factotum: cleanup getnvramkey()

- remove secstore password code, it is not used anymore.
- zero the Nvrsafe structure on the stack before returning.
- use smprint(), can't overflow.

3 files changed, 6 insertions, 16 deletions

diff --git a/sys/src/cmd/auth/factotum/dat.h b/sys/src/cmd/auth/factotum/dat.h
index 10cdc9a34..5cc0c1b8b 100644
--- a/sys/src/cmd/auth/factotum/dat.h
+++ b/sys/src/cmd/auth/factotum/dat.h
@@ -201,7 +201,7 @@ Keyinfo*	mkkeyinfo(Keyinfo*, Fsstate*, Attr*);
 int		findkey(Key**, Keyinfo*, char*, ...);
 int		findp9authkey(Key**, Fsstate*);
 Proto	*findproto(char*);
-char		*getnvramkey(int, char**);
+char		*getnvramkey(int);
 void		initcap(void);
 int		isclient(char*);
 int		matchattr(Attr*, Attr*, Attr*);
diff --git a/sys/src/cmd/auth/factotum/fs.c b/sys/src/cmd/auth/factotum/fs.c
index b9a51d383..7d195ac01 100644
--- a/sys/src/cmd/auth/factotum/fs.c
+++ b/sys/src/cmd/auth/factotum/fs.c
@@ -148,7 +148,7 @@ main(int argc, char **argv)
 	}
 
 	if(sflag){
-		s = getnvramkey(kflag ? NVwrite : NVwriteonerr, nil);
+		s = getnvramkey(kflag ? NVwrite : NVwriteonerr);
 		if(s == nil)
 			fprint(2, "factotum warning: cannot read nvram: %r\n");
 		else if(ctlwrite(s, 0) < 0)
diff --git a/sys/src/cmd/auth/factotum/util.c b/sys/src/cmd/auth/factotum/util.c
index a8eab1db7..411935bc1 100644
--- a/sys/src/cmd/auth/factotum/util.c
+++ b/sys/src/cmd/auth/factotum/util.c
@@ -472,11 +472,10 @@ findproto(char *name)
 }
 
 char*
-getnvramkey(int flag, char **secstorepw)
+getnvramkey(int flag)
 {
-	char *s;
 	Nvrsafe safe;
-	char spw[CONFIGLEN+1];
+	char *s;
 	int i;
 
 	memset(&safe, 0, sizeof safe);
@@ -488,15 +487,6 @@ getnvramkey(int flag, char **secstorepw)
 		return nil;
 
 	/*
-	 *  we're using the config area to hold the secstore
-	 *  password.  if there's anything there, return it.
-	 */
-	memmove(spw, safe.config, CONFIGLEN);
-	spw[CONFIGLEN] = 0;
-	if(spw[0] != 0 && secstorepw != nil)
-		*secstorepw = estrdup(spw);
-
-	/*
 	 *  only use nvram key if it is non-zero
 	 */
 	for(i = 0; i < DESKEYLEN; i++)
@@ -505,11 +495,11 @@ getnvramkey(int flag, char **secstorepw)
 	if(i == DESKEYLEN)
 		return nil;
 
-	s = emalloc(512);
 	fmtinstall('H', encodefmt);
-	sprint(s, "key proto=p9sk1 user=%q dom=%q !hex=%.*H !password=______", 
+	s = smprint("key proto=p9sk1 user=%q dom=%q !hex=%.*H !password=______", 
 		safe.authid, safe.authdom, DESKEYLEN, safe.machkey);
 	writehostowner(safe.authid);
+	memset(&safe, 0, sizeof safe);
 
 	return s;
 }