basic support for nip19.

nip19/nip19.go

@@ -0,0 +1,61 @@
+package nip19
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+)
+
+func EncodePrivateKey(privateKeyHex string) (string, error) {
+	b, err := hex.DecodeString(privateKeyHex)
+	if err != nil {
+		return "", err
+	}
+
+	return encode("nsec", b)
+}
+
+func EncodePublicKey(publicKeyHex string, masterRelay string) (string, error) {
+	b, err := hex.DecodeString(publicKeyHex)
+	if err != nil {
+		return "", err
+	}
+
+	tlv := make([]byte, 0, 64)
+	if masterRelay != "" {
+		relayBytes := []byte(masterRelay)
+		length := len(relayBytes)
+		if length >= 65536 {
+			return "", fmt.Errorf("masterRelay URL is too large")
+		}
+
+		binary.BigEndian.PutUint16(tlv, 1)
+		binary.BigEndian.PutUint16(tlv, uint16(length))
+		tlv = append(tlv, relayBytes...)
+	}
+	b = append(b, tlv...)
+
+	return encode("nsec", b)
+}
+
+func EncodeNote(eventIdHex string) (string, error) {
+	b, err := hex.DecodeString(eventIdHex)
+	if err != nil {
+		return "", err
+	}
+
+	return encode("note", b)
+}
+
+func Decode(bech32string string) ([]byte, string, error) {
+	prefix, data, err := decode(bech32string)
+	if err != nil {
+		return nil, "", err
+	}
+
+	if len(data) < 32 {
+		return nil, "", fmt.Errorf("data is less than 32 bytes (%d)", len(data))
+	}
+
+	return data[0:32], prefix, nil
+}