfree(token);
 447                return -ENOMEM;
 448        }
 449
 450        token->security_index = RXRPC_SECURITY_RXK5;
 451        token->k5 = rxk5;
 452
 453        /* extract the principals */
 454        ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
 455        if (ret < 0)
 456                goto error;
 457        ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
 458        if (ret < 0)
 459                goto error;
 460
 461        /* extract the session key and the encoding type (the tag field ->
 462         * ENCTYPE_xxx) */
 463        ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
 464                                            &xdr, &toklen);
 465        if (ret < 0)
 466                goto error;
 467
 468        if (toklen < 4 * 8 + 2 * 4)
 469                goto inval;
 470        rxk5->authtime  = be64_to_cpup((const __be64 *) xdr);
 471        xdr += 2;
 472        rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
 473        xdr += 2;
 474        rxk5->endtime   = be64_to_cpup((const __be64 *) xdr);
 475        xdr += 2;
 476        rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
 477        xdr += 2;
 478        rxk5->is_skey = ntohl(*xdr++);
 479        rxk5->flags = ntohl(*xdr++);
 480        toklen -= 4 * 8 + 2 * 4;
 481
 482        _debug("times: a=%llx s=%llx e=%llx rt=%llx",
 483               rxk5->authtime, rxk5->starttime, rxk5->endtime,
 484               rxk5->renew_till);
 485        _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
 486
 487        /* extract the permitted client addresses */
 488        ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
 489                                             &rxk5->n_addresses,
 490                                             AFSTOKEN_K5_ADDRESSES_MAX,
 491                                             AFSTOKEN_DATA_MAX,
 492                                             &xdr, &toklen);
 493        if (ret < 0)
 494                goto error;
 495
 496        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 497
 498        /* extract the tickets */
 499        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
 500                                       &xdr, &toklen);
 501        if (ret < 0)
 502                goto error;
 503        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
 504                                       &xdr, &toklen);
 505        if (ret < 0)
 506                goto error;
 507
 508        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 509
 510        /* extract the typed auth data */
 511        ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
 512                                             &rxk5->n_authdata,
 513                                             AFSTOKEN_K5_AUTHDATA_MAX,
 514                                             AFSTOKEN_BDATALN_MAX,
 515                                             &xdr, &toklen);
 516        if (ret < 0)
 517                goto error;
 518
 519        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 520
 521        if (toklen != 0)
 522                goto inval;
 523
 524        /* attach the payload */
 525        for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
 526             *pptoken;
 527             pptoken = &(*pptoken)->next)
 528                continue;
 529        *pptoken = token;
 530        if (token->kad->expiry < prep->expiry)
 531                prep->expiry = token->kad->expiry;
 532
 533        _leave(" = 0");
 534        return 0;
 535
 536inval:
 537        ret = -EINVAL;
 538error:
 539        rxrpc_rxk5_free(rxk5);
 540        kfree(token);
 541        _leave(" = %d", ret);
 542        return ret;
 543}
 544
 545/*
 546 * attempt to parse the data as the XDR format
 547 * - the caller guarantees we have more than 7 words
 548 */
 549static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
 550{
 551        const __be32 *xdr = prep->data, *token;
 552        const char *cp;
 553        unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
 554        size_t datalen = prep->datalen;
 555        int ret;
 556
 557        _enter(",{%x,%x,%x,%x},%zu",
 558               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 559               prep->datalen);
 560
 561        if (datalen > AFSTOKEN_LENGTH_MAX)
 562                goto not_xdr;
 563
 564        /* XDR is an array of __be32's */
 565        if (datalen & 3)
 566                goto not_xdr;
 567
 568        /* the flags should be 0 (the setpag bit must be handled by
 569         * userspace) */
 570        if (ntohl(*xdr++) != 0)
 571                goto not_xdr;
 572        datalen -= 4;
 573
 574        /* check the cell name */
 575        len = ntohl(*xdr++);
 576        if (len < 1 || len > AFSTOKEN_CELL_MAX)
 577                goto not_xdr;
 578        datalen -= 4;
 579        tmp = (len + 3) & ~3;
 580        if (tmp > datalen)
 581                goto not_xdr;
 582
 583        cp = (const char *) xdr;
 584        for (loop = 0; loop < len; loop++)
 585                if (!isprint(cp[loop]))
 586                        goto not_xdr;
 587        if (len < tmp)
 588                for (; loop < tmp; loop++)
 589                        if (cp[loop])
 590                                goto not_xdr;
 591        _debug("cellname: [%u/%u] '%*.*s'",
 592               len, tmp, len, len, (const char *) xdr);
 593        datalen -= tmp;
 594        xdr += tmp >> 2;
 595
 596        /* get the token count */
 597        if (datalen < 12)
 598                goto not_xdr;
 599        ntoken = ntohl(*xdr++);
 600        datalen -= 4;
 601        _debug("ntoken: %x", ntoken);
 602        if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
 603                goto not_xdr;
 604
 605        /* check each token wrapper */
 606        token = xdr;
 607        loop = ntoken;
 608        do {
 609                if (datalen < 8)
 610                        goto not_xdr;
 611                toklen = ntohl(*xdr++);
 612                sec_ix = ntohl(*xdr);
 613                datalen -= 4;
 614                _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
 615                if (toklen < 20 || toklen > datalen)
 616                        goto not_xdr;
 617                datalen -= (toklen + 3) & ~3;
 618                xdr += (toklen + 3) >> 2;
 619
 620        } while (--loop > 0);
 621
 622        _debug("remainder: %zu", datalen);
 623        if (datalen != 0)
 624                goto not_xdr;
 625
 626        /* okay: we're going to assume it's valid XDR format
 627         * - we ignore the cellname, relying on the key to be correctly named
 628         */
 629        do {
 630                xdr = token;
 631                toklen = ntohl(*xdr++);
 632                token = xdr + ((toklen + 3) >> 2);
 633                sec_ix = ntohl(*xdr++);
 634                toklen -= 4;
 635
 636                _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
 637
 638                switch (sec_ix) {
 639                case RXRPC_SECURITY_RXKAD:
 640                        ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
 641                        if (ret != 0)
 642                                goto error;
 643                        break;
 644
 645                case RXRPC_SECURITY_RXK5:
 646                        ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
 647                        if (ret != 0)
 648                                goto error;
 649                        break;
 650
 651                default:
 652                        ret = -EPROTONOSUPPORT;
 653                        goto error;
 654                }
 655
 656        } while (--ntoken > 0);
 657
 658        _leave(" = 0");
 659        return 0;
 660
 661not_xdr:
 662        _leave(" = -EPROTO");
 663        return -EPROTO;
 664error:
 665        _leave(" = %d", ret);
 666        return ret;
 667}
 668
 669/*
 670 * Preparse an rxrpc defined key.
 671 *
 672 * Data should be of the form:
 673 *      OFFSET  LEN     CONTENT
 674 *      0       4       key interface version number
 675 *      4       2       security index (type)
 676 *      6       2       ticket length
 677 *      8       4       key expiry time (time_t)
 678 *      12      4       kvno
 679 *      16      8       session key
 680 *      24      [len]   ticket
 681 *
 682 * if no data is provided, then a no-security key is made
 683 */
 684static int rxrpc_preparse(struct key_preparsed_payload *prep)
 685{
 686        const struct rxrpc_key_data_v1 *v1;
 687        struct rxrpc_key_token *token, **pp;
 688        size_t plen;
 689        u32 kver;
 690        int ret;
 691
 692        _enter("%zu", prep->datalen);
 693
 694        /* handle a no-security key */
 695        if (!prep->data && prep->datalen == 0)
 696                return 0;
 697
 698        /* determine if the XDR payload format is being used */
 699        if (prep->datalen > 7 * 4) {
 700                ret = rxrpc_preparse_xdr(prep);
 701                if (ret != -EPROTO)
 702                        return ret;
 703        }
 704
 705        /* get the key interface version number */
 706        ret = -EINVAL;
 707        if (prep->datalen <= 4 || !prep->data)
 708                goto error;
 709        memcpy(&kver, prep->data, sizeof(kver));
 710        prep->data += sizeof(kver);
 711        prep->datalen -= sizeof(kver);
 712
 713        _debug("KEY I/F VERSION: %u", kver);
 714
 715        ret = -EKEYREJECTED;
 716        if (kver != 1)
 717                goto error;
 718
 719        /* deal with a version 1 key */
 720        ret = -EINVAL;
 721        if (prep->datalen < sizeof(*v1))
 722                goto error;
 723
 724        v1 = prep->data;
 725        if (prep->datalen != sizeof(*v1) + v1->ticket_length)
 726                goto error;
 727
 728        _debug("SCIX: %u", v1->security_index);
 729        _debug("TLEN: %u", v1->ticket_length);
 730        _debug("EXPY: %x", v1->expiry);
 731        _debug("KVNO: %u", v1->kvno);
 732        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 733               v1->session_key[0], v1->session_key[1],
 734               v1->session_key[2], v1->session_key[3],
 735               v1->session_key[4], v1->session_key[5],
 736               v1->session_key[6], v1->session_key[7]);
 737        if (v1->ticket_length >= 8)
 738                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 739                       v1->ticket[0], v1->ticket[1],
 740                       v1->ticket[2], v1->ticket[3],
 741                       v1->ticket[4], v1->ticket[5],
 742                       v1->ticket[6], v1->ticket[7]);
 743
 744        ret = -EPROTONOSUPPORT;
 745        if (v1->security_index != RXRPC_SECURITY_RXKAD)
 746                goto error;
 747
 748        plen = sizeof(*token->kad) + v1->ticket_length;
 749        prep->quotalen = plen + sizeof(*token);
 750
 751        ret = -ENOMEM;
 752        token = kzalloc(sizeof(*token), GFP_KERNEL);
 753        if (!token)
 754                goto error;
 755        token->kad = kzalloc(plen, GFP_KERNEL);
 756        if (!token->kad)
 757                goto error_free;
 758
 759        token->security_index           = RXRPC_SECURITY_RXKAD;
 760        token->kad->ticket_len          = v1->ticket_length;
 761        token->kad->expiry              = v1->expiry;
 762        token->kad->kvno                = v1->kvno;
 763        memcpy(&token->kad->session_key, &v1->session_key, 8);
 764        memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
 765
 766        /* count the number of tokens attached */
 767        prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);
 768
 769        /* attach the data */
 770        pp = (struct rxrpc_key_token **)&prep->payload[0];
 771        while (*pp)
 772                pp = &(*pp)->next;
 773        *pp = token;
 774        if (token->kad->expiry < prep->expiry)
 775                prep->expiry = token->kad->expiry;
 776        token = NULL;
 777        ret = 0;
 778
 779error_free:
 780        kfree(token);
 781error:
 782        return ret;
 783}
 784
 785/*
 786 * Free token list.
 787 */
 788static void rxrpc_free_token_list(struct rxrpc_key_token *token)
 789{
 790        struct rxrpc_key_token *next;
 791
 792        for (; token; token = next) {
 793                next = token->next;
 794                switch (token->security_index) {
 795                case RXRPC_SECURITY_RXKAD:
 796                        kfree(token->kad);
 797                        break;
 798                case RXRPC_SECURITY_RXK5:
 799                        if (token->k5)
 800                                rxrpc_rxk5_free(token->k5);
 801                        break;
 802                default:
 803                        printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
 804                               token->security_index);
 805                        BUG();
 806                }
 807
 808                kfree(token);
 809        }
 810}
 811
 812/*
 813 * Clean up preparse data.
 814 */
 815static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
 816{
 817        rxrpc_free_token_list(prep->payload[0]);
 818}
 819
 820/*
 821 * Preparse a server secret key.
 822 *
 823 * The data should be the 8-byte secret key.
 824 */
 825static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
 826{
 827        struct crypto_blkcipher *ci;
 828
 829        _enter("%zu", prep->datalen);
 830
 831        if (prep->datalen != 8)
 832                return -EINVAL;
 833
 834        memcpy(&prep->type_data, prep->data, 8);
 835
 836        ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
 837        if (IS_ERR(ci)) {
 838                _leave(" = %ld", PTR_ERR(ci));
 839                return PTR_ERR(ci);
 840        }
 841
 842        if (crypto_blkcipher_setkey(ci, prep->data, 8) < 0)
 843                BUG();
 844
 845        prep->payload[0] = ci;
 846        _leave(" = 0");
 847        return 0;
 848}
 849
 850/*
 851 * Clean up preparse data.
 852 */
 853static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
 854{
 855        if (prep->payload[0])
 856                crypto_free_blkcipher(prep->payload[0]);
 857}
 858
 859/*
 860 * dispose of the data dangling from the corpse of a rxrpc key
 861 */
 862static void rxrpc_destroy(struct key *key)
 863{
 864        rxrpc_free_token_list(key->payload.data);
 865}
 866
 867/*
 868 * dispose of the data dangling from the corpse of a rxrpc key
 869 */
 870static void rxrpc_destroy_s(struct key *key)
 871{
 872        if (key->payload.data) {
 873                crypto_free_blkcipher(key->payload.data);
 874                key->payload.data = NULL;
 875        }
 876}
 877
 878/*
 879 * describe the rxrpc key
 880 */
 881static void rxrpc_describe(const struct key *key, struct seq_file *m)
 882{
 883        seq_puts(m, key->description);
 884}
 885
 886/*
 887 * grab the security key for a socket
 888 */
 889int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
 890{
 891        struct key *key;
 892        char *description;
 893
 894        _enter("");
 895
 896        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 897                return -EINVAL;
 898
 899        description = kmalloc(optlen + 1, GFP_KERNEL);
 900        if (!description)
 901                return -ENOMEM;
 902
 903        if (copy_from_user(description, optval, optlen)) {
 904                kfree(description);
 905                return -EFAULT;
 906        }
 907        description[optlen] = 0;
 908
 909        key = request_key(&key_type_rxrpc, description, NULL);
 910        if (IS_ERR(key)) {
 911                kfree(description);
 912                _leave(" = %ld", PTR_ERR(key));
 913                return PTR_ERR(key);
 914        }
 915
 916        rx->key = key;
 917        kfree(description);
 918        _leave(" = 0 [key %x]", key->serial);
 919        return 0;
 920}
 921
 922/*
 923 * grab the security keyring for a server socket
 924 */
 925int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
 926                         int optlen)
 927{
 928        struct key *key;
 929        char *description;
 930
 931        _enter("");
 932
 933        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 934                return -EINVAL;
 935
 936        description = kmalloc(optlen + 1, GFP_KERNEL);
 937        if (!description)
 938                return -ENOMEM;
 939
 940        if (copy_from_user(description, optval, optlen)) {
 941                kfree(description);
 942                return -EFAULT;
 943        }
 944        description[optlen] = 0;
 945
 946        key = request_key(&key_type_keyring, description, NULL);
 947        if (IS_ERR(key)) {
 948                kfree(description);
 949                _leave(" = %ld", PTR_ERR(key));
 950                return PTR_ERR(key);
 951        }
 952
 953        rx->securities = key;
 954        kfree(description);
 955        _leave(" = 0 [key %x]", key->serial);
 956        return 0;
 957}
 958
 959/*
 960 * generate a server data key
 961 */
 962int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 963                              const void *session_key,
 964                              time_t expiry,
 965                              u32 kvno)
 966{
 967        const struct cred *cred = current_cred();
 968        struct key *key;
 969        int ret;
 970
 971        struct {
 972                u32 kver;
 973                struct rxrpc_key_data_v1 v1;
 974        } data;
 975
 976        _enter("");
 977
 978        key = key_alloc(&key_type_rxrpc, "x",
 979                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
 980                        KEY_ALLOC_NOT_IN_QUOTA);
 981        if (IS_ERR(key)) {
 982                _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
 983                return -ENOMEM;
 984        }
 985
 986        _debug("key %d", key_serial(key));
 987
 988        data.kver = 1;
 989        data.v1.security_index = RXRPC_SECURITY_RXKAD;
 990        data.v1.ticket_length = 0;
 991        data.v1.expiry = expiry;
 992        data.v1.kvno = 0;
 993
 994        memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
 995
 996        ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
 997        if (ret < 0)
 998                goto error;
 999
1000        conn->key = key;
1001        _leave(" = 0 [%d]", key_serial(key));
1002        return 0;
1003
1004error:
1005        key_revoke(key);
1006        key_put(key);
1007        _leave(" = -ENOMEM [ins %d]", ret);
1008        return -ENOMEM;
1009}
1010EXPORT_SYMBOL(rxrpc_get_server_data_key);
1011
1012/**
1013 * rxrpc_get_null_key - Generate a null RxRPC key
1014 * @keyname: The name to give the key.
1015 *
1016 * Generate a null RxRPC key that can be used to indicate anonymous security is
1017 * required for a particular domain.
1018 */
1019struct key *rxrpc_get_null_key(const char *keyname)
1020{
1021        const struct cred *cred = current_cred();
1022        struct key *key;
1023        int ret;
1024
1025        key = key_alloc(&key_type_rxrpc, keyname,
1026                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
1027                        KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
1028        if (IS_ERR(key))
1029                return key;
1030
1031        ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1032        if (ret < 0) {
1033                key_revoke(key);
1034                key_put(key);
1035                return ERR_PTR(ret);
1036        }
1037
1038        return key;
1039}
1040EXPORT_SYMBOL(rxrpc_get_null_key);
1041
1042/*
1043 * read the contents of an rxrpc key
1044 * - this returns the result in XDR form
1045 */
1046static long rxrpc_read(const struct key *key,
1047                       char __user *buffer, size_t buflen)
1048{
1049        const struct rxrpc_key_token *token;
1050        const struct krb5_principal *princ;
1051        size_t size;
1052        __be32 __user *xdr, *oldxdr;
1053        u32 cnlen, toksize, ntoks, tok, zero;
1054        u16 toksizes[AFSTOKEN_MAX];
1055        int loop;
1056
1057        _enter("");
1058
1059        /* we don't know what form we should return non-AFS keys in */
1060        if (memcmp(key->description, "afs@", 4) != 0)
1061                return -EOPNOTSUPP;
1062        cnlen = strlen(key->description + 4);
1063
1064#define RND(X) (((X) + 3) & ~3)
1065
1066        /* AFS keys we return in XDR form, so we need to work out the size of
1067         * the XDR */
1068        size = 2 * 4;   /* flags, cellname len */
1069        size += RND(cnlen);     /* cellname */
1070        size += 1 * 4;  /* token count */
1071
1072        ntoks = 0;
1073        for (token = key->payload.data; token; token = token->next) {
1074                toksize = 4;    /* sec index */
1075
1076                switch (token->security_index) {
1077                case RXRPC_SECURITY_RXKAD:
1078                        toksize += 8 * 4;       /* viceid, kvno, key*2, begin,
1079                                                 * end, primary, tktlen */
1080                        toksize += RND(token->kad->ticket_len);
1081                        break;
1082
1083                case RXRPC_SECURITY_RXK5:
1084                        princ = &token->k5->client;
1085                        toksize += 4 + princ->n_name_parts * 4;
1086                        for (loop = 0; loop < princ->n_name_parts; loop++)
1087                                toksize += RND(strlen(princ->name_parts[loop]));
1088                        toksize += 4 + RND(strlen(princ->realm));
1089
1090                        princ = &token->k5->server;
1091                        toksize += 4 + princ->n_name_parts * 4;
1092                        for (loop = 0; loop < princ->n_name_parts; loop++)
1093                                toksize += RND(strlen(princ->name_parts[loop]));
1094                        toksize += 4 + RND(strlen(princ->realm));
1095
1096                        toksize += 8 + RND(token->k5->session.data_len);
1097
1098                        toksize += 4 * 8 + 2 * 4;
1099
1100                        toksize += 4 + token->k5->n_addresses * 8;
1101                        for (loop = 0; loop < token->k5->n_addresses; loop++)
1102                                toksize += RND(token->k5->addresses[loop].data_len);
1103
1104                        toksize += 4 + RND(token->k5->ticket_len);
1105                        toksize += 4 + RND(token->k5->ticket2_len);
1106
1107                        toksize += 4 + token->k5->n_authdata * 8;
1108                        for (loop = 0; loop < token->k5->n_authdata; loop++)
1109                                toksize += RND(token->k5->authdata[loop].data_len);
1110                        break;
1111
1112                default: /* we have a ticket we can't encode */
1113                        BUG();
1114                        continue;
1115                }
1116
1117                _debug("token[%u]: toksize=%u", ntoks, toksize);
1118                ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1119
1120                toksizes[ntoks++] = toksize;
1121                size += toksize + 4; /* each token has a length word */
1122        }
1123
1124#undef RND
1125
1126        if (!buffer || buflen < size)
1127                return size;
1128
1129        xdr = (__be32 __user *) buffer;
1130        zero = 0;
1131#define ENCODE(x)                               \
1132        do {                                    \
1133                __be32 y = htonl(x);            \
1134                if (put_user(y, xdr++) < 0)     \
1135                        goto fault;             \
1136        } while(0)
1137#define ENCODE_DATA(l, s)                                               \
1138        do {                                                            \
1139                u32 _l = (l);                                           \
1140                ENCODE(l);                                              \
1141                if (copy_to_user(xdr, (s), _l) != 0)                    \
1142                        goto fault;                                     \
1143                if (_l & 3 &&                                           \
1144                    copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1145                        goto fault;                                     \
1146                xdr += (_l + 3) >> 2;                                   \
1147        } while(0)
1148#define ENCODE64(x)                                     \
1149        do {                                            \
1150                __be64 y = cpu_to_be64(x);              \
1151                if (copy_to_user(xdr, &y, 8) != 0)      \
1152                        goto fault;                     \
1153                xdr += 8 >> 2;                          \
1154        } while(0)
1155#define ENCODE_STR(s)                           \
1156        do {                                    \
1157                const char *_s = (s);           \
1158                ENCODE_DATA(strlen(_s), _s);    \
1159        } while(0)
1160
1161        ENCODE(0);                                      /* flags */
1162        ENCODE_DATA(cnlen, key->description + 4);       /* cellname */
1163        ENCODE(ntoks);
1164
1165        tok = 0;
1166        for (token = key->payload.data; token; token = token->next) {
1167                toksize = toksizes[tok++];
1168                ENCODE(toksize);
1169                oldxdr = xdr;
1170                ENCODE(token->security_index);
1171
1172                switch (token->security_index) {
1173                case RXRPC_SECURITY_RXKAD:
1174                        ENCODE(token->kad->vice_id);
1175                        ENCODE(token->kad->kvno);
1176                        ENCODE_DATA(8, token->kad->session_key);
1177                        ENCODE(token->kad->start);
1178                        ENCODE(token->kad->expiry);
1179                        ENCODE(token->kad->primary_flag);
1180                        ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1181                        break;
1182
1183                case RXRPC_SECURITY_RXK5:
1184                        princ = &token->k5->client;
1185                        ENCODE(princ->n_name_parts);
1186                        for (loop = 0; loop < princ->n_name_parts; loop++)
1187                                ENCODE_STR(princ->name_parts[loop]);
1188                        ENCODE_STR(princ->realm);
1189
1190                        princ = &token->k5->server;
1191                        ENCODE(princ->n_name_parts);
1192                        for (loop = 0; loop < princ->n_name_parts; loop++)
1193                                ENCODE_STR(princ->name_parts[loop]);
1194                        ENCODE_STR(princ->realm);
1195
1196                        ENCODE(token->k5->session.tag);
1197                        ENCODE_DATA(token->k5->session.data_len,
1198                                    token->k5->session.data);
1199
1200                        ENCODE64(token->k5->authtime);
1201                        ENCODE64(token->k5->starttime);
1202                        ENCODE64(token->k5->endtime);
1203                        ENCODE64(token->k5->renew_till);
1204                        ENCODE(token->k5->is_skey);
1205                        ENCODE(token->k5->flags);
1206
1207                        ENCODE(token->k5->n_addresses);
1208                        for (loop = 0; loop < token->k5->n_addresses; loop++) {
1209                                ENCODE(token->k5->addresses[loop].tag);
1210                                ENCODE_DATA(token->k5->addresses[loop].data_len,
1211                                            token->k5->addresses[loop].data);
1212                        }
1213
1214                        ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1215                        ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1216
1217                        ENCODE(token->k5->n_authdata);
1218                        for (loop = 0; loop < token->k5->n_authdata; loop++) {
1219                                ENCODE(token->k5->authdata[loop].tag);
1220                                ENCODE_DATA(token->k5->authdata[loop].data_len,
1221                                            token->k5->authdata[loop].data);
1222                        }
1223                        break;
1224
1225                default:
1226                        BUG();
1227                        break;
1228                }
1229
1230                ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1231                          toksize);
1232        }
1233
1234#undef ENCODE_STR
1235#undef ENCODE_DATA
1236#undef ENCODE64
1237#undef ENCODE
1238
1239        ASSERTCMP(tok, ==, ntoks);
1240        ASSERTCMP((char __user *) xdr - buffer, ==, size);
1241        _leave(" = %zu", size);
1242        return size;
1243
1244fault:
1245        _leave(" = -EFAULT");
1246        return -EFAULT;
1247}
1248