#include <u.h>#include <libc.h>#include <auth.h>#include "authsrv.h" intreadfile(char *file, char *buf, int n){	int fd; 	fd = open(file, OREAD);	if(fd < 0){		werrstr("%s: %r", file);		return -1;	}	n = read(fd, buf, n);	close(fd);	return n;} intwritefile(char *file, char *buf, int n){	int fd; 	fd = open(file, OWRITE);	if(fd < 0)		return -1;	n = write(fd, buf, n);	close(fd);	return n;} char*findkey(char *db, char *user, char *key){	int n;	char filename[3*NAMELEN]; 	sprint(filename, "%s/%s/key", db, user);	n = readfile(filename, key, DESKEYLEN);	if(n != DESKEYLEN)		return 0;	else		return key;} char*setkey(char *db, char *user, char *key){	int n;	char filename[3*NAMELEN]; 	sprint(filename, "%s/%s/key", db, user);	n = writefile(filename, key, DESKEYLEN);	if(n != DESKEYLEN)		return 0;	else		return key;}