trezor: show support in version string

Show enable_trezor in the version string if we were compiled
with `-tags enable_trezor`. And hide the `-trezor` flag from
the help output if we were not.

2 files changed, 5 insertions, 1 deletions

diff --git a/internal/readpassword/trezor.go b/internal/readpassword/trezor.go
index 43e2805..a4d32cf 100644
--- a/internal/readpassword/trezor.go
+++ b/internal/readpassword/trezor.go
@@ -21,6 +21,8 @@ const (
 	trezorNonce             = "" // the "nonce" is optional and has no use in here
 	trezorKeyName           = "gocryptfs"
 	trezorKeyDerivationPath = `m/10019'/0'`
+	// TrezorSupport is true when gocryptfs has been compile with -tags enable_trezor
+	TrezorSupport = true
 )
 
 func trezorGetPin(title, description, ok, cancel string) ([]byte, error) {
diff --git a/internal/readpassword/trezor_disabled.go b/internal/readpassword/trezor_disabled.go
index c512f1b..96a6082 100644
--- a/internal/readpassword/trezor_disabled.go
+++ b/internal/readpassword/trezor_disabled.go
@@ -12,12 +12,14 @@ const (
 	// TrezorPayloadLen is the length of the payload data passed to Trezor's
 	// CipherKeyValue function.
 	TrezorPayloadLen = 32
+	// TrezorSupport is true when gocryptfs has been compile with -tags enable_trezor
+	TrezorSupport = false
 )
 
 // Trezor determinitically derives 32 bytes from the payload and the connected
 // USB security module.
 func Trezor(payload []byte) []byte {
-	tlog.Fatal.Printf("\"-trezor\" is not implemented yet.")
+	tlog.Fatal.Printf("This binary has been compiled without Trezor support")
 	os.Exit(1)
 	return nil
 }