#include <u.h>#include <libc.h>#include <mp.h>#include <libsec.h> voidusage(void){	fprint(2, "usage: tlsclient [-t /sys/lib/tls/xxx] [-x /sys/lib/tls/xxx.exclude] dialstring\n");	exits("usage");} voidxfer(int from, int to){	char buf[12*1024];	int n; 	while((n = read(from, buf, sizeof buf)) > 0)		if(write(to, buf, n) < 0)			break;} voidmain(int argc, char **argv){	int fd, netfd;	uchar digest[20];	TLSconn conn;	char *addr, *file, *filex;	Thumbprint *thumb; 	file = nil;	filex = nil;	thumb = nil;	ARGBEGIN{	case 't':		file = EARGF(usage());		break;	case 'x':		filex = EARGF(usage());		break;	default:		usage();	}ARGEND 	if(argc != 1)		usage(); 	if(filex && !file)			sysfatal("specifying -x without -t is useless");	if(file){		thumb = initThumbprints(file, filex);		if(thumb == nil)			sysfatal("initThumbprints: %r");	} 	addr = argv[0];	if((netfd = dial(addr, 0, 0, 0)) < 0)		sysfatal("dial %s: %r", addr); 	memset(&conn, 0, sizeof conn);	fd = tlsClient(netfd, &conn);	if(fd < 0)		sysfatal("tlsclient: %r");	if(thumb){		if(conn.cert==nil || conn.certlen<=0)			sysfatal("server did not provide TLS certificate");		sha1(conn.cert, conn.certlen, digest, nil);		if(!okThumbprint(digest, thumb)){			fmtinstall('H', encodefmt);			sysfatal("server certificate %.*H not recognized", SHA1dlen, digest);		}	}	free(conn.cert);	close(netfd); 	rfork(RFNOTEG);	switch(fork()){	case -1:		fprint(2, "%s: fork: %r\n", argv0);		exits("dial");	case 0:		xfer(0, fd);		break;	default:		xfer(fd, 1);		break;	}	postnote(PNGROUP, getpid(), "die yankee pig dog");	exits(0);}