add function to return current registered provider

sjlombardo · sjlombardo · commit c9ec48ded835 · 2013-06-21T11:11:02.000-04:00
diff --git a/src/crypto_impl.c b/src/crypto_impl.c
@@ -81,13 +81,23 @@ struct codec_ctx {
 };
 
 int sqlcipher_register_provider(sqlcipher_provider *p) {
-  if(default_provider != NULL) {
+  if(default_provider != NULL && default_provider != p) {
+    /* only free the current registerd provider if it has been initialized
+       and it isn't a pointer to the same provider passed to the function
+       (i.e. protect against a caller calling register twice for the same provider) */
     sqlcipher_free(default_provider, sizeof(sqlcipher_provider));
   }
   default_provider = p;   
   return SQLITE_OK;
 }
 
+/* return a pointer to the currently registered provider. This will
+   allow an application to fetch the current registered provider and
+   make minor changes to it */
+sqlcipher_provider* sqlcipher_get_provider() {
+  return default_provider;
+}
+
 void sqlcipher_activate() {
   sqlcipher_provider *p;
   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
diff --git a/src/sqlcipher.h b/src/sqlcipher.h
@@ -65,7 +65,9 @@ int sqlcipher_ismemset(const void *v, unsigned char value, int len);
 int sqlcipher_memcmp(const void *v0, const void *v1, int len);
 void sqlcipher_free(void *, int);
 
+/* provider interfaces */
 int sqlcipher_register_provider(sqlcipher_provider *p);
+sqlcipher_provider* sqlcipher_get_provider();
 
 #endif
 #endif
