Add base dialers module

mtglib/secret.go

@@ -0,0 +1,71 @@
+package mtglib
+
+import (
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type Secret struct {
+	Key  []byte
+	Host string
+}
+
+func (s *Secret) MarshalText() ([]byte, error) {
+	if s == nil {
+		return nil, nil
+	}
+
+	return []byte(s.String()), nil
+}
+
+func (s *Secret) UnmarshalText(text []byte) error {
+	sc, err := ParseSecret(string(text))
+	if err != nil {
+		return err
+	}
+
+	*s = sc
+
+	return nil
+}
+
+func (s Secret) Base64() string {
+	return s.String()
+}
+
+func (s Secret) EE() string {
+	return "ee" + hex.EncodeToString(append(s.Key, s.Host...))
+}
+
+func (s Secret) String() string {
+	return base64.StdEncoding.EncodeToString(append(s.Key, s.Host...))
+}
+
+func ParseSecret(secret string) (Secret, error) {
+	rv := Secret{}
+
+	if secret == "" {
+		return rv, errors.New("secret cannot be empty")
+	}
+
+	decoded, err := base64.RawStdEncoding.DecodeString(secret)
+	if err != nil && strings.HasPrefix(secret, "ee") {
+		decoded, err = hex.DecodeString(strings.TrimPrefix(secret, "ee"))
+	}
+
+	if err != nil {
+		return rv, fmt.Errorf("incorrect secret format: %w", err)
+	}
+
+	if len(decoded) < 33 {
+		return rv, fmt.Errorf("secret %s has incorrect length", secret)
+	}
+
+	rv.Key = decoded[:32]
+	rv.Host = string(decoded[32:])
+
+	return rv, nil
+}