Add "--masterkey=" parameter for recovery purposes

1 files changed, 54 insertions, 0 deletions

diff --git a/gocryptfs_main/masterkey.go b/gocryptfs_main/masterkey.go
new file mode 100644
index 0000000..205f2ab
--- /dev/null
+++ b/gocryptfs_main/masterkey.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"os"
+	"fmt"
+	"encoding/hex"
+	"strings"
+	"github.com/rfjakob/gocryptfs/cryptfs"
+)
+
+
+// printMasterKey - remind the user that he should store the master key in
+// a safe place
+func printMasterKey(key []byte) {
+	h := hex.EncodeToString(key)
+	var hChunked string
+
+	// Try to make it less scary by splitting it up in chunks
+	for i := 0; i < len(h); i+=8 {
+		hChunked += h[i:i+8]
+		if i < 52 {
+			hChunked += "-"
+		}
+		if i == 24 {
+			hChunked += "\n                      "
+		}
+	}
+
+	fmt.Printf(`
+ATTENTION:
+
+  Your master key is: %s
+
+If the gocryptfs.conf file becomes corrupted or you ever forget your password,
+there is only one hope for recovery: The master key. Print it to a piece of
+paper and store it in a drawer.
+
+`, hChunked)
+}
+
+// Parse a hex-encoded master key that was passed on the command line
+func parseMasterKey(masterkey string) []byte {
+	masterkey = strings.Replace(masterkey, "-", "", -1)
+	key, err := hex.DecodeString(masterkey)
+	if err != nil {
+		fmt.Printf("Could not parse master key: %v\n", err)
+		os.Exit(1)
+	}
+	if len(key) != cryptfs.KEY_LEN {
+		fmt.Printf("Master key has length %d but we require length %d\n", len(key), cryptfs.KEY_LEN)
+		os.Exit(1)
+	}
+	return key
+}