Default settings for encryption are to encrypt using rijndael-128 (AES)
algorithm, in cfb mode (with an IV), and attach a sha1 checksum to the
encrypted file to check for errors in transmission. There is a number of
global enc_* variables defined in seekcrypt_internal.h which
control this behavior. CAVEAT: THESE VARIABLES ARE INTERNAL TO THE
IMPLEMENTATION, AND WILL LIKELY CHANGE IN THE FUTURE, THUS BREAKING YOUR
CODE. So don't touch them unless you really need to change the encryption
details.
Any cipher from libmcrypt and any hash algorithm from libmhash can
be used. However, for now you can only use stream modes (such as cfb)
for encryption/decryption. Also, note the caveat from the previous
paragraph.
The files produced by encio will be readable by MCrypt, version
2.6. Similarly, encio can read files produced by MCrypt, version 2.6,
if they're in stream mode (eg., cfb).