src/tpm_library.c

   1 /********************************************************************************/
   2 /*                                                                              */
   3 /*                      LibTPM interface functions                              */
   4 /*                           Written by Stefan Berger                           */
   5 /*                     IBM Thomas J. Watson Research Center                     */
   6 /*            $Id: tpm_library.c 4615 2011-08-30 15:35:24Z stefanb $            */
   7 /*                                                                              */
   8 /* (c) Copyright IBM Corporation 2010.                                          */
   9 /*                                                                              */
  10 /* All rights reserved.                                                         */
  11 /*                                                                              */
  12 /* Redistribution and use in source and binary forms, with or without           */
  13 /* modification, are permitted provided that the following conditions are       */
  14 /* met:                                                                         */
  15 /*                                                                              */
  16 /* Redistributions of source code must retain the above copyright notice,       */
  17 /* this list of conditions and the following disclaimer.                        */
  18 /*                                                                              */
  19 /* Redistributions in binary form must reproduce the above copyright            */
  20 /* notice, this list of conditions and the following disclaimer in the          */
  21 /* documentation and/or other materials provided with the distribution.         */
  22 /*                                                                              */
  23 /* Neither the names of the IBM Corporation nor the names of its                */
  24 /* contributors may be used to endorse or promote products derived from         */
  25 /* this software without specific prior written permission.                     */
  26 /*                                                                              */
  27 /* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS          */
  28 /* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT            */
  29 /* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR        */
  30 /* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT         */
  31 /* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,       */
  32 /* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT             */
  33 /* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,        */
  34 /* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY        */
  35 /* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT          */
  36 /* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE        */
  37 /* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.         */
  38 /********************************************************************************/
  39
  40 #include <config.h>
  41
  42 #include <assert.h>
  43 #include <string.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <ctype.h>
  47
  48 #ifdef USE_FREEBL_CRYPTO_LIBRARY
  49 # include <plbase64.h>
  50 #endif
  51
  52 #ifdef USE_OPENSSL_CRYPTO_LIBRARY
  53 # include <openssl/bio.h>
  54 # include <openssl/evp.h>
  55 #endif
  56
  57 #include "tpm_debug.h"
  58 #include "tpm_error.h"
  59 #include "tpm_init.h"
  60 #include "tpm_library.h"
  61 #include "tpm_library_intern.h"
  62 #include "tpm_key.h"
  63 #include "tpm_memory.h"
  64 #include "tpm_process.h"
  65 #include "tpm_startup.h"
  66
  67 #define ROUNDUP(VAL, SIZE) \
  68   ( ( (VAL) + (SIZE) - 1 ) / (SIZE) ) * (SIZE)
  69
  70
  71
  72 static const struct tags_and_indices {
  73     const char    *starttag;
  74     const char    *endtag;
  75 } tags_and_indices[] = {
  76   [TPMLIB_BLOB_TYPE_INITSTATE] =
  77     {
  78       .starttag = TPMLIB_INITSTATE_START_TAG,
  79       .endtag   = TPMLIB_INITSTATE_END_TAG,
  80     },
  81 };
  82
  83
  84
  85 uint32_t TPMLIB_GetVersion(void)
  86 {
  87     return TPM_LIBRARY_VERSION;
  88 }
  89
  90 TPM_RESULT TPMLIB_MainInit(void)
  91 {
  92     return TPM_MainInit();
  93 }
  94
  95
  96 void TPMLIB_Terminate(void)
  97 {
  98     TPM_Global_Delete(tpm_instances[0]);
  99 }
 100
 101
 102 /*
 103  * Send a command to the TPM. The command buffer must hold a well formatted
 104  * TPM command and the command_size indicate the size of the command.
 105  * The respbuffer parameter may be provided by the user and grow if
 106  * the respbufsize size indicator is determined to be too small for the
 107  * response. In that case a new buffer will be allocated and the size of that
 108  * buffer returned in the respbufsize parameter. resp_size describes the
 109  * size of the actual response within the respbuffer.
 110  */
 111 TPM_RESULT TPMLIB_Process(unsigned char **respbuffer, uint32_t *resp_size,
 112                           uint32_t *respbufsize,
 113                           unsigned char *command, uint32_t command_size)
 114 {
 115     *resp_size = 0;
 116     return TPM_ProcessA(respbuffer, resp_size, respbufsize,
 117                         command, command_size);
 118 }
 119
 120
 121 /*
 122  * Get the volatile state from the TPM. This function will return the
 123  * buffer and the length of the buffer to the caller in case everything
 124  * went alright.
 125  */
 126 TPM_RESULT TPMLIB_VolatileAll_Store(unsigned char **buffer,
 127                                     uint32_t *buflen)
 128 {
 129     TPM_RESULT rc;
 130     TPM_STORE_BUFFER tsb;
 131     TPM_Sbuffer_Init(&tsb);
 132     uint32_t total;
 133
 134 #ifdef TPM_DEBUG
 135     assert(tpm_instances[0] != NULL);
 136 #endif
 137
 138     rc = TPM_VolatileAll_Store(&tsb, tpm_instances[0]);
 139
 140     if (rc == TPM_SUCCESS) {
 141         /* caller now owns the buffer and needs to free it */
 142         TPM_Sbuffer_GetAll(&tsb, buffer, buflen, &total);
 143     } else {
 144         TPM_Sbuffer_Delete(&tsb);
 145         *buflen = 0;
 146         *buffer = NULL;
 147     }
 148
 149     return rc;
 150 }
 151
 152
 153 /*
 154  * Get a property of the TPM. The functions currently only
 155  * return compile-time #defines but this may change in future
 156  * versions where we may return parameters with which the TPM
 157  * was created (rather than compiled).
 158  */
 159 TPM_RESULT TPMLIB_GetTPMProperty(enum TPMLIB_TPMProperty prop,
 160                                  int *result)
 161 {
 162     switch (prop) {
 163     case  TPMPROP_TPM_RSA_KEY_LENGTH_MAX:
 164         *result = TPM_RSA_KEY_LENGTH_MAX;
 165         break;
 166
 167     case  TPMPROP_TPM_BUFFER_MAX:
 168         *result = TPM_BUFFER_MAX;
 169         break;
 170
 171     case  TPMPROP_TPM_KEY_HANDLES:
 172         *result = TPM_KEY_HANDLES;
 173         break;
 174
 175     case  TPMPROP_TPM_OWNER_EVICT_KEY_HANDLES:
 176         *result = TPM_OWNER_EVICT_KEY_HANDLES;
 177         break;
 178
 179     case  TPMPROP_TPM_MIN_AUTH_SESSIONS:
 180         *result = TPM_MIN_AUTH_SESSIONS;
 181         break;
 182
 183     case  TPMPROP_TPM_MIN_TRANS_SESSIONS:
 184         *result = TPM_MIN_TRANS_SESSIONS;
 185         break;
 186
 187     case  TPMPROP_TPM_MIN_DAA_SESSIONS:
 188         *result = TPM_MIN_DAA_SESSIONS;
 189         break;
 190
 191     case  TPMPROP_TPM_MIN_SESSION_LIST:
 192         *result = TPM_MIN_SESSION_LIST;
 193         break;
 194
 195     case  TPMPROP_TPM_MIN_COUNTERS:
 196         *result = TPM_MIN_COUNTERS;
 197         break;
 198
 199     case  TPMPROP_TPM_NUM_FAMILY_TABLE_ENTRY_MIN:
 200         *result = TPM_NUM_FAMILY_TABLE_ENTRY_MIN;
 201         break;
 202
 203     case  TPMPROP_TPM_NUM_DELEGATE_TABLE_ENTRY_MIN:
 204         *result = TPM_NUM_DELEGATE_TABLE_ENTRY_MIN;
 205         break;
 206
 207     case  TPMPROP_TPM_SPACE_SAFETY_MARGIN:
 208         *result = TPM_SPACE_SAFETY_MARGIN;
 209         break;
 210
 211     case  TPMPROP_TPM_MAX_NV_SPACE:
 212         /* fill up 20 kb.; this provides some safety margin (currently
 213            >4Kb) for possible future expansion of this blob */
 214         *result = ROUNDUP(TPM_MAX_NV_SPACE, 20 * 1024);
 215         break;
 216
 217     case  TPMPROP_TPM_MAX_SAVESTATE_SPACE:
 218         *result = TPM_MAX_SAVESTATE_SPACE;
 219         break;
 220
 221     case  TPMPROP_TPM_MAX_VOLATILESTATE_SPACE:
 222         *result = TPM_MAX_VOLATILESTATE_SPACE;
 223         break;
 224
 225     default:
 226         return TPM_FAIL;
 227     }
 228
 229     return TPM_SUCCESS;
 230 }
 231
 232 static struct libtpms_callbacks libtpms_cbs;
 233
 234 struct libtpms_callbacks *TPMLIB_GetCallbacks(void)
 235 {
 236     return &libtpms_cbs;
 237 }
 238
 239
 240 TPM_RESULT TPMLIB_RegisterCallbacks(struct libtpms_callbacks *callbacks)
 241 {
 242     int max_size = sizeof(struct libtpms_callbacks);
 243
 244     /* restrict the size of the structure to what we know currently
 245        future versions may know more callbacks */
 246     if (callbacks->sizeOfStruct < max_size)
 247         max_size = callbacks->sizeOfStruct;
 248
 249     /* clear the internal callback structure and copy the user provided
 250        callbacks into it */
 251     memset(&libtpms_cbs, 0x0, sizeof(libtpms_cbs));
 252     memcpy(&libtpms_cbs, callbacks, max_size);
 253
 254     return TPM_SUCCESS;
 255 }
 256
 257
 258 static int is_base64ltr(char c)
 259 {
 260     return ((c >= 'A' && c <= 'Z') ||
 261             (c >= 'a' && c <= 'z') ||
 262             (c >= '0' && c <= '9') ||
 263              c == '+' ||
 264              c == '/' ||
 265              c == '=');
 266 }
 267
 268 #ifdef USE_OPENSSL_CRYPTO_LIBRARY
 269 static unsigned char *TPMLIB_OpenSSL_Base64Decode(char *input,
 270                                                   unsigned int outputlen)
 271 {
 272     BIO *b64, *bmem;
 273     unsigned char *res = NULL;
 274     int n;
 275     TPM_RESULT rc;
 276
 277     b64 = BIO_new(BIO_f_base64());
 278     if (!b64) {
 279         return NULL;
 280     }
 281
 282     bmem = BIO_new_mem_buf(input, strlen(input));
 283     if (!bmem) {
 284         BIO_free(b64);
 285         goto cleanup;
 286     }
 287     bmem = BIO_push(b64, bmem);
 288     BIO_set_flags(bmem, BIO_FLAGS_BASE64_NO_NL);
 289
 290     rc = TPM_Malloc(&res, outputlen);
 291     if (rc != TPM_SUCCESS) {
 292         goto cleanup;
 293     }
 294
 295     n = BIO_read(bmem, res, outputlen);
 296     if (n <= 0) {
 297         TPM_Free(res);
 298         res = NULL;
 299         goto cleanup;
 300     }
 301
 302 cleanup:
 303     BIO_free_all(bmem);
 304
 305     return res;
 306 }
 307 #endif
 308
 309 /*
 310  * Base64 decode the string starting at 'start' and the last
 311  * valid character may be a 'end'. The length of the decoded string
 312  * is returned in *length.
 313  */
 314 static unsigned char *TPMLIB_Base64Decode(const char *start, const char *end,
 315                                           size_t *length)
 316 {
 317     unsigned char *ret = NULL;
 318     char *input = NULL, *d;
 319     const char *s;
 320     char c;
 321     unsigned int numbase64chars = 0;
 322
 323     if (end < start)
 324         return NULL;
 325
 326     while (end > start && !is_base64ltr(*end))
 327         end--;
 328
 329     end++;
 330
 331     if (TPM_Malloc((unsigned char **)&input, end - start + 1) != TPM_SUCCESS)
 332         return NULL;
 333
 334     /* copy from source string skipping '\n' and '\r' and using
 335        '=' to calculate the exact length */
 336     d = input;
 337     s = start;
 338
 339     while (s < end) {
 340         c = *s;
 341         if (is_base64ltr(c)) {
 342             *d = c;
 343             d++;
 344             if (c != '=') {
 345                 numbase64chars++;
 346             }
 347         } else if (c == 0) {
 348             break;
 349         }
 350         s++;
 351     }
 352     *d = 0;
 353
 354     *length = (numbase64chars / 4) * 3;
 355     switch (numbase64chars % 4) {
 356     case 2:
 357     case 3:
 358         *length += (numbase64chars % 4) - 1;
 359         break;
 360     case 0:
 361         break;
 362     case 1:
 363         fprintf(stderr,"malformed base64\n");
 364         goto err_exit;
 365     break;
 366     }
 367
 368 #ifdef USE_FREEBL_CRYPTO_LIBRARY
 369     ret = (unsigned char *)PL_Base64Decode(input, 0, NULL);
 370 #endif
 371
 372 #ifdef USE_OPENSSL_CRYPTO_LIBRARY
 373     ret = TPMLIB_OpenSSL_Base64Decode(input, *length);
 374 #endif
 375
 376 err_exit:
 377     free(input);
 378
 379     return ret;
 380 }
 381
 382
 383 static unsigned char *TPMLIB_GetPlaintext(const char *stream,
 384                                           const char *starttag,
 385                                           const char *endtag,
 386                                           size_t *length)
 387 {
 388     char *start, *end;
 389     unsigned char *plaintext = NULL;
 390
 391     start = strstr(stream, starttag);
 392     if (start) {
 393         start += strlen(starttag);
 394         while (isspace((int)*start))
 395             start++;
 396         end = strstr(start, endtag);
 397         if (end) {
 398             plaintext = TPMLIB_Base64Decode(start, --end, length);
 399         }
 400     }
 401     return plaintext;
 402 }
 403
 404
 405 TPM_RESULT TPMLIB_DecodeBlob(const char *buffer, enum TPMLIB_BlobType type,
 406                              unsigned char **result, size_t *result_len)
 407 {
 408     TPM_RESULT res = TPM_SUCCESS;
 409
 410     *result = TPMLIB_GetPlaintext(buffer,
 411                                   tags_and_indices[type].starttag,
 412                                   tags_and_indices[type].endtag,
 413                                   result_len);
 414
 415     if (*result == NULL) {
 416         res = TPM_FAIL;
 417     }
 418
 419     return res;
 420 }
 421