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crypto/signatures/ecdsa/ecdsa_signature.go

@@ -0,0 +1,33 @@
+package ecdsa
+
+import (
+	"errors"
+	"math/big"
+
+	"github.com/onsonr/hway/crypto/core/curves"
+)
+
+// SerializeSecp256k1Signature serializes an ECDSA signature into a byte slice
+func SerializeSecp256k1Signature(sig *curves.EcdsaSignature) ([]byte, error) {
+	rBytes := sig.R.Bytes()
+	sBytes := sig.S.Bytes()
+
+	sigBytes := make([]byte, 66) // V (1 byte) + R (32 bytes) + S (32 bytes)
+	sigBytes[0] = byte(sig.V)
+	copy(sigBytes[33-len(rBytes):33], rBytes)
+	copy(sigBytes[66-len(sBytes):66], sBytes)
+	return sigBytes, nil
+}
+
+// DeserializeSecp256k1Signature deserializes an ECDSA signature from a byte slice
+func DeserializeSecp256k1Signature(sigBytes []byte) (*curves.EcdsaSignature, error) {
+	if len(sigBytes) != 66 {
+		return nil, errors.New("malformed signature: not the correct size")
+	}
+	sig := &curves.EcdsaSignature{
+		V: int(sigBytes[0]),
+		R: new(big.Int).SetBytes(sigBytes[1:33]),
+		S: new(big.Int).SetBytes(sigBytes[33:66]),
+	}
+	return sig, nil
+}