InputStreamDecrypter read() is not InputStream compliant

[spheroid]

The InputStream.read() spec states:

The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned.

The current InputStreamDecrypter.read() currently behaves incorrectly as it returns signed ints which both:

1. Breaks every implementation that relies on this behavior.
2. Masks the -1 return value as it cannot be distinguished from 0xff.

[juergw]

Thanks for finding this! Yes, this is an obvious bug.