#include <u.h>#include <libc.h>#include <auth.h>#include <fcall.h>#include <thread.h>#include <9p.h> Tree *authtree; typedef struct Crypt	Crypt;struct Crypt{	Ticket		t;	Authenticator	a;	char		tbuf[TICKETLEN];	/* remote ticket */}; enum {	Qauthcheck,	Qauthenticator,	Qauthserver,	Qcs,	Qhostowner,	Qkey,	Quser,}; char user[NAMELEN];char hostowner[NAMELEN];char authserver[NAMELEN];char key[DESKEYLEN]; static char Ebadarg[] = "bad argument in system call";static char Eperm[] = "permission denied"; Crypt*newcrypt(void){	Crypt *c; 	c = malloc(sizeof *c);	if(c == nil)		sysfatal("out of memory");	memset(c, 0, sizeof *c);	return c;} voidfreecrypt(Crypt *c){	free(c);} char*oserror(void){	static char buf[ERRLEN]; 	buf[0] = 0;	errstr(buf);	return buf;} voidauthopen(Req *r, Fid *fid, int omode, Qid*){	int fd; 	switch((long)fid->file->aux){	case Qcs:		fd = open("/net/cs", omode);		if(fd < 0){			respond(r, oserror());			return;		} 		fid->aux = (void*)fd;		break;	}	respond(r, nil);} /* *  called by devcons() for #c/authcheck * *  a write of a ticket+authenticator [+challenge+id] succeeds if they match */char*authcheckwrite(Fid *c, char *a, long *n, vlong){	Crypt *cp;	char *chal;	ulong id; 	if(*n != TICKETLEN+AUTHENTLEN && *n != TICKETLEN+AUTHENTLEN+CHALLEN+4)		return Ebadarg;	if(c->aux == 0)		c->aux = newcrypt();	cp = c->aux; 	memmove(cp->tbuf, a, TICKETLEN);	convM2T(cp->tbuf, &cp->t, key);	if(cp->t.num != AuthTc)		return(Ebadarg);	if(strcmp(user, cp->t.cuid))		return(cp->t.cuid); 	memmove(cp->tbuf, a+TICKETLEN, AUTHENTLEN);	convM2A(cp->tbuf, &cp->a, cp->t.key);	if(*n == TICKETLEN+AUTHENTLEN+CHALLEN+4){		uchar *p = (uchar *)&a[TICKETLEN+AUTHENTLEN+CHALLEN];		id = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);		chal = &a[TICKETLEN+AUTHENTLEN];	}else{		id = 0;		chal = cp->t.chal;	}	if(cp->a.num != AuthAs || memcmp(chal, cp->a.chal, CHALLEN) || cp->a.id != id)		return(Eperm);	return nil;} /* *  reading authcheck after writing into it yields the *  unencrypted ticket */char*authcheckread(Fid *c, char *a, long *n, vlong){	Crypt *cp; 	cp = c->aux;	if(cp == nil)		return(Ebadarg);	if(*n < TICKETLEN)		return(Ebadarg);	convT2M(&cp->t, a, nil);	*n = sizeof(cp->t);	return nil;} /* *  called by devcons() for #c/authenticator * *  a read after a write of a ticket (or ticket+id) returns an authenticator *  for that ticket. */char*authentwrite(Fid *c, char *a, long *n, vlong){	Crypt *cp; 	if(*n != TICKETLEN && *n != TICKETLEN+4)		return(Ebadarg);	if(c->aux == 0)		c->aux = newcrypt();	cp = c->aux; 	memmove(cp->tbuf, a, TICKETLEN);	convM2T(cp->tbuf, &cp->t, key);	if(cp->t.num != AuthTc || strcmp(cp->t.cuid, user)){		freecrypt(cp);		c->aux = 0;		return(Ebadarg);	}	if(*n == TICKETLEN+4){		uchar *p = (uchar *)&a[TICKETLEN];		cp->a.id = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);	}else		cp->a.id = 0; 	return nil;} /* *  create an authenticator and return it and optionally the *  unencripted ticket */char*authentread(Fid *c, char *a, long *n, vlong){	Crypt *cp; 	cp = c->aux;	if(cp == 0)		return("authenticator read must follow a write"); 	cp->a.num = AuthAc;	memmove(cp->a.chal, cp->t.chal, CHALLEN);	convA2M(&cp->a, cp->tbuf, cp->t.key); 	if(*n >= AUTHENTLEN)		memmove(a, cp->tbuf, AUTHENTLEN);	return nil;} char*keyread(Fid*, char*, long *n, vlong offset){	if(*n<DESKEYLEN || offset != 0)		return(Ebadarg);	return(Eperm);} char*keywrite(Fid*, char *a, long *n, vlong){	if(*n != DESKEYLEN)		return(Ebadarg);	memmove(key, a, DESKEYLEN);	return nil;} voidauthclunkaux(Fid *fid){	switch((long)fid->file->aux){	case Qauthcheck:	case Qauthenticator:		free(fid->aux);		fid->aux = nil;		break;	case Qcs:		close((int)fid->aux);		fid->aux = (void*)-1;		break;	}} voidauthread(Req *r, Fid *fid, void *buf, long *count, vlong offset){	int n;	switch((long)fid->file->aux){	case Qauthcheck:		respond(r, authcheckread(fid, buf, count, offset));		break;	case Qauthenticator:		respond(r, authentread(fid, buf, count, offset));		break;	case Qauthserver:		readstr(offset, buf, count, authserver);		respond(r, nil);		break;	case Qcs:		if(offset != 0){			*count = 0;			respond(r, nil);			break;		}		seek((int)fid->aux, 0, 0);		n = read((int)fid->aux, buf, *count);		if(n < 0)			respond(r, oserror());		else{			*count = n;			respond(r, nil);		}		break;	case Qhostowner:		readstr(offset, buf, count, hostowner);		respond(r, nil);		break;	case Qkey:		respond(r, keyread(fid, buf, count, offset));		break;	case Quser:		readstr(offset, buf, count, user);		respond(r, nil);		break;	default:		abort();	}} char Eoffset[] = "nonzero offset in write"; char*namewrite(char *dst, char *src, long *count, vlong offset){	int i;	if(offset != 0)		return Eoffset;	if(*count < 0 || *count > NAMELEN)		return "bad count in write"; 	memmove(dst, src, *count);	if(*count >= NAMELEN)		i = NAMELEN-1;	else		i = *count;	dst[i] = 0;	while(i > 0 && dst[i-1] == ' ' || dst[i-1] == '\n' || dst[i-1] == '\t')		dst[--i] = 0;		return nil;} voidauthwrite(Req *r, Fid *fid, void *buf, long *count, vlong offset){	char s[128];	char t[128];	char *p; 	switch((long)fid->file->aux){	case Qauthcheck:		respond(r, authcheckwrite(fid, buf, count, offset));		break;	case Qauthenticator:		respond(r, authentwrite(fid, buf, count, offset));		break;	case Qauthserver:		respond(r, namewrite(authserver, buf, count, offset));		break;	case Qcs:		if(*count > sizeof(s)-1){			respond(r, "count too big");			break;		}		memmove(s, buf, *count);		s[*count] = 0;		if(p = strstr(s, "$auth"))			snprint(t, sizeof t, "%.*s%s%s", utfnlen(s, p-s), s, authserver, p+strlen("$auth"));		else			strcpy(t, s); 		seek((int)fid->aux, 0, 0);		if(write((int)fid->aux, t, strlen(t)) != strlen(t)){			respond(r, oserror());			break;		}		respond(r, nil);		break;	case Qhostowner:		respond(r, namewrite(hostowner, buf, count, offset));		break;	case Qkey:		respond(r, keywrite(fid, buf, count, offset));		break;	case Quser:		respond(r, namewrite(user, buf, count, offset));		break;	default:		abort();	}} voidmkfile(char *name, int v){	File *f;	f = fcreate(authtree->root, name, user, user, 0666);	if(f == nil)		sysfatal("creating %s", name);	f->aux = (void*)v;} Srv authsrv = {	.open=	authopen,	.read=	authread,	.write=	authwrite,	.clunkaux=	authclunkaux,}; intreadln(char *prompt, char *line, int len){	char *p;	int fd, ctl, n, nr; 	fd = open("/dev/cons", ORDWR);	if(fd < 0)		sysfatal("couldn't open cons");	ctl = open("/dev/consctl", OWRITE);	if(ctl < 0)		sysfatal("couldn't set raw mode");	write(ctl, "rawon", 5);	fprint(fd, "%s", prompt);	nr = 0;	p = line;	for(;;){		n = read(fd, p, 1);		if(n < 0){			close(fd);			close(ctl);			return -1;		}		if(n == 0 || *p == '\n' || *p == '\r'){			*p = '\0';			write(fd, "\n", 1);			close(fd);			close(ctl);			return nr;		}		if(*p == '\b'){			if(nr > 0){				nr--;				p--;			}		}else if(*p == 21){		/* cntrl-u */			fprint(fd, "\n%s", prompt);			nr = 0;			p = line;		}else{			nr++;			p++;		}		if(nr == len){			fprint(fd, "line too long; try again\n%s", prompt);			nr = 0;			p = line;		}	}	return -1;} voidusage(void){	fprint(2, "usage: authfs [-a authsrv] [-u user] [-h hostowner] [-p]\n");	exits("usage");} voidmain(int argc, char **argv){	char *u;	long l;	char pass[32]; 	rfork(RFNOTEG);	strcpy(authserver, "$auth"); 	u = getuser();	if(u == nil)		u = "none";	strcpy(user, u); 	ARGBEGIN{	case 'a':		u = EARGF(usage());		l = strlen(u);		namewrite(authserver, u, &l, 0);		break;	case 'u':		u = EARGF(usage());		l = strlen(u);		namewrite(user, u, &l, 0);		break;	case 'h':		u = EARGF(usage());		l = strlen(u);		namewrite(hostowner, u, &l, 0);		break;	case 'p':		readln("Password: ", pass, sizeof pass);		passtokey(key, pass);		break;	case 'v':		lib9p_chatty++;		break;	default:		usage();	}ARGEND; 	if(hostowner[0] == 0)		strcpy(hostowner, user); 	if(argc != 0)		usage(); 	authtree = mktree(user, user, CHDIR|0555);	authsrv.tree = authtree;	mkfile("authcheck", Qauthcheck);	mkfile("authenticator", Qauthenticator);	mkfile("authserver", Qauthserver);	mkfile("cs", Qcs);	mkfile("hostowner", Qhostowner);	mkfile("key", Qkey);	mkfile("user", Quser); 	postmountsrv(&authsrv, nil, "/dev", MBEFORE);	bind("/dev/cs", "/net/cs", MREPL);	exits(0);}