From be0aa7e809aed587dd257433e1a6aaf1952d2c35 Mon Sep 17 00:00:00 2001
From: Cristian G <113917899+cristianIOHK@users.noreply.github.com>
Date: Tue, 25 Apr 2023 10:16:29 -0400
Subject: [PATCH] feat: Implement X25519 - Keypair generation (#53)

* feat: Implement X25519 - Keypair generation

* Fix linting issues
---
 .../atala/prism/walletsdk/apollo/X25519.kt    | 20 ++++++++++---------
 .../prism/walletsdk/apollo/ApolloTests.kt     |  9 +++++++++
 .../atala/prism/walletsdk/apollo/X25519.kt    | 20 ++++++++++---------
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/atala-prism-sdk/src/androidMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt b/atala-prism-sdk/src/androidMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
index 571de8ba8..a8424195d 100644
--- a/atala-prism-sdk/src/androidMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
+++ b/atala-prism-sdk/src/androidMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
@@ -5,28 +5,30 @@ import io.iohk.atala.prism.walletsdk.domain.models.KeyCurve
 import io.iohk.atala.prism.walletsdk.domain.models.KeyPair
 import io.iohk.atala.prism.walletsdk.domain.models.PrivateKey
 import io.iohk.atala.prism.walletsdk.domain.models.PublicKey
-import org.bouncycastle.jcajce.spec.XDHParameterSpec
-import org.bouncycastle.jce.provider.BouncyCastleProvider
-import java.security.KeyPairGenerator
+import org.bouncycastle.crypto.generators.X25519KeyPairGenerator
+import org.bouncycastle.crypto.params.X25519KeyGenerationParameters
+import org.bouncycastle.crypto.params.X25519PrivateKeyParameters
+import org.bouncycastle.crypto.params.X25519PublicKeyParameters
+import java.security.SecureRandom
 
 /**
  * X25519
  */
 actual object X25519 {
     actual fun createKeyPair(): KeyPair {
-        val provider = BouncyCastleProvider()
-        val kpg = KeyPairGenerator.getInstance("X25519", provider)
-        kpg.initialize(XDHParameterSpec(XDHParameterSpec.X25519))
-        val javaKeyPair = kpg.generateKeyPair()
+        val generator = X25519KeyPairGenerator()
+        generator.init(X25519KeyGenerationParameters(SecureRandom()))
+        val keyPair = generator.generateKeyPair()
+
         return KeyPair(
             KeyCurve(Curve.X25519),
             PrivateKey(
                 KeyCurve(Curve.X25519),
-                javaKeyPair.private.encoded
+                (keyPair.private as X25519PrivateKeyParameters).encoded
             ),
             PublicKey(
                 KeyCurve(Curve.X25519),
-                javaKeyPair.public.encoded
+                (keyPair.public as X25519PublicKeyParameters).encoded
             )
         )
     }
diff --git a/atala-prism-sdk/src/commonTest/kotlin/io/iohk/atala/prism/walletsdk/apollo/ApolloTests.kt b/atala-prism-sdk/src/commonTest/kotlin/io/iohk/atala/prism/walletsdk/apollo/ApolloTests.kt
index 1bcae9faf..68e7c9832 100644
--- a/atala-prism-sdk/src/commonTest/kotlin/io/iohk/atala/prism/walletsdk/apollo/ApolloTests.kt
+++ b/atala-prism-sdk/src/commonTest/kotlin/io/iohk/atala/prism/walletsdk/apollo/ApolloTests.kt
@@ -107,4 +107,13 @@ class ApolloTests {
         assertEquals(32, privateKey.value.size)
         assertEquals(32, publicKey.value.size)
     }
+
+    @Test
+    fun testCreateKeyPair_whenNoSeedAndKeyCurveX25519_thenPrivateKeyLengthIsCorrect() {
+        val keyPair = apollo.createKeyPair(curve = KeyCurve(Curve.X25519))
+        val privateKey = keyPair.privateKey
+        val publicKey = keyPair.publicKey
+        assertEquals(32, privateKey.value.size)
+        assertEquals(32, publicKey.value.size)
+    }
 }
diff --git a/atala-prism-sdk/src/jvmMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt b/atala-prism-sdk/src/jvmMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
index 571de8ba8..a8424195d 100644
--- a/atala-prism-sdk/src/jvmMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
+++ b/atala-prism-sdk/src/jvmMain/kotlin/io/iohk/atala/prism/walletsdk/apollo/X25519.kt
@@ -5,28 +5,30 @@ import io.iohk.atala.prism.walletsdk.domain.models.KeyCurve
 import io.iohk.atala.prism.walletsdk.domain.models.KeyPair
 import io.iohk.atala.prism.walletsdk.domain.models.PrivateKey
 import io.iohk.atala.prism.walletsdk.domain.models.PublicKey
-import org.bouncycastle.jcajce.spec.XDHParameterSpec
-import org.bouncycastle.jce.provider.BouncyCastleProvider
-import java.security.KeyPairGenerator
+import org.bouncycastle.crypto.generators.X25519KeyPairGenerator
+import org.bouncycastle.crypto.params.X25519KeyGenerationParameters
+import org.bouncycastle.crypto.params.X25519PrivateKeyParameters
+import org.bouncycastle.crypto.params.X25519PublicKeyParameters
+import java.security.SecureRandom
 
 /**
  * X25519
  */
 actual object X25519 {
     actual fun createKeyPair(): KeyPair {
-        val provider = BouncyCastleProvider()
-        val kpg = KeyPairGenerator.getInstance("X25519", provider)
-        kpg.initialize(XDHParameterSpec(XDHParameterSpec.X25519))
-        val javaKeyPair = kpg.generateKeyPair()
+        val generator = X25519KeyPairGenerator()
+        generator.init(X25519KeyGenerationParameters(SecureRandom()))
+        val keyPair = generator.generateKeyPair()
+
         return KeyPair(
             KeyCurve(Curve.X25519),
             PrivateKey(
                 KeyCurve(Curve.X25519),
-                javaKeyPair.private.encoded
+                (keyPair.private as X25519PrivateKeyParameters).encoded
             ),
             PublicKey(
                 KeyCurve(Curve.X25519),
-                javaKeyPair.public.encoded
+                (keyPair.public as X25519PublicKeyParameters).encoded
             )
         )
     }