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_instantiate(struct key *, const void *, size_t);
  30static int rxrpc_instantiate_s(struct key *, const void *, size_t);
  31static void rxrpc_destroy(struct key *);
  32static void rxrpc_destroy_s(struct key *);
  33static void rxrpc_describe(const struct key *, struct seq_file *);
  34static long rxrpc_read(const struct key *, char __user *, size_t);
  35
  36/*
  37 * rxrpc defined keys take an arbitrary string as the description and an
  38 * arbitrary blob of data as the payload
  39 */
  40struct key_type key_type_rxrpc = {
  41        .name           = "rxrpc",
  42        .instantiate    = rxrpc_instantiate,
  43        .match          = user_match,
  44        .destroy        = rxrpc_destroy,
  45        .describe       = rxrpc_describe,
  46        .read           = rxrpc_read,
  47};
  48EXPORT_SYMBOL(key_type_rxrpc);
  49
  50/*
  51 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
  52 * description and an 8-byte decryption key as the payload
  53 */
  54struct key_type key_type_rxrpc_s = {
  55        .name           = "rxrpc_s",
  56        .vet_description = rxrpc_vet_description_s,
  57        .instantiate    = rxrpc_instantiate_s,
  58        .match          = user_match,
  59        .destroy        = rxrpc_destroy_s,
  60        .describe       = rxrpc_describe,
  61};
  62
  63/*
  64 * Vet the description for an RxRPC server key
  65 */
  66static int rxrpc_vet_description_s(const char *desc)
  67{
  68        unsigned long num;
  69        char *p;
  70
  71        num = simple_strtoul(desc, &p, 10);
  72        if (*p != ':' || num > 65535)
  73                return -EINVAL;
  74        num = simple_strtoul(p + 1, &p, 10);
  75        if (*p || num < 1 || num > 255)
  76                return -EINVAL;
  77        return 0;
  78}
  79
  80/*
  81 * parse an RxKAD type XDR format token
  82 * - the caller guarantees we have at least 4 words
  83 */
  84static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
  85                                       unsigned toklen)
  86{
  87        struct rxrpc_key_token *token, **pptoken;
  88        size_t plen;
  89        u32 tktlen;
  90        int ret;
  91
  92        _enter(",{%x,%x,%x,%x},%u",
  93               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
  94               toklen);
  95
  96        if (toklen <= 8 * 4)
  97                return -EKEYREJECTED;
  98        tktlen = ntohl(xdr[7]);
  99        _debug("tktlen: %x", tktlen);
 100        if (tktlen > AFSTOKEN_RK_TIX_MAX)
 101                return -EKEYREJECTED;
 102        if (8 * 4 + tktlen != toklen)
 103                return -EKEYREJECTED;
 104
 105        plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
 106        ret = key_payload_reserve(key, key->datalen + plen);
 107        if (ret < 0)
 108                return ret;
 109
 110        plen -= sizeof(*token);
 111        token = kzalloc(sizeof(*token), GFP_KERNEL);
 112        if (!token)
 113                return -ENOMEM;
 114
 115        token->kad = kzalloc(plen, GFP_KERNEL);
 116        if (!token->kad) {
 117                kfree(token);
 118                return -ENOMEM;
 119        }
 120
 121        token->security_index   = RXRPC_SECURITY_RXKAD;
 122        token->kad->ticket_len  = tktlen;
 123        token->kad->vice_id     = ntohl(xdr[0]);
 124        token->kad->kvno        = ntohl(xdr[1]);
 125        token->kad->start       = ntohl(xdr[4]);
 126        token->kad->expiry      = ntohl(xdr[5]);
 127        token->kad->primary_flag = ntohl(xdr[6]);
 128        memcpy(&token->kad->session_key, &xdr[2], 8);
 129        memcpy(&token->kad->ticket, &xdr[8], tktlen);
 130
 131        _debug("SCIX: %u", token->security_index);
 132        _debug("TLEN: %u", token->kad->ticket_len);
 133        _debug("EXPY: %x", token->kad->expiry);
 134        _debug("KVNO: %u", token->kad->kvno);
 135        _debug("PRIM: %u", token->kad->primary_flag);
 136        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 137               token->kad->session_key[0], token->kad->session_key[1],
 138               token->kad->session_key[2], token->kad->session_key[3],
 139               token->kad->session_key[4], token->kad->session_key[5],
 140               token->kad->session_key[6], token->kad->session_key[7]);
 141        if (token->kad->ticket_len >= 8)
 142                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 143                       token->kad->ticket[0], token->kad->ticket[1],
 144                       token->kad->ticket[2], token->kad->ticket[3],
 145                       token->kad->ticket[4], token->kad->ticket[5],
 146                       token->kad->ticket[6], token->kad->ticket[7]);
 147
 148        /* count the number of tokens attached */
 149        key->type_data.x[0]++;
 150
 151        /* attach the data */
 152        for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
 153             *pptoken;
 154             pptoken = &(*pptoken)->next)
 155                continue;
 156        *pptoken = token;
 157        if (token->kad->expiry < key->expiry)
 158                key->expiry = token->kad->expiry;
 159
 160        _leave(" = 0");
 161        return 0;
 162}
 163
 164static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
 165{
 166        int loop;
 167
 168        if (princ->name_parts) {
 169                for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
 170                        kfree(princ->name_parts[loop]);
 171                kfree(princ->name_parts);
 172        }
 173        kfree(princ->realm);
 174}
 175
 176static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
 177{
 178        kfree(td->data);
 179}
 180
 181/*
 182 * free up an RxK5 token
 183 */
 184static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
 185{
 186        int loop;
 187
 188        rxrpc_free_krb5_principal(&rxk5->client);
 189        rxrpc_free_krb5_principal(&rxk5->server);
 190        rxrpc_free_krb5_tagged(&rxk5->session);
 191
 192        if (rxk5->addresses) {
 193                for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
 194                        rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
 195                kfree(rxk5->addresses);
 196        }
 197        if (rxk5->authdata) {
 198                for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
 199                        rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
 200                kfree(rxk5->authdata);
 201        }
 202
 203        kfree(rxk5->ticket);
 204        kfree(rxk5->ticket2);
 205        kfree(rxk5);
 206}
 207
 208/*
 209 * extract a krb5 principal
 210 */
 211static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
 212                                       const __be32 **_xdr,
 213                                       unsigned *_toklen)
 214{
 215        const __be32 *xdr = *_xdr;
 216        unsigned toklen = *_toklen, n_parts, loop, tmp;
 217
 218        /* there must be at least one name, and at least #names+1 length
 219         * words */
 220        if (toklen <= 12)
 221                return -EINVAL;
 222
 223        _enter(",{%x,%x,%x},%u",
 224               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
 225
 226        n_parts = ntohl(*xdr++);
 227        toklen -= 4;
 228        if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
 229                return -EINVAL;
 230        princ->n_name_parts = n_parts;
 231
 232        if (toklen <= (n_parts + 1) * 4)
 233                return -EINVAL;
 234
 235        princ->name_parts = kcalloc(sizeof(char *), n_parts, GFP_KERNEL);
 236        if (!princ->name_parts)
 237                return -ENOMEM;
 238
 239        for (loop = 0; loop < n_parts; loop++) {
 240                if (toklen < 4)
 241                        return -EINVAL;
 242                tmp = ntohl(*xdr++);
 243                toklen -= 4;
 244                if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
 245                        return -EINVAL;
 246                if (tmp > toklen)
 247                        return -EINVAL;
 248                princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
 249                if (!princ->name_parts[loop])
 250                        return -ENOMEM;
 251                memcpy(princ->name_parts[loop], xdr, tmp);
 252                princ->name_parts[loop][tmp] = 0;
 253                tmp = (tmp + 3) & ~3;
 254                toklen -= tmp;
 255                xdr += tmp >> 2;
 256        }
 257
 258        if (toklen < 4)
 259                return -EINVAL;
 260        tmp = ntohl(*xdr++);
 261        toklen -= 4;
 262        if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
 263                return -EINVAL;
 264        if (tmp > toklen)
 265                return -EINVAL;
 266        princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
 267        if (!princ->realm)
 268                return -ENOMEM;
 269        memcpy(princ->realm, xdr, tmp);
 270        princ->realm[tmp] = 0;
 271        tmp = (tmp + 3) & ~3;
 272        toklen -= tmp;
 273        xdr += tmp >> 2;
 274
 275        _debug("%s/...@%s", princ->name_parts[0], princ->realm);
 276
 277        *_xdr = xdr;
 278        *_toklen = toklen;
 279        _leave(" = 0 [toklen=%u]", toklen);
 280        return 0;
 281}
 282
 283/*
 284 * extract a piece of krb5 tagged data
 285 */
 286static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
 287                                         size_t max_data_size,
 288                                         const __be32 **_xdr,
 289                                         unsigned *_toklen)
 290{
 291        const __be32 *xdr = *_xdr;
 292        unsigned toklen = *_toklen, len;
 293
 294        /* there must be at least one tag and one length word */
 295        if (toklen <= 8)
 296                return -EINVAL;
 297
 298        _enter(",%zu,{%x,%x},%u",
 299               max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
 300
 301        td->tag = ntohl(*xdr++);
 302        len = ntohl(*xdr++);
 303        toklen -= 8;
 304        if (len > max_data_size)
 305                return -EINVAL;
 306        td->data_len = len;
 307
 308        if (len > 0) {
 309                td->data = kmalloc(len, GFP_KERNEL);
 310                if (!td->data)
 311                        return -ENOMEM;
 312                memcpy(td->data, xdr, len);
 313                len = (len + 3) & ~3;
 314                toklen -= len;
 315                xdr += len >> 2;
 316        }
 317
 318        _debug("tag %x len %x", td->tag, td->data_len);
 319
 320        *_xdr = xdr;
 321        *_toklen = toklen;
 322        _leave(" = 0 [toklen=%u]", toklen);
 323        return 0;
 324}
 325
 326/*
 327 * extract an array of tagged data
 328 */
 329static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
 330                                          u8 *_n_elem,
 331                                          u8 max_n_elem,
 332                                          size_t max_elem_size,
 333                                          const __be32 **_xdr,
 334                                          unsigned *_toklen)
 335{
 336        struct krb5_tagged_data *td;
 337        const __be32 *xdr = *_xdr;
 338        unsigned toklen = *_toklen, n_elem, loop;
 339        int ret;
 340
 341        /* there must be at least one count */
 342        if (toklen < 4)
 343                return -EINVAL;
 344
 345        _enter(",,%u,%zu,{%x},%u",
 346               max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
 347
 348        n_elem = ntohl(*xdr++);
 349        toklen -= 4;
 350        if (n_elem < 0 || n_elem > max_n_elem)
 351                return -EINVAL;
 352        *_n_elem = n_elem;
 353        if (n_elem > 0) {
 354                if (toklen <= (n_elem + 1) * 4)
 355                        return -EINVAL;
 356
 357                _debug("n_elem %d", n_elem);
 358
 359                td = kcalloc(sizeof(struct krb5_tagged_data), n_elem,
 360                             GFP_KERNEL);
 361                if (!td)
 362                        return -ENOMEM;
 363                *_td = td;
 364
 365                for (loop = 0; loop < n_elem; loop++) {
 366                        ret = rxrpc_krb5_decode_tagged_data(&td[loop],
 367                                                            max_elem_size,
 368                                                            &xdr, &toklen);
 369                        if (ret < 0)
 370                                return ret;
 371                }
 372        }
 373
 374        *_xdr = xdr;
 375        *_toklen = toklen;
 376        _leave(" = 0 [toklen=%u]", toklen);
 377        return 0;
 378}
 379
 380/*
 381 * extract a krb5 ticket
 382 */
 383static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
 384                                    const __be32 **_xdr, unsigned *_toklen)
 385{
 386        const __be32 *xdr = *_xdr;
 387        unsigned toklen = *_toklen, len;
 388
 389        /* there must be at least one length word */
 390        if (toklen <= 4)
 391                return -EINVAL;
 392
 393        _enter(",{%x},%u", ntohl(xdr[0]), toklen);
 394
 395        len = ntohl(*xdr++);
 396        toklen -= 4;
 397        if (len > AFSTOKEN_K5_TIX_MAX)
 398                return -EINVAL;
 399        *_tktlen = len;
 400
 401        _debug("ticket len %u", len);
 402
 403        if (len > 0) {
 404                *_ticket = kmalloc(len, GFP_KERNEL);
 405                if (!*_ticket)
 406                        return -ENOMEM;
 407                memcpy(*_ticket, xdr, len);
 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_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
 424                                      unsigned toklen)
 425{
 426        struct rxrpc_key_token *token, **pptoken;
 427        struct rxk5_key *rxk5;
 428        const __be32 *end_xdr = xdr + (toklen >> 2);
 429        int ret;
 430
 431        _enter(",{%x,%x,%x,%x},%u",
 432               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 433               toklen);
 434
 435        /* reserve some payload space for this subkey - the length of the token
 436         * is a reasonable approximation */
 437        ret = key_payload_reserve(key, key->datalen + toklen);
 438        if (ret < 0)
 439                return ret;
 440
 441        token = kzalloc(sizeof(*token), GFP_KERNEL);
 442        if (!token)
 443                return -ENOMEM;
 444
 445        rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
 446        if (!rxk5) {
 447                kfree(token);
 448                return -ENOMEM;
 449        }
 450
 451        token->security_index = RXRPC_SECURITY_RXK5;
 452        token->k5 = rxk5;
 453
 454        /* extract the principals */
 455        ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
 456        if (ret < 0)
 457                goto error;
 458        ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
 459        if (ret < 0)
 460                goto error;
 461
 462        /* extract the session key and the encoding type (the tag field ->
 463         * ENCTYPE_xxx) */
 464        ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
 465                                            &xdr, &toklen);
 466        if (ret < 0)
 467                goto error;
 468
 469        if (toklen < 4 * 8 + 2 * 4)
 470                goto inval;
 471        rxk5->authtime  = be64_to_cpup((const __be64 *) xdr);
 472        xdr += 2;
 473        rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
 474        xdr += 2;
 475        rxk5->endtime   = be64_to_cpup((const __be64 *) xdr);
 476        xdr += 2;
 477        rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
 478        xdr += 2;
 479        rxk5->is_skey = ntohl(*xdr++);
 480        rxk5->flags = ntohl(*xdr++);
 481        toklen -= 4 * 8 + 2 * 4;
 482
 483        _debug("times: a=%llx s=%llx e=%llx rt=%llx",
 484               rxk5->authtime, rxk5->starttime, rxk5->endtime,
 485               rxk5->renew_till);
 486        _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
 487
 488        /* extract the permitted client addresses */
 489        ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
 490                                             &rxk5->n_addresses,
 491                                             AFSTOKEN_K5_ADDRESSES_MAX,
 492                                             AFSTOKEN_DATA_MAX,
 493                                             &xdr, &toklen);
 494        if (ret < 0)
 495                goto error;
 496
 497        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 498
 499        /* extract the tickets */
 500        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
 501                                       &xdr, &toklen);
 502        if (ret < 0)
 503                goto error;
 504        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
 505                                       &xdr, &toklen);
 506        if (ret < 0)
 507                goto error;
 508
 509        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 510
 511        /* extract the typed auth data */
 512        ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
 513                                             &rxk5->n_authdata,
 514                                             AFSTOKEN_K5_AUTHDATA_MAX,
 515                                             AFSTOKEN_BDATALN_MAX,
 516                                             &xdr, &toklen);
 517        if (ret < 0)
 518                goto error;
 519
 520        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 521
 522        if (toklen != 0)
 523                goto inval;
 524
 525        /* attach the payload to the key */
 526        for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
 527             *pptoken;
 528             pptoken = &(*pptoken)->next)
 529                continue;
 530        *pptoken = token;
 531        if (token->kad->expiry < key->expiry)
 532                key->expiry = token->kad->expiry;
 533
 534        _leave(" = 0");
 535        return 0;
 536
 537inval:
 538        ret = -EINVAL;
 539error:
 540        rxrpc_rxk5_free(rxk5);
 541        kfree(token);
 542        _leave(" = %d", ret);
 543        return ret;
 544}
 545
 546/*
 547 * attempt to parse the data as the XDR format
 548 * - the caller guarantees we have more than 7 words
 549 */
 550static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datalen)
 551{
 552        const __be32 *xdr = data, *token;
 553        const char *cp;
 554        unsigned len, tmp, loop, ntoken, toklen, sec_ix;
 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               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_instantiate_xdr_rxkad(key, xdr, toklen);
 641                        if (ret != 0)
 642                                goto error;
 643                        break;
 644
 645                case RXRPC_SECURITY_RXK5:
 646                        ret = rxrpc_instantiate_xdr_rxk5(key, 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 * instantiate an rxrpc defined key
 671 * data should be of the form:
 672 *      OFFSET  LEN     CONTENT
 673 *      0       4       key interface version number
 674 *      4       2       security index (type)
 675 *      6       2       ticket length
 676 *      8       4       key expiry time (time_t)
 677 *      12      4       kvno
 678 *      16      8       session key
 679 *      24      [len]   ticket
 680 *
 681 * if no data is provided, then a no-security key is made
 682 */
 683static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
 684{
 685        const struct rxrpc_key_data_v1 *v1;
 686        struct rxrpc_key_token *token, **pp;
 687        size_t plen;
 688        u32 kver;
 689        int ret;
 690
 691        _enter("{%x},,%zu", key_serial(key), datalen);
 692
 693        /* handle a no-security key */
 694        if (!data && datalen == 0)
 695                return 0;
 696
 697        /* determine if the XDR payload format is being used */
 698        if (datalen > 7 * 4) {
 699                ret = rxrpc_instantiate_xdr(key, data, datalen);
 700                if (ret != -EPROTO)
 701                        return ret;
 702        }
 703
 704        /* get the key interface version number */
 705        ret = -EINVAL;
 706        if (datalen <= 4 || !data)
 707                goto error;
 708        memcpy(&kver, data, sizeof(kver));
 709        data += sizeof(kver);
 710        datalen -= sizeof(kver);
 711
 712        _debug("KEY I/F VERSION: %u", kver);
 713
 714        ret = -EKEYREJECTED;
 715        if (kver != 1)
 716                goto error;
 717
 718        /* deal with a version 1 key */
 719        ret = -EINVAL;
 720        if (datalen < sizeof(*v1))
 721                goto error;
 722
 723        v1 = data;
 724        if (datalen != sizeof(*v1) + v1->ticket_length)
 725                goto error;
 726
 727        _debug("SCIX: %u", v1->security_index);
 728        _debug("TLEN: %u", v1->ticket_length);
 729        _debug("EXPY: %x", v1->expiry);
 730        _debug("KVNO: %u", v1->kvno);
 731        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 732               v1->session_key[0], v1->session_key[1],
 733               v1->session_key[2], v1->session_key[3],
 734               v1->session_key[4], v1->session_key[5],
 735               v1->session_key[6], v1->session_key[7]);
 736        if (v1->ticket_length >= 8)
 737                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 738                       v1->ticket[0], v1->ticket[1],
 739                       v1->ticket[2], v1->ticket[3],
 740                       v1->ticket[4], v1->ticket[5],
 741                       v1->ticket[6], v1->ticket[7]);
 742
 743        ret = -EPROTONOSUPPORT;
 744        if (v1->security_index != RXRPC_SECURITY_RXKAD)
 745                goto error;
 746
 747        plen = sizeof(*token->kad) + v1->ticket_length;
 748        ret = key_payload_reserve(key, plen + sizeof(*token));
 749        if (ret < 0)
 750                goto error;
 751
 752        ret = -ENOMEM;
 753        token = kzalloc(sizeof(*token), GFP_KERNEL);
 754        if (!token)
 755                goto error;
 756        token->kad = kzalloc(plen, GFP_KERNEL);
 757        if (!token->kad)
 758                goto error_free;
 759
 760        token->security_index           = RXRPC_SECURITY_RXKAD;
 761        token->kad->ticket_len          = v1->ticket_length;
 762        token->kad->expiry              = v1->expiry;
 763        token->kad->kvno                = v1->kvno;
 764        memcpy(&token->kad->session_key, &v1->session_key, 8);
 765        memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
 766
 767        /* attach the data */
 768        key->type_data.x[0]++;
 769
 770        pp = (struct rxrpc_key_token **)&key->payload.data;
 771        while (*pp)
 772                pp = &(*pp)->next;
 773        *pp = token;
 774        if (token->kad->expiry < key->expiry)
 775                key->expiry = token->kad->expiry;
 776        token = NULL;
 777        ret = 0;
 778
 779error_free:
 780        kfree(token);
 781error:
 782        return ret;
 783}
 784
 785/*
 786 * instantiate a server secret key
 787 * data should be a pointer to the 8-byte secret key
 788 */
 789static int rxrpc_instantiate_s(struct key *key, const void *data,
 790                               size_t datalen)
 791{
 792        struct crypto_blkcipher *ci;
 793
 794        _enter("{%x},,%zu", key_serial(key), datalen);
 795
 796        if (datalen != 8)
 797                return -EINVAL;
 798
 799        memcpy(&key->type_data, data, 8);
 800
 801        ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
 802        if (IS_ERR(ci)) {
 803                _leave(" = %ld", PTR_ERR(ci));
 804                return PTR_ERR(ci);
 805        }
 806
 807        if (crypto_blkcipher_setkey(ci, data, 8) < 0)
 808                BUG();
 809
 810        key->payload.data = ci;
 811        _leave(" = 0");
 812        return 0;
 813}
 814
 815/*
 816 * dispose of the data dangling from the corpse of a rxrpc key
 817 */
 818static void rxrpc_destroy(struct key *key)
 819{
 820        struct rxrpc_key_token *token;
 821
 822        while ((token = key->payload.data)) {
 823                key->payload.data = token->next;
 824                switch (token->security_index) {
 825                case RXRPC_SECURITY_RXKAD:
 826                        kfree(token->kad);
 827                        break;
 828                case RXRPC_SECURITY_RXK5:
 829                        if (token->k5)
 830                                rxrpc_rxk5_free(token->k5);
 831                        break;
 832                default:
 833                        printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
 834                               token->security_index);
 835                        BUG();
 836                }
 837
 838                kfree(token);
 839        }
 840}
 841
 842/*
 843 * dispose of the data dangling from the corpse of a rxrpc key
 844 */
 845static void rxrpc_destroy_s(struct key *key)
 846{
 847        if (key->payload.data) {
 848                crypto_free_blkcipher(key->payload.data);
 849                key->payload.data = NULL;
 850        }
 851}
 852
 853/*
 854 * describe the rxrpc key
 855 */
 856static void rxrpc_describe(const struct key *key, struct seq_file *m)
 857{
 858        seq_puts(m, key->description);
 859}
 860
 861/*
 862 * grab the security key for a socket
 863 */
 864int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
 865{
 866        struct key *key;
 867        char *description;
 868
 869        _enter("");
 870
 871        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 872                return -EINVAL;
 873
 874        description = kmalloc(optlen + 1, GFP_KERNEL);
 875        if (!description)
 876                return -ENOMEM;
 877
 878        if (copy_from_user(description, optval, optlen)) {
 879                kfree(description);
 880                return -EFAULT;
 881        }
 882        description[optlen] = 0;
 883
 884        key = request_key(&key_type_rxrpc, description, NULL);
 885        if (IS_ERR(key)) {
 886                kfree(description);
 887                _leave(" = %ld", PTR_ERR(key));
 888                return PTR_ERR(key);
 889        }
 890
 891        rx->key = key;
 892        kfree(description);
 893        _leave(" = 0 [key %x]", key->serial);
 894        return 0;
 895}
 896
 897/*
 898 * grab the security keyring for a server socket
 899 */
 900int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
 901                         int optlen)
 902{
 903        struct key *key;
 904        char *description;
 905
 906        _enter("");
 907
 908        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 909                return -EINVAL;
 910
 911        description = kmalloc(optlen + 1, GFP_KERNEL);
 912        if (!description)
 913                return -ENOMEM;
 914
 915        if (copy_from_user(description, optval, optlen)) {
 916                kfree(description);
 917                return -EFAULT;
 918        }
 919        description[optlen] = 0;
 920
 921        key = request_key(&key_type_keyring, description, NULL);
 922        if (IS_ERR(key)) {
 923                kfree(description);
 924                _leave(" = %ld", PTR_ERR(key));
 925                return PTR_ERR(key);
 926        }
 927
 928        rx->securities = key;
 929        kfree(description);
 930        _leave(" = 0 [key %x]", key->serial);
 931        return 0;
 932}
 933
 934/*
 935 * generate a server data key
 936 */
 937int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 938                              const void *session_key,
 939                              time_t expiry,
 940                              u32 kvno)
 941{
 942        const struct cred *cred = current_cred();
 943        struct key *key;
 944        int ret;
 945
 946        struct {
 947                u32 kver;
 948                struct rxrpc_key_data_v1 v1;
 949        } data;
 950
 951        _enter("");
 952
 953        key = key_alloc(&key_type_rxrpc, "x", 0, 0, cred, 0,
 954                        KEY_ALLOC_NOT_IN_QUOTA);
 955        if (IS_ERR(key)) {
 956                _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
 957                return -ENOMEM;
 958        }
 959
 960        _debug("key %d", key_serial(key));
 961
 962        data.kver = 1;
 963        data.v1.security_index = RXRPC_SECURITY_RXKAD;
 964        data.v1.ticket_length = 0;
 965        data.v1.expiry = expiry;
 966        data.v1.kvno = 0;
 967
 968        memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
 969
 970        ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
 971        if (ret < 0)
 972                goto error;
 973
 974        conn->key = key;
 975        _leave(" = 0 [%d]", key_serial(key));
 976        return 0;
 977
 978error:
 979        key_revoke(key);
 980        key_put(key);
 981        _leave(" = -ENOMEM [ins %d]", ret);
 982        return -ENOMEM;
 983}
 984EXPORT_SYMBOL(rxrpc_get_server_data_key);
 985
 986/**
 987 * rxrpc_get_null_key - Generate a null RxRPC key
 988 * @keyname: The name to give the key.
 989 *
 990 * Generate a null RxRPC key that can be used to indicate anonymous security is
 991 * required for a particular domain.
 992 */
 993struct key *rxrpc_get_null_key(const char *keyname)
 994{
 995        const struct cred *cred = current_cred();
 996        struct key *key;
 997        int ret;
 998
 999        key = key_alloc(&key_type_rxrpc, keyname, 0, 0, cred,
1000                        KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
1001        if (IS_ERR(key))
1002                return key;
1003
1004        ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1005        if (ret < 0) {
1006                key_revoke(key);
1007                key_put(key);
1008                return ERR_PTR(ret);
1009        }
1010
1011        return key;
1012}
1013EXPORT_SYMBOL(rxrpc_get_null_key);
1014
1015/*
1016 * read the contents of an rxrpc key
1017 * - this returns the result in XDR form
1018 */
1019static long rxrpc_read(const struct key *key,
1020                       char __user *buffer, size_t buflen)
1021{
1022        const struct rxrpc_key_token *token;
1023        const struct krb5_principal *princ;
1024        size_t size;
1025        __be32 __user *xdr, *oldxdr;
1026        u32 cnlen, toksize, ntoks, tok, zero;
1027        u16 toksizes[AFSTOKEN_MAX];
1028        int loop;
1029
1030        _enter("");
1031
1032        /* we don't know what form we should return non-AFS keys in */
1033        if (memcmp(key->description, "afs@", 4) != 0)
1034                return -EOPNOTSUPP;
1035        cnlen = strlen(key->description + 4);
1036
1037#define RND(X) (((X) + 3) & ~3)
1038
1039        /* AFS keys we return in XDR form, so we need to work out the size of
1040         * the XDR */
1041        size = 2 * 4;   /* flags, cellname len */
1042        size += RND(cnlen);     /* cellname */
1043        size += 1 * 4;  /* token count */
1044
1045        ntoks = 0;
1046        for (token = key->payload.data; token; token = token->next) {
1047                toksize = 4;    /* sec index */
1048
1049                switch (token->security_index) {
1050                case RXRPC_SECURITY_RXKAD:
1051                        toksize += 8 * 4;       /* viceid, kvno, key*2, begin,
1052                                                 * end, primary, tktlen */
1053                        toksize += RND(token->kad->ticket_len);
1054                        break;
1055
1056                case RXRPC_SECURITY_RXK5:
1057                        princ = &token->k5->client;
1058                        toksize += 4 + princ->n_name_parts * 4;
1059                        for (loop = 0; loop < princ->n_name_parts; loop++)
1060                                toksize += RND(strlen(princ->name_parts[loop]));
1061                        toksize += 4 + RND(strlen(princ->realm));
1062
1063                        princ = &token->k5->server;
1064                        toksize += 4 + princ->n_name_parts * 4;
1065                        for (loop = 0; loop < princ->n_name_parts; loop++)
1066                                toksize += RND(strlen(princ->name_parts[loop]));
1067                        toksize += 4 + RND(strlen(princ->realm));
1068
1069                        toksize += 8 + RND(token->k5->session.data_len);
1070
1071                        toksize += 4 * 8 + 2 * 4;
1072
1073                        toksize += 4 + token->k5->n_addresses * 8;
1074                        for (loop = 0; loop < token->k5->n_addresses; loop++)
1075                                toksize += RND(token->k5->addresses[loop].data_len);
1076
1077                        toksize += 4 + RND(token->k5->ticket_len);
1078                        toksize += 4 + RND(token->k5->ticket2_len);
1079
1080                        toksize += 4 + token->k5->n_authdata * 8;
1081                        for (loop = 0; loop < token->k5->n_authdata; loop++)
1082                                toksize += RND(token->k5->authdata[loop].data_len);
1083                        break;
1084
1085                default: /* we have a ticket we can't encode */
1086                        BUG();
1087                        continue;
1088                }
1089
1090                _debug("token[%u]: toksize=%u", ntoks, toksize);
1091                ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1092
1093                toksizes[ntoks++] = toksize;
1094                size += toksize + 4; /* each token has a length word */
1095        }
1096
1097#undef RND
1098
1099        if (!buffer || buflen < size)
1100                return size;
1101
1102        xdr = (__be32 __user *) buffer;
1103        zero = 0;
1104#define ENCODE(x)                               \
1105        do {                                    \
1106                __be32 y = htonl(x);            \
1107                if (put_user(y, xdr++) < 0)     \
1108                        goto fault;             \
1109        } while(0)
1110#define ENCODE_DATA(l, s)                                               \
1111        do {                                                            \
1112                u32 _l = (l);                                           \
1113                ENCODE(l);                                              \
1114                if (copy_to_user(xdr, (s), _l) != 0)                    \
1115                        goto fault;                                     \
1116                if (_l & 3 &&                                           \
1117                    copy_to_user((u8 *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1118                        goto fault;                                     \
1119                xdr += (_l + 3) >> 2;                                   \
1120        } while(0)
1121#define ENCODE64(x)                                     \
1122        do {                                            \
1123                __be64 y = cpu_to_be64(x);              \
1124                if (copy_to_user(xdr, &y, 8) != 0)      \
1125                        goto fault;                     \
1126                xdr += 8 >> 2;                          \
1127        } while(0)
1128#define ENCODE_STR(s)                           \
1129        do {                                    \
1130                const char *_s = (s);           \
1131                ENCODE_DATA(strlen(_s), _s);    \
1132        } while(0)
1133
1134        ENCODE(0);                                      /* flags */
1135        ENCODE_DATA(cnlen, key->description + 4);       /* cellname */
1136        ENCODE(ntoks);
1137
1138        tok = 0;
1139        for (token = key->payload.data; token; token = token->next) {
1140                toksize = toksizes[tok++];
1141                ENCODE(toksize);
1142                oldxdr = xdr;
1143                ENCODE(token->security_index);
1144
1145                switch (token->security_index) {
1146                case RXRPC_SECURITY_RXKAD:
1147                        ENCODE(token->kad->vice_id);
1148                        ENCODE(token->kad->kvno);
1149                        ENCODE_DATA(8, token->kad->session_key);
1150                        ENCODE(token->kad->start);
1151                        ENCODE(token->kad->expiry);
1152                        ENCODE(token->kad->primary_flag);
1153                        ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1154                        break;
1155
1156                case RXRPC_SECURITY_RXK5:
1157                        princ = &token->k5->client;
1158                        ENCODE(princ->n_name_parts);
1159                        for (loop = 0; loop < princ->n_name_parts; loop++)
1160                                ENCODE_STR(princ->name_parts[loop]);
1161                        ENCODE_STR(princ->realm);
1162
1163                        princ = &token->k5->server;
1164                        ENCODE(princ->n_name_parts);
1165                        for (loop = 0; loop < princ->n_name_parts; loop++)
1166                                ENCODE_STR(princ->name_parts[loop]);
1167                        ENCODE_STR(princ->realm);
1168
1169                        ENCODE(token->k5->session.tag);
1170                        ENCODE_DATA(token->k5->session.data_len,
1171                                    token->k5->session.data);
1172
1173                        ENCODE64(token->k5->authtime);
1174                        ENCODE64(token->k5->starttime);
1175                        ENCODE64(token->k5->endtime);
1176                        ENCODE64(token->k5->renew_till);
1177                        ENCODE(token->k5->is_skey);
1178                        ENCODE(token->k5->flags);
1179
1180                        ENCODE(token->k5->n_addresses);
1181                        for (loop = 0; loop < token->k5->n_addresses; loop++) {
1182                                ENCODE(token->k5->addresses[loop].tag);
1183                                ENCODE_DATA(token->k5->addresses[loop].data_len,
1184                                            token->k5->addresses[loop].data);
1185                        }
1186
1187                        ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1188                        ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1189
1190                        ENCODE(token->k5->n_authdata);
1191                        for (loop = 0; loop < token->k5->n_authdata; loop++) {
1192                                ENCODE(token->k5->authdata[loop].tag);
1193                                ENCODE_DATA(token->k5->authdata[loop].data_len,
1194                                            token->k5->authdata[loop].data);
1195                        }
1196                        break;
1197
1198                default:
1199                        BUG();
1200                        break;
1201                }
1202
1203                ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1204                          toksize);
1205        }
1206
1207#undef ENCODE_STR
1208#undef ENCODE_DATA
1209#undef ENCODE64
1210#undef ENCODE
1211
1212        ASSERTCMP(tok, ==, ntoks);
1213        ASSERTCMP((char __user *) xdr - buffer, ==, size);
1214        _leave(" = %zu", size);
1215        return size;
1216
1217fault:
1218        _leave(" = -EFAULT");
1219        return -EFAULT;
1220}
1221