Merge pull request pquerna#12 from maxvw/10-fix-padding

fix missing padding in secrets

hotp/hotp.go

@@ -70,6 +70,12 @@ func GenerateCode(secret string, counter uint64) (string, error) {
 // GenerateCodeCustom uses a counter and secret value and options struct to
 // create a passcode.
 func GenerateCodeCustom(secret string, counter uint64, opts ValidateOpts) (passcode string, err error) {
+	// As noted in issue #10 this adds support for TOTP secrets that are
+	// missing their padding.
+	if n := len(secret) % 8; n != 0 {
+		secret = secret + strings.Repeat("=", 8-n)
+	}
+
 	secretBytes, err := base32.StdEncoding.DecodeString(secret)
 	if err != nil {
 		return "", otp.ErrValidateSecretInvalidBase32

hotp/hotp_test.go

@@ -109,6 +109,17 @@ func TestValidateInvalid(t *testing.T) {
 	require.Equal(t, false, valid, "Valid should be false.")
 }
 
+// This tests for issue #10 - secrets without padding
+func TestValidatePadding(t *testing.T) {
+	valid, err := ValidateCustom("831097", 0, "JBSWY3DPEHPK3PX",
+		ValidateOpts{
+			Digits:    otp.DigitsSix,
+			Algorithm: otp.AlgorithmSHA1,
+		})
+	require.NoError(t, err, "Expected no error.")
+	require.Equal(t, true, valid, "Valid should be true.")
+}
+
 func TestGenerate(t *testing.T) {
 	k, err := Generate(GenerateOpts{
 		Issuer:      "SnakeOil",