/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ /* delimited, authenticated, encrypted connection */enum {	Maxmsg	= 4096,		/* messages > Maxmsg bytes are truncated */}; typedef struct SConn SConn;struct SConn {	void 	*chan;	int 	secretlen;	int 	(*secret)(SConn*, uchar*, int);	int 	(*read)(SConn*, uchar*, int); /* <0 if error; errmess in buffer */	int	(*write)(SConn*, uchar*, int);	void	(*free)(SConn*);	/* also closes file descriptor */}; SConn *newSConn(int);			/* arg is open file descriptor */ /* * secret(s,b,dir) sets secret for digest, encrypt, using the secretlen *		bytes in b to form keys 	for the two directions; *	  set dir=0 in client, dir=1 in server */ /* error convention: write !message in-band */void	writerr(SConn*, char*); /* * returns -1 upon error, with error message in buf * call with buf of size Maxmsg+1 */int	readstr(SConn*, char*); void	*emalloc(ulong);		/* dies on failure; clears memory */void	*erealloc(void*, ulong);char	*estrdup(char*);