ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with local SQL databases in AIR
Creating an encrypted database
Adobe AIR 1.5 and later
To use an encrypted database, the database file must be encrypted when it is created. Once a database is created as
unencrypted, it can’t be encrypted later. Likewise, an encrypted database can’t be unencrypted later. If needed you can
change the encryption key of an encrypted database. For details, see “Changing the encryption key of a database” on
page 760. If you have an existing database that’s not encrypted and you want to use database encryption, you can create
a new encrypted database and copy the existing table structure and data to the new database.
Creating an encrypted database is nearly identical to creating an unencrypted database, as described in “Creating a
database” on page 718. You first create a SQLConnection instance that represents the connection to the database. You
create the database by calling the SQLConnection object’s open() method or openAsync() method, specifying for the
database location a file that doesn’t exist yet. The only difference when creating an encrypted database is that you
provide a value for the encryptionKey parameter (the open() method’s fifth parameter and the openAsync()
method’s sixth parameter).
A valid encryptionKey parameter value is a ByteArray object containing exactly 16 bytes.
The following examples demonstrate creating an encrypted database. For simplicity, in these examples the encryption
key is hard-coded in the application code. However, this technique is strongly discouraged because it is not secure.
var conn:SQLConnection = new SQLConnection();
var encryptionKey:ByteArray = new ByteArray();
encryptionKey.writeUTFBytes("Some16ByteString"); // This technique is not secure!
// Create an encrypted database in asynchronous mode
conn.openAsync(dbFile, SQLMode.CREATE, null, false, 1024, encryptionKey);
// Create an encrypted database in synchronous mode
conn.open(dbFile, SQLMode.CREATE, false, 1024, encryptionKey);
For an example demonstrating a recommended way to generate an encryption key, see “Example: Generating and
using an encryption key” on page 762.
Connecting to an encrypted database
Adobe AIR 1.5 and later
Like creating an encrypted database, the procedure for opening a connection to an encrypted database is like
connecting to an unencrypted database. That procedure is described in greater detail in “Connecting to a database” on
page 725. You use the open() method to open a connection in synchronous execution mode, or the openAsync()
method to open a connection in asynchronous execution mode. The only difference is that to open an encrypted
database, you specify the correct value for the encryptionKey parameter (the open() method’s fifth parameter and
the openAsync() method’s sixth parameter).
If the encryption key that’s provided is not correct, an error occurs. For the open() method, a SQLError exception is
thrown. For the openAsync() method, the SQLConnection object dispatches a SQLErrorEvent, whose error
property contains a SQLError object. In either case, the SQLError object generated by the exception has the errorID
property value 3138. That error ID corresponds to the error message “File opened is not a database file.”
The following example demonstrates opening an encrypted database in asynchronous execution mode. For simplicity,
in this example the encryption key is hard-coded in the application code. However, this technique is strongly
discouraged because it is not secure.
Last updated 6/6/2012
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