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;
 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                if (tmp > toklen)
 251                        return -EINVAL;
 252                princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
 253                if (!princ->name_parts[loop])
 254                        return -ENOMEM;
 255                memcpy(princ->name_parts[loop], xdr, tmp);
 256                princ->name_parts[loop][tmp] = 0;
 257                tmp = (tmp + 3) & ~3;
 258                toklen -= tmp;
 259                xdr += tmp >> 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        if (tmp > toklen)
 269                return -EINVAL;
 270        princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
 271        if (!princ->realm)
 272                return -ENOMEM;
 273        memcpy(princ->realm, xdr, tmp);
 274        princ->realm[tmp] = 0;
 275        tmp = (tmp + 3) & ~3;
 276        toklen -= tmp;
 277        xdr += tmp >> 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;
 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        td->data_len = len;
 311
 312        if (len > 0) {
 313                td->data = kmemdup(xdr, len, GFP_KERNEL);
 314                if (!td->data)
 315                        return -ENOMEM;
 316                len = (len + 3) & ~3;
 317                toklen -= len;
 318                xdr += len >> 2;
 319        }
 320
 321        _debug("tag %x len %x", td->tag, td->data_len);
 322
 323        *_xdr = xdr;
 324        *_toklen = toklen;
 325        _leave(" = 0 [toklen=%u]", toklen);
 326        return 0;
 327}
 328
 329/*
 330 * extract an array of tagged data
 331 */
 332static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
 333                                          u8 *_n_elem,
 334                                          u8 max_n_elem,
 335                                          size_t max_elem_size,
 336                                          const __be32 **_xdr,
 337                                          unsigned int *_toklen)
 338{
 339        struct krb5_tagged_data *td;
 340        const __be32 *xdr = *_xdr;
 341        unsigned int toklen = *_toklen, n_elem, loop;
 342        int ret;
 343
 344        /* there must be at least one count */
 345        if (toklen < 4)
 346                return -EINVAL;
 347
 348        _enter(",,%u,%zu,{%x},%u",
 349               max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
 350
 351        n_elem = ntohl(*xdr++);
 352        toklen -= 4;
 353        if (n_elem > max_n_elem)
 354                return -EINVAL;
 355        *_n_elem = n_elem;
 356        if (n_elem > 0) {
 357                if (toklen <= (n_elem + 1) * 4)
 358                        return -EINVAL;
 359
 360                _debug("n_elem %d", n_elem);
 361
 362                td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
 363                             GFP_KERNEL);
 364                if (!td)
 365                        return -ENOMEM;
 366                *_td = td;
 367
 368                for (loop = 0; loop < n_elem; loop++) {
 369                        ret = rxrpc_krb5_decode_tagged_data(&td[loop],
 370                                                            max_elem_size,
 371                                                            &xdr, &toklen);
 372                        if (ret < 0)
 373                                return ret;
 374                }
 375        }
 376
 377        *_xdr = xdr;
 378        *_toklen = toklen;
 379        _leave(" = 0 [toklen=%u]", toklen);
 380        return 0;
 381}
 382
 383/*
 384 * extract a krb5 ticket
 385 */
 386static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
 387                                    const __be32 **_xdr, unsigned int *_toklen)
 388{
 389        const __be32 *xdr = *_xdr;
 390        unsigned int toklen = *_toklen, len;
 391
 392        /* there must be at least one length word */
 393        if (toklen <= 4)
 394                return -EINVAL;
 395
 396        _enter(",{%x},%u", ntohl(xdr[0]), toklen);
 397
 398        len = ntohl(*xdr++);
 399        toklen -= 4;
 400        if (len > AFSTOKEN_K5_TIX_MAX)
 401                return -EINVAL;
 402        *_tktlen = len;
 403
 404        _debug("ticket len %u", len);
 405
 406        if (len > 0) {
 407                *_ticket = kmemdup(xdr, len, GFP_KERNEL);
 408                if (!*_ticket)
 409                        return -ENOMEM;
 410                len = (len + 3) & ~3;
 411                toklen -= len;
 412                xdr += len >> 2;
 413        }
 414
 415        *_xdr = xdr;
 416        *_toklen = toklen;
 417        _leave(" = 0 [toklen=%u]", toklen);
 418        return 0;
 419}
 420
 421/*
 422 * parse an RxK5 type XDR format token
 423 * - the caller guarantees we have at least 4 words
 424 */
 425static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
 426                                   size_t datalen,
 427                                   const __be32 *xdr, unsigned int toklen)
 428{
 429        struct rxrpc_key_token *token, **pptoken;
 430        struct rxk5_key *rxk5;
 431        const __be32 *end_xdr = xdr + (toklen >> 2);
 432        int ret;
 433
 434        _enter(",{%x,%x,%x,%x},%u",
 435               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 436               toklen);
 437
 438        /* reserve some payload space for this subkey - the length of the token
 439         * is a reasonable approximation */
 440        prep->quotalen = datalen + toklen;
 441
 442        token = kzalloc(sizeof(*token), GFP_KERNEL);
 443        if (!token)
 444                return -ENOMEM;
 445
 446        rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
 447        if (!rxk5) {
 448                kfree(token);
 449                return -ENOMEM;
 450        }
 451
 452        token->security_index = RXRPC_SECURITY_RXK5;
 453        token->k5 = rxk5;
 454
 455        /* extract the principals */
 456        ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
 457        if (ret < 0)
 458                goto error;
 459        ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
 460        if (ret < 0)
 461                goto error;
 462
 463        /* extract the session key and the encoding type (the tag field ->
 464         * ENCTYPE_xxx) */
 465        ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
 466                                            &xdr, &toklen);
 467        if (ret < 0)
 468                goto error;
 469
 470        if (toklen < 4 * 8 + 2 * 4)
 471                goto inval;
 472        rxk5->authtime  = be64_to_cpup((const __be64 *) xdr);
 473        xdr += 2;
 474        rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
 475        xdr += 2;
 476        rxk5->endtime   = be64_to_cpup((const __be64 *) xdr);
 477        xdr += 2;
 478        rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
 479        xdr += 2;
 480        rxk5->is_skey = ntohl(*xdr++);
 481        rxk5->flags = ntohl(*xdr++);
 482        toklen -= 4 * 8 + 2 * 4;
 483
 484        _debug("times: a=%llx s=%llx e=%llx rt=%llx",
 485               rxk5->authtime, rxk5->starttime, rxk5->endtime,
 486               rxk5->renew_till);
 487        _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
 488
 489        /* extract the permitted client addresses */
 490        ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
 491                                             &rxk5->n_addresses,
 492                                             AFSTOKEN_K5_ADDRESSES_MAX,
 493                                             AFSTOKEN_DATA_MAX,
 494                                             &xdr, &toklen);
 495        if (ret < 0)
 496                goto error;
 497
 498        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 499
 500        /* extract the tickets */
 501        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
 502                                       &xdr, &toklen);
 503        if (ret < 0)
 504                goto error;
 505        ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
 506                                       &xdr, &toklen);
 507        if (ret < 0)
 508                goto error;
 509
 510        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 511
 512        /* extract the typed auth data */
 513        ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
 514                                             &rxk5->n_authdata,
 515                                             AFSTOKEN_K5_AUTHDATA_MAX,
 516                                             AFSTOKEN_BDATALN_MAX,
 517                                             &xdr, &toklen);
 518        if (ret < 0)
 519                goto error;
 520
 521        ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
 522
 523        if (toklen != 0)
 524                goto inval;
 525
 526        /* attach the payload */
 527        for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
 528             *pptoken;
 529             pptoken = &(*pptoken)->next)
 530                continue;
 531        *pptoken = token;
 532        if (token->kad->expiry < prep->expiry)
 533                prep->expiry = token->kad->expiry;
 534
 535        _leave(" = 0");
 536        return 0;
 537
 538inval:
 539        ret = -EINVAL;
 540error:
 541        rxrpc_rxk5_free(rxk5);
 542        kfree(token);
 543        _leave(" = %d", ret);
 544        return ret;
 545}
 546
 547/*
 548 * attempt to parse the data as the XDR format
 549 * - the caller guarantees we have more than 7 words
 550 */
 551static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
 552{
 553        const __be32 *xdr = prep->data, *token;
 554        const char *cp;
 555        unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
 556        size_t datalen = prep->datalen;
 557        int ret;
 558
 559        _enter(",{%x,%x,%x,%x},%zu",
 560               ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
 561               prep->datalen);
 562
 563        if (datalen > AFSTOKEN_LENGTH_MAX)
 564                goto not_xdr;
 565
 566        /* XDR is an array of __be32's */
 567        if (datalen & 3)
 568                goto not_xdr;
 569
 570        /* the flags should be 0 (the setpag bit must be handled by
 571         * userspace) */
 572        if (ntohl(*xdr++) != 0)
 573                goto not_xdr;
 574        datalen -= 4;
 575
 576        /* check the cell name */
 577        len = ntohl(*xdr++);
 578        if (len < 1 || len > AFSTOKEN_CELL_MAX)
 579                goto not_xdr;
 580        datalen -= 4;
 581        tmp = (len + 3) & ~3;
 582        if (tmp > datalen)
 583                goto not_xdr;
 584
 585        cp = (const char *) xdr;
 586        for (loop = 0; loop < len; loop++)
 587                if (!isprint(cp[loop]))
 588                        goto not_xdr;
 589        if (len < tmp)
 590                for (; loop < tmp; loop++)
 591                        if (cp[loop])
 592                                goto not_xdr;
 593        _debug("cellname: [%u/%u] '%*.*s'",
 594               len, tmp, len, len, (const char *) xdr);
 595        datalen -= tmp;
 596        xdr += tmp >> 2;
 597
 598        /* get the token count */
 599        if (datalen < 12)
 600                goto not_xdr;
 601        ntoken = ntohl(*xdr++);
 602        datalen -= 4;
 603        _debug("ntoken: %x", ntoken);
 604        if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
 605                goto not_xdr;
 606
 607        /* check each token wrapper */
 608        token = xdr;
 609        loop = ntoken;
 610        do {
 611                if (datalen < 8)
 612                        goto not_xdr;
 613                toklen = ntohl(*xdr++);
 614                sec_ix = ntohl(*xdr);
 615                datalen -= 4;
 616                _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
 617                if (toklen < 20 || toklen > datalen)
 618                        goto not_xdr;
 619                datalen -= (toklen + 3) & ~3;
 620                xdr += (toklen + 3) >> 2;
 621
 622        } while (--loop > 0);
 623
 624        _debug("remainder: %zu", datalen);
 625        if (datalen != 0)
 626                goto not_xdr;
 627
 628        /* okay: we're going to assume it's valid XDR format
 629         * - we ignore the cellname, relying on the key to be correctly named
 630         */
 631        do {
 632                xdr = token;
 633                toklen = ntohl(*xdr++);
 634                token = xdr + ((toklen + 3) >> 2);
 635                sec_ix = ntohl(*xdr++);
 636                toklen -= 4;
 637
 638                _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
 639
 640                switch (sec_ix) {
 641                case RXRPC_SECURITY_RXKAD:
 642                        ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
 643                        if (ret != 0)
 644                                goto error;
 645                        break;
 646
 647                case RXRPC_SECURITY_RXK5:
 648                        ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
 649                        if (ret != 0)
 650                                goto error;
 651                        break;
 652
 653                default:
 654                        ret = -EPROTONOSUPPORT;
 655                        goto error;
 656                }
 657
 658        } while (--ntoken > 0);
 659
 660        _leave(" = 0");
 661        return 0;
 662
 663not_xdr:
 664        _leave(" = -EPROTO");
 665        return -EPROTO;
 666error:
 667        _leave(" = %d", ret);
 668        return ret;
 669}
 670
 671/*
 672 * Preparse an rxrpc defined key.
 673 *
 674 * Data should be of the form:
 675 *      OFFSET  LEN     CONTENT
 676 *      0       4       key interface version number
 677 *      4       2       security index (type)
 678 *      6       2       ticket length
 679 *      8       4       key expiry time (time_t)
 680 *      12      4       kvno
 681 *      16      8       session key
 682 *      24      [len]   ticket
 683 *
 684 * if no data is provided, then a no-security key is made
 685 */
 686static int rxrpc_preparse(struct key_preparsed_payload *prep)
 687{
 688        const struct rxrpc_key_data_v1 *v1;
 689        struct rxrpc_key_token *token, **pp;
 690        size_t plen;
 691        u32 kver;
 692        int ret;
 693
 694        _enter("%zu", prep->datalen);
 695
 696        /* handle a no-security key */
 697        if (!prep->data && prep->datalen == 0)
 698                return 0;
 699
 700        /* determine if the XDR payload format is being used */
 701        if (prep->datalen > 7 * 4) {
 702                ret = rxrpc_preparse_xdr(prep);
 703                if (ret != -EPROTO)
 704                        return ret;
 705        }
 706
 707        /* get the key interface version number */
 708        ret = -EINVAL;
 709        if (prep->datalen <= 4 || !prep->data)
 710                goto error;
 711        memcpy(&kver, prep->data, sizeof(kver));
 712        prep->data += sizeof(kver);
 713        prep->datalen -= sizeof(kver);
 714
 715        _debug("KEY I/F VERSION: %u", kver);
 716
 717        ret = -EKEYREJECTED;
 718        if (kver != 1)
 719                goto error;
 720
 721        /* deal with a version 1 key */
 722        ret = -EINVAL;
 723        if (prep->datalen < sizeof(*v1))
 724                goto error;
 725
 726        v1 = prep->data;
 727        if (prep->datalen != sizeof(*v1) + v1->ticket_length)
 728                goto error;
 729
 730        _debug("SCIX: %u", v1->security_index);
 731        _debug("TLEN: %u", v1->ticket_length);
 732        _debug("EXPY: %x", v1->expiry);
 733        _debug("KVNO: %u", v1->kvno);
 734        _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
 735               v1->session_key[0], v1->session_key[1],
 736               v1->session_key[2], v1->session_key[3],
 737               v1->session_key[4], v1->session_key[5],
 738               v1->session_key[6], v1->session_key[7]);
 739        if (v1->ticket_length >= 8)
 740                _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
 741                       v1->ticket[0], v1->ticket[1],
 742                       v1->ticket[2], v1->ticket[3],
 743                       v1->ticket[4], v1->ticket[5],
 744                       v1->ticket[6], v1->ticket[7]);
 745
 746        ret = -EPROTONOSUPPORT;
 747        if (v1->security_index != RXRPC_SECURITY_RXKAD)
 748                goto error;
 749
 750        plen = sizeof(*token->kad) + v1->ticket_length;
 751        prep->quotalen = plen + sizeof(*token);
 752
 753        ret = -ENOMEM;
 754        token = kzalloc(sizeof(*token), GFP_KERNEL);
 755        if (!token)
 756                goto error;
 757        token->kad = kzalloc(plen, GFP_KERNEL);
 758        if (!token->kad)
 759                goto error_free;
 760
 761        token->security_index           = RXRPC_SECURITY_RXKAD;
 762        token->kad->ticket_len          = v1->ticket_length;
 763        token->kad->expiry              = v1->expiry;
 764        token->kad->kvno                = v1->kvno;
 765        memcpy(&token->kad->session_key, &v1->session_key, 8);
 766        memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
 767
 768        /* count the number of tokens attached */
 769        prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
 770
 771        /* attach the data */
 772        pp = (struct rxrpc_key_token **)&prep->payload.data[0];
 773        while (*pp)
 774                pp = &(*pp)->next;
 775        *pp = token;
 776        if (token->kad->expiry < prep->expiry)
 777                prep->expiry = token->kad->expiry;
 778        token = NULL;
 779        ret = 0;
 780
 781error_free:
 782        kfree(token);
 783error:
 784        return ret;
 785}
 786
 787/*
 788 * Free token list.
 789 */
 790static void rxrpc_free_token_list(struct rxrpc_key_token *token)
 791{
 792        struct rxrpc_key_token *next;
 793
 794        for (; token; token = next) {
 795                next = token->next;
 796                switch (token->security_index) {
 797                case RXRPC_SECURITY_RXKAD:
 798                        kfree(token->kad);
 799                        break;
 800                case RXRPC_SECURITY_RXK5:
 801                        if (token->k5)
 802                                rxrpc_rxk5_free(token->k5);
 803                        break;
 804                default:
 805                        pr_err("Unknown token type %x on rxrpc key\n",
 806                               token->security_index);
 807                        BUG();
 808                }
 809
 810                kfree(token);
 811        }
 812}
 813
 814/*
 815 * Clean up preparse data.
 816 */
 817static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
 818{
 819        rxrpc_free_token_list(prep->payload.data[0]);
 820}
 821
 822/*
 823 * Preparse a server secret key.
 824 *
 825 * The data should be the 8-byte secret key.
 826 */
 827static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
 828{
 829        struct crypto_skcipher *ci;
 830
 831        _enter("%zu", prep->datalen);
 832
 833        if (prep->datalen != 8)
 834                return -EINVAL;
 835
 836        memcpy(&prep->payload.data[2], prep->data, 8);
 837
 838        ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
 839        if (IS_ERR(ci)) {
 840                _leave(" = %ld", PTR_ERR(ci));
 841                return PTR_ERR(ci);
 842        }
 843
 844        if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
 845                BUG();
 846
 847        prep->payload.data[0] = ci;
 848        _leave(" = 0");
 849        return 0;
 850}
 851
 852/*
 853 * Clean up preparse data.
 854 */
 855static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
 856{
 857        if (prep->payload.data[0])
 858                crypto_free_skcipher(prep->payload.data[0]);
 859}
 860
 861/*
 862 * dispose of the data dangling from the corpse of a rxrpc key
 863 */
 864static void rxrpc_destroy(struct key *key)
 865{
 866        rxrpc_free_token_list(key->payload.data[0]);
 867}
 868
 869/*
 870 * dispose of the data dangling from the corpse of a rxrpc key
 871 */
 872static void rxrpc_destroy_s(struct key *key)
 873{
 874        if (key->payload.data[0]) {
 875                crypto_free_skcipher(key->payload.data[0]);
 876                key->payload.data[0] = NULL;
 877        }
 878}
 879
 880/*
 881 * describe the rxrpc key
 882 */
 883static void rxrpc_describe(const struct key *key, struct seq_file *m)
 884{
 885        seq_puts(m, key->description);
 886}
 887
 888/*
 889 * grab the security key for a socket
 890 */
 891int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
 892{
 893        struct key *key;
 894        char *description;
 895
 896        _enter("");
 897
 898        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 899                return -EINVAL;
 900
 901        description = memdup_user_nul(optval, optlen);
 902        if (IS_ERR(description))
 903                return PTR_ERR(description);
 904
 905        key = request_key(&key_type_rxrpc, description, NULL);
 906        if (IS_ERR(key)) {
 907                kfree(description);
 908                _leave(" = %ld", PTR_ERR(key));
 909                return PTR_ERR(key);
 910        }
 911
 912        rx->key = key;
 913        kfree(description);
 914        _leave(" = 0 [key %x]", key->serial);
 915        return 0;
 916}
 917
 918/*
 919 * grab the security keyring for a server socket
 920 */
 921int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
 922                         int optlen)
 923{
 924        struct key *key;
 925        char *description;
 926
 927        _enter("");
 928
 929        if (optlen <= 0 || optlen > PAGE_SIZE - 1)
 930                return -EINVAL;
 931
 932        description = memdup_user_nul(optval, optlen);
 933        if (IS_ERR(description))
 934                return PTR_ERR(description);
 935
 936        key = request_key(&key_type_keyring, description, NULL);
 937        if (IS_ERR(key)) {
 938                kfree(description);
 939                _leave(" = %ld", PTR_ERR(key));
 940                return PTR_ERR(key);
 941        }
 942
 943        rx->securities = key;
 944        kfree(description);
 945        _leave(" = 0 [key %x]", key->serial);
 946        return 0;
 947}
 948
 949/*
 950 * generate a server data key
 951 */
 952int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
 953                              const void *session_key,
 954                              time_t expiry,
 955                              u32 kvno)
 956{
 957        const struct cred *cred = current_cred();
 958        struct key *key;
 959        int ret;
 960
 961        struct {
 962                u32 kver;
 963                struct rxrpc_key_data_v1 v1;
 964        } data;
 965
 966        _enter("");
 967
 968        key = key_alloc(&key_type_rxrpc, "x",
 969                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
 970                        KEY_ALLOC_NOT_IN_QUOTA, NULL);
 971        if (IS_ERR(key)) {
 972                _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
 973                return -ENOMEM;
 974        }
 975
 976        _debug("key %d", key_serial(key));
 977
 978        data.kver = 1;
 979        data.v1.security_index = RXRPC_SECURITY_RXKAD;
 980        data.v1.ticket_length = 0;
 981        data.v1.expiry = expiry;
 982        data.v1.kvno = 0;
 983
 984        memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
 985
 986        ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
 987        if (ret < 0)
 988                goto error;
 989
 990        conn->params.key = key;
 991        _leave(" = 0 [%d]", key_serial(key));
 992        return 0;
 993
 994error:
 995        key_revoke(key);
 996        key_put(key);
 997        _leave(" = -ENOMEM [ins %d]", ret);
 998        return -ENOMEM;
 999}
1000EXPORT_SYMBOL(rxrpc_get_server_data_key);
1001
1002/**
1003 * rxrpc_get_null_key - Generate a null RxRPC key
1004 * @keyname: The name to give the key.
1005 *
1006 * Generate a null RxRPC key that can be used to indicate anonymous security is
1007 * required for a particular domain.
1008 */
1009struct key *rxrpc_get_null_key(const char *keyname)
1010{
1011        const struct cred *cred = current_cred();
1012        struct key *key;
1013        int ret;
1014
1015        key = key_alloc(&key_type_rxrpc, keyname,
1016                        GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
1017                        KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
1018        if (IS_ERR(key))
1019                return key;
1020
1021        ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
1022        if (ret < 0) {
1023                key_revoke(key);
1024                key_put(key);
1025                return ERR_PTR(ret);
1026        }
1027
1028        return key;
1029}
1030EXPORT_SYMBOL(rxrpc_get_null_key);
1031
1032/*
1033 * read the contents of an rxrpc key
1034 * - this returns the result in XDR form
1035 */
1036static long rxrpc_read(const struct key *key,
1037                       char __user *buffer, size_t buflen)
1038{
1039        const struct rxrpc_key_token *token;
1040        const struct krb5_principal *princ;
1041        size_t size;
1042        __be32 __user *xdr, *oldxdr;
1043        u32 cnlen, toksize, ntoks, tok, zero;
1044        u16 toksizes[AFSTOKEN_MAX];
1045        int loop;
1046
1047        _enter("");
1048
1049        /* we don't know what form we should return non-AFS keys in */
1050        if (memcmp(key->description, "afs@", 4) != 0)
1051                return -EOPNOTSUPP;
1052        cnlen = strlen(key->description + 4);
1053
1054#define RND(X) (((X) + 3) & ~3)
1055
1056        /* AFS keys we return in XDR form, so we need to work out the size of
1057         * the XDR */
1058        size = 2 * 4;   /* flags, cellname len */
1059        size += RND(cnlen);     /* cellname */
1060        size += 1 * 4;  /* token count */
1061
1062        ntoks = 0;
1063        for (token = key->payload.data[0]; token; token = token->next) {
1064                toksize = 4;    /* sec index */
1065
1066                switch (token->security_index) {
1067                case RXRPC_SECURITY_RXKAD:
1068                        toksize += 8 * 4;       /* viceid, kvno, key*2, begin,
1069                                                 * end, primary, tktlen */
1070                        toksize += RND(token->kad->ticket_len);
1071                        break;
1072
1073                case RXRPC_SECURITY_RXK5:
1074                        princ = &token->k5->client;
1075                        toksize += 4 + princ->n_name_parts * 4;
1076                        for (loop = 0; loop < princ->n_name_parts; loop++)
1077                                toksize += RND(strlen(princ->name_parts[loop]));
1078                        toksize += 4 + RND(strlen(princ->realm));
1079
1080                        princ = &token->k5->server;
1081                        toksize += 4 + princ->n_name_parts * 4;
1082                        for (loop = 0; loop < princ->n_name_parts; loop++)
1083                                toksize += RND(strlen(princ->name_parts[loop]));
1084                        toksize += 4 + RND(strlen(princ->realm));
1085
1086                        toksize += 8 + RND(token->k5->session.data_len);
1087
1088                        toksize += 4 * 8 + 2 * 4;
1089
1090                        toksize += 4 + token->k5->n_addresses * 8;
1091                        for (loop = 0; loop < token->k5->n_addresses; loop++)
1092                                toksize += RND(token->k5->addresses[loop].data_len);
1093
1094                        toksize += 4 + RND(token->k5->ticket_len);
1095                        toksize += 4 + RND(token->k5->ticket2_len);
1096
1097                        toksize += 4 + token->k5->n_authdata * 8;
1098                        for (loop = 0; loop < token->k5->n_authdata; loop++)
1099                                toksize += RND(token->k5->authdata[loop].data_len);
1100                        break;
1101
1102                default: /* we have a ticket we can't encode */
1103                        BUG();
1104                        continue;
1105                }
1106
1107                _debug("token[%u]: toksize=%u", ntoks, toksize);
1108                ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
1109
1110                toksizes[ntoks++] = toksize;
1111                size += toksize + 4; /* each token has a length word */
1112        }
1113
1114#undef RND
1115
1116        if (!buffer || buflen < size)
1117                return size;
1118
1119        xdr = (__be32 __user *) buffer;
1120        zero = 0;
1121#define ENCODE(x)                               \
1122        do {                                    \
1123                __be32 y = htonl(x);            \
1124                if (put_user(y, xdr++) < 0)     \
1125                        goto fault;             \
1126        } while(0)
1127#define ENCODE_DATA(l, s)                                               \
1128        do {                                                            \
1129                u32 _l = (l);                                           \
1130                ENCODE(l);                                              \
1131                if (copy_to_user(xdr, (s), _l) != 0)                    \
1132                        goto fault;                                     \
1133                if (_l & 3 &&                                           \
1134                    copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
1135                        goto fault;                                     \
1136                xdr += (_l + 3) >> 2;                                   \
1137        } while(0)
1138#define ENCODE64(x)                                     \
1139        do {                                            \
1140                __be64 y = cpu_to_be64(x);              \
1141                if (copy_to_user(xdr, &y, 8) != 0)      \
1142                        goto fault;                     \
1143                xdr += 8 >> 2;                          \
1144        } while(0)
1145#define ENCODE_STR(s)                           \
1146        do {                                    \
1147                const char *_s = (s);           \
1148                ENCODE_DATA(strlen(_s), _s);    \
1149        } while(0)
1150
1151        ENCODE(0);                                      /* flags */
1152        ENCODE_DATA(cnlen, key->description + 4);       /* cellname */
1153        ENCODE(ntoks);
1154
1155        tok = 0;
1156        for (token = key->payload.data[0]; token; token = token->next) {
1157                toksize = toksizes[tok++];
1158                ENCODE(toksize);
1159                oldxdr = xdr;
1160                ENCODE(token->security_index);
1161
1162                switch (token->security_index) {
1163                case RXRPC_SECURITY_RXKAD:
1164                        ENCODE(token->kad->vice_id);
1165                        ENCODE(token->kad->kvno);
1166                        ENCODE_DATA(8, token->kad->session_key);
1167                        ENCODE(token->kad->start);
1168                        ENCODE(token->kad->expiry);
1169                        ENCODE(token->kad->primary_flag);
1170                        ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
1171                        break;
1172
1173                case RXRPC_SECURITY_RXK5:
1174                        princ = &token->k5->client;
1175                        ENCODE(princ->n_name_parts);
1176                        for (loop = 0; loop < princ->n_name_parts; loop++)
1177                                ENCODE_STR(princ->name_parts[loop]);
1178                        ENCODE_STR(princ->realm);
1179
1180                        princ = &token->k5->server;
1181                        ENCODE(princ->n_name_parts);
1182                        for (loop = 0; loop < princ->n_name_parts; loop++)
1183                                ENCODE_STR(princ->name_parts[loop]);
1184                        ENCODE_STR(princ->realm);
1185
1186                        ENCODE(token->k5->session.tag);
1187                        ENCODE_DATA(token->k5->session.data_len,
1188                                    token->k5->session.data);
1189
1190                        ENCODE64(token->k5->authtime);
1191                        ENCODE64(token->k5->starttime);
1192                        ENCODE64(token->k5->endtime);
1193                        ENCODE64(token->k5->renew_till);
1194                        ENCODE(token->k5->is_skey);
1195                        ENCODE(token->k5->flags);
1196
1197                        ENCODE(token->k5->n_addresses);
1198                        for (loop = 0; loop < token->k5->n_addresses; loop++) {
1199                                ENCODE(token->k5->addresses[loop].tag);
1200                                ENCODE_DATA(token->k5->addresses[loop].data_len,
1201                                            token->k5->addresses[loop].data);
1202                        }
1203
1204                        ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
1205                        ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
1206
1207                        ENCODE(token->k5->n_authdata);
1208                        for (loop = 0; loop < token->k5->n_authdata; loop++) {
1209                                ENCODE(token->k5->authdata[loop].tag);
1210                                ENCODE_DATA(token->k5->authdata[loop].data_len,
1211                                            token->k5->authdata[loop].data);
1212                        }
1213                        break;
1214
1215                default:
1216                        BUG();
1217                        break;
1218                }
1219
1220                ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
1221                          toksize);
1222        }
1223
1224#undef ENCODE_STR
1225#undef ENCODE_DATA
1226#undef ENCODE64
1227#undef ENCODE
1228
1229        ASSERTCMP(tok, ==, ntoks);
1230        ASSERTCMP((char __user *) xdr - buffer, ==, size);
1231        _leave(" = %zu", size);
1232        return size;
1233
1234fault:
1235        _leave(" = -EFAULT");
1236        return -EFAULT;
1237}
1238