successful implementation of direct dynamic linking

examples/ecdsa/main.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"fmt"
+	"log"
+
+	secp "p8k.mleku.dev"
+)
+
+func main() {
+	// Create a context for signing and verification
+	ctx, err := secp.NewContext(secp.ContextSign | secp.ContextVerify)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer ctx.Destroy()
+
+	// Generate a private key (32 random bytes)
+	privKey := make([]byte, 32)
+	if _, err := rand.Read(privKey); err != nil {
+		log.Fatal(err)
+	}
+
+	// Create public key from private key
+	pubKey, err := ctx.CreatePublicKey(privKey)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Serialize public key (compressed)
+	pubKeyBytes, err := ctx.SerializePublicKey(pubKey, true)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Public key: %x\n", pubKeyBytes)
+
+	// Sign a message
+	message := []byte("Hello, libsecp256k1!")
+	msgHash := sha256.Sum256(message)
+
+	sig, err := ctx.Sign(msgHash[:], privKey)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Signature: %x\n", sig)
+
+	// Verify the signature
+	valid, err := ctx.Verify(msgHash[:], sig, pubKey)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Signature valid: %v\n", valid)
+
+	// Test with serialized/parsed public key
+	parsedPubKey, err := ctx.ParsePublicKey(pubKeyBytes)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	valid2, err := ctx.Verify(msgHash[:], sig, parsedPubKey)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Signature valid (parsed key): %v\n", valid2)
+
+	// Test DER encoding
+	derSig, err := ctx.SerializeSignatureDER(sig)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("DER signature: %x\n", derSig)
+
+	// Parse DER signature
+	parsedSig, err := ctx.ParseSignatureDER(derSig)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	valid3, err := ctx.Verify(msgHash[:], parsedSig, pubKey)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Signature valid (DER): %v\n", valid3)
+}