fix nip19 bech32 encoding and decoding.

nip19/bech32.go

@@ -9,14 +9,13 @@ const charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
 
 var gen = []int{0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3}
 
-// Decode decodes a bech32 encoded string, returning the human-readable
+// decode decodes a bech32 encoded string, returning the human-readable
 // part and the data part excluding the checksum.
 func decode(bech string) (string, []byte, error) {
 	// Only ASCII characters between 33 and 126 are allowed.
 	for i := 0; i < len(bech); i++ {
 		if bech[i] < 33 || bech[i] > 126 {
-			return "", nil, fmt.Errorf("invalid character in "+
-				"string: '%c'", bech[i])
+			return "", nil, fmt.Errorf("invalid character in string: '%c'", bech[i])
 		}
 	}
 
@@ -24,8 +23,7 @@ func decode(bech string) (string, []byte, error) {
 	lower := strings.ToLower(bech)
 	upper := strings.ToUpper(bech)
 	if bech != lower && bech != upper {
-		return "", nil, fmt.Errorf("string not all lowercase or all " +
-			"uppercase")
+		return "", nil, fmt.Errorf("string not all lowercase or all uppercase")
 	}
 
 	// We'll work with the lowercase string from now on.
@@ -48,8 +46,7 @@ func decode(bech string) (string, []byte, error) {
 	// 'charset'.
 	decoded, err := toBytes(data)
 	if err != nil {
-		return "", nil, fmt.Errorf("failed converting data to bytes: "+
-			"%v", err)
+		return "", nil, fmt.Errorf("failed converting data to bytes: %s", err.Error())
 	}
 
 	if !bech32VerifyChecksum(hrp, decoded) {
@@ -58,8 +55,7 @@ func decode(bech string) (string, []byte, error) {
 		expected, err := toChars(bech32Checksum(hrp,
 			decoded[:len(decoded)-6]))
 		if err == nil {
-			moreInfo = fmt.Sprintf("Expected %v, got %v.",
-				expected, checksum)
+			moreInfo = fmt.Sprintf("Expected %v, got %v.", expected, checksum)
 		}
 		return "", nil, fmt.Errorf("checksum failed. " + moreInfo)
 	}
@@ -81,8 +77,7 @@ func encode(hrp string, data []byte) (string, error) {
 	// represented using the specified charset.
 	dataChars, err := toChars(combined)
 	if err != nil {
-		return "", fmt.Errorf("unable to convert data bytes to chars: "+
-			"%v", err)
+		return "", fmt.Errorf("unable to convert data bytes to chars: %s", err.Error())
 	}
 	return hrp + "1" + dataChars, nil
 }
@@ -115,9 +110,9 @@ func toChars(data []byte) (string, error) {
 	return string(result), nil
 }
 
-// ConvertBits converts a byte slice where each byte is encoding fromBits bits,
+// convertBits converts a byte slice where each byte is encoding fromBits bits,
 // to a byte slice where each byte is encoding toBits bits.
-func ConvertBits(data []byte, fromBits, toBits uint8, pad bool) ([]byte, error) {
+func convertBits(data []byte, fromBits, toBits uint8, pad bool) ([]byte, error) {
 	if fromBits < 1 || fromBits > 8 || toBits < 1 || toBits > 8 {
 		return nil, fmt.Errorf("only bit groups between 1 and 8 allowed")
 	}

nip19/nip19.go

@@ -18,7 +18,7 @@ func EncodePrivateKey(privateKeyHex string) (string, error) {
 func EncodePublicKey(publicKeyHex string, masterRelay string) (string, error) {
 	b, err := hex.DecodeString(publicKeyHex)
 	if err != nil {
-		return "", err
+		return "", fmt.Errorf("failed to decode public key hex: %w", err)
 	}
 
 	tlv := make([]byte, 0, 64)
@@ -35,7 +35,12 @@ func EncodePublicKey(publicKeyHex string, masterRelay string) (string, error) {
 	}
 	b = append(b, tlv...)
 
-	return encode("nsec", b)
+	bits5, err := convertBits(b, 8, 5, true)
+	if err != nil {
+		return "", err
+	}
+
+	return encode("npub", bits5)
 }
 
 func EncodeNote(eventIdHex string) (string, error) {
@@ -53,9 +58,14 @@ func Decode(bech32string string) ([]byte, string, error) {
 		return nil, "", err
 	}
 
+	bits8, err := convertBits(data, 5, 8, false)
+	if err != nil {
+		return nil, "", fmt.Errorf("failed translating data into 8 bits: %s", err.Error())
+	}
+
 	if len(data) < 32 {
 		return nil, "", fmt.Errorf("data is less than 32 bytes (%d)", len(data))
 	}
 
-	return data[0:32], prefix, nil
+	return bits8[0:32], prefix, nil
 }

nip19/utils.go

@@ -0,0 +1,17 @@
+package nip19
+
+import (
+	"encoding/hex"
+	"strings"
+)
+
+// TranslatePublicKey turns a hex or bech32 public key into always hex
+func TranslatePublicKey(bech32orHexKey string) string {
+	if strings.HasPrefix(bech32orHexKey, "npub1") {
+		data, _, _ := Decode(bech32orHexKey)
+		return hex.EncodeToString(data)
+	}
+
+	// just return what we got
+	return bech32orHexKey
+}