src/crypto_impl.c

   1 /*
   2 ** SQLCipher
   3 ** http://sqlcipher.net
   4 **
   5 ** Copyright (c) 2008 - 2013, ZETETIC LLC
   6 ** All rights reserved.
   7 **
   8 ** Redistribution and use in source and binary forms, with or without
   9 ** modification, are permitted provided that the following conditions are met:
  10 **     * Redistributions of source code must retain the above copyright
  11 **       notice, this list of conditions and the following disclaimer.
  12 **     * Redistributions in binary form must reproduce the above copyright
  13 **       notice, this list of conditions and the following disclaimer in the
  14 **       documentation and/or other materials provided with the distribution.
  15 **     * Neither the name of the ZETETIC LLC nor the
  16 **       names of its contributors may be used to endorse or promote products
  17 **       derived from this software without specific prior written permission.
  18 **
  19 ** THIS SOFTWARE IS PROVIDED BY ZETETIC LLC ''AS IS'' AND ANY
  20 ** EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21 ** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22 ** DISCLAIMED. IN NO EVENT SHALL ZETETIC LLC BE LIABLE FOR ANY
  23 ** DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24 ** (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25 ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  26 ** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28 ** SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29 **
  30 */
  31 /* BEGIN SQLCIPHER */
  32 #ifdef SQLITE_HAS_CODEC
  33
  34 #include "sqlcipher.h"
  35 #include "crypto.h"
  36
  37 #ifdef SQLCIPHER_TEST
  38 static volatile unsigned int cipher_test_flags = 0;
  39 unsigned int sqlcipher_get_test_flags() {
  40   return cipher_test_flags;
  41 }
  42 void sqlcipher_set_test_flags(unsigned int flags) {
  43   cipher_test_flags = flags;
  44 }
  45
  46 static volatile int cipher_test_rand = 0;
  47 int sqlcipher_get_test_rand() {
  48   return cipher_test_rand;
  49 }
  50 void sqlcipher_set_test_rand(int rand) {
  51   cipher_test_rand = rand;
  52 }
  53 int sqlcipher_get_test_fail() {
  54   int x;
  55
  56   /* if cipher_test_rand is not set to a non-zero value always fail (return true) */
  57   if (cipher_test_rand == 0) return 1;
  58
  59   sqlite3_randomness(sizeof(x), &x);
  60   return ((x % cipher_test_rand) == 0);
  61 }
  62 #endif
  63
  64 /* Generate code to return a string value */
  65
  66 static volatile unsigned int default_flags = DEFAULT_CIPHER_FLAGS;
  67 static volatile unsigned char hmac_salt_mask = HMAC_SALT_MASK;
  68 static volatile int default_kdf_iter = PBKDF2_ITER;
  69 static volatile int default_page_size = 4096;
  70 static volatile int default_plaintext_header_sz = 0;
  71 static volatile int default_hmac_algorithm = SQLCIPHER_HMAC_SHA512;
  72 static volatile int default_kdf_algorithm = SQLCIPHER_PBKDF2_HMAC_SHA512;
  73 static volatile int sqlcipher_mem_security_on = 0;
  74 static volatile int sqlcipher_mem_executed = 0;
  75 static volatile int sqlcipher_mem_initialized = 0;
  76 static volatile unsigned int sqlcipher_activate_count = 0;
  77 static volatile sqlite3_mem_methods default_mem_methods;
  78 static sqlcipher_provider *default_provider = NULL;
  79
  80 static sqlite3_mutex* sqlcipher_static_mutex[SQLCIPHER_MUTEX_COUNT];
  81 static FILE* sqlcipher_log_file = NULL;
  82 static volatile int sqlcipher_log_logcat = 0;
  83 static volatile unsigned int sqlcipher_log_level = SQLCIPHER_LOG_NONE;
  84
  85 sqlite3_mutex* sqlcipher_mutex(int mutex) {
  86   if(mutex < 0 || mutex >= SQLCIPHER_MUTEX_COUNT) return NULL;
  87   return sqlcipher_static_mutex[mutex];
  88 }
  89
  90 static int sqlcipher_mem_init(void *pAppData) {
  91   return default_mem_methods.xInit(pAppData);
  92 }
  93 static void sqlcipher_mem_shutdown(void *pAppData) {
  94   default_mem_methods.xShutdown(pAppData);
  95 }
  96 static void *sqlcipher_mem_malloc(int n) {
  97   void *ptr = default_mem_methods.xMalloc(n);
  98   if(!sqlcipher_mem_executed) sqlcipher_mem_executed = 1;
  99   if(sqlcipher_mem_security_on) {
 100     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_malloc: calling sqlcipher_mlock(%p,%d)", ptr, n);
 101     sqlcipher_mlock(ptr, n);
 102   }
 103   return ptr;
 104 }
 105 static int sqlcipher_mem_size(void *p) {
 106   return default_mem_methods.xSize(p);
 107 }
 108 static void sqlcipher_mem_free(void *p) {
 109   int sz;
 110   if(!sqlcipher_mem_executed) sqlcipher_mem_executed = 1;
 111   if(sqlcipher_mem_security_on) {
 112     sz = sqlcipher_mem_size(p);
 113     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_free: calling sqlcipher_memset(%p,0,%d) and sqlcipher_munlock(%p, %d)", p, sz, p, sz);
 114     sqlcipher_memset(p, 0, sz);
 115     sqlcipher_munlock(p, sz);
 116   }
 117   default_mem_methods.xFree(p);
 118 }
 119 static void *sqlcipher_mem_realloc(void *p, int n) {
 120   void *new = NULL;
 121   int orig_sz = 0;
 122   if(sqlcipher_mem_security_on) {
 123     orig_sz = sqlcipher_mem_size(p);
 124     if (n==0) {
 125       sqlcipher_mem_free(p);
 126       return NULL;
 127     } else if (!p) {
 128       return sqlcipher_mem_malloc(n);
 129     } else if(n <= orig_sz) {
 130       return p;
 131     } else {
 132       new = sqlcipher_mem_malloc(n);
 133       if(new) {
 134         memcpy(new, p, orig_sz);
 135         sqlcipher_mem_free(p);
 136       }
 137       return new;
 138     }
 139   } else {
 140     return default_mem_methods.xRealloc(p, n);
 141   }
 142 }
 143
 144 static int sqlcipher_mem_roundup(int n) {
 145   return default_mem_methods.xRoundup(n);
 146 }
 147
 148 static sqlite3_mem_methods sqlcipher_mem_methods = {
 149   sqlcipher_mem_malloc,
 150   sqlcipher_mem_free,
 151   sqlcipher_mem_realloc,
 152   sqlcipher_mem_size,
 153   sqlcipher_mem_roundup,
 154   sqlcipher_mem_init,
 155   sqlcipher_mem_shutdown,
 156   0
 157 };
 158
 159 void sqlcipher_init_memmethods() {
 160   if(sqlcipher_mem_initialized) return;
 161   if(sqlite3_config(SQLITE_CONFIG_GETMALLOC, &default_mem_methods) != SQLITE_OK ||
 162      sqlite3_config(SQLITE_CONFIG_MALLOC, &sqlcipher_mem_methods)  != SQLITE_OK) {
 163      sqlcipher_mem_security_on = sqlcipher_mem_executed = sqlcipher_mem_initialized = 0;
 164   } else {
 165     sqlcipher_mem_initialized = 1;
 166   }
 167 }
 168
 169 int sqlcipher_register_provider(sqlcipher_provider *p) {
 170   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_register_provider: entering SQLCIPHER_MUTEX_PROVIDER");
 171   sqlite3_mutex_enter(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 172   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_register_provider: entered SQLCIPHER_MUTEX_PROVIDER");
 173
 174   if(default_provider != NULL && default_provider != p) {
 175     /* only free the current registerd provider if it has been initialized
 176        and it isn't a pointer to the same provider passed to the function
 177        (i.e. protect against a caller calling register twice for the same provider) */
 178     sqlcipher_free(default_provider, sizeof(sqlcipher_provider));
 179   }
 180   default_provider = p;
 181   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_register_provider: leaving SQLCIPHER_MUTEX_PROVIDER");
 182   sqlite3_mutex_leave(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 183   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_register_provider: left SQLCIPHER_MUTEX_PROVIDER");
 184
 185   return SQLITE_OK;
 186 }
 187
 188 /* return a pointer to the currently registered provider. This will
 189    allow an application to fetch the current registered provider and
 190    make minor changes to it */
 191 sqlcipher_provider* sqlcipher_get_provider() {
 192   return default_provider;
 193 }
 194
 195 void sqlcipher_activate() {
 196   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_activate: entering static master mutex");
 197   sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
 198   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_activate: entered static master mutex");
 199
 200   /* allocate new mutexes */
 201   if(sqlcipher_activate_count == 0) {
 202     int i;
 203     for(i = 0; i < SQLCIPHER_MUTEX_COUNT; i++) {
 204       sqlcipher_static_mutex[i] = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
 205     }
 206   }
 207
 208   /* check to see if there is a provider registered at this point
 209      if there no provider registered at this point, register the
 210      default provider */
 211   if(sqlcipher_get_provider() == NULL) {
 212     sqlcipher_provider *p = sqlcipher_malloc(sizeof(sqlcipher_provider));
 213 #if defined (SQLCIPHER_CRYPTO_CC)
 214     extern int sqlcipher_cc_setup(sqlcipher_provider *p);
 215     sqlcipher_cc_setup(p);
 216 #elif defined (SQLCIPHER_CRYPTO_LIBTOMCRYPT)
 217     extern int sqlcipher_ltc_setup(sqlcipher_provider *p);
 218     sqlcipher_ltc_setup(p);
 219 #elif defined (SQLCIPHER_CRYPTO_NSS)
 220     extern int sqlcipher_nss_setup(sqlcipher_provider *p);
 221     sqlcipher_nss_setup(p);
 222 #elif defined (SQLCIPHER_CRYPTO_OPENSSL)
 223     extern int sqlcipher_openssl_setup(sqlcipher_provider *p);
 224     sqlcipher_openssl_setup(p);
 225 #else
 226 #error "NO DEFAULT SQLCIPHER CRYPTO PROVIDER DEFINED"
 227 #endif
 228     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_activate: calling sqlcipher_register_provider(%p)", p);
 229 #ifdef SQLCIPHER_EXT
 230     sqlcipher_ext_provider_setup(p);
 231 #endif
 232     sqlcipher_register_provider(p);
 233     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_activate: called sqlcipher_register_provider(%p)",p);
 234   }
 235
 236   sqlcipher_activate_count++; /* increment activation count */
 237
 238   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_activate: leaving static master mutex");
 239   sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
 240   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_activate: left static master mutex");
 241 }
 242
 243 void sqlcipher_deactivate() {
 244   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: entering static master mutex");
 245   sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
 246   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: entered static master mutex");
 247
 248   sqlcipher_activate_count--;
 249   /* if no connections are using sqlcipher, cleanup globals */
 250   if(sqlcipher_activate_count < 1) {
 251     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: entering SQLCIPHER_MUTEX_PROVIDER");
 252     sqlite3_mutex_enter(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 253     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: entered SQLCIPHER_MUTEX_PROVIDER");
 254
 255     if(default_provider != NULL) {
 256       sqlcipher_free(default_provider, sizeof(sqlcipher_provider));
 257       default_provider = NULL;
 258     }
 259
 260     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: leaving SQLCIPHER_MUTEX_PROVIDER");
 261     sqlite3_mutex_leave(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 262     sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: left SQLCIPHER_MUTEX_PROVIDER");
 263
 264 #ifdef SQLCIPHER_EXT
 265     sqlcipher_ext_provider_destroy();
 266 #endif
 267
 268     /* last connection closed, free mutexes */
 269     if(sqlcipher_activate_count == 0) {
 270       int i;
 271       for(i = 0; i < SQLCIPHER_MUTEX_COUNT; i++) {
 272         sqlite3_mutex_free(sqlcipher_static_mutex[i]);
 273       }
 274     }
 275     sqlcipher_activate_count = 0; /* reset activation count */
 276   }
 277
 278   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: leaving static master mutex");
 279   sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER));
 280   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_deactivate: left static master mutex");
 281 }
 282
 283 /* constant time memset using volitile to avoid having the memset
 284    optimized out by the compiler.
 285    Note: As suggested by Joachim Schipper (joachim.schipper@fox-it.com)
 286 */
 287 void* sqlcipher_memset(void *v, unsigned char value, sqlite_uint64 len) {
 288   volatile sqlite_uint64 i = 0;
 289   volatile unsigned char *a = v;
 290
 291   if (v == NULL) return v;
 292
 293   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_memset: setting %p[0-%llu]=%d)", a, len, value);
 294   for(i = 0; i < len; i++) {
 295     a[i] = value;
 296   }
 297
 298   return v;
 299 }
 300
 301 /* constant time memory check tests every position of a memory segement
 302    matches a single value (i.e. the memory is all zeros)
 303    returns 0 if match, 1 of no match */
 304 int sqlcipher_ismemset(const void *v, unsigned char value, sqlite_uint64 len) {
 305   const volatile unsigned char *a = v;
 306   volatile sqlite_uint64 i = 0, result = 0;
 307
 308   for(i = 0; i < len; i++) {
 309     result |= a[i] ^ value;
 310   }
 311
 312   return (result != 0);
 313 }
 314
 315 /* constant time memory comparison routine.
 316    returns 0 if match, 1 if no match */
 317 int sqlcipher_memcmp(const void *v0, const void *v1, int len) {
 318   const volatile unsigned char *a0 = v0, *a1 = v1;
 319   volatile int i = 0, result = 0;
 320
 321   for(i = 0; i < len; i++) {
 322     result |= a0[i] ^ a1[i];
 323   }
 324
 325   return (result != 0);
 326 }
 327
 328 void sqlcipher_mlock(void *ptr, sqlite_uint64 sz) {
 329 #ifndef OMIT_MEMLOCK
 330 #if defined(__unix__) || defined(__APPLE__)
 331   int rc;
 332   unsigned long pagesize = sysconf(_SC_PAGESIZE);
 333   unsigned long offset = (unsigned long) ptr % pagesize;
 334
 335   if(ptr == NULL || sz == 0) return;
 336
 337   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_lock: calling mlock(%p,%lu); _SC_PAGESIZE=%lu", ptr - offset, sz + offset, pagesize);
 338   rc = mlock(ptr - offset, sz + offset);
 339   if(rc!=0) {
 340     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_mem_lock: mlock(%p,%lu) returned %d errno=%d", ptr - offset, sz + offset, rc, errno);
 341   }
 342 #elif defined(_WIN32)
 343 #if !(defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP || WINAPI_FAMILY == WINAPI_FAMILY_APP))
 344   int rc;
 345   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_lock: calling VirtualLock(%p,%d)", ptr, sz);
 346   rc = VirtualLock(ptr, sz);
 347   if(rc==0) {
 348     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_mem_lock: VirtualLock(%p,%d) returned %d LastError=%d", ptr, sz, rc, GetLastError());
 349   }
 350 #endif
 351 #endif
 352 #endif
 353 }
 354
 355 void sqlcipher_munlock(void *ptr, sqlite_uint64 sz) {
 356 #ifndef OMIT_MEMLOCK
 357 #if defined(__unix__) || defined(__APPLE__)
 358   int rc;
 359   unsigned long pagesize = sysconf(_SC_PAGESIZE);
 360   unsigned long offset = (unsigned long) ptr % pagesize;
 361
 362   if(ptr == NULL || sz == 0) return;
 363
 364   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_unlock: calling munlock(%p,%lu)", ptr - offset, sz + offset);
 365   rc = munlock(ptr - offset, sz + offset);
 366   if(rc!=0) {
 367     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_mem_unlock: munlock(%p,%lu) returned %d errno=%d", ptr - offset, sz + offset, rc, errno);
 368   }
 369 #elif defined(_WIN32)
 370 #if !(defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP || WINAPI_FAMILY == WINAPI_FAMILY_APP))
 371   int rc;
 372   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_mem_lock: calling VirtualUnlock(%p,%d)", ptr, sz);
 373   rc = VirtualUnlock(ptr, sz);
 374   if(!rc) {
 375     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_mem_unlock: VirtualUnlock(%p,%d) returned %d LastError=%d", ptr, sz, rc, GetLastError());
 376   }
 377 #endif
 378 #endif
 379 #endif
 380 }
 381
 382 /**
 383   * Free and wipe memory. Uses SQLites internal sqlite3_free so that memory
 384   * can be countend and memory leak detection works in the test suite.
 385   * If ptr is not null memory will be freed.
 386   * If sz is greater than zero, the memory will be overwritten with zero before it is freed
 387   * If sz is > 0, and not compiled with OMIT_MEMLOCK, system will attempt to unlock the
 388   * memory segment so it can be paged
 389   */
 390 void sqlcipher_free(void *ptr, sqlite_uint64 sz) {
 391   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_free: calling sqlcipher_memset(%p,0,%llu)", ptr, sz);
 392   sqlcipher_memset(ptr, 0, sz);
 393   sqlcipher_munlock(ptr, sz);
 394   sqlite3_free(ptr);
 395 }
 396
 397 /**
 398   * allocate memory. Uses sqlite's internall malloc wrapper so memory can be
 399   * reference counted and leak detection works. Unless compiled with OMIT_MEMLOCK
 400   * attempts to lock the memory pages so sensitive information won't be swapped
 401   */
 402 void* sqlcipher_malloc(sqlite_uint64 sz) {
 403   void *ptr;
 404   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_malloc: calling sqlite3Malloc(%llu)", sz);
 405   ptr = sqlite3Malloc(sz);
 406   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_malloc: calling sqlcipher_memset(%p,0,%llu)", ptr, sz);
 407   sqlcipher_memset(ptr, 0, sz);
 408   sqlcipher_mlock(ptr, sz);
 409   return ptr;
 410 }
 411
 412 char* sqlcipher_version() {
 413 #ifdef CIPHER_VERSION_QUALIFIER
 414     char *version = sqlite3_mprintf("%s %s %s", CIPHER_XSTR(CIPHER_VERSION_NUMBER), CIPHER_XSTR(CIPHER_VERSION_QUALIFIER), CIPHER_XSTR(CIPHER_VERSION_BUILD));
 415 #else
 416     char *version = sqlite3_mprintf("%s %s", CIPHER_XSTR(CIPHER_VERSION_NUMBER), CIPHER_XSTR(CIPHER_VERSION_BUILD));
 417 #endif
 418     return version;
 419 }
 420
 421 /**
 422   * Initialize new cipher_ctx struct. This function will allocate memory
 423   * for the cipher context and for the key
 424   *
 425   * returns SQLITE_OK if initialization was successful
 426   * returns SQLITE_NOMEM if an error occured allocating memory
 427   */
 428 static int sqlcipher_cipher_ctx_init(codec_ctx *ctx, cipher_ctx **iCtx) {
 429   cipher_ctx *c_ctx;
 430   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_init: allocating context");
 431   *iCtx = (cipher_ctx *) sqlcipher_malloc(sizeof(cipher_ctx));
 432   c_ctx = *iCtx;
 433   if(c_ctx == NULL) return SQLITE_NOMEM;
 434
 435   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_init: allocating key");
 436   c_ctx->key = (unsigned char *) sqlcipher_malloc(ctx->key_sz);
 437
 438   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_init: allocating hmac_key");
 439   c_ctx->hmac_key = (unsigned char *) sqlcipher_malloc(ctx->key_sz);
 440
 441   if(c_ctx->key == NULL) return SQLITE_NOMEM;
 442   if(c_ctx->hmac_key == NULL) return SQLITE_NOMEM;
 443
 444   return SQLITE_OK;
 445 }
 446
 447 /**
 448   * Free and wipe memory associated with a cipher_ctx
 449   */
 450 static void sqlcipher_cipher_ctx_free(codec_ctx* ctx, cipher_ctx **iCtx) {
 451   cipher_ctx *c_ctx = *iCtx;
 452   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "cipher_ctx_free: iCtx=%p", iCtx);
 453   sqlcipher_free(c_ctx->key, ctx->key_sz);
 454   sqlcipher_free(c_ctx->hmac_key, ctx->key_sz);
 455   sqlcipher_free(c_ctx->pass, c_ctx->pass_sz);
 456   sqlcipher_free(c_ctx->keyspec, ctx->keyspec_sz);
 457   sqlcipher_free(c_ctx, sizeof(cipher_ctx));
 458 }
 459
 460 static int sqlcipher_codec_ctx_reserve_setup(codec_ctx *ctx) {
 461   int base_reserve = ctx->iv_sz; /* base reserve size will be IV only */
 462   int reserve = base_reserve;
 463
 464   ctx->hmac_sz = ctx->provider->get_hmac_sz(ctx->provider_ctx, ctx->hmac_algorithm);
 465
 466   if(sqlcipher_codec_ctx_get_use_hmac(ctx))
 467     reserve += ctx->hmac_sz; /* if reserve will include hmac, update that size */
 468
 469   /* calculate the amount of reserve needed in even increments of the cipher block size */
 470   if(ctx->block_sz > 0) {
 471     reserve = ((reserve % ctx->block_sz) == 0) ? reserve :
 472                ((reserve / ctx->block_sz) + 1) * ctx->block_sz;
 473   }
 474
 475   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_reserve_setup: base_reserve=%d block_sz=%d md_size=%d reserve=%d",
 476                 base_reserve, ctx->block_sz, ctx->hmac_sz, reserve);
 477
 478   ctx->reserve_sz = reserve;
 479
 480   return SQLITE_OK;
 481 }
 482
 483 /**
 484   * Compare one cipher_ctx to another.
 485   *
 486   * returns 0 if all the parameters (except the derived key data) are the same
 487   * returns 1 otherwise
 488   */
 489 static int sqlcipher_cipher_ctx_cmp(cipher_ctx *c1, cipher_ctx *c2) {
 490   int are_equal = (
 491     c1->pass_sz == c2->pass_sz
 492     && (
 493       c1->pass == c2->pass
 494       || !sqlcipher_memcmp((const unsigned char*)c1->pass,
 495                            (const unsigned char*)c2->pass,
 496                            c1->pass_sz)
 497     ));
 498
 499   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_cmp: c1=%p c2=%p sqlcipher_memcmp(c1->pass, c2_pass)=%d are_equal=%d",
 500     c1, c2,
 501     (c1->pass == NULL || c2->pass == NULL) ?
 502       -1 :
 503       sqlcipher_memcmp(
 504         (const unsigned char*)c1->pass,
 505         (const unsigned char*)c2->pass,
 506         c1->pass_sz
 507       ),
 508     are_equal
 509   );
 510
 511   return !are_equal; /* return 0 if they are the same, 1 otherwise */
 512 }
 513
 514 /**
 515   * Copy one cipher_ctx to another. For instance, assuming that read_ctx is a
 516   * fully initialized context, you could copy it to write_ctx and all yet data
 517   * and pass information across
 518   *
 519   * returns SQLITE_OK if initialization was successful
 520   * returns SQLITE_NOMEM if an error occured allocating memory
 521   */
 522 static int sqlcipher_cipher_ctx_copy(codec_ctx *ctx, cipher_ctx *target, cipher_ctx *source) {
 523   void *key = target->key;
 524   void *hmac_key = target->hmac_key;
 525
 526   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_copy: target=%p, source=%p", target, source);
 527   sqlcipher_free(target->pass, target->pass_sz);
 528   sqlcipher_free(target->keyspec, ctx->keyspec_sz);
 529   memcpy(target, source, sizeof(cipher_ctx));
 530
 531   target->key = key; /* restore pointer to previously allocated key data */
 532   memcpy(target->key, source->key, ctx->key_sz);
 533
 534   target->hmac_key = hmac_key; /* restore pointer to previously allocated hmac key data */
 535   memcpy(target->hmac_key, source->hmac_key, ctx->key_sz);
 536
 537   if(source->pass && source->pass_sz) {
 538     target->pass = sqlcipher_malloc(source->pass_sz);
 539     if(target->pass == NULL) return SQLITE_NOMEM;
 540     memcpy(target->pass, source->pass, source->pass_sz);
 541   }
 542   if(source->keyspec) {
 543     target->keyspec = sqlcipher_malloc(ctx->keyspec_sz);
 544     if(target->keyspec == NULL) return SQLITE_NOMEM;
 545     memcpy(target->keyspec, source->keyspec, ctx->keyspec_sz);
 546   }
 547   return SQLITE_OK;
 548 }
 549
 550 /**
 551   * Set the keyspec for the cipher_ctx
 552   *
 553   * returns SQLITE_OK if assignment was successfull
 554   * returns SQLITE_NOMEM if an error occured allocating memory
 555   */
 556 static int sqlcipher_cipher_ctx_set_keyspec(codec_ctx *ctx, cipher_ctx *c_ctx, const unsigned char *key) {
 557   /* free, zero existing pointers and size */
 558   sqlcipher_free(c_ctx->keyspec, ctx->keyspec_sz);
 559   c_ctx->keyspec = NULL;
 560
 561   c_ctx->keyspec = sqlcipher_malloc(ctx->keyspec_sz);
 562   if(c_ctx->keyspec == NULL) return SQLITE_NOMEM;
 563
 564   c_ctx->keyspec[0] = 'x';
 565   c_ctx->keyspec[1] = '\'';
 566   cipher_bin2hex(key, ctx->key_sz, c_ctx->keyspec + 2);
 567   cipher_bin2hex(ctx->kdf_salt, ctx->kdf_salt_sz, c_ctx->keyspec + (ctx->key_sz * 2) + 2);
 568   c_ctx->keyspec[ctx->keyspec_sz - 1] = '\'';
 569   return SQLITE_OK;
 570 }
 571
 572 int sqlcipher_codec_get_store_pass(codec_ctx *ctx) {
 573   return ctx->store_pass;
 574 }
 575
 576 void sqlcipher_codec_set_store_pass(codec_ctx *ctx, int value) {
 577   ctx->store_pass = value;
 578 }
 579
 580 void sqlcipher_codec_get_pass(codec_ctx *ctx, void **zKey, int *nKey) {
 581   *zKey = ctx->read_ctx->pass;
 582   *nKey = ctx->read_ctx->pass_sz;
 583 }
 584
 585 static void sqlcipher_set_derive_key(codec_ctx *ctx, int derive) {
 586   if(ctx->read_ctx != NULL) ctx->read_ctx->derive_key = derive;
 587   if(ctx->write_ctx != NULL) ctx->write_ctx->derive_key = derive;
 588 }
 589
 590 /**
 591   * Set the passphrase for the cipher_ctx
 592   *
 593   * returns SQLITE_OK if assignment was successfull
 594   * returns SQLITE_NOMEM if an error occured allocating memory
 595   */
 596 static int sqlcipher_cipher_ctx_set_pass(cipher_ctx *ctx, const void *zKey, int nKey) {
 597   /* free, zero existing pointers and size */
 598   sqlcipher_free(ctx->pass, ctx->pass_sz);
 599   ctx->pass = NULL;
 600   ctx->pass_sz = 0;
 601
 602   if(zKey && nKey) { /* if new password is provided, copy it */
 603     ctx->pass_sz = nKey;
 604     ctx->pass = sqlcipher_malloc(nKey);
 605     if(ctx->pass == NULL) return SQLITE_NOMEM;
 606     memcpy(ctx->pass, zKey, nKey);
 607   }
 608   return SQLITE_OK;
 609 }
 610
 611 int sqlcipher_codec_ctx_set_pass(codec_ctx *ctx, const void *zKey, int nKey, int for_ctx) {
 612   cipher_ctx *c_ctx = for_ctx ? ctx->write_ctx : ctx->read_ctx;
 613   int rc;
 614
 615   if((rc = sqlcipher_cipher_ctx_set_pass(c_ctx, zKey, nKey)) != SQLITE_OK) {
 616     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_set_pass: error %d from sqlcipher_cipher_ctx_set_pass", rc);
 617     return rc;
 618   }
 619
 620   c_ctx->derive_key = 1;
 621
 622   if(for_ctx == 2) {
 623     if((rc = sqlcipher_cipher_ctx_copy(ctx, for_ctx ? ctx->read_ctx : ctx->write_ctx, c_ctx)) != SQLITE_OK) {
 624       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_set_pass: error %d from sqlcipher_cipher_ctx_copy", rc);
 625       return rc;
 626     }
 627   }
 628
 629   return SQLITE_OK;
 630 }
 631
 632 const char* sqlcipher_codec_ctx_get_cipher(codec_ctx *ctx) {
 633   return ctx->provider->get_cipher(ctx->provider_ctx);
 634 }
 635
 636 /* set the global default KDF iteration */
 637 void sqlcipher_set_default_kdf_iter(int iter) {
 638   default_kdf_iter = iter;
 639 }
 640
 641 int sqlcipher_get_default_kdf_iter() {
 642   return default_kdf_iter;
 643 }
 644
 645 int sqlcipher_codec_ctx_set_kdf_iter(codec_ctx *ctx, int kdf_iter) {
 646   ctx->kdf_iter = kdf_iter;
 647   sqlcipher_set_derive_key(ctx, 1);
 648   return SQLITE_OK;
 649 }
 650
 651 int sqlcipher_codec_ctx_get_kdf_iter(codec_ctx *ctx) {
 652   return ctx->kdf_iter;
 653 }
 654
 655 int sqlcipher_codec_ctx_set_fast_kdf_iter(codec_ctx *ctx, int fast_kdf_iter) {
 656   ctx->fast_kdf_iter = fast_kdf_iter;
 657   sqlcipher_set_derive_key(ctx, 1);
 658   return SQLITE_OK;
 659 }
 660
 661 int sqlcipher_codec_ctx_get_fast_kdf_iter(codec_ctx *ctx) {
 662   return ctx->fast_kdf_iter;
 663 }
 664
 665 /* set the global default flag for HMAC */
 666 void sqlcipher_set_default_use_hmac(int use) {
 667   if(use) SQLCIPHER_FLAG_SET(default_flags, CIPHER_FLAG_HMAC);
 668   else SQLCIPHER_FLAG_UNSET(default_flags,CIPHER_FLAG_HMAC);
 669 }
 670
 671 int sqlcipher_get_default_use_hmac() {
 672   return SQLCIPHER_FLAG_GET(default_flags, CIPHER_FLAG_HMAC);
 673 }
 674
 675 void sqlcipher_set_hmac_salt_mask(unsigned char mask) {
 676   hmac_salt_mask = mask;
 677 }
 678
 679 unsigned char sqlcipher_get_hmac_salt_mask() {
 680   return hmac_salt_mask;
 681 }
 682
 683 /* set the codec flag for whether this individual database should be using hmac */
 684 int sqlcipher_codec_ctx_set_use_hmac(codec_ctx *ctx, int use) {
 685   if(use) {
 686     SQLCIPHER_FLAG_SET(ctx->flags, CIPHER_FLAG_HMAC);
 687   } else {
 688     SQLCIPHER_FLAG_UNSET(ctx->flags, CIPHER_FLAG_HMAC);
 689   }
 690
 691   return sqlcipher_codec_ctx_reserve_setup(ctx);
 692 }
 693
 694 int sqlcipher_codec_ctx_get_use_hmac(codec_ctx *ctx) {
 695   return SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HMAC);
 696 }
 697
 698 /* the length of plaintext header size must be:
 699  * 1. greater than or equal to zero
 700  * 2. a multiple of the cipher block size
 701  * 3. less than the usable size of the first database page
 702  */
 703 int sqlcipher_set_default_plaintext_header_size(int size) {
 704   default_plaintext_header_sz = size;
 705   return SQLITE_OK;
 706 }
 707
 708 int sqlcipher_codec_ctx_set_plaintext_header_size(codec_ctx *ctx, int size) {
 709   if(size >= 0 && ctx->block_sz > 0 && (size % ctx->block_sz) == 0 && size < (ctx->page_sz - ctx->reserve_sz)) {
 710     ctx->plaintext_header_sz = size;
 711     return SQLITE_OK;
 712   }
 713   ctx->plaintext_header_sz = -1;
 714   sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_set_plaintext_header_size: attempt to set invalid plantext_header_size %d", size);
 715   return SQLITE_ERROR;
 716 }
 717
 718 int sqlcipher_get_default_plaintext_header_size() {
 719   return default_plaintext_header_sz;
 720 }
 721
 722 int sqlcipher_codec_ctx_get_plaintext_header_size(codec_ctx *ctx) {
 723   return ctx->plaintext_header_sz;
 724 }
 725
 726 /* manipulate HMAC algorithm */
 727 int sqlcipher_set_default_hmac_algorithm(int algorithm) {
 728   default_hmac_algorithm = algorithm;
 729   return SQLITE_OK;
 730 }
 731
 732 int sqlcipher_codec_ctx_set_hmac_algorithm(codec_ctx *ctx, int algorithm) {
 733   ctx->hmac_algorithm = algorithm;
 734   return sqlcipher_codec_ctx_reserve_setup(ctx);
 735 }
 736
 737 int sqlcipher_get_default_hmac_algorithm() {
 738   return default_hmac_algorithm;
 739 }
 740
 741 int sqlcipher_codec_ctx_get_hmac_algorithm(codec_ctx *ctx) {
 742   return ctx->hmac_algorithm;
 743 }
 744
 745 /* manipulate KDF algorithm */
 746 int sqlcipher_set_default_kdf_algorithm(int algorithm) {
 747   default_kdf_algorithm = algorithm;
 748   return SQLITE_OK;
 749 }
 750
 751 int sqlcipher_codec_ctx_set_kdf_algorithm(codec_ctx *ctx, int algorithm) {
 752   ctx->kdf_algorithm = algorithm;
 753   return SQLITE_OK;
 754 }
 755
 756 int sqlcipher_get_default_kdf_algorithm() {
 757   return default_kdf_algorithm;
 758 }
 759
 760 int sqlcipher_codec_ctx_get_kdf_algorithm(codec_ctx *ctx) {
 761   return ctx->kdf_algorithm;
 762 }
 763
 764 void sqlcipher_codec_ctx_set_error(codec_ctx *ctx, int error) {
 765   sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_set_error: ctx=%p, error=%d", ctx, error);
 766   sqlite3pager_error(ctx->pBt->pBt->pPager, error);
 767   ctx->pBt->pBt->db->errCode = error;
 768 }
 769
 770 int sqlcipher_codec_ctx_get_reservesize(codec_ctx *ctx) {
 771   return ctx->reserve_sz;
 772 }
 773
 774 void* sqlcipher_codec_ctx_get_data(codec_ctx *ctx) {
 775   return ctx->buffer;
 776 }
 777
 778 static int sqlcipher_codec_ctx_init_kdf_salt(codec_ctx *ctx) {
 779   sqlite3_file *fd = sqlite3PagerFile(ctx->pBt->pBt->pPager);
 780
 781   if(SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HAS_KDF_SALT)) {
 782     return SQLITE_OK; /* don't reload salt when not needed */
 783   }
 784
 785   /* read salt from header, if present, otherwise generate a new random salt */
 786   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init_kdf_salt: obtaining salt");
 787   if(fd == NULL || fd->pMethods == 0 || sqlite3OsRead(fd, ctx->kdf_salt, ctx->kdf_salt_sz, 0) != SQLITE_OK) {
 788     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init_kdf_salt: unable to read salt from file header, generating random");
 789     if(ctx->provider->random(ctx->provider_ctx, ctx->kdf_salt, ctx->kdf_salt_sz) != SQLITE_OK) {
 790       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init_kdf_salt: error retrieving random bytes from provider");
 791       return SQLITE_ERROR;
 792     }
 793   }
 794   SQLCIPHER_FLAG_SET(ctx->flags, CIPHER_FLAG_HAS_KDF_SALT);
 795   return SQLITE_OK;
 796 }
 797
 798 int sqlcipher_codec_ctx_set_kdf_salt(codec_ctx *ctx, unsigned char *salt, int size) {
 799   if(size >= ctx->kdf_salt_sz) {
 800     memcpy(ctx->kdf_salt, salt, ctx->kdf_salt_sz);
 801     SQLCIPHER_FLAG_SET(ctx->flags, CIPHER_FLAG_HAS_KDF_SALT);
 802     return SQLITE_OK;
 803   }
 804   sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_set_kdf_salt: attempt to set salt of incorrect size %d", size);
 805   return SQLITE_ERROR;
 806 }
 807
 808 int sqlcipher_codec_ctx_get_kdf_salt(codec_ctx *ctx, void** salt) {
 809   int rc = SQLITE_OK;
 810   if(!SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HAS_KDF_SALT)) {
 811     if((rc = sqlcipher_codec_ctx_init_kdf_salt(ctx)) != SQLITE_OK) {
 812       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_get_kdf_salt: error %d from sqlcipher_codec_ctx_init_kdf_salt", rc);
 813     }
 814   }
 815   *salt = ctx->kdf_salt;
 816
 817   return rc;
 818 }
 819
 820 void sqlcipher_codec_get_keyspec(codec_ctx *ctx, void **zKey, int *nKey) {
 821   *zKey = ctx->read_ctx->keyspec;
 822   *nKey = ctx->keyspec_sz;
 823 }
 824
 825 int sqlcipher_codec_ctx_set_pagesize(codec_ctx *ctx, int size) {
 826   if(!((size != 0) && ((size & (size - 1)) == 0)) || size < 512 || size > 65536) {
 827     sqlcipher_log(SQLCIPHER_LOG_ERROR, "cipher_page_size not a power of 2 and between 512 and 65536 inclusive");
 828     return SQLITE_ERROR;
 829   }
 830   /* attempt to free the existing page buffer */
 831   sqlcipher_free(ctx->buffer,ctx->page_sz);
 832   ctx->page_sz = size;
 833
 834   /* pre-allocate a page buffer of PageSize bytes. This will
 835      be used as a persistent buffer for encryption and decryption
 836      operations to avoid overhead of multiple memory allocations*/
 837   ctx->buffer = sqlcipher_malloc(size);
 838   if(ctx->buffer == NULL) return SQLITE_NOMEM;
 839
 840   return SQLITE_OK;
 841 }
 842
 843 int sqlcipher_codec_ctx_get_pagesize(codec_ctx *ctx) {
 844   return ctx->page_sz;
 845 }
 846
 847 void sqlcipher_set_default_pagesize(int page_size) {
 848   default_page_size = page_size;
 849 }
 850
 851 int sqlcipher_get_default_pagesize() {
 852   return default_page_size;
 853 }
 854
 855 void sqlcipher_set_mem_security(int on) {
 856   /* memory security can only be enabled, not disabled */
 857   if(on) {
 858     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_set_mem_security: on");
 859     sqlcipher_mem_security_on = on;
 860   }
 861 }
 862
 863 int sqlcipher_get_mem_security() {
 864   /* only report that memory security is enabled if pragma cipher_memory_security is ON and
 865      SQLCipher's allocator/deallocator was run at least one timecurrently used */
 866   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_get_mem_security: sqlcipher_mem_security_on = %d, sqlcipher_mem_executed = %d", sqlcipher_mem_security_on, sqlcipher_mem_executed);
 867   return sqlcipher_mem_security_on && sqlcipher_mem_executed;
 868 }
 869
 870
 871 int sqlcipher_codec_ctx_init(codec_ctx **iCtx, Db *pDb, Pager *pPager, const void *zKey, int nKey) {
 872   int rc;
 873   codec_ctx *ctx;
 874
 875   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init: allocating context");
 876
 877   *iCtx = sqlcipher_malloc(sizeof(codec_ctx));
 878   ctx = *iCtx;
 879
 880   if(ctx == NULL) return SQLITE_NOMEM;
 881
 882   ctx->pBt = pDb->pBt; /* assign pointer to database btree structure */
 883
 884   /* allocate space for salt data. Then read the first 16 bytes
 885        directly off the database file. This is the salt for the
 886        key derivation function. If we get a short read allocate
 887        a new random salt value */
 888   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init: allocating kdf_salt");
 889   ctx->kdf_salt_sz = FILE_HEADER_SZ;
 890   ctx->kdf_salt = sqlcipher_malloc(ctx->kdf_salt_sz);
 891   if(ctx->kdf_salt == NULL) return SQLITE_NOMEM;
 892
 893   /* allocate space for separate hmac salt data. We want the
 894      HMAC derivation salt to be different than the encryption
 895      key derivation salt */
 896   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init: allocating hmac_kdf_salt");
 897   ctx->hmac_kdf_salt = sqlcipher_malloc(ctx->kdf_salt_sz);
 898   if(ctx->hmac_kdf_salt == NULL) return SQLITE_NOMEM;
 899
 900   /* setup default flags */
 901   ctx->flags = default_flags;
 902
 903   /* setup the crypto provider  */
 904   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_ctx_init: allocating provider");
 905   ctx->provider = (sqlcipher_provider *) sqlcipher_malloc(sizeof(sqlcipher_provider));
 906   if(ctx->provider == NULL) return SQLITE_NOMEM;
 907
 908   /* make a copy of the provider to be used for the duration of the context */
 909   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_codec_ctx_init: entering SQLCIPHER_MUTEX_PROVIDER");
 910   sqlite3_mutex_enter(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 911   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_codec_ctx_init: entered SQLCIPHER_MUTEX_PROVIDER");
 912
 913   memcpy(ctx->provider, default_provider, sizeof(sqlcipher_provider));
 914
 915   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_codec_ctx_init: leaving SQLCIPHER_MUTEX_PROVIDER");
 916   sqlite3_mutex_leave(sqlcipher_mutex(SQLCIPHER_MUTEX_PROVIDER));
 917   sqlcipher_log(SQLCIPHER_LOG_TRACE, "sqlcipher_codec_ctx_init: left SQLCIPHER_MUTEX_PROVIDER");
 918
 919   if((rc = ctx->provider->ctx_init(&ctx->provider_ctx)) != SQLITE_OK) {
 920     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d returned from ctx_init", rc);
 921     return rc;
 922   }
 923
 924   ctx->key_sz = ctx->provider->get_key_sz(ctx->provider_ctx);
 925   ctx->iv_sz = ctx->provider->get_iv_sz(ctx->provider_ctx);
 926   ctx->block_sz = ctx->provider->get_block_sz(ctx->provider_ctx);
 927
 928   /* establic the size for a hex-formated key specification, containing the
 929      raw encryption key and the salt used to generate it format. will be x'hexkey...hexsalt'
 930      so oversize by 3 bytes */
 931   ctx->keyspec_sz = ((ctx->key_sz + ctx->kdf_salt_sz) * 2) + 3;
 932
 933   /*
 934      Always overwrite page size and set to the default because the first page of the database
 935      in encrypted and thus sqlite can't effectively determine the pagesize. this causes an issue in
 936      cases where bytes 16 & 17 of the page header are a power of 2 as reported by John Lehman
 937   */
 938   if((rc = sqlcipher_codec_ctx_set_pagesize(ctx, default_page_size)) != SQLITE_OK) {
 939     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d returned from sqlcipher_codec_ctx_set_pagesize with %d", rc, default_page_size);
 940     return rc;
 941   }
 942
 943   /* establish settings for the KDF iterations and fast (HMAC) KDF iterations */
 944   if((rc = sqlcipher_codec_ctx_set_kdf_iter(ctx, default_kdf_iter)) != SQLITE_OK) {
 945     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting default_kdf_iter %d", rc, default_kdf_iter);
 946     return rc;
 947   }
 948
 949   if((rc = sqlcipher_codec_ctx_set_fast_kdf_iter(ctx, FAST_PBKDF2_ITER)) != SQLITE_OK) {
 950     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting fast_kdf_iter to %d", rc, FAST_PBKDF2_ITER);
 951     return rc;
 952   }
 953
 954   /* set the default HMAC and KDF algorithms which will determine the reserve size */
 955   if((rc = sqlcipher_codec_ctx_set_hmac_algorithm(ctx, default_hmac_algorithm)) != SQLITE_OK) {
 956     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting sqlcipher_codec_ctx_set_hmac_algorithm with %d", rc, default_hmac_algorithm);
 957     return rc;
 958   }
 959
 960   /* Note that use_hmac is a special case that requires recalculation of page size
 961      so we call set_use_hmac to perform setup */
 962   if((rc = sqlcipher_codec_ctx_set_use_hmac(ctx, SQLCIPHER_FLAG_GET(default_flags, CIPHER_FLAG_HMAC))) != SQLITE_OK) {
 963     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting use_hmac %d", rc, SQLCIPHER_FLAG_GET(default_flags, CIPHER_FLAG_HMAC));
 964     return rc;
 965   }
 966
 967   if((rc = sqlcipher_codec_ctx_set_kdf_algorithm(ctx, default_kdf_algorithm)) != SQLITE_OK) {
 968     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting sqlcipher_codec_ctx_set_kdf_algorithm with %d", rc, default_kdf_algorithm);
 969     return rc;
 970   }
 971
 972   /* setup the default plaintext header size */
 973   if((rc = sqlcipher_codec_ctx_set_plaintext_header_size(ctx, default_plaintext_header_sz)) != SQLITE_OK) {
 974     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting sqlcipher_codec_ctx_set_plaintext_header_size with %d", rc, default_plaintext_header_sz);
 975     return rc;
 976   }
 977
 978   /* initialize the read and write sub-contexts. this must happen after key_sz is established  */
 979   if((rc = sqlcipher_cipher_ctx_init(ctx, &ctx->read_ctx)) != SQLITE_OK) {
 980     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d initializing read_ctx", rc);
 981     return rc;
 982   }
 983
 984   if((rc = sqlcipher_cipher_ctx_init(ctx, &ctx->write_ctx)) != SQLITE_OK) {
 985     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d initializing write_ctx", rc);
 986     return rc;
 987   }
 988
 989   /* set the key material on one of the sub cipher contexts and sync them up */
 990   if((rc = sqlcipher_codec_ctx_set_pass(ctx, zKey, nKey, 0)) != SQLITE_OK) {
 991     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d setting pass key", rc);
 992     return rc;
 993   }
 994
 995   if((rc = sqlcipher_cipher_ctx_copy(ctx, ctx->write_ctx, ctx->read_ctx)) != SQLITE_OK) {
 996     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_ctx_init: error %d copying write_ctx to read_ctx", rc);
 997     return rc;
 998   }
 999
1000   return SQLITE_OK;
1001 }
1002
1003 /**
1004   * Free and wipe memory associated with a cipher_ctx, including the allocated
1005   * read_ctx and write_ctx.
1006   */
1007 void sqlcipher_codec_ctx_free(codec_ctx **iCtx) {
1008   codec_ctx *ctx = *iCtx;
1009   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "codec_ctx_free: iCtx=%p", iCtx);
1010   sqlcipher_free(ctx->kdf_salt, ctx->kdf_salt_sz);
1011   sqlcipher_free(ctx->hmac_kdf_salt, ctx->kdf_salt_sz);
1012   sqlcipher_free(ctx->buffer, ctx->page_sz);
1013
1014   ctx->provider->ctx_free(&ctx->provider_ctx);
1015   sqlcipher_free(ctx->provider, sizeof(sqlcipher_provider));
1016
1017   sqlcipher_cipher_ctx_free(ctx, &ctx->read_ctx);
1018   sqlcipher_cipher_ctx_free(ctx, &ctx->write_ctx);
1019   sqlcipher_free(ctx, sizeof(codec_ctx));
1020 }
1021
1022 /** convert a 32bit unsigned integer to little endian byte ordering */
1023 static void sqlcipher_put4byte_le(unsigned char *p, u32 v) {
1024   p[0] = (u8)v;
1025   p[1] = (u8)(v>>8);
1026   p[2] = (u8)(v>>16);
1027   p[3] = (u8)(v>>24);
1028 }
1029
1030 static int sqlcipher_page_hmac(codec_ctx *ctx, cipher_ctx *c_ctx, Pgno pgno, unsigned char *in, int in_sz, unsigned char *out) {
1031   unsigned char pgno_raw[sizeof(pgno)];
1032   /* we may convert page number to consistent representation before calculating MAC for
1033      compatibility across big-endian and little-endian platforms.
1034
1035      Note: The public release of sqlcipher 2.0.0 to 2.0.6 had a bug where the bytes of pgno
1036      were used directly in the MAC. SQLCipher convert's to little endian by default to preserve
1037      backwards compatibility on the most popular platforms, but can optionally be configured
1038      to use either big endian or native byte ordering via pragma. */
1039
1040   if(SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_LE_PGNO)) { /* compute hmac using little endian pgno*/
1041     sqlcipher_put4byte_le(pgno_raw, pgno);
1042   } else if(SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_BE_PGNO)) { /* compute hmac using big endian pgno */
1043     sqlite3Put4byte(pgno_raw, pgno); /* sqlite3Put4byte converts 32bit uint to big endian  */
1044   } else { /* use native byte ordering */
1045     memcpy(pgno_raw, &pgno, sizeof(pgno));
1046   }
1047
1048   /* include the encrypted page data,  initialization vector, and page number in HMAC. This will
1049      prevent both tampering with the ciphertext, manipulation of the IV, or resequencing otherwise
1050      valid pages out of order in a database */
1051   return ctx->provider->hmac(
1052     ctx->provider_ctx, ctx->hmac_algorithm, c_ctx->hmac_key,
1053     ctx->key_sz, in,
1054     in_sz, (unsigned char*) &pgno_raw,
1055     sizeof(pgno), out);
1056 }
1057
1058 /*
1059  * ctx - codec context
1060  * pgno - page number in database
1061  * size - size in bytes of input and output buffers
1062  * mode - 1 to encrypt, 0 to decrypt
1063  * in - pointer to input bytes
1064  * out - pouter to output bytes
1065  */
1066 int sqlcipher_page_cipher(codec_ctx *ctx, int for_ctx, Pgno pgno, int mode, int page_sz, unsigned char *in, unsigned char *out) {
1067   cipher_ctx *c_ctx = for_ctx ? ctx->write_ctx : ctx->read_ctx;
1068   unsigned char *iv_in, *iv_out, *hmac_in, *hmac_out, *out_start;
1069   int size;
1070
1071   /* calculate some required positions into various buffers */
1072   size = page_sz - ctx->reserve_sz; /* adjust size to useable size and memset reserve at end of page */
1073   iv_out = out + size;
1074   iv_in = in + size;
1075
1076   /* hmac will be written immediately after the initialization vector. the remainder of the page reserve will contain
1077      random bytes. note, these pointers are only valid when using hmac */
1078   hmac_in = in + size + ctx->iv_sz;
1079   hmac_out = out + size + ctx->iv_sz;
1080   out_start = out; /* note the original position of the output buffer pointer, as out will be rewritten during encryption */
1081
1082   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_page_cipher: pgno=%d, mode=%d, size=%d", pgno, mode, size);
1083   CODEC_HEXDUMP("sqlcipher_page_cipher: input page data", in, page_sz);
1084
1085   /* the key size should never be zero. If it is, error out. */
1086   if(ctx->key_sz == 0) {
1087     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_page_cipher: error possible context corruption, key_sz is zero for pgno=%d", pgno);
1088     goto error;
1089   }
1090
1091   if(mode == CIPHER_ENCRYPT) {
1092     /* start at front of the reserve block, write random data to the end */
1093     if(ctx->provider->random(ctx->provider_ctx, iv_out, ctx->reserve_sz) != SQLITE_OK) goto error;
1094   } else { /* CIPHER_DECRYPT */
1095     memcpy(iv_out, iv_in, ctx->iv_sz); /* copy the iv from the input to output buffer */
1096   }
1097
1098   if(SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HMAC) && (mode == CIPHER_DECRYPT)) {
1099     if(sqlcipher_page_hmac(ctx, c_ctx, pgno, in, size + ctx->iv_sz, hmac_out) != SQLITE_OK) {
1100       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_page_cipher: hmac operation on decrypt failed for pgno=%d", pgno);
1101       goto error;
1102     }
1103
1104     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_page_cipher: comparing hmac on in=%p out=%p hmac_sz=%d", hmac_in, hmac_out, ctx->hmac_sz);
1105     if(sqlcipher_memcmp(hmac_in, hmac_out, ctx->hmac_sz) != 0) { /* the hmac check failed */
1106       if(sqlite3BtreeGetAutoVacuum(ctx->pBt) != BTREE_AUTOVACUUM_NONE && sqlcipher_ismemset(in, 0, page_sz) == 0) {
1107         /* first check if the entire contents of the page is zeros. If so, this page
1108            resulted from a short read (i.e. sqlite attempted to pull a page after the end of the file. these
1109            short read failures must be ignored for autovaccum mode to work so wipe the output buffer
1110            and return SQLITE_OK to skip the decryption step. */
1111         sqlcipher_log(SQLCIPHER_LOG_WARN, "sqlcipher_page_cipher: zeroed page (short read) for pgno %d, encryption but returning SQLITE_OK", pgno);
1112         sqlcipher_memset(out, 0, page_sz);
1113         return SQLITE_OK;
1114       } else {
1115         /* if the page memory is not all zeros, it means the there was data and a hmac on the page.
1116            since the check failed, the page was either tampered with or corrupted. wipe the output buffer,
1117            and return SQLITE_ERROR to the caller */
1118         sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_page_cipher: hmac check failed for pgno=%d returning SQLITE_ERROR", pgno);
1119         goto error;
1120       }
1121     }
1122   }
1123
1124   if(ctx->provider->cipher(ctx->provider_ctx, mode, c_ctx->key, ctx->key_sz, iv_out, in, size, out) != SQLITE_OK) {
1125     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_page_cipher: cipher operation mode=%d failed for pgno=%d returning SQLITE_ERROR", mode, pgno);
1126     goto error;
1127   };
1128
1129   if(SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HMAC) && (mode == CIPHER_ENCRYPT)) {
1130     if(sqlcipher_page_hmac(ctx, c_ctx, pgno, out_start, size + ctx->iv_sz, hmac_out) != SQLITE_OK) {
1131       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_page_cipher: hmac operation on encrypt failed for pgno=%d", pgno);
1132       goto error;
1133     };
1134   }
1135
1136   CODEC_HEXDUMP("sqlcipher_page_cipher: output page data", out_start, page_sz);
1137
1138   return SQLITE_OK;
1139 error:
1140   sqlcipher_memset(out, 0, page_sz);
1141   return SQLITE_ERROR;
1142 }
1143
1144 /**
1145   * Derive an encryption key for a cipher contex key based on the raw password.
1146   *
1147   * If the raw key data is formated as x'hex' and there are exactly enough hex chars to fill
1148   * the key (i.e 64 hex chars for a 256 bit key) then the key data will be used directly.
1149
1150   * Else, if the raw key data is formated as x'hex' and there are exactly enough hex chars to fill
1151   * the key and the salt (i.e 92 hex chars for a 256 bit key and 16 byte salt) then it will be unpacked
1152   * as the key followed by the salt.
1153   *
1154   * Otherwise, a key data will be derived using PBKDF2
1155   *
1156   * returns SQLITE_OK if initialization was successful
1157   * returns SQLITE_ERROR if the key could't be derived (for instance if pass is NULL or pass_sz is 0)
1158   */
1159 static int sqlcipher_cipher_ctx_key_derive(codec_ctx *ctx, cipher_ctx *c_ctx) {
1160   int rc;
1161   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_cipher_ctx_key_derive: ctx->kdf_salt_sz=%d ctx->kdf_iter=%d ctx->fast_kdf_iter=%d ctx->key_sz=%d",
1162     ctx->kdf_salt_sz, ctx->kdf_iter, ctx->fast_kdf_iter, ctx->key_sz);
1163
1164   if(c_ctx->pass && c_ctx->pass_sz) {  /* if key material is present on the context for derivation */
1165
1166     /* if necessary, initialize the salt from the header or random source */
1167     if(!SQLCIPHER_FLAG_GET(ctx->flags, CIPHER_FLAG_HAS_KDF_SALT)) {
1168       if((rc = sqlcipher_codec_ctx_init_kdf_salt(ctx)) != SQLITE_OK) {
1169         sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_cipher_ctx_key_derive: error %d from sqlcipher_codec_ctx_init_kdf_salt", rc);
1170         return rc;
1171       }
1172     }
1173
1174     if (c_ctx->pass_sz == ((ctx->key_sz * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0 && cipher_isHex(c_ctx->pass + 2, ctx->key_sz * 2)) {
1175       int n = c_ctx->pass_sz - 3; /* adjust for leading x' and tailing ' */
1176       const unsigned char *z = c_ctx->pass + 2; /* adjust lead offset of x' */
1177       sqlcipher_log(SQLCIPHER_LOG_DEBUG, "cipher_ctx_key_derive: using raw key from hex");
1178       cipher_hex2bin(z, n, c_ctx->key);
1179     } else if (c_ctx->pass_sz == (((ctx->key_sz + ctx->kdf_salt_sz) * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0 && cipher_isHex(c_ctx->pass + 2, (ctx->key_sz + ctx->kdf_salt_sz) * 2)) {
1180       const unsigned char *z = c_ctx->pass + 2; /* adjust lead offset of x' */
1181       sqlcipher_log(SQLCIPHER_LOG_DEBUG, "cipher_ctx_key_derive: using raw key from hex");
1182       cipher_hex2bin(z, (ctx->key_sz * 2), c_ctx->key);
1183       cipher_hex2bin(z + (ctx->key_sz * 2), (ctx->kdf_salt_sz * 2), ctx->kdf_salt);
1184     } else {
1185       sqlcipher_log(SQLCIPHER_LOG_DEBUG, "cipher_ctx_key_derive: deriving key using full PBKDF2 with %d iterations", ctx->kdf_iter);
1186       if(ctx->provider->kdf(ctx->provider_ctx, ctx->kdf_algorithm, c_ctx->pass, c_ctx->pass_sz,
1187                     ctx->kdf_salt, ctx->kdf_salt_sz, ctx->kdf_iter,
1188                     ctx->key_sz, c_ctx->key) != SQLITE_OK) {
1189         sqlcipher_log(SQLCIPHER_LOG_ERROR, "cipher_ctx_key_derive: error occurred from provider kdf generating encryption key");
1190         return SQLITE_ERROR;
1191       }
1192     }
1193
1194     /* set the context "keyspec" containing the hex-formatted key and salt to be used when attaching databases */
1195     if((rc = sqlcipher_cipher_ctx_set_keyspec(ctx, c_ctx, c_ctx->key)) != SQLITE_OK) {
1196       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_cipher_ctx_key_derive: error %d from sqlcipher_cipher_ctx_set_keyspec", rc);
1197       return rc;
1198     }
1199
1200     /* if this context is setup to use hmac checks, generate a seperate and different
1201        key for HMAC. In this case, we use the output of the previous KDF as the input to
1202        this KDF run. This ensures a distinct but predictable HMAC key. */
1203     if(ctx->flags & CIPHER_FLAG_HMAC) {
1204       int i;
1205
1206       /* start by copying the kdf key into the hmac salt slot
1207          then XOR it with the fixed hmac salt defined at compile time
1208          this ensures that the salt passed in to derive the hmac key, while
1209          easy to derive and publically known, is not the same as the salt used
1210          to generate the encryption key */
1211       memcpy(ctx->hmac_kdf_salt, ctx->kdf_salt, ctx->kdf_salt_sz);
1212       for(i = 0; i < ctx->kdf_salt_sz; i++) {
1213         ctx->hmac_kdf_salt[i] ^= hmac_salt_mask;
1214       }
1215
1216       sqlcipher_log(SQLCIPHER_LOG_DEBUG, "cipher_ctx_key_derive: deriving hmac key from encryption key using PBKDF2 with %d iterations",
1217         ctx->fast_kdf_iter);
1218
1219
1220       if(ctx->provider->kdf(ctx->provider_ctx, ctx->kdf_algorithm, c_ctx->key, ctx->key_sz,
1221                     ctx->hmac_kdf_salt, ctx->kdf_salt_sz, ctx->fast_kdf_iter,
1222                     ctx->key_sz, c_ctx->hmac_key) != SQLITE_OK) {
1223         sqlcipher_log(SQLCIPHER_LOG_ERROR, "cipher_ctx_key_derive: error occurred from provider kdf generating HMAC key");
1224         return SQLITE_ERROR;
1225       }
1226     }
1227
1228     c_ctx->derive_key = 0;
1229     return SQLITE_OK;
1230   }
1231   sqlcipher_log(SQLCIPHER_LOG_ERROR, "cipher_ctx_key_derive: key material is not present on the context for key derivation");
1232   return SQLITE_ERROR;
1233 }
1234
1235 int sqlcipher_codec_key_derive(codec_ctx *ctx) {
1236   /* derive key on first use if necessary */
1237   if(ctx->read_ctx->derive_key) {
1238     if(sqlcipher_cipher_ctx_key_derive(ctx, ctx->read_ctx) != SQLITE_OK) {
1239       sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_key_derive: error occurred deriving read_ctx key");
1240       return SQLITE_ERROR;
1241     }
1242   }
1243
1244   if(ctx->write_ctx->derive_key) {
1245     if(sqlcipher_cipher_ctx_cmp(ctx->write_ctx, ctx->read_ctx) == 0) {
1246       /* the relevant parameters are the same, just copy read key */
1247       if(sqlcipher_cipher_ctx_copy(ctx, ctx->write_ctx, ctx->read_ctx) != SQLITE_OK) {
1248         sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_key_derive: error occurred copying read_ctx to write_ctx");
1249         return SQLITE_ERROR;
1250       }
1251     } else {
1252       if(sqlcipher_cipher_ctx_key_derive(ctx, ctx->write_ctx) != SQLITE_OK) {
1253         sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_key_derive: error occurred deriving write_ctx key");
1254         return SQLITE_ERROR;
1255       }
1256     }
1257   }
1258
1259   /* TODO: wipe and free passphrase after key derivation */
1260   if(ctx->store_pass  != 1) {
1261     sqlcipher_cipher_ctx_set_pass(ctx->read_ctx, NULL, 0);
1262     sqlcipher_cipher_ctx_set_pass(ctx->write_ctx, NULL, 0);
1263   }
1264
1265   return SQLITE_OK;
1266 }
1267
1268 int sqlcipher_codec_key_copy(codec_ctx *ctx, int source) {
1269   if(source == CIPHER_READ_CTX) {
1270       return sqlcipher_cipher_ctx_copy(ctx, ctx->write_ctx, ctx->read_ctx);
1271   } else {
1272       return sqlcipher_cipher_ctx_copy(ctx, ctx->read_ctx, ctx->write_ctx);
1273   }
1274 }
1275
1276 const char* sqlcipher_codec_get_cipher_provider(codec_ctx *ctx) {
1277   return ctx->provider->get_provider_name(ctx->provider_ctx);
1278 }
1279
1280
1281 static int sqlcipher_check_connection(const char *filename, char *key, int key_sz, char *sql, int *user_version, char** journal_mode) {
1282   int rc;
1283   sqlite3 *db = NULL;
1284   sqlite3_stmt *statement = NULL;
1285   char *query_journal_mode = "PRAGMA journal_mode;";
1286   char *query_user_version = "PRAGMA user_version;";
1287
1288   rc = sqlite3_open(filename, &db);
1289   if(rc != SQLITE_OK) goto cleanup;
1290
1291   rc = sqlite3_key(db, key, key_sz);
1292   if(rc != SQLITE_OK) goto cleanup;
1293
1294   rc = sqlite3_exec(db, sql, NULL, NULL, NULL);
1295   if(rc != SQLITE_OK) goto cleanup;
1296
1297   /* start by querying the user version.
1298      this will fail if the key is incorrect */
1299   rc = sqlite3_prepare(db, query_user_version, -1, &statement, NULL);
1300   if(rc != SQLITE_OK) goto cleanup;
1301
1302   rc = sqlite3_step(statement);
1303   if(rc == SQLITE_ROW) {
1304     *user_version = sqlite3_column_int(statement, 0);
1305   } else {
1306     goto cleanup;
1307   }
1308   sqlite3_finalize(statement);
1309
1310   rc = sqlite3_prepare(db, query_journal_mode, -1, &statement, NULL);
1311   if(rc != SQLITE_OK) goto cleanup;
1312
1313   rc = sqlite3_step(statement);
1314   if(rc == SQLITE_ROW) {
1315     *journal_mode = sqlite3_mprintf("%s", sqlite3_column_text(statement, 0));
1316   } else {
1317     goto cleanup;
1318   }
1319   rc = SQLITE_OK;
1320   /* cleanup will finalize open statement */
1321
1322 cleanup:
1323   if(statement) sqlite3_finalize(statement);
1324   if(db) sqlite3_close(db);
1325   return rc;
1326 }
1327
1328 int sqlcipher_codec_ctx_integrity_check(codec_ctx *ctx, Parse *pParse, char *column) {
1329   Pgno page = 1;
1330   int rc = 0;
1331   char *result;
1332   unsigned char *hmac_out = NULL;
1333   sqlite3_file *fd = sqlite3PagerFile(ctx->pBt->pBt->pPager);
1334   i64 file_sz;
1335
1336   Vdbe *v = sqlite3GetVdbe(pParse);
1337   sqlite3VdbeSetNumCols(v, 1);
1338   sqlite3VdbeSetColName(v, 0, COLNAME_NAME, column, SQLITE_STATIC);
1339
1340   if(fd == NULL || fd->pMethods == 0) {
1341     sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, "database file is undefined", P4_TRANSIENT);
1342     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1343     goto cleanup;
1344   }
1345
1346   if(!(ctx->flags & CIPHER_FLAG_HMAC)) {
1347     sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, "HMAC is not enabled, unable to integrity check", P4_TRANSIENT);
1348     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1349     goto cleanup;
1350   }
1351
1352   if((rc = sqlcipher_codec_key_derive(ctx)) != SQLITE_OK) {
1353     sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, "unable to derive keys", P4_TRANSIENT);
1354     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1355     goto cleanup;
1356   }
1357
1358   sqlite3OsFileSize(fd, &file_sz);
1359   hmac_out = sqlcipher_malloc(ctx->hmac_sz);
1360
1361   for(page = 1; page <= file_sz / ctx->page_sz; page++) {
1362     i64 offset = (page - 1) * ctx->page_sz;
1363     int payload_sz = ctx->page_sz - ctx->reserve_sz + ctx->iv_sz;
1364     int read_sz = ctx->page_sz;
1365
1366     /* skip integrity check on PAGER_SJ_PGNO since it will have no valid content */
1367     if(sqlite3pager_is_sj_pgno(ctx->pBt->pBt->pPager, page)) continue;
1368
1369     if(page==1) {
1370       int page1_offset = ctx->plaintext_header_sz ? ctx->plaintext_header_sz : FILE_HEADER_SZ;
1371       read_sz = read_sz - page1_offset;
1372       payload_sz = payload_sz - page1_offset;
1373       offset += page1_offset;
1374     }
1375
1376     sqlcipher_memset(ctx->buffer, 0, ctx->page_sz);
1377     sqlcipher_memset(hmac_out, 0, ctx->hmac_sz);
1378     if(sqlite3OsRead(fd, ctx->buffer, read_sz, offset) != SQLITE_OK) {
1379       result = sqlite3_mprintf("error reading %d bytes from file page %d at offset %d", read_sz, page, offset);
1380       sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, result, P4_DYNAMIC);
1381       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1382     } else if(sqlcipher_page_hmac(ctx, ctx->read_ctx, page, ctx->buffer, payload_sz, hmac_out) != SQLITE_OK) {
1383       result = sqlite3_mprintf("HMAC operation failed for page %d", page);
1384       sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, result, P4_DYNAMIC);
1385       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1386     } else if(sqlcipher_memcmp(ctx->buffer + payload_sz, hmac_out, ctx->hmac_sz) != 0) {
1387       result = sqlite3_mprintf("HMAC verification failed for page %d", page);
1388       sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, result, P4_DYNAMIC);
1389       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1390     }
1391   }
1392
1393   if(file_sz % ctx->page_sz != 0) {
1394     result = sqlite3_mprintf("page %d has an invalid size of %lld bytes (expected %d bytes)", page, file_sz - ((file_sz / ctx->page_sz) * ctx->page_sz), ctx->page_sz);
1395     sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, result, P4_DYNAMIC);
1396     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1397   }
1398
1399 cleanup:
1400   if(hmac_out != NULL) sqlcipher_free(hmac_out, ctx->hmac_sz);
1401   return SQLITE_OK;
1402 }
1403
1404 int sqlcipher_codec_ctx_migrate(codec_ctx *ctx) {
1405   int i, pass_sz, keyspec_sz, nRes, user_version, rc, oflags;
1406   Db *pDb = 0;
1407   sqlite3 *db = ctx->pBt->db;
1408   const char *db_filename = sqlite3_db_filename(db, "main");
1409   char *set_user_version = NULL, *pass = NULL, *attach_command = NULL, *migrated_db_filename = NULL, *keyspec = NULL, *temp = NULL, *journal_mode = NULL, *set_journal_mode = NULL, *pragma_compat = NULL;
1410   Btree *pDest = NULL, *pSrc = NULL;
1411   sqlite3_file *srcfile, *destfile;
1412 #if defined(_WIN32) || defined(SQLITE_OS_WINRT)
1413   LPWSTR w_db_filename = NULL, w_migrated_db_filename = NULL;
1414   int w_db_filename_sz = 0, w_migrated_db_filename_sz = 0;
1415 #endif
1416   pass_sz = keyspec_sz = rc = user_version = 0;
1417
1418   if(!db_filename || sqlite3Strlen30(db_filename) < 1)
1419     goto cleanup; /* exit immediately if this is an in memory database */
1420
1421   /* pull the provided password / key material off the current codec context */
1422   pass_sz = ctx->read_ctx->pass_sz;
1423   pass = sqlcipher_malloc(pass_sz+1);
1424   memset(pass, 0, pass_sz+1);
1425   memcpy(pass, ctx->read_ctx->pass, pass_sz);
1426
1427   /* Version 4 - current, no upgrade required, so exit immediately */
1428   rc = sqlcipher_check_connection(db_filename, pass, pass_sz, "", &user_version, &journal_mode);
1429   if(rc == SQLITE_OK){
1430     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "No upgrade required - exiting");
1431     goto cleanup;
1432   }
1433
1434   for(i = 3; i > 0; i--) {
1435     pragma_compat = sqlite3_mprintf("PRAGMA cipher_compatibility = %d;", i);
1436     rc = sqlcipher_check_connection(db_filename, pass, pass_sz, pragma_compat, &user_version, &journal_mode);
1437     if(rc == SQLITE_OK) {
1438       sqlcipher_log(SQLCIPHER_LOG_DEBUG, "Version %d format found", i);
1439       goto migrate;
1440     }
1441     if(pragma_compat) sqlcipher_free(pragma_compat, sqlite3Strlen30(pragma_compat));
1442     pragma_compat = NULL;
1443   }
1444
1445   /* if we exit the loop normally we failed to determine the version, this is an error */
1446   sqlcipher_log(SQLCIPHER_LOG_ERROR, "Upgrade format not determined");
1447   goto handle_error;
1448
1449 migrate:
1450
1451   temp = sqlite3_mprintf("%s-migrated", db_filename);
1452   /* overallocate migrated_db_filename, because sqlite3OsOpen will read past the null terminator
1453    * to determine whether the filename was URI formatted */
1454   migrated_db_filename = sqlcipher_malloc(sqlite3Strlen30(temp)+2);
1455   memcpy(migrated_db_filename, temp, sqlite3Strlen30(temp));
1456   sqlcipher_free(temp, sqlite3Strlen30(temp));
1457
1458   attach_command = sqlite3_mprintf("ATTACH DATABASE '%s' as migrate;", migrated_db_filename, pass);
1459   set_user_version = sqlite3_mprintf("PRAGMA migrate.user_version = %d;", user_version);
1460
1461   rc = sqlite3_exec(db, pragma_compat, NULL, NULL, NULL);
1462   if(rc != SQLITE_OK){
1463     sqlcipher_log(SQLCIPHER_LOG_ERROR, "set compatibility mode failed, error code %d", rc);
1464     goto handle_error;
1465   }
1466
1467   /* force journal mode to DELETE, we will set it back later if different */
1468   rc = sqlite3_exec(db, "PRAGMA journal_mode = delete;", NULL, NULL, NULL);
1469   if(rc != SQLITE_OK){
1470     sqlcipher_log(SQLCIPHER_LOG_ERROR, "force journal mode DELETE failed, error code %d", rc);
1471     goto handle_error;
1472   }
1473
1474   rc = sqlite3_exec(db, attach_command, NULL, NULL, NULL);
1475   if(rc != SQLITE_OK){
1476     sqlcipher_log(SQLCIPHER_LOG_ERROR, "attach failed, error code %d", rc);
1477     goto handle_error;
1478   }
1479
1480   rc = sqlite3_key_v2(db, "migrate", pass, pass_sz);
1481   if(rc != SQLITE_OK){
1482     sqlcipher_log(SQLCIPHER_LOG_ERROR, "keying attached database failed, error code %d", rc);
1483     goto handle_error;
1484   }
1485
1486   rc = sqlite3_exec(db, "SELECT sqlcipher_export('migrate');", NULL, NULL, NULL);
1487   if(rc != SQLITE_OK){
1488     sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_export failed, error code %d", rc);
1489     goto handle_error;
1490   }
1491
1492 #ifdef SQLCIPHER_TEST
1493   if((sqlcipher_get_test_flags() & TEST_FAIL_MIGRATE) > 0) {
1494     rc = SQLITE_ERROR;
1495     sqlcipher_log(SQLCIPHER_LOG_ERROR, "simulated migrate failure, error code %d", rc);
1496     goto handle_error;
1497   }
1498 #endif
1499
1500   rc = sqlite3_exec(db, set_user_version, NULL, NULL, NULL);
1501   if(rc != SQLITE_OK){
1502     sqlcipher_log(SQLCIPHER_LOG_ERROR, "set user version failed, error code %d", rc);
1503     goto handle_error;
1504   }
1505
1506   if( !db->autoCommit ){
1507     sqlcipher_log(SQLCIPHER_LOG_ERROR, "cannot migrate from within a transaction");
1508     goto handle_error;
1509   }
1510   if( db->nVdbeActive>1 ){
1511     sqlcipher_log(SQLCIPHER_LOG_ERROR, "cannot migrate - SQL statements in progress");
1512     goto handle_error;
1513   }
1514
1515   pDest = db->aDb[0].pBt;
1516   pDb = &(db->aDb[db->nDb-1]);
1517   pSrc = pDb->pBt;
1518
1519   nRes = sqlite3BtreeGetRequestedReserve(pSrc);
1520   /* unset the BTS_PAGESIZE_FIXED flag to avoid SQLITE_READONLY */
1521   pDest->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;
1522   rc = sqlite3BtreeSetPageSize(pDest, default_page_size, nRes, 0);
1523   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "set btree page size to %d res %d rc %d", default_page_size, nRes, rc);
1524   if( rc!=SQLITE_OK ) goto handle_error;
1525
1526   sqlcipherCodecGetKey(db, db->nDb - 1, (void**)&keyspec, &keyspec_sz);
1527   SQLCIPHER_FLAG_UNSET(ctx->flags, CIPHER_FLAG_KEY_USED);
1528   sqlcipherCodecAttach(db, 0, keyspec, keyspec_sz);
1529
1530   srcfile = sqlite3PagerFile(pSrc->pBt->pPager);
1531   destfile = sqlite3PagerFile(pDest->pBt->pPager);
1532
1533   sqlite3OsClose(srcfile);
1534   sqlite3OsClose(destfile);
1535
1536 #if defined(_WIN32) || defined(SQLITE_OS_WINRT)
1537   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "performing windows MoveFileExA");
1538
1539   w_db_filename_sz = MultiByteToWideChar(CP_UTF8, 0, (LPCCH) db_filename, -1, NULL, 0);
1540   w_db_filename = sqlcipher_malloc(w_db_filename_sz * sizeof(wchar_t));
1541   w_db_filename_sz = MultiByteToWideChar(CP_UTF8, 0, (LPCCH) db_filename, -1, (const LPWSTR) w_db_filename, w_db_filename_sz);
1542
1543   w_migrated_db_filename_sz = MultiByteToWideChar(CP_UTF8, 0, (LPCCH) migrated_db_filename, -1, NULL, 0);
1544   w_migrated_db_filename = sqlcipher_malloc(w_migrated_db_filename_sz * sizeof(wchar_t));
1545   w_migrated_db_filename_sz = MultiByteToWideChar(CP_UTF8, 0, (LPCCH) migrated_db_filename, -1, (const LPWSTR) w_migrated_db_filename, w_migrated_db_filename_sz);
1546
1547   if(!MoveFileExW(w_migrated_db_filename, w_db_filename, MOVEFILE_REPLACE_EXISTING)) {
1548     rc = SQLITE_ERROR;
1549     sqlcipher_log(SQLCIPHER_LOG_ERROR, "error occurred while renaming %d", rc);
1550     goto handle_error;
1551   }
1552 #else
1553   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "performing POSIX rename");
1554   if ((rc = rename(migrated_db_filename, db_filename)) != 0) {
1555     sqlcipher_log(SQLCIPHER_LOG_ERROR, "error occurred while renaming %d", rc);
1556     goto handle_error;
1557   }
1558 #endif
1559   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "renamed migration database %s to main database %s: %d", migrated_db_filename, db_filename, rc);
1560
1561   rc = sqlite3OsOpen(db->pVfs, migrated_db_filename, srcfile, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MAIN_DB, &oflags);
1562   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "reopened migration database: %d", rc);
1563   if( rc!=SQLITE_OK ) goto handle_error;
1564
1565   rc = sqlite3OsOpen(db->pVfs, db_filename, destfile, SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MAIN_DB, &oflags);
1566   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "reopened main database: %d", rc);
1567   if( rc!=SQLITE_OK ) goto handle_error;
1568
1569   sqlite3pager_reset(pDest->pBt->pPager);
1570   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "reset pager");
1571
1572   rc = sqlite3_exec(db, "DETACH DATABASE migrate;", NULL, NULL, NULL);
1573   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "DETACH DATABASE called %d", rc);
1574   if(rc != SQLITE_OK) goto cleanup;
1575
1576   sqlite3ResetAllSchemasOfConnection(db);
1577   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "reset all schemas");
1578
1579   set_journal_mode = sqlite3_mprintf("PRAGMA journal_mode = %s;", journal_mode);
1580   rc = sqlite3_exec(db, set_journal_mode, NULL, NULL, NULL);
1581   sqlcipher_log(SQLCIPHER_LOG_DEBUG, "%s: %d", set_journal_mode, rc);
1582   if( rc!=SQLITE_OK ) goto handle_error;
1583
1584   goto cleanup;
1585
1586 handle_error:
1587   sqlcipher_log(SQLCIPHER_LOG_ERROR, "An error occurred attempting to migrate the database - last error %d", rc);
1588
1589 cleanup:
1590   if(migrated_db_filename) {
1591     int del_rc = sqlite3OsDelete(db->pVfs, migrated_db_filename, 0);
1592     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "deleted migration database: %d", del_rc);
1593   }
1594
1595   if(pass) sqlcipher_free(pass, pass_sz);
1596   if(attach_command) sqlcipher_free(attach_command, sqlite3Strlen30(attach_command));
1597   if(migrated_db_filename) sqlcipher_free(migrated_db_filename, sqlite3Strlen30(migrated_db_filename));
1598   if(set_user_version) sqlcipher_free(set_user_version, sqlite3Strlen30(set_user_version));
1599   if(set_journal_mode) sqlcipher_free(set_journal_mode, sqlite3Strlen30(set_journal_mode));
1600   if(journal_mode) sqlcipher_free(journal_mode, sqlite3Strlen30(journal_mode));
1601   if(pragma_compat) sqlcipher_free(pragma_compat, sqlite3Strlen30(pragma_compat));
1602 #if defined(_WIN32) || defined(SQLITE_OS_WINRT)
1603   if(w_db_filename) sqlcipher_free(w_db_filename, w_db_filename_sz);
1604   if(w_migrated_db_filename) sqlcipher_free(w_migrated_db_filename, w_migrated_db_filename_sz);
1605 #endif
1606   return rc;
1607 }
1608
1609 int sqlcipher_codec_add_random(codec_ctx *ctx, const char *zRight, int random_sz){
1610   const char *suffix = &zRight[random_sz-1];
1611   int n = random_sz - 3; /* adjust for leading x' and tailing ' */
1612   if (n > 0 &&
1613       sqlite3StrNICmp((const char *)zRight ,"x'", 2) == 0 &&
1614       sqlite3StrNICmp(suffix, "'", 1) == 0 &&
1615       n % 2 == 0) {
1616     int rc = 0;
1617     int buffer_sz = n / 2;
1618     unsigned char *random;
1619     const unsigned char *z = (const unsigned char *)zRight + 2; /* adjust lead offset of x' */
1620     sqlcipher_log(SQLCIPHER_LOG_DEBUG, "sqlcipher_codec_add_random: using raw random blob from hex");
1621     random = sqlcipher_malloc(buffer_sz);
1622     memset(random, 0, buffer_sz);
1623     cipher_hex2bin(z, n, random);
1624     rc = ctx->provider->add_random(ctx->provider_ctx, random, buffer_sz);
1625     sqlcipher_free(random, buffer_sz);
1626     return rc;
1627   }
1628   sqlcipher_log(SQLCIPHER_LOG_ERROR, "sqlcipher_codec_add_random: attemt to add random with invalid format");
1629   return SQLITE_ERROR;
1630 }
1631
1632 #if !defined(SQLITE_OMIT_TRACE)
1633 static int sqlcipher_profile_callback(unsigned int trace, void *file, void *stmt, void *run_time){
1634   FILE *f = (FILE*) file;
1635   char *fmt = "Elapsed time:%.3f ms - %s\n";
1636   double elapsed = (*((sqlite3_uint64*)run_time))/1000000.0;
1637 #ifdef __ANDROID__
1638   if(f == NULL) {
1639     __android_log_print(ANDROID_LOG_DEBUG, "sqlcipher", fmt, elapsed, sqlite3_sql((sqlite3_stmt*)stmt));
1640   }
1641 #endif
1642   if(f) fprintf(f, fmt, elapsed, sqlite3_sql((sqlite3_stmt*)stmt));
1643   return SQLITE_OK;
1644 }
1645 #endif
1646
1647 int sqlcipher_cipher_profile(sqlite3 *db, const char *destination){
1648 #if defined(SQLITE_OMIT_TRACE)
1649   return SQLITE_ERROR;
1650 #else
1651   FILE *f = NULL;
1652   if(sqlite3_stricmp(destination, "off") == 0){
1653     sqlite3_trace_v2(db, 0, NULL, NULL); /* disable tracing */
1654   } else {
1655     if(sqlite3_stricmp(destination, "stdout") == 0){
1656       f = stdout;
1657     }else if(sqlite3_stricmp(destination, "stderr") == 0){
1658       f = stderr;
1659     }else if(sqlite3_stricmp(destination, "logcat") == 0){
1660       f = NULL; /* file pointer will be NULL indicating logcat on android */
1661     }else{
1662 #if !defined(SQLCIPHER_PROFILE_USE_FOPEN) && (defined(_WIN32) && (__STDC_VERSION__ > 199901L) || defined(SQLITE_OS_WINRT))
1663       if(fopen_s(&f, destination, "a") != 0) return SQLITE_ERROR;
1664 #else
1665       if((f = fopen(destination, "a")) == 0) return SQLITE_ERROR;
1666 #endif
1667     }
1668     sqlite3_trace_v2(db, SQLITE_TRACE_PROFILE, sqlcipher_profile_callback, f);
1669   }
1670   return SQLITE_OK;
1671 #endif
1672 }
1673
1674 int sqlcipher_codec_fips_status(codec_ctx *ctx) {
1675   return ctx->provider->fips_status(ctx->provider_ctx);
1676 }
1677
1678 const char* sqlcipher_codec_get_provider_version(codec_ctx *ctx) {
1679   return ctx->provider->get_provider_version(ctx->provider_ctx);
1680 }
1681
1682 #ifndef SQLCIPHER_OMIT_LOG
1683 /* constants from https://github.com/Alexpux/mingw-w64/blob/master/mingw-w64-crt/misc/gettimeofday.c */
1684 #define FILETIME_1970 116444736000000000ull /* seconds between 1/1/1601 and 1/1/1970 */
1685 #define HECTONANOSEC_PER_SEC 10000000ull
1686 void sqlcipher_log(unsigned int level, const char *message, ...) {
1687   va_list params;
1688   va_start(params, message);
1689
1690 #ifdef CODEC_DEBUG
1691 #ifdef __ANDROID__
1692     __android_log_vprint(ANDROID_LOG_DEBUG, "sqlcipher", message, params);
1693 #else
1694     vfprintf(stderr, message, params);
1695     fprintf(stderr, "\n");
1696 #endif
1697 #endif
1698
1699   if(level > sqlcipher_log_level || (sqlcipher_log_logcat == 0 && sqlcipher_log_file == NULL)) {
1700     /* no log target or tag not in included filters */
1701     goto end;
1702   }
1703   if(sqlcipher_log_file != NULL){
1704     char buffer[24];
1705     struct tm tt;
1706     int ms;
1707     time_t sec;
1708 #ifdef _WIN32
1709     SYSTEMTIME st;
1710     FILETIME ft;
1711     GetSystemTime(&st);
1712     SystemTimeToFileTime(&st, &ft);
1713     sec = (time_t) ((*((sqlite_int64*)&ft) - FILETIME_1970) / HECTONANOSEC_PER_SEC);
1714     ms = st.wMilliseconds;
1715     localtime_s(&tt, &sec);
1716 #else
1717     struct timeval tv;
1718     gettimeofday(&tv, NULL);
1719     sec = tv.tv_sec;
1720     ms = tv.tv_usec/1000.0;
1721     localtime_r(&sec, &tt);
1722 #endif
1723     if(strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", &tt)) {
1724       fprintf((FILE*)sqlcipher_log_file, "%s.%03d: ", buffer, ms);
1725       vfprintf((FILE*)sqlcipher_log_file, message, params);
1726       fprintf((FILE*)sqlcipher_log_file, "\n");
1727     }
1728   }
1729 #ifdef __ANDROID__
1730   if(sqlcipher_log_logcat) {
1731     __android_log_vprint(ANDROID_LOG_DEBUG, "sqlcipher", message, params);
1732   }
1733 #endif
1734 end:
1735   va_end(params);
1736 }
1737 #endif
1738
1739 void sqlcipher_set_log_level(unsigned int level) {
1740   sqlcipher_log_level = level;
1741 }
1742
1743 int sqlcipher_set_log(const char *destination){
1744 #ifdef SQLCIPHER_OMIT_LOG
1745   return SQLITE_ERROR;
1746 #else
1747   /* close open trace file if it is not stdout or stderr, then
1748      reset trace settings */
1749   if(sqlcipher_log_file != NULL && sqlcipher_log_file != stdout && sqlcipher_log_file != stderr) {
1750     fclose((FILE*)sqlcipher_log_file);
1751   }
1752   sqlcipher_log_file = NULL;
1753   sqlcipher_log_logcat = 0;
1754
1755   if(sqlite3_stricmp(destination, "logcat") == 0){
1756     sqlcipher_log_logcat = 1;
1757   } else if(sqlite3_stricmp(destination, "stdout") == 0){
1758     sqlcipher_log_file = stdout;
1759   }else if(sqlite3_stricmp(destination, "stderr") == 0){
1760     sqlcipher_log_file = stderr;
1761   }else if(sqlite3_stricmp(destination, "off") != 0){
1762 #if !defined(SQLCIPHER_PROFILE_USE_FOPEN) && (defined(_WIN32) && (__STDC_VERSION__ > 199901L) || defined(SQLITE_OS_WINRT))
1763     if(fopen_s(&sqlcipher_log_file, destination, "a") != 0) return SQLITE_ERROR;
1764 #else
1765     if((sqlcipher_log_file = fopen(destination, "a")) == 0) return SQLITE_ERROR;
1766 #endif
1767   }
1768   sqlcipher_log(SQLCIPHER_LOG_INFO, "sqlcipher_set_log: set log to %s", destination);
1769   return SQLITE_OK;
1770 #endif
1771 }
1772
1773 #endif
1774 /* END SQLCIPHER */