Release v2.2.0

vendor/github.com/muun/libwallet/btcsuitew/btcutilw/segwit.go

@@ -0,0 +1,84 @@
+package btcutilw
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/muun/libwallet/btcsuitew/bech32m"
+)
+
+// -------------------------------------------------------------------------------------------------
+// Methods below copied from btcd (address.go), but using our bech32m module instead of their bech32.
+// Only that change was made. Some comments inside this code are not correct.
+
+func encodeSegWitAddressV1(hrp string, witnessVersion byte, witnessProgram []byte) (string, error) {
+	// Group the address bytes into 5 bit groups, as this is what is used to
+	// encode each character in the address string.
+	converted, err := bech32m.ConvertBits(witnessProgram, 8, 5, true)
+	if err != nil {
+		return "", err
+	}
+
+	// Concatenate the witness version and program, and encode the resulting
+	// bytes using bech32 encoding.
+	combined := make([]byte, len(converted)+1)
+	combined[0] = witnessVersion
+	copy(combined[1:], converted)
+	bech, err := bech32m.Encode(hrp, combined)
+	if err != nil {
+		return "", err
+	}
+
+	// Check validity by decoding the created address.
+	version, program, err := decodeSegWitAddressV1(bech)
+	if err != nil {
+		return "", fmt.Errorf("invalid taproot address: %v", err)
+	}
+
+	if version != witnessVersion || !bytes.Equal(program, witnessProgram) {
+		return "", fmt.Errorf("invalid taproot address")
+	}
+
+	return bech, nil
+}
+
+func decodeSegWitAddressV1(address string) (byte, []byte, error) {
+	// Decode the bech32 encoded address.
+	_, data, err := bech32m.Decode(address)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	// The first byte of the decoded address is the witness version, it must
+	// exist.
+	if len(data) < 1 {
+		return 0, nil, fmt.Errorf("no witness version")
+	}
+
+	// ...and be <= 16.
+	version := data[0]
+	if version > 16 {
+		return 0, nil, fmt.Errorf("invalid witness version for taproot: %v", version)
+	}
+
+	// The remaining characters of the address returned are grouped into
+	// words of 5 bits. In order to restore the original witness program
+	// bytes, we'll need to regroup into 8 bit words.
+	regrouped, err := bech32m.ConvertBits(data[1:], 5, 8, false)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	// The regrouped data must be between 2 and 40 bytes.
+	if len(regrouped) < 2 || len(regrouped) > 40 {
+		return 0, nil, fmt.Errorf("invalid data length")
+	}
+
+	// For witness version 0, address MUST be exactly 20 or 32 bytes.
+	if version == 0 && len(regrouped) != 20 && len(regrouped) != 32 {
+		return 0, nil, fmt.Errorf("invalid data length for witness "+
+			"version 0: %v", len(regrouped))
+	}
+
+	return version, regrouped, nil
+}