"FFFFFF"s in encrypted data ?

[kutlay]

Hi, when i try the example code it gives me this. The encrypted data is not normal, and more than 32byte because of the FFFFFF's. What are they ? I couldn't understand the problem. When i tried to write bytes one by one ( by doing a for loop ) i didn't get them.

Initializing AES256... 
Key: 
000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F
Unencrypted data: 
61736466617364666173646661736466
Encrypted data: 
024117FFFFFFFD2E737145582CFFFFFF976F47FFFFFFBEFFFFFFDA20
Back decrypted data: 
61736466617364666173646661736466

[qistoph]

It looks like there might be something going on with signed vs unsigned types...