krb5_roundup
plaintext.length=krb5_roundup(input->length+CONFOUNDERLENGTH,blocksize);
ciphertext.length=krb5_roundup(input->length+CONFOUNDERLENGTH,blocksize);
*length = hashsize + krb5_roundup(8 + inputlen, blocksize);
*length = krb5_roundup(blocksize+inputlen, blocksize) + hashsize;
plainlen = krb5_roundup(blocksize+input->length, blocksize);
*length = krb5_roundup(blocksize+hashsize+inputlen, blocksize);
*length = krb5_roundup(inputlen, blocksize);
#ifndef krb5_roundup