Fix issue utelle#164

- Incorrect number of reserved bytes values could cause assertions - Check for valid values of config parameter plaintext_header_size - Use correct HMAC size for SQLCipher HMAC algorithm SHA256 - Ensure that error messages are returnde correctly from rekey
Qriist · Jun 7, 2024 · 02b69ad · 02b69ad
1 parent efdb694
commit 02b69ad
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Showing 5 changed files with 25 additions and 25 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,13 +13,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Cleaned up white space
 - Added SQLITE_PRIVATE for several internal functions
 - The cipher configuration parameter `legacy_page_size` now accepts only valid page sizes
+- The cipher configuration parameter `plaintext_header_size` now accepts only values that are multiples of 16
 
 ### Fixed
 
 - Fixed issue [#156](../../issues/156)) - corrupted database if MMAP_SIZE > 0 was used
 - Fixed issue [#158](../../issues/158)) - add check to verify compatibility of source and target database in backup operation
 - Fixed issue [#160](../../issues/160)) - fix accessing memory out of array bounds
 - Fixed issue [#162](../../issues/162)) - fix loading/storing misaligned data
+- Fixed issue [#164](../../issues/164)) - fix return of error messages from rekey
 - Fixed issue [#165](../../issues/165)) - fix rekey function by enforcing page size and number of reserved bytes per page
 - Fixed issue [#166](../../issues/166)) - missing attribute SQLITE_PRIVATE for several internal functions
 

diff --git a/src/cipher_common.c b/src/cipher_common.c
@@ -428,22 +428,22 @@ sqlite3mcGetPageSizeWriteCipher(Codec* codec)
 SQLITE_PRIVATE int
 sqlite3mcGetReservedReadCipher(Codec* codec)
 {
-  int reserved = (codec->m_hasReadCipher  && codec->m_readCipher != NULL) ? globalCodecDescriptorTable[codec->m_readCipherType-1].m_getReserved(codec->m_readCipher) : -1;
+  int reserved = (codec->m_hasReadCipher  && codec->m_readCipher != NULL) ? globalCodecDescriptorTable[codec->m_readCipherType-1].m_getReserved(codec->m_readCipher) : 0;
   return reserved;
 }
 
 SQLITE_PRIVATE int
 sqlite3mcGetReservedWriteCipher(Codec* codec)
 {
-  int reserved = (codec->m_hasWriteCipher && codec->m_writeCipher != NULL) ? globalCodecDescriptorTable[codec->m_writeCipherType-1].m_getReserved(codec->m_writeCipher) : -1;
+  int reserved = (codec->m_hasWriteCipher && codec->m_writeCipher != NULL) ? globalCodecDescriptorTable[codec->m_writeCipherType-1].m_getReserved(codec->m_writeCipher) : 0;
   return reserved;
 }
 
 SQLITE_PRIVATE int
 sqlite3mcReservedEqual(Codec* codec)
 {
-  int readReserved  = (codec->m_hasReadCipher  && codec->m_readCipher  != NULL) ? globalCodecDescriptorTable[codec->m_readCipherType-1].m_getReserved(codec->m_readCipher)   : -1;
-  int writeReserved = (codec->m_hasWriteCipher && codec->m_writeCipher != NULL) ? globalCodecDescriptorTable[codec->m_writeCipherType-1].m_getReserved(codec->m_writeCipher) : -1;
+  int readReserved  = (codec->m_hasReadCipher  && codec->m_readCipher  != NULL) ? globalCodecDescriptorTable[codec->m_readCipherType-1].m_getReserved(codec->m_readCipher)   : 0;
+  int writeReserved = (codec->m_hasWriteCipher && codec->m_writeCipher != NULL) ? globalCodecDescriptorTable[codec->m_writeCipherType-1].m_getReserved(codec->m_writeCipher) : 0;
   return (readReserved == writeReserved);
 }
 

diff --git a/src/cipher_config.c b/src/cipher_config.c
@@ -189,12 +189,16 @@ sqlite3mc_cipher_name(int cipherIndex)
 }
 
 static
-int checkLegacyPageSize(const char* paramName, int pageSize)
+int checkParameterValue(const char* paramName, int value)
 {
   int ok = 1;
-  if (sqlite3_stricmp(paramName, "legacy_page_size") == 0 && pageSize > 0)
+  if (sqlite3_stricmp(paramName, "legacy_page_size") == 0 && value > 0)
   {
-    ok = pageSize >= 512 && pageSize <= SQLITE_MAX_PAGE_SIZE && ((pageSize - 1) & pageSize) == 0;
+    ok = value >= 512 && value <= SQLITE_MAX_PAGE_SIZE && ((value - 1) & value) == 0;
+  }
+  if (ok && sqlite3_stricmp(paramName, "plaintext_header_size") == 0 && value > 0)
+  {
+    ok = value % 16 == 0;
   }
   return ok;
 }
@@ -306,7 +310,7 @@ sqlite3mc_config_cipher(sqlite3* db, const char* cipherName, const char* paramNa
       if (!hasMinPrefix && !hasMaxPrefix)
       {
         if (newValue >= 0 && newValue >= param->m_minValue && newValue <= param->m_maxValue &&
-            checkLegacyPageSize(paramName, newValue))
+            checkParameterValue(paramName, newValue))
         {
           if (hasDefaultPrefix)
           {

diff --git a/src/cipher_sqlcipher.c b/src/cipher_sqlcipher.c
@@ -338,6 +338,8 @@ GetHmacSizeSQLCipherCipher(int algorithm)
       hmacSize = SHA1_DIGEST_SIZE;
       break;
     case SQLCIPHER_HMAC_ALGORITHM_SHA256:
+      hmacSize = SHA256_DIGEST_SIZE;
+      break;
     case SQLCIPHER_HMAC_ALGORITHM_SHA512:
     default:
       hmacSize = SHA512_DIGEST_SIZE;

diff --git a/src/codecext.c b/src/codecext.c
@@ -380,6 +380,8 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
   Codec* codec;
   int codecAllocated = 0;
   int rc = SQLITE_ERROR;
+  char* err = NULL;
+
   if (zKey != NULL && nKey < 0)
   {
     /* Key is zero-terminated string */
@@ -450,22 +452,17 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
         if (nReserved != nReservedWriteCipher)
         {
           /* Use VACUUM to change the number of reserved bytes */
-          char* err = NULL;
           sqlite3mcSetReadReserved(codec, nReserved);
           sqlite3mcSetWriteReserved(codec, nReservedWriteCipher);
           rc = sqlite3mcRunVacuumForRekey(&err, db, dbIndex, NULL, nReservedWriteCipher);
-          if (rc != SQLITE_OK && err != NULL)
-          {
-            sqlite3ErrorWithMsg(db, rc, err);
-          }
           goto leave_rekey;
         }
       }
       else
       {
         /* Pagesize cannot be changed for an encrypted database */
         rc = SQLITE_ERROR;
-        sqlite3ErrorWithMsg(db, rc, "Rekeying failed. Pagesize cannot be changed for an encrypted database.");
+        err = "Rekeying failed. Pagesize cannot be changed for an encrypted database.";
         goto leave_rekey;
       }
     }
@@ -491,10 +488,6 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
       sqlite3mcSetReadReserved(codec, nReserved);
       sqlite3mcSetWriteReserved(codec, 0);
       rc = sqlite3mcRunVacuumForRekey(&err, db, dbIndex, NULL, 0);
-      if (rc != SQLITE_OK && err != NULL)
-      {
-        sqlite3ErrorWithMsg(db, rc, err);
-      }
       goto leave_rekey;
     }
   }
@@ -516,25 +509,21 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
           sqlite3mcSetReadReserved(codec, nReserved);
           sqlite3mcSetWriteReserved(codec, nReservedWriteCipher);
           rc = sqlite3mcRunVacuumForRekey(&err, db, dbIndex, NULL, nReservedWriteCipher);
-          if (rc != SQLITE_OK && err != NULL)
-          {
-            sqlite3ErrorWithMsg(db, rc, err);
-          }
           goto leave_rekey;
         }
       }
       else
       {
         /* Pagesize cannot be changed for an encrypted database */
         rc = SQLITE_ERROR;
-        sqlite3ErrorWithMsg(db, rc, "Rekeying failed. Pagesize cannot be changed for an encrypted database.");
+        err = "Rekeying failed. Pagesize cannot be changed for an encrypted database.";
         goto leave_rekey;
       }
     }
     else
     {
       /* Setup of write cipher failed */
-      sqlite3ErrorWithMsg(db, rc, "Rekeying failed. Setup of write cipher failed.");
+      err = "Rekeying failed. Setup of write cipher failed.";
       goto leave_rekey;
     }
   }
@@ -599,7 +588,6 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
     {
       sqlite3mcSetIsEncrypted(codec, 0);
     }
-    mcReportCodecError(sqlite3mcGetBtShared(codec), rc);
   }
   else
   {
@@ -622,6 +610,10 @@ sqlite3_rekey_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
     /* Remove codec for unencrypted database */
     sqlite3mcSetCodec(db, zDbName, dbFileName, NULL);
   }
+  if (rc != SQLITE_OK && err != NULL)
+  {
+    sqlite3ErrorWithMsg(db, rc, err);
+  }
   return rc;
 }