SEC-3: Digest authentication static method for encoding password about spring-security

[spring-projects-issues]

Ben Alex said:

The correct URL post Spring forum changes is http://forum.springframework.org/showthread.php?t=13292

[spring-projects-issues]

Ben Alex said:

Checked into CVS, unit tests pass. New static method on DigestProcessingFilter:

```
public static String encodePasswordInA1Format(String username, String realm, String password)
```

There is also a property on DigestProcessingFilter, passwordAlreadyEncoded. It should be set to true (it defaults to false) if your AuthenticationDao will present passwords that were encoded using the above form. Obviously the encoded password uses the username and realm name, so these cannot change otherwise the MD5 hash code will be incorrect.