From fa6931b7485468788a8157201258c13e41153d3d Mon Sep 17 00:00:00 2001
From: Muzzammil Shahid <muzzammil@xconn.io>
Date: Thu, 29 Feb 2024 19:00:12 +0500
Subject: [PATCH] implement cryptosign

---
 .../java/io/xconn/cryptology/CryptoSign.java  | 41 +++++++++++++++++
 .../io/xconn/cryptology/CryptoSignTest.java   | 45 +++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 src/main/java/io/xconn/cryptology/CryptoSign.java
 create mode 100644 src/test/java/io/xconn/cryptology/CryptoSignTest.java

diff --git a/src/main/java/io/xconn/cryptology/CryptoSign.java b/src/main/java/io/xconn/cryptology/CryptoSign.java
new file mode 100644
index 0000000..1b85f61
--- /dev/null
+++ b/src/main/java/io/xconn/cryptology/CryptoSign.java
@@ -0,0 +1,41 @@
+package io.xconn.cryptology;
+
+import java.security.SecureRandom;
+
+import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
+import org.bouncycastle.crypto.generators.Ed25519KeyPairGenerator;
+import org.bouncycastle.crypto.params.Ed25519KeyGenerationParameters;
+import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters;
+import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
+import org.bouncycastle.crypto.signers.Ed25519Signer;
+
+public class CryptoSign {
+    public static KeyPair generateKeyPair() {
+        Ed25519KeyPairGenerator keyPairGenerator = new Ed25519KeyPairGenerator();
+        keyPairGenerator.init(new Ed25519KeyGenerationParameters(new SecureRandom()));
+
+        AsymmetricCipherKeyPair keyPair = keyPairGenerator.generateKeyPair();
+
+        Ed25519PrivateKeyParameters privateKey = (Ed25519PrivateKeyParameters) keyPair.getPrivate();
+        Ed25519PublicKeyParameters publicKey = (Ed25519PublicKeyParameters) keyPair.getPublic();
+
+        return new KeyPair(publicKey.getEncoded(), privateKey.getEncoded());
+    }
+
+    public static byte[] getPublicKey(byte[] privateKey) {
+        Ed25519PrivateKeyParameters privateKeyParam = new Ed25519PrivateKeyParameters(privateKey, 0);
+
+        return privateKeyParam.generatePublicKey().getEncoded();
+    }
+
+
+    public static byte[] sign(byte[] privateKey, byte[] challenge) {
+        Ed25519PrivateKeyParameters privateKeyParam = new Ed25519PrivateKeyParameters(privateKey, 0);
+
+        Ed25519Signer signer = new Ed25519Signer();
+        signer.init(true, privateKeyParam);
+        signer.update(challenge, 0, challenge.length);
+
+        return signer.generateSignature();
+    }
+}
diff --git a/src/test/java/io/xconn/cryptology/CryptoSignTest.java b/src/test/java/io/xconn/cryptology/CryptoSignTest.java
new file mode 100644
index 0000000..57c1554
--- /dev/null
+++ b/src/test/java/io/xconn/cryptology/CryptoSignTest.java
@@ -0,0 +1,45 @@
+package io.xconn.cryptology;
+
+import org.bouncycastle.util.encoders.Hex;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import static io.xconn.cryptology.CryptoSign.generateKeyPair;
+import static io.xconn.cryptology.CryptoSign.getPublicKey;
+import static io.xconn.cryptology.CryptoSign.sign;
+
+public class CryptoSignTest {
+    private static final String privateKey = "6b19991b461d1073918a25525652c4c913fb28b07142faf1146f6bde228653c5";
+    private static final String publicKey = "568850ef3a95c4fc3720f534004f1837ed4e32049271b2e1a8c3d979b571e3e4";
+
+    @Test
+    public void testGenerateKeyPair() {
+        KeyPair keyPair = generateKeyPair();
+
+        assertNotNull(keyPair.getPublicKey());
+        assertNotNull(keyPair.getPrivateKey());
+        assertEquals(32, keyPair.getPublicKey().length);
+        assertEquals(32, keyPair.getPrivateKey().length);
+    }
+
+    @Test
+    public void testGetPublicKey() {
+        byte[] publicKey = getPublicKey(Hex.decode(privateKey));
+
+        assertArrayEquals(Hex.decode(CryptoSignTest.publicKey), publicKey);
+    }
+
+    @Test
+    public void testSign() {
+        String challengeString = "f9d17535fb925e9f674d648cbfc41399";
+        String expectedSignedString = "054932bce44c62d749723f808c2f7ba8b3eb6fe27a2886644317" +
+                "cc95022da5b6211866f36572da9ee783fb229e63d0c76ab050e8aa840a48d8285537ed57f70f";
+
+        byte[] signedChallenge = sign(Hex.decode(privateKey), Hex.decode(challengeString));
+
+        assertArrayEquals(Hex.decode(expectedSignedString), signedChallenge);
+    }
+}