clear() also removes auto-generated key

[inktomi]

When you call clear() on your SecurePreferences instance, it also removes the encryption key used. This means that if you do the following, you can't read out the values you'd expect:

new SecurePreferences(context, "", "file-name");
.putString("foo", "bar");
.getString("foo")  // returns bar as expected
.clear();
.putString("foo", "bar");

new SecurePreferences(context, "", "file-name");
getString("foo") // returns null since the key was recreated after .clear removed it. 

The problem is that clear() does not also remove the SecureKeys instance, but it does remove the preference that backs it. The following "putString" encrypts with the old SecureKeys instance. Then, when the constructor fires, it can't find the preference and recreates it causing a new SecureKeys instance to be created as well.

[ShinJJang]

In progress? public void handlePasswordChange(String newPassword, Context context, int iterationCount) have same problem. If nobody take out this issue, I'll take it.

[scottyab]

@ShinJJang please do, Thanks!