passfile: directly read file instead of invoking cat

Allows better error handling, gets rid of the call to an
external program, and fixes https://github.com/rfjakob/gocryptfs/issues/278 .

1 files changed, 7 insertions, 3 deletions

diff --git a/cli_args.go b/cli_args.go
index c073958..b3f2834 100644
--- a/cli_args.go
+++ b/cli_args.go
@@ -243,9 +243,13 @@ func parseCliOpts() (args argContainer) {
 		args.allow_other = false
 		args.ko = "noexec"
 	}
-	// '-passfile FILE' is a shortcut for -extpass='/bin/cat -- FILE'
-	if args.passfile != "" {
-		args.extpass = "/bin/cat -- " + args.passfile
+	if args.extpass != "" && args.passfile != "" {
+		tlog.Fatal.Printf("The options -extpass and -passfile cannot be used at the same time")
+		os.Exit(exitcodes.Usage)
+	}
+	if args.passfile != "" && args.masterkey != "" {
+		tlog.Fatal.Printf("The options -passfile and -masterkey cannot be used at the same time")
+		os.Exit(exitcodes.Usage)
 	}
 	if args.extpass != "" && args.masterkey != "" {
 		tlog.Fatal.Printf("The options -extpass and -masterkey cannot be used at the same time")