src/afs/afs_tokens.c

   1 /*
   2  * Copyright (c) 2010 Your Filesystem Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #include <afsconfig.h>
  26 #include "afs/param.h"
  27 #include "afs/sysincludes.h"
  28 #include "afsincludes.h"
  29 #include "token.h"
  30
  31 /* A jar for storing tokens in */
  32
  33 /*!
  34  * Return a token of the specified type from the selected tokenjar.
  35  *
  36  * @param[in] tokens
  37  *      The tokenjar in which to search
  38  * @param[in] type
  39  *      The type of token to return
  40  *
  41  * @return
  42  *      A tokenUnion structure, from which the desired token can be
  43  *      accessed using the appropriate element of the union.
  44  */
  45 union tokenUnion *
  46 afs_FindToken(struct tokenJar *tokens, rx_securityIndex type) {
  47     while (tokens != NULL) {
  48         if (tokens->type == type) {
  49             return &tokens->content;
  50         }
  51         tokens = tokens->next;
  52     }
  53     return NULL;
  54 }
  55
  56 /*!
  57  * Free a single token
  58  *
  59  * This will free the given token. No attempt is made to unlink
  60  * the token from its container, and it is an error to attempt to
  61  * free a token which is still linked.
  62  *
  63  * This performs a secure free, setting all token information to 0
  64  * before returning allocated data blocks to the kernel.
  65  *
  66  * Intended primarily for internal use.
  67  *
  68  * @param[in] token
  69  *      The token to free
  70  */
  71
  72 void
  73 afs_FreeOneToken(struct tokenJar *token) {
  74     if (token->next != NULL)
  75         osi_Panic("Freeing linked token");
  76
  77     switch (token->type) {
  78       case RX_SECIDX_KAD:
  79         if (token->content.rxkad.ticket != NULL) {
  80                 memset(token->content.rxkad.ticket, 0, token->content.rxkad.ticketLen);
  81                 afs_osi_Free(token->content.rxkad.ticket,
  82                              token->content.rxkad.ticketLen);
  83         }
  84         break;
  85       default:
  86         break;
  87     }
  88     memset(token, 0, sizeof(struct tokenJar));
  89     afs_osi_Free(token, sizeof(struct tokenJar));
  90 }
  91
  92 /*!
  93  * Free a token jar
  94  *
  95  * Free all of the tokens in a given token jar. This will also set the
  96  * pointer to the jar to NULL, to indicate that it has been freed.
  97  *
  98  * @param[in] tokenPtr
  99  *      A pointer to the address of the tokenjar to free.
 100  */
 101 void
 102 afs_FreeTokens(struct tokenJar **tokenPtr) {
 103     struct tokenJar *next, *tokens;
 104
 105     tokens = *tokenPtr;
 106     *tokenPtr = NULL;
 107     while(tokens != NULL) {
 108         next = tokens->next;
 109         tokens->next = NULL; /* Unlink from chain */
 110         afs_FreeOneToken(tokens);
 111         tokens = next;
 112     }
 113 }
 114
 115 /*!
 116  * Add a token to a token jar
 117  *
 118  * Add a new token to a token jar. If the jar already exists,
 119  * then this token becomes the first in the jar. If it doesn't
 120  * exist, then a new jar is created. The contents of the new
 121  * token are initialised to 0 upon creation.
 122  *
 123  * @param[in] tokens
 124  *      A pointer to the address of the token jar to populate
 125  * @param[in] type
 126  *      The type of token to create
 127  *
 128  * @return
 129  *      A pointer to the tokenUnion of the newly created token,
 130  *      which may then be used to populate the token.
 131  */
 132 union tokenUnion *
 133 afs_AddToken(struct tokenJar **tokens, rx_securityIndex type) {
 134     struct tokenJar *newToken;
 135
 136     newToken = afs_osi_Alloc(sizeof(struct tokenJar));
 137     osi_Assert(newToken != NULL);
 138     memset(newToken, 0, sizeof(*newToken));
 139
 140     newToken->type = type;
 141     newToken->next = *tokens;
 142     *tokens = newToken;
 143
 144     return &newToken->content;
 145 }
 146
 147 /*!
 148  * Indicate if a single token is expired
 149  *
 150  * @param[in] token
 151  *      The token to check
 152  * @param[in] now
 153  *      The time to check against for expiry (typically the results of
 154  *      calling osi_Time())
 155  *
 156  * @returns
 157  *      True if the token has expired, false otherwise
 158  */
 159 int
 160 afs_IsTokenExpired(struct tokenJar *token, afs_int32 now) {
 161     switch (token->type) {
 162       case RX_SECIDX_KAD:
 163         if (token->content.rxkad.clearToken.EndTimestamp < now - NOTOKTIMEOUT)
 164             return 1;
 165         break;
 166       default:
 167         return 0;
 168     }
 169     return 0; /* not reached, but keep gcc happy */
 170 }
 171
 172 /*!
 173  * Indicate if a token is usable by the kernel module
 174  *
 175  * This determines whether a token is usable. A usable token is one that
 176  * has not expired, and which is otherwise suitable for use.
 177  *
 178  * @param[in] token
 179  *      The token to check
 180  * @param[in] now
 181  *      The time to use for the expiry check
 182  *
 183  * @returns
 184  *      True if the token is usable, false otherwise
 185  */
 186 int
 187 afs_IsTokenUsable(struct tokenJar *token, afs_int32 now) {
 188
 189     if (afs_IsTokenExpired(token, now))
 190         return 0;
 191
 192     switch (token->type) {
 193       case RX_SECIDX_KAD:
 194         /* We assume that all non-expired rxkad tokens are usable by us */
 195         return 1;
 196       default :
 197         return 0;
 198     }
 199 }
 200
 201 /*!
 202  * Discard all expired tokens from a token jar
 203  *
 204  * This permanently removes all tokens which have expired from the token
 205  * jar. Note that tokens which are not usable, but which have not expired,
 206  * will not be deleted.
 207  *
 208  * @param[in] tokenPtr
 209  *      A pointer to the address of the token jar to check
 210  * @param[in] now
 211  *      The time to use for the expiry check
 212  */
 213
 214 void
 215 afs_DiscardExpiredTokens(struct tokenJar **tokenPtr, afs_int32 now) {
 216     struct tokenJar *next;
 217
 218     while (*tokenPtr != NULL) {
 219         if (afs_IsTokenExpired(*tokenPtr, now)) {
 220             next = (*tokenPtr)->next;
 221             (*tokenPtr)->next = NULL;
 222             afs_FreeOneToken(*tokenPtr);
 223             *tokenPtr = next;
 224         } else {
 225             tokenPtr = &(*tokenPtr)->next;
 226         }
 227     }
 228 }
 229
 230 /*!
 231  * Indicate whether a token jar contains one, or more usable tokens
 232  *
 233  * @param[in] token
 234  *      The token jar to check
 235  * @param[in] now
 236  *      The cime to use for the expiry check
 237  *
 238  * @returns
 239  *      True if the jar contains usable tokens, otherwise false
 240  */
 241 int
 242 afs_HasUsableTokens(struct tokenJar *token, afs_int32 now) {
 243     while (token != NULL) {
 244         if (afs_IsTokenUsable(token, now))
 245             return 1;
 246         token = token->next;
 247     }
 248     return 0;
 249 }
 250
 251 /*!
 252  * Indicate whether a token jar contains a valid (non-expired) token
 253  *
 254  * @param[in] token
 255  *      The token jar to check
 256  * @param[in] now
 257  *      The time to use for the expiry check
 258  *
 259  * @returns
 260  *      True if the jar contains valid tokens, otherwise false
 261  *
 262  */
 263 int
 264 afs_HasValidTokens(struct tokenJar *token, afs_int32 now) {
 265     while (token != NULL) {
 266         if (!afs_IsTokenExpired(token, now))
 267             return 1;
 268         token = token->next;
 269     }
 270     return 0;
 271 }
 272
 273 /*!
 274  * Count the number of valid tokens in a jar. A valid token is
 275  * one which is not expired - note that valid tokens may not be
 276  * usable by the kernel.
 277  *
 278  * @param[in] token
 279  *      The token jar to check
 280  * @param[in] now
 281  *      The time to use for the expiry check
 282  *
 283  * @returns
 284  *      The number of valid tokens in the jar
 285  */
 286 static int
 287 countValidTokens(struct tokenJar *token, time_t now) {
 288     int count = 0;
 289
 290     while (token != NULL) {
 291         if (!afs_IsTokenExpired(token, now))
 292             count ++;
 293         token = token->next;
 294     }
 295     return count;
 296 }
 297
 298 /*!
 299  * Add an rxkad token to the token jar
 300  *
 301  * @param[in] tokens
 302  *      A pointer to the address of the jar to add the token to
 303  * @param[in] ticket
 304  *      A data block containing the token's opaque ticket
 305  * @param[in] ticketLen
 306  *      The length of the ticket data block
 307  * @param[in] clearToken
 308  *      The cleartext token information
 309  */
 310 void
 311 afs_AddRxkadToken(struct tokenJar **tokens, char *ticket, int ticketLen,
 312                   struct ClearToken *clearToken) {
 313     union tokenUnion *tokenU;
 314     struct rxkadToken *rxkad;
 315
 316     tokenU = afs_AddToken(tokens, RX_SECIDX_KAD);
 317     rxkad = &tokenU->rxkad;
 318
 319     rxkad->ticket = afs_osi_Alloc(ticketLen);
 320     osi_Assert(rxkad->ticket != NULL);
 321     rxkad->ticketLen = ticketLen;
 322     memcpy(rxkad->ticket, ticket, ticketLen);
 323     rxkad->clearToken = *clearToken;
 324 }
 325
 326 static int
 327 afs_AddRxkadTokenFromPioctl(struct tokenJar **tokens,
 328                             struct ktc_tokenUnion *pioctlToken) {
 329     struct ClearToken clear;
 330
 331     clear.AuthHandle = pioctlToken->ktc_tokenUnion_u.at_kad.rk_kvno;
 332     clear.ViceId = pioctlToken->ktc_tokenUnion_u.at_kad.rk_viceid;
 333     clear.BeginTimestamp = pioctlToken->ktc_tokenUnion_u.at_kad.rk_begintime;
 334     clear.EndTimestamp = pioctlToken->ktc_tokenUnion_u.at_kad.rk_endtime;
 335     memcpy(clear.HandShakeKey, pioctlToken->ktc_tokenUnion_u.at_kad.rk_key, 8);
 336     afs_AddRxkadToken(tokens,
 337                       pioctlToken->ktc_tokenUnion_u.at_kad.rk_ticket.rk_ticket_val,
 338                       pioctlToken->ktc_tokenUnion_u.at_kad.rk_ticket.rk_ticket_len,
 339                       &clear);
 340
 341     /* Security means never having to say you're sorry */
 342     memset(clear.HandShakeKey, 0, 8);
 343
 344     return 0;
 345 }
 346
 347 static int
 348 rxkad_extractTokenForPioctl(struct tokenJar *token,
 349                                struct ktc_tokenUnion *pioctlToken) {
 350
 351     struct token_rxkad *rxkadPioctl;
 352     struct rxkadToken *rxkadInternal;
 353
 354     rxkadPioctl = &pioctlToken->ktc_tokenUnion_u.at_kad;
 355     rxkadInternal = &token->content.rxkad;
 356
 357     rxkadPioctl->rk_kvno = rxkadInternal->clearToken.AuthHandle;
 358     rxkadPioctl->rk_viceid = rxkadInternal->clearToken.ViceId;
 359     rxkadPioctl->rk_begintime = rxkadInternal->clearToken.BeginTimestamp;
 360     rxkadPioctl->rk_endtime = rxkadInternal->clearToken.EndTimestamp;
 361     memcpy(rxkadPioctl->rk_key, rxkadInternal->clearToken.HandShakeKey, 8);
 362
 363     rxkadPioctl->rk_ticket.rk_ticket_val = xdr_alloc(rxkadInternal->ticketLen);
 364     if (rxkadPioctl->rk_ticket.rk_ticket_val == NULL)
 365         return ENOMEM;
 366     rxkadPioctl->rk_ticket.rk_ticket_len = rxkadInternal->ticketLen;
 367     memcpy(rxkadPioctl->rk_ticket.rk_ticket_val,
 368            rxkadInternal->ticket, rxkadInternal->ticketLen);
 369
 370     return 0;
 371 }
 372
 373 /*!
 374  * Add a token to a token jar based on the input from a new-style
 375  * SetToken pioctl
 376  *
 377  * @param[in] tokens
 378  *      Pointer to the address of a token jar
 379  * @param[in] pioctlToken
 380  *      The token structure obtained through the pioctl (note this
 381  *      is a single, XDR decoded, token)
 382  *
 383  * @returns
 384  *      0 on success, an error code on failure
 385  */
 386 int
 387 afs_AddTokenFromPioctl(struct tokenJar **tokens,
 388                        struct ktc_tokenUnion *pioctlToken) {
 389
 390     switch (pioctlToken->at_type) {
 391       case RX_SECIDX_KAD:
 392         return afs_AddRxkadTokenFromPioctl(tokens, pioctlToken);
 393     }
 394
 395     return EINVAL;
 396 }
 397
 398 static int
 399 extractPioctlToken(struct tokenJar *token,
 400                    struct token_opaque *opaque) {
 401     XDR xdrs;
 402     struct ktc_tokenUnion *pioctlToken;
 403     int code;
 404
 405     memset(opaque, 0, sizeof(token_opaque));
 406
 407     pioctlToken = osi_Alloc(sizeof(struct ktc_tokenUnion));
 408     if (pioctlToken == NULL)
 409         return ENOMEM;
 410
 411     pioctlToken->at_type = token->type;
 412
 413     switch (token->type) {
 414       case RX_SECIDX_KAD:
 415         code = rxkad_extractTokenForPioctl(token, pioctlToken);
 416         break;
 417       default:
 418         code = EINVAL;;
 419     }
 420
 421     if (code)
 422         goto out;
 423
 424     xdrlen_create(&xdrs);
 425     if (!xdr_ktc_tokenUnion(&xdrs, pioctlToken)) {
 426         code = EINVAL;
 427         xdr_destroy(&xdrs);
 428         goto out;
 429     }
 430
 431     opaque->token_opaque_len = xdr_getpos(&xdrs);
 432     xdr_destroy(&xdrs);
 433
 434     opaque->token_opaque_val = osi_Alloc(opaque->token_opaque_len);
 435     if (opaque->token_opaque_val == NULL) {
 436         code = ENOMEM;
 437         goto out;
 438     }
 439
 440     xdrmem_create(&xdrs,
 441                   opaque->token_opaque_val,
 442                   opaque->token_opaque_len,
 443                   XDR_ENCODE);
 444     if (!xdr_ktc_tokenUnion(&xdrs, pioctlToken)) {
 445         code = EINVAL;
 446         xdr_destroy(&xdrs);
 447         goto out;
 448     }
 449     xdr_destroy(&xdrs);
 450
 451 out:
 452     xdr_free((xdrproc_t) xdr_ktc_tokenUnion, &pioctlToken);
 453     osi_Free(pioctlToken, sizeof(struct ktc_tokenUnion));
 454
 455     if (code != 0) {
 456         if (opaque->token_opaque_val != NULL)
 457             osi_Free(opaque->token_opaque_val, opaque->token_opaque_len);
 458         opaque->token_opaque_val = NULL;
 459         opaque->token_opaque_len = 0;
 460     }
 461     return code;
 462 }
 463
 464 int
 465 afs_ExtractTokensForPioctl(struct tokenJar *token,
 466                            time_t now,
 467                            struct ktc_setTokenData *tokenSet)
 468 {
 469     int numTokens, pos;
 470     int code = 0;
 471
 472     numTokens = countValidTokens(token, now);
 473
 474     tokenSet->tokens.tokens_len = numTokens;
 475     tokenSet->tokens.tokens_val
 476         = xdr_alloc(sizeof(struct token_opaque) * numTokens);
 477
 478     if (tokenSet->tokens.tokens_val == NULL)
 479         return ENOMEM;
 480
 481     pos = 0;
 482     while (token != NULL && pos < numTokens) {
 483         code = extractPioctlToken(token, &tokenSet->tokens.tokens_val[pos]);
 484         if (code)
 485             goto out;
 486         token = token->next;
 487         pos++;
 488     }
 489
 490 out:
 491     if (code)
 492         xdr_free((xdrproc_t) xdr_ktc_setTokenData, tokenSet);
 493
 494     return code;
 495 }