Merge pull request #97 from /issues/85

issues/85 - Implements support for key pair generation using seed for…
casper-network · Apr 6, 2022 · ae0b323 · ae0b323
2 parents 09c70b9 + c5617b7
commit ae0b323
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Showing 6 changed files with 69 additions and 9 deletions.
diff --git a/src/main/java/com/casper/sdk/service/signing/AbstractKeyPairBuilder.java b/src/main/java/com/casper/sdk/service/signing/AbstractKeyPairBuilder.java
@@ -27,11 +27,12 @@ public Algorithm getAlgorithm() {
         return algorithm;
     }
 
-    KeyPair generateKeyPair(final String algorithm, final String curve) {
+    KeyPair generateKeyPair(final String algorithm, final String curve, final byte[] seed) {
         try {
             final KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm, PROVIDER);
             final ECGenParameterSpec ecGenParameterSpec = new ECGenParameterSpec(curve);
-            keyPairGenerator.initialize(ecGenParameterSpec, new SecureRandom());
+            final SecureRandom secureRandom = seed != null ? new SecureRandom(seed) : new SecureRandom();
+            keyPairGenerator.initialize(ecGenParameterSpec, secureRandom);
             return keyPairGenerator.generateKeyPair();
         } catch (Exception e) {
             throw new SignatureException(e);

diff --git a/src/main/java/com/casper/sdk/service/signing/Ed25519KeyPariBuilder.java b/src/main/java/com/casper/sdk/service/signing/Ed25519KeyPariBuilder.java
@@ -22,8 +22,8 @@ class Ed25519KeyPariBuilder extends AbstractKeyPairBuilder {
     }
 
     @Override
-    public KeyPair generateKeyPair() {
-        return generateKeyPair(ALGORITHM, ALGORITHM);
+    public KeyPair generateKeyPair(final byte[] seed) {
+        return generateKeyPair(ALGORITHM, ALGORITHM, seed);
     }
 
     @Override

diff --git a/src/main/java/com/casper/sdk/service/signing/KeyPairBuilder.java b/src/main/java/com/casper/sdk/service/signing/KeyPairBuilder.java
@@ -3,6 +3,7 @@
 
 import com.casper.sdk.types.Algorithm;
 
+import javax.annotation.Nullable;
 import java.security.KeyPair;
 import java.security.PublicKey;
 
@@ -13,10 +14,10 @@ public interface KeyPairBuilder {
 
     /**
      * Generates a new key pair
-     *
+     * @param seed the optional entropy source to be used when generating a key pair
      * @return a new key pain
      */
-    KeyPair generateKeyPair();
+    KeyPair generateKeyPair(@Nullable final byte [] seed);
 
     /**
      * The algorithm of the signer

diff --git a/src/main/java/com/casper/sdk/service/signing/Secp256k1KeyPairBuilder.java b/src/main/java/com/casper/sdk/service/signing/Secp256k1KeyPairBuilder.java
@@ -33,8 +33,9 @@ public class Secp256k1KeyPairBuilder extends AbstractKeyPairBuilder {
         super(Algorithm.SECP256K1);
     }
 
-    public KeyPair generateKeyPair() {
-        return generateKeyPair(ALGORITHM, CURVE_NAME);
+    @Override
+    public KeyPair generateKeyPair(final byte[] seed) {
+        return generateKeyPair(ALGORITHM, CURVE_NAME, seed);
     }
 
     @Override

diff --git a/src/main/java/com/casper/sdk/service/signing/SigningService.java b/src/main/java/com/casper/sdk/service/signing/SigningService.java
@@ -37,7 +37,18 @@ public class SigningService {
      * @return a new key pair of the specified algorithm
      */
     public KeyPair generateKeyPair(final Algorithm algorithm) {
-        return getKeyPairBuilder(algorithm).generateKeyPair();
+        return getKeyPairBuilder(algorithm).generateKeyPair(null);
+    }
+
+    /**
+     * Generates a key pair for the specified algorithm.
+     *
+     * @param algorithm the algorithm of new key pair to generate
+     * @param seed      the entropy source to be used when generating a key pair
+     * @return a new key pair of the specified algorithm
+     */
+    public KeyPair generateKeyPair(final Algorithm algorithm, final byte[] seed) {
+        return getKeyPairBuilder(algorithm).generateKeyPair(seed);
     }
 
     /**

diff --git a/src/test/java/com/casper/sdk/service/signing/SigningServiceTest.java b/src/test/java/com/casper/sdk/service/signing/SigningServiceTest.java
@@ -15,6 +15,7 @@
 import java.nio.charset.StandardCharsets;
 import java.security.KeyPair;
 import java.security.PrivateKey;
+import java.security.SecureRandom;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
@@ -88,6 +89,25 @@ void generateEd25519KeyPair() {
         assertThat(signingService.verifySignature(keyPair.getPublic(), message, signature), is(true));
     }
 
+    @Test
+    void generateEd25519KeyPairFromSeed() {
+
+        final SecureRandom random = new SecureRandom();
+        byte[] seed = new byte[20];
+        random.nextBytes(seed);
+
+        final KeyPair keyPair = signingService.generateKeyPair(Algorithm.ED25519, seed);
+        assertThat(keyPair.getPublic(), is(notNullValue()));
+        assertThat(keyPair.getPrivate(), is(notNullValue()));
+
+        // the message
+        byte[] message = "Message to sign".getBytes(StandardCharsets.UTF_8);
+
+        byte[] signature = signingService.signWithPrivateKey(keyPair.getPrivate(), message);
+
+        assertThat(signingService.verifySignature(keyPair.getPublic(), message, signature), is(true));
+    }
+
     @Test
     @SuppressWarnings("ConstantConditions")
     void loadSecp256k1KeyPair() throws Exception {
@@ -123,6 +143,32 @@ void generateSecp256k1KeyPair() {
         assertThat(signingService.verifySignature(keyPair.getPublic(), message, signedMessage), is(true));
     }
 
+
+    @Test
+    void generateSecp256k1KeyPairFromSeed() {
+
+        final SecureRandom random = new SecureRandom();
+        byte[] seed = new byte[20];
+        random.nextBytes(seed);
+
+        final byte[] message = {
+                (byte) 153, (byte) 144, (byte) 19, (byte) 83, (byte) 219, (byte) 161, (byte) 143, (byte) 137, (byte) 59,
+                (byte) 67, (byte) 187, (byte) 238, (byte) 65, (byte) 111, (byte) 80, (byte) 243, (byte) 142, (byte) 77,
+                (byte) 113, (byte) 46, (byte) 2, (byte) 166, (byte) 121, (byte) 118, (byte) 34, (byte) 205, (byte) 123,
+                (byte) 14, (byte) 215, (byte) 85, (byte) 234, (byte) 161
+        };
+
+        final KeyPair keyPair = signingService.generateKeyPair(Algorithm.SECP256K1, seed);
+
+        assertThat(keyPair, is(notNullValue()));
+        assertThat(keyPair.getPublic(), is(notNullValue()));
+        assertThat(keyPair.getPrivate(), is(notNullValue()));
+
+        final byte[] signedMessage = signingService.signWithPrivateKey(keyPair.getPrivate(), message);
+
+        assertThat(signingService.verifySignature(keyPair.getPublic(), message, signedMessage), is(true));
+    }
+
     @Test
     @SuppressWarnings("ConstantConditions")
     void signWithSecp256k1PrivateKeyAndVerifySignature() throws Exception {