1 /* delimited, authenticated, encrypted connection */
2 enum{ Maxmsg=4096 };	/* messages > Maxmsg bytes are truncated */
3 typedef struct SConn SConn;
4 
5 extern SConn* newSConn(int);	/* arg is open file descriptor */
6 struct SConn{
7 	void *chan;
8 	int secretlen;
9 	int (*secret)(SConn*, uchar*, int);/*  */
10 	int (*read)(SConn*, uchar*, int); /* <0 if error;  errmess in buffer */
11 	int (*write)(SConn*, uchar*, int);
12 	void (*free)(SConn*);		/* also closes file descriptor */
13 };
14 /* secret(s,b,dir) sets secret for digest, encrypt, using the secretlen */
15 /*		bytes in b to form keys 	for the two directions; */
16 /*	  set dir=0 in client, dir=1 in server */
17 
18 /* error convention: write !message in-band */
19 extern void writerr(SConn*, char*);
20 extern int readstr(SConn*, char*);  /* call with buf of size Maxmsg+1 */
21 	/* returns -1 upon error, with error message in buf */
22 
23 extern void *emalloc(ulong); /* dies on failure; clears memory */
24 extern void *erealloc(void *, ulong);
25 extern char *estrdup(char *);
26