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