tth: redesign api surface

--HG--
branch : adc

tth.go

@@ -8,9 +8,16 @@ import (
 	"github.com/cxmcc/tiger"
 )
 
-// TTH returns the TTH hash of a string. This is a rudimentary implementation
-// that only supports content up to 1024 bytes in length.
-func TTH(input string) (string, error) {
+// Base32 encodes the input slice in BASE32 string format without any trailing
+// padding equals characters.
+func Base32(input []byte) string {
+	return strings.TrimRight(base32.StdEncoding.EncodeToString(input), "=")
+}
+
+// TTH returns the TTH hash of a string in raw byte format. Use the Base32()
+// function to convert it to normal string format.
+// This is a basic implementation that only supports content up to 1024 bytes in length.
+func TTH(input string) ([]byte, error) {
 
 	// Short segments do not need to be padded.
 	// Content above 1024 bytes needs tree handling (0x00 prefix for leaf nodes,
@@ -18,13 +25,11 @@ func TTH(input string) (string, error) {
 	// return the leaf hash
 	// @ref http://adc.sourceforge.net/draft-jchapweske-thex-02.html
 	if len(input) > 1024 {
-		return "", errors.New("TTH content exceeded 1024 bytes")
+		return nil, errors.New("TTH content exceeded 1024 bytes")
 	}
 
 	// Single leaf hash only
 	leafHash := tiger.New()
 	leafHash.Write([]byte("\x00" + input))
-	leafHashBytes := leafHash.Sum(nil)
-
-	return strings.TrimRight(base32.StdEncoding.EncodeToString(leafHashBytes), "="), nil
+	return leafHash.Sum(nil), nil
 }

tth_test.go

@@ -28,7 +28,8 @@ func TestTTH(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Error getting TTH for '%s': %s", short(input), err.Error())
 		}
-		if result != expected {
+
+		if Base32(result) != expected {
 			t.Fatalf("Wrong TTH for '%s' (got '%s' expected '%s')", short(input), result, expected)
 		}
 	}