Apply minor adjustments

- Allow empty passphrase for `PRAGMA key`
- Allow to fully disable including of user authentication by defining `SQLITE_USER_AUTHENTICATION=0`

Author: utelle

configure.ac

@@ -4,7 +4,7 @@ dnl Copyright (C) 2019-2021 Ulrich Telle <[email protected]>
 dnl
 dnl This file is covered by the same licence as the entire SQLite3 Multiple Ciphers package.
 
-AC_INIT([sqlite3mc], [1.3.3], [[email protected]])
+AC_INIT([sqlite3mc], [1.3.4], [[email protected]])
 
 dnl This is the version tested with, might work with earlier ones.
 AC_PREREQ([2.69])

readme.md

@@ -12,6 +12,9 @@ The code was mainly developed under Windows, but was tested under Linux as well.
 
 ## Version history
 
+* 1.3.4 - *July 2021* (pending)
+  - Allow empty passphrase for `PRAGMA key`
+  - Allow to fully disable including of user authentication by defining `SQLITE_USER_AUTHENTICATION=0`
 * 1.3.3 - *June 2021*
   - Based on SQLite version 3.36.0
 * 1.3.2 - *May 2021*

src/codecext.c

@@ -243,6 +243,11 @@ sqlite3mcCodecAttach(sqlite3* db, int nDb, const char* zPath, const void* zKey,
     {
       /* Main database not encrypted, no key given for attached database */
       sqlite3mcCodecFree(codec);
+      /* Remove codec for main database */
+      if (nDb == 0 && nKey == 0)
+      {
+        sqlite3mcSetCodec(db, dbFileName, NULL);
+      }
     }
   }
   else
@@ -322,7 +327,8 @@ sqlite3_key_v2(sqlite3* db, const char* zDbName, const void* zKey, int nKey)
     /* Key is zero-terminated string */
     nKey = sqlite3Strlen30((const char*) zKey);
   }
-  if ((db != NULL) && (zKey != NULL) && (nKey > 0))
+  /* Database handle db and key must be given, but key length 0 is allowed */
+  if ((db != NULL) && (zKey != NULL) && (nKey >= 0))
   {
     int dbIndex;
     const char* dbFileName = sqlite3_db_filename(db, zDbName);

src/sqlite3mc.c

@@ -45,8 +45,15 @@ void sqlite3mc_shutdown(void);
 /*
 ** Enable the user authentication feature
 */
+#if !SQLITE_USER_AUTHENTICATION
+/* Option not defined or explicitly disabled */
 #ifndef SQLITE_USER_AUTHENTICATION
+/* Option not defined, therefore enable by default */
 #define SQLITE_USER_AUTHENTICATION 1
+#else
+/* Option defined and disabled, therefore undefine option */
+#undef SQLITE_USER_AUTHENTICATION
+#endif
 #endif
 
 #if defined(_WIN32) || defined(WIN32)

src/sqlite3mc_version.h

@@ -14,8 +14,8 @@
 
 #define SQLITE3MC_VERSION_MAJOR      1
 #define SQLITE3MC_VERSION_MINOR      3
-#define SQLITE3MC_VERSION_RELEASE    3
+#define SQLITE3MC_VERSION_RELEASE    4
 #define SQLITE3MC_VERSION_SUBRELEASE 0
-#define SQLITE3MC_VERSION_STRING     "SQLite3 Multiple Ciphers 1.3.3"
+#define SQLITE3MC_VERSION_STRING     "SQLite3 Multiple Ciphers 1.3.4"
 
 #endif /* SQLITE3MC_VERSION_H_ */

src/sqlite3mc_vfs.c

@@ -244,18 +244,21 @@ SQLITE_PRIVATE void sqlite3mcSetCodec(sqlite3* db, const char* zFileName, Codec*
   sqlite3mc_file* pDbMain = mcFindDbMainFileName(&mcVfsGlobal, zFileName);
   if (pDbMain)
   {
-    if (pDbMain->codec)
+    Codec* prevCodec = pDbMain->codec;
+    Codec* msgCodec = (codec) ? codec : prevCodec;
+    if (msgCodec)
+    {
+      /* Reset error state of pager */
+      mcReportCodecError(sqlite3mcGetBtShared(msgCodec), SQLITE_OK);
+    }
+    if (prevCodec)
     {
       /*
       ** Free a codec that was already associated with this main database file handle
       */
-      sqlite3mcCodecFree(pDbMain->codec);
+      sqlite3mcCodecFree(prevCodec);
     }
     pDbMain->codec = codec;
-    if (codec)
-    {
-      mcReportCodecError(sqlite3mcGetBtShared(codec), SQLITE_OK);
-    }
   }
   else
   {