feat: ED25519 keypair instead of P256

dialer/android/app/src/main/kotlin/com/icing/dialer/KeyDeleter.kt

@@ -1,28 +0,0 @@
-package com.icing.dialer
-
-import java.security.KeyStore
-
-object KeyDeleterHelper {
-
-    private const val ANDROID_KEYSTORE = "AndroidKeyStore"
-
-    /**
-     * Deletes the key pair associated with the given alias from the Android Keystore.
-     *
-     * @param alias The alias of the key pair to delete.
-     * @throws Exception if deletion fails.
-     */
-    fun deleteKeyPair(alias: String) {
-        try {
-            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
-
-            if (!keyStore.containsAlias(alias)) {
-                throw Exception("No key found with alias \"$alias\" to delete.")
-            }
-
-            keyStore.deleteEntry(alias)
-        } catch (e: Exception) {
-            throw Exception("Failed to delete key pair: ${e.message}", e)
-        }
-    }
-}

dialer/android/app/src/main/kotlin/com/icing/dialer/KeyGenerator.kt

@@ -1,47 +0,0 @@
-package com.icing.dialer
-
-import android.security.keystore.KeyGenParameterSpec
-import android.security.keystore.KeyProperties
-import java.security.KeyPairGenerator
-import java.security.KeyStore
-
-object KeyGeneratorHelper {
-
-    private const val ANDROID_KEYSTORE = "AndroidKeyStore"
-
-    /**
-     * Generates an ECDSA P-256 key pair and stores it in the Android Keystore.
-     *
-     * @param alias Unique identifier for the key pair.
-     * @throws Exception if key generation fails.
-     */
-    fun generateECKeyPair(alias: String) {
-        try {
-            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
-
-            // Check if the key already exists
-            if (keyStore.containsAlias(alias)) {
-                throw Exception("Key with alias \"$alias\" already exists.")
-            }
-
-            val keyPairGenerator = KeyPairGenerator.getInstance(
-                KeyProperties.KEY_ALGORITHM_EC,
-                ANDROID_KEYSTORE
-            )
-
-            val parameterSpec = KeyGenParameterSpec.Builder(
-                alias,
-                KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
-            )
-                .setAlgorithmParameterSpec(java.security.spec.ECGenParameterSpec("secp256r1"))
-                .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA384, KeyProperties.DIGEST_SHA512)
-                .setUserAuthenticationRequired(false) // Set to true if you require user authentication
-                .build()
-
-            keyPairGenerator.initialize(parameterSpec)
-            keyPairGenerator.generateKeyPair()
-        } catch (e: Exception) {
-            throw Exception("Failed to generate EC key pair: ${e.message}", e)
-        }
-    }
-}

dialer/android/app/src/main/kotlin/com/icing/dialer/KeystoreHelper.kt

@@ -1,6 +1,6 @@
 package com.icing.dialer
 
-import java.security.PrivateKey
+import android.os.Build
 import android.security.keystore.KeyGenParameterSpec
 import android.security.keystore.KeyProperties
 import android.util.Base64
@@ -8,15 +8,21 @@ import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import java.security.KeyPairGenerator
 import java.security.KeyStore
+import java.security.PrivateKey
 import java.security.Signature
+import java.security.spec.ECGenParameterSpec
 
 class KeystoreHelper(private val call: MethodCall, private val result: MethodChannel.Result) {
 
     private val ANDROID_KEYSTORE = "AndroidKeyStore"
 
     fun handleMethodCall() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
+            result.error("UNSUPPORTED_API", "ED25519 requires Android 11 (API 30) or higher", null)
+            return
+        }
         when (call.method) {
-            "generateKeyPair" -> generateECKeyPair()
+            "generateKeyPair" -> generateEDKeyPair()
             "signData" -> signData()
             "getPublicKey" -> getPublicKey()
             "deleteKeyPair" -> deleteKeyPair()
@@ -25,7 +31,7 @@ class KeystoreHelper(private val call: MethodCall, private val result: MethodCha
         }
     }
 
-    private fun generateECKeyPair() {
+    private fun generateEDKeyPair() {
         val alias = call.argument<String>("alias")
         if (alias == null) {
             result.error("INVALID_ARGUMENT", "Alias is required", null)
@@ -44,16 +50,14 @@ class KeystoreHelper(private val call: MethodCall, private val result: MethodCha
                 KeyProperties.KEY_ALGORITHM_EC,
                 ANDROID_KEYSTORE
             )
-
             val parameterSpec = KeyGenParameterSpec.Builder(
                 alias,
                 KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
             )
-                .setAlgorithmParameterSpec(java.security.spec.ECGenParameterSpec("secp256r1"))
+                .setAlgorithmParameterSpec(ECGenParameterSpec("ed25519"))
-                .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA384, KeyProperties.DIGEST_SHA512)
+                .setDigests(KeyProperties.DIGEST_SHA256)
                 .setUserAuthenticationRequired(false)
                 .build()
-
             keyPairGenerator.initialize(parameterSpec)
             keyPairGenerator.generateKeyPair()
 
@@ -73,17 +77,14 @@ class KeystoreHelper(private val call: MethodCall, private val result: MethodCha
 
         try {
             val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
-
             val privateKey = keyStore.getKey(alias, null) as? PrivateKey ?: run {
                 result.error("KEY_NOT_FOUND", "Private key not found for alias \"$alias\".", null)
                 return
             }
-
+            val signature = Signature.getInstance("Ed25519")
-            val signature = Signature.getInstance("SHA256withECDSA")
             signature.initSign(privateKey)
             signature.update(data.toByteArray())
             val signedBytes = signature.sign()
-
             val signatureBase64 = Base64.encodeToString(signedBytes, Base64.DEFAULT)
             result.success(signatureBase64)
         } catch (e: Exception) {

dialer/android/app/src/main/kotlin/com/icing/dialer/PublicKeyRetriever.kt

@@ -1,30 +0,0 @@
-package com.icing.dialer
-
-import java.security.KeyStore
-import java.security.PublicKey
-import android.util.Base64
-
-object PublicKeyHelper {
-
-    private const val ANDROID_KEYSTORE = "AndroidKeyStore"
-
-    /**
-     * Retrieves the public key associated with the given alias.
-     *
-     * @param alias The alias of the key pair.
-     * @return The public key as a Base64-encoded string.
-     * @throws Exception if retrieval fails.
-     */
-    fun getPublicKey(alias: String): String {
-        try {
-            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
-
-            val certificate = keyStore.getCertificate(alias) ?: throw Exception("Certificate not found for alias \"$alias\".")
-            val publicKey: PublicKey = certificate.publicKey
-
-            return Base64.encodeToString(publicKey.encoded, Base64.DEFAULT)
-        } catch (e: Exception) {
-            throw Exception("Failed to retrieve public key: ${e.message}", e)
-        }
-    }
-}

dialer/android/app/src/main/kotlin/com/icing/dialer/Signer.kt

@@ -1,37 +0,0 @@
-package com.icing.dialer
-
-import android.security.keystore.KeyProperties
-import java.security.KeyStore
-import java.security.Signature
-import android.util.Base64
-import java.security.PrivateKey
-
-object SignerHelper {
-
-    private const val ANDROID_KEYSTORE = "AndroidKeyStore"
-
-    /**
-     * Signs the provided data using the private key associated with the given alias.
-     *
-     * @param alias The alias of the key pair.
-     * @param data The data to sign.
-     * @return The signature as a Base64-encoded string.
-     * @throws Exception if signing fails.
-     */
-    fun signData(alias: String, data: ByteArray): String {
-        try {
-            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
-
-            val privateKey = keyStore.getKey(alias, null) as? PrivateKey?: throw Exception("Private key not found for alias \"$alias\".")
-
-            val signature = Signature.getInstance("SHA256withECDSA")
-            signature.initSign(privateKey)
-            signature.update(data)
-            val signedBytes = signature.sign()
-
-            return Base64.encodeToString(signedBytes, Base64.DEFAULT)
-        } catch (e: Exception) {
-            throw Exception("Failed to sign data: ${e.message}", e)
-        }
-    }
-}

dialer/lib/domain/services/cryptography/asymmetric_crypto_service.dart

@@ -10,7 +10,7 @@ class AsymmetricCryptoService {
   final String _aliasPrefix = 'icing_';
   final Uuid _uuid = Uuid();
 
-  /// Generates an ECDSA P-256 key pair with a unique alias and stores its metadata.
+  /// Generates an ED25519 key pair with a unique alias and stores its metadata.
   Future<String> generateKeyPair({String? label}) async {
     try {
       // Generate a unique identifier for the key