An issue of sqlite3_key function

[pal98]

Hello:
I am using "sqlite3_key" and "sqlite3_rekey" for my project, it nearly works, only one issue.
Here's my code :

    /* function of open a datebase with password */
    bool SQLite3DB::OpenDb(const char *dbName, const char *pw)
    {
	    int nResult = sqlite3_open(dbName, &db);
	    nResult = sqlite3_key(db, pw, strlen(pw));
            .......
     }
     
     /* function of reset password for a datebase*/
    bool SQLite3DB::SetDbPassword(const char *pw)
    {
	    if (sqlite3_rekey(db, pw, strlen(pw)) == SQLITE_OK)
		    return true;
	    else
		    return false;
    }

The problem is, when I call the function of "sqlite3_key", it always returns 0 (nResult is always 0), no matter the password (pw value) is correct or not.

While the function of "sqlite3_rekey" returns the value of 0 if the password is correct(for "sqlite3_key" function) and returns Nonzero value if the password is wrong.

Please give me some suggestion on how to determine whether the datebase password is correct or not by call "sqlite3_key" function.

[utelle]

The problem is, when I call the function of "sqlite3_key", it always returns 0 (nResult is always 0), no matter the password (pw value) is correct or not.

Well, this is by design. The function sqlite3_key does not check whether the database is actually encrypted or not. This is documented in the description of the official SQLite Encryption Extension (SEE) - and this project does not change the behaviour. Here is the relevant quote from the documentation:

If you specify an incorrect key, you will not get an error message right away. But the first time you try to access the database you will get an SQLITE_NOTADB error with a message of "file is encrypted or is not a database".

If you want to check whether the given password is correct or not, you have to issue an SQL command that actually accesses the database (like for example SELECT count(*) FROM SQLITE_SCHEMA;. If you get the SQLITE_NOTADB error, you can then display a message to the user, ask for the correct password, and repeat the call to sqlite3_key.

While the function of "sqlite3_rekey" returns the value of 0 if the password is correct(for "sqlite3_key" function) and returns Nonzero value if the password is wrong.

This is not surprising, because sqlite3_rekey accesses the database file, and if the password given in sqlite3_key was wrong, you will get an error, of course.

Please give me some suggestion on how to determine whether the datebase password is correct or not by call "sqlite3_key" function.

As said sqlite3_key does not check whether the password is correct or not. sqlite3_key will only fail, if the encryption scheme could not be set up correctly. For example, you can't set up encryption for a memory database or a temporary database.