/*
* Blowfish mechanism for udp tunnel
*
+ * mechanisms: blowfish-cbc, blowfish-cbcmac
* arguments: key size in bits (must be multiple of 8)
*
* key values: 8 byte random IV and n byte random key
*
+ * restrictions: plaintext length must be multiple of block size (8 bytes)
* encoding: do CBC encryption overwriting message
* encoding for MAC: do CBC and prepend last ciphertext block
*/