[DBD-SQLite] Adding support for SQLCipher.

[Dmitri Tikhonov]

Hello,

I have been working with SQLCipher [1] and I have noticed that DBD::SQLite does not work out of the box with it.  In order to use an encrypted database, the first thing that should happen is to issue a pragma that specifies the key to decrypt pages.  I modified the login function (the patch is attached) to use the password, if set, as the key.

I was hoping this (or a modified, but equivalent) change could be made to the main line: it should not break existing code and will make DBD::SQLite work with SQLCipher.

  - Dmitri.

1. "SQLCipher is an open source extension that provides transparent encryption of SQLite databases. Data pages are encrypted before being written to storage and decrypted on read."  http://www.zetetic.net/software/sqlcipher/



      
-------------- next part --------------
Index: dbdimp.c
===================================================================
--- dbdimp.c	(revision 31)
+++ dbdimp.c	(revision 32)
@@ -106,6 +106,28 @@
 
     sqlite3_busy_timeout(imp_dbh->db, SQL_TIMEOUT);
 
+    if (pass) {
+        /* If password is set, issue pragma to decrypt the database.  Works
+         * with SQLCipher.
+         */
+        char pragma[0x100];
+        if (snprintf(pragma, sizeof(pragma), "PRAGMA key='%s'", pass) >=
+            sizeof(pragma))
+        {
+            sqlite_error(dbh, (imp_xxh_t*)imp_dbh, 1,
+                         strdup("password too long"));
+            return FALSE;
+        }
+
+        if ((retval = sqlite3_exec(imp_dbh->db, pragma, NULL, NULL, &errmsg))
+            != SQLITE_OK)
+        {
+            /*  warn("failed to set pragma: %s\n", errmsg); */
+            sqlite_error(dbh, (imp_xxh_t*)imp_dbh, retval, errmsg);
+            return FALSE;
+        }
+    }
+
     if ((retval = sqlite3_exec(imp_dbh->db, "PRAGMA empty_result_callbacks = ON",
         NULL, NULL, &errmsg))
         != SQLITE_OK)