implement Cipher; include "sys.m"; include "keyring.m";	kr: Keyring;	DESstate: import kr; include "sshio.m"; Cipherstate: adt{	enc: ref DESstate;	dec: ref DESstate;}; cs: ref Cipherstate; id(): int{	return SSH_CIPHER_DES;} init(key: array of byte, nil: int){	kr = load Keyring Keyring->PATH;	cs = ref Cipherstate(kr->dessetup(key, nil), kr->dessetup(key, nil));} encrypt(buf: array of byte, nbuf: int){	kr->descbc(cs.enc, buf, nbuf, Keyring->Encrypt);} decrypt(buf: array of byte, nbuf: int){	kr->descbc(cs.dec, buf, nbuf, Keyring->Decrypt);}