implement Createsignerkey; include "sys.m";	sys: Sys; include "draw.m"; include "daytime.m"; include "ipints.m";include "crypt.m";	crypt: Crypt; include "oldauth.m";	oldauth: Oldauth; include "arg.m"; # signer key never expiresSKexpire:       con 0; # size in bits of modulus for public keysPKmodlen:		con 1024; # size in bits of modulus for diffie hellmanDHmodlen:		con 1024; algs := array[] of {"rsa", "elgamal"};	# first entry is default Createsignerkey: module{	init:	fn(nil: ref Draw->Context, nil: list of string);}; init(nil: ref Draw->Context, args: list of string){	err: string; 	sys = load Sys Sys->PATH;	crypt = load Crypt Crypt->PATH;	oldauth = load Oldauth Oldauth->PATH;	oldauth->init();	arg := load Arg Arg->PATH; 	arg->init(args);	arg->setusage("createsignerkey [-a algorithm] [-f keyfile] [-e ddmmyyyy] [-b size-in-bits] name-of-owner");	alg := algs[0];	filename := "/keydb/signerkey";	expire := SKexpire;	bits := PKmodlen;	while((c := arg->opt()) != 0){		case c {		'a' =>			alg = arg->arg();			if(alg == nil)				arg->usage();			for(i:=0;; i++){				if(i >= len algs)					error(sys->sprint("unknown algorithm: %s", alg));				else if(alg == algs[i])					break;			}		'f' or 'k' =>			filename = arg->earg();		'e' =>			s := arg->earg();			(err, expire) = checkdate(s);			if(err != nil)				error(err);		'b' =>			s := arg->earg();			bits = int s;			if(bits < 32 || bits > 4096)				error("modulus must be in the range of 32 to 4096 bits");		* =>			arg->usage();		}	}	args = arg->argv();	if(args == nil)		arg->usage();	arg = nil; 	owner := hd args; 	# generate a local key, self-signed	info := ref Oldauth->Authinfo;	info.mysk = crypt->genSK(alg, bits);	if(info.mysk == nil)		error(sys->sprint("algorithm %s not configured in system", alg));	info.owner = owner;	info.mypk = crypt->sktopk(info.mysk);	info.spk = crypt->sktopk(info.mysk);	myPKbuf := array of byte oldauth->pktostr(info.mypk, owner);	state := crypt->sha1(myPKbuf, len myPKbuf, nil, nil);	info.cert = oldauth->sign(info.mysk, owner, expire, state, "sha1");	(info.alpha, info.p) = crypt->dhparams(DHmodlen); 	if(oldauth->writeauthinfo(filename, info) < 0)		error(sys->sprint("can't write signerkey file %s: %r", filename));} error(s: string){	sys->fprint(sys->fildes(2), "createsignerkey: %s\n", s);	raise "fail:error";} checkdate(word: string): (string, int){	if(len word != 8)		return ("!date must be in form ddmmyyyy", 0); 	daytime := load Daytime Daytime->PATH; 	now := daytime->now(); 	tm := daytime->local(now);	tm.sec = 59;	tm.min = 59;	tm.hour = 24; 	tm.mday = int word[0:2];	if(tm.mday > 31 || tm.mday < 1)		return ("!bad day of month", 0); 	tm.mon = int word[2:4] - 1;	if(tm.mon > 11 || tm.mday < 0)		return ("!bad month", 0); 	tm.year = int word[4:8] - 1900;	if(tm.year < 70)		return ("!bad year", 0); 	newdate := daytime->tm2epoch(tm);	if(newdate < now)		return ("!expiration date must be in the future", 0); 	return (nil, newdate);}