Update kotlin specific code

android/build.gradle

@@ -25,7 +25,7 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 29
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'

android/src/main/kotlin/fr/pointcheval/native_crypto/Cipher.kt

@@ -0,0 +1,101 @@
+package fr.pointcheval.native_crypto
+
+import java.lang.Exception
+import javax.crypto.Cipher
+import javax.crypto.SecretKey
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
+
+enum class CipherAlgorithm(val spec: String) {
+    AES("AES"),
+    BlowFish("BLOWFISH")
+}
+
+enum class BlockCipherMode(val instance: String) {
+    ECB("ECB"),
+    CBC("CBC"),
+    CFB("CFB"),
+    GCM("GCM"),
+    CGM("CGM"),
+}
+
+enum class Padding(val instance: String) {
+    PKCS5("PKCS5Padding"),
+    None("NoPadding")
+}
+
+class CipherParameters(private val mode: BlockCipherMode, private val padding: Padding) {
+    override fun toString(): String {
+        return mode.instance + "/" + padding.instance
+    }
+}
+
+class Cipher {
+
+    fun getCipherAlgorithm(dartAlgorithm: String) : CipherAlgorithm {
+        return when (dartAlgorithm) {
+            "aes" -> CipherAlgorithm.AES
+            "blowfish" -> CipherAlgorithm.BlowFish
+            else -> CipherAlgorithm.AES
+        }
+    }
+
+    fun getInstance(mode : String, padding : String) : CipherParameters {
+        val m = when (mode) {
+            "ecb" -> BlockCipherMode.ECB
+            "cbc" -> BlockCipherMode.CBC
+            "cfb" -> BlockCipherMode.CFB
+            "gcm" -> BlockCipherMode.GCM
+            "cgm" -> BlockCipherMode.CGM
+            else -> throw Exception()
+        }
+        val p = when (padding) {
+            "pkcs5" -> Padding.PKCS5
+            else -> Padding.None
+        }
+        return CipherParameters(m,p)
+    }
+
+    fun encrypt(data: ByteArray, key: ByteArray, algorithm: String, mode: String, padding: String) : List<ByteArray> {
+        val algo = getCipherAlgorithm(algorithm)
+        val params = getInstance(mode, padding)
+
+        val keySpecification = algo.spec + "/" + params.toString()
+
+        val mac = Hash().digest(key + data)
+        val sk: SecretKey = SecretKeySpec(key, algo.spec)
+
+        val cipher = Cipher.getInstance(keySpecification)
+        cipher.init(Cipher.ENCRYPT_MODE, sk)
+
+        val encryptedBytes = cipher.doFinal(mac + data)
+        val iv = cipher.iv
+
+        return listOf(encryptedBytes, iv);
+    }
+
+    fun decrypt(payload: Collection<ByteArray>, key: ByteArray, algorithm: String, mode: String, padding: String) : ByteArray? {
+        val algo = getCipherAlgorithm(algorithm)
+        val params = getInstance(mode, padding)
+
+        val keySpecification = algo.spec + "/" + params.toString()
+
+        val sk: SecretKey = SecretKeySpec(key, algo.spec)
+        val cipher = Cipher.getInstance(keySpecification);
+        val iv = payload.last();
+        val ivSpec = IvParameterSpec(iv)
+        cipher.init(Cipher.DECRYPT_MODE, sk, ivSpec);
+
+        val decryptedBytes = cipher.doFinal(payload.first());
+
+        val mac = decryptedBytes.copyOfRange(0, 32)
+        val decryptedContent : ByteArray = decryptedBytes.copyOfRange(32, decryptedBytes.size)
+        val verificationMac = Hash().digest(key + decryptedContent)
+
+        return if (mac.contentEquals(verificationMac)) {
+            decryptedContent
+        } else {
+            null;
+        }
+    }
+}

android/src/main/kotlin/fr/pointcheval/native_crypto/HashAlgorithm.kt

@@ -0,0 +1,39 @@
+package fr.pointcheval.native_crypto
+
+import java.security.MessageDigest
+
+enum class HashAlgorithm(val length : Int) {
+    SHA1(160),
+    SHA128(128),
+    SHA256(256),
+    SHA512(512);
+}
+
+
+class Hash() {
+    fun digest(data: ByteArray?, algorithm: HashAlgorithm): ByteArray {
+        val func : String = when (algorithm) {
+            HashAlgorithm.SHA1 -> "SHA-1"
+            HashAlgorithm.SHA128 -> "SHA-128"
+            HashAlgorithm.SHA256 -> "SHA-256"
+            HashAlgorithm.SHA512 -> "SHA-512"
+        }
+        val md = MessageDigest.getInstance(func)
+        return md.digest(data)
+    }
+
+    fun digest(data: ByteArray?, algorithm: String): ByteArray {
+        val func : HashAlgorithm = when (algorithm) {
+            "sha1" -> HashAlgorithm.SHA1
+            "sha128" -> HashAlgorithm.SHA128
+            "sha256" -> HashAlgorithm.SHA256
+            "sha512" -> HashAlgorithm.SHA512
+            else -> HashAlgorithm.SHA256
+        }
+        return digest(data, func)
+    }
+
+    fun digest(data: ByteArray?): ByteArray {
+        return digest(data, HashAlgorithm.SHA256)
+    }
+}

android/src/main/kotlin/fr/pointcheval/native_crypto/KeyDerivation.kt

@@ -0,0 +1,35 @@
+package fr.pointcheval.native_crypto
+
+import android.os.Build
+import java.lang.IllegalArgumentException
+import javax.crypto.SecretKeyFactory
+import javax.crypto.spec.PBEKeySpec
+
+class KeyDerivation {
+    fun pbkdf2(password: String, salt: String, keyLength: Int, iteration: Int, algorithm: String): ByteArray {
+        val chars: CharArray = password.toCharArray()
+        val availableHashAlgorithm: Map<String, String> = mapOf(
+                "sha1" to "PBKDF2withHmacSHA1",
+                "sha224" to "PBKDF2withHmacSHA224",
+                "sha256" to "PBKDF2WithHmacSHA256",
+                "sha284" to "PBKDF2withHmacSHA384",
+                "sha512" to "PBKDF2withHmacSHA512"
+        )
+
+        if (Build.VERSION.SDK_INT >= 26) {
+            // SHA-1 and SHA-2 implemented
+            val spec = PBEKeySpec(chars, salt.toByteArray(), iteration, keyLength * 8)
+            val skf: SecretKeyFactory = SecretKeyFactory.getInstance(availableHashAlgorithm[algorithm]);
+            return skf.generateSecret(spec).encoded
+        } else if (Build.VERSION.SDK_INT >= 10) {
+            // Only SHA-1 is implemented
+            if (!algorithm.equals("sha1")) {
+                throw PlatformVersionException("Only SHA1 is implemented on this SDK version!")
+            }
+            val spec = PBEKeySpec(chars, salt.toByteArray(), iteration, keyLength * 8)
+            val skf: SecretKeyFactory = SecretKeyFactory.getInstance("PBKDF2withHmacSHA1");
+            return skf.generateSecret(spec).encoded
+        }
+        throw PlatformVersionException("Invalid SDK version!")
+    }
+}

android/src/main/kotlin/fr/pointcheval/native_crypto/KeyGeneration.kt

@@ -0,0 +1,32 @@
+package fr.pointcheval.native_crypto
+
+import java.security.KeyPairGenerator
+import java.security.SecureRandom
+import javax.crypto.KeyGenerator
+
+class KeyGeneration {
+    fun keygen(size : Int) : ByteArray {
+        val secureRandom = SecureRandom()
+        val keyGenerator = if (size in listOf<Int>(128,192,256)) {
+            KeyGenerator.getInstance("AES")
+        } else {
+            KeyGenerator.getInstance("BLOWFISH")
+        }
+
+        keyGenerator.init(size, secureRandom)
+        val sk = keyGenerator.generateKey()
+
+        return sk!!.encoded
+    }
+
+    fun rsaKeypairGen(size : Int) : List<ByteArray> {
+        val secureRandom = SecureRandom()
+        val keyGenerator = KeyPairGenerator.getInstance("RSA")
+
+        keyGenerator.initialize(size, secureRandom)
+        val keypair = keyGenerator.genKeyPair()
+        val res : List<ByteArray> = listOf(keypair.public.encoded, keypair.private.encoded)
+
+        return res
+    }
+}

android/src/main/kotlin/fr/pointcheval/native_crypto/NativeCryptoPlugin.kt

@@ -11,162 +11,132 @@ import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugin.common.MethodChannel.Result
 import io.flutter.plugin.common.PluginRegistry.Registrar
-import java.security.MessageDigest
-import java.security.SecureRandom
-import javax.crypto.Cipher
-import javax.crypto.KeyGenerator
-import javax.crypto.SecretKey
-import javax.crypto.SecretKeyFactory
-import javax.crypto.spec.IvParameterSpec
-import javax.crypto.spec.PBEKeySpec
-import javax.crypto.spec.SecretKeySpec
 
 
 /** NativeCryptoPlugin */
-public class NativeCryptoPlugin : FlutterPlugin, MethodCallHandler {
-    // CRYPTO CONSTS
-    private val HASH_FUNC = "SHA-256"
-    private val SYM_CRYPTO_METHOD = "AES"
-    private val SYM_CRYPTO_PADDING = "AES/CBC/PKCS5PADDING"
-
+class NativeCryptoPlugin : FlutterPlugin, MethodCallHandler {
     override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
-        val channel = MethodChannel(flutterPluginBinding.getFlutterEngine().getDartExecutor(), "native.crypto.helper")
+        val channel = MethodChannel(flutterPluginBinding.getFlutterEngine().getDartExecutor(), "native.crypto")
         channel.setMethodCallHandler(NativeCryptoPlugin());
     }
 
     companion object {
         @JvmStatic
         fun registerWith(registrar: Registrar) {
-            val channel = MethodChannel(registrar.messenger(), "native.crypto.helper")
+            val channel = MethodChannel(registrar.messenger(), "native.crypto")
             channel.setMethodCallHandler(NativeCryptoPlugin())
         }
     }
 
     override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
-        if (call.method == "pbkdf2") {
 
-            val password = call.argument<String>("password")
-            val salt = call.argument<String>("salt")
-            val keyLength = call.argument<Int>("keyLength")
-            val iteration = call.argument<Int>("iteration")
-            val algorithm = call.argument<String>("algorithm")
+        when (call.method) {
+            "digest" -> {
+                val message = call.argument<ByteArray>("message")
+                val algorithm = call.argument<String>("algorithm")
 
-            val key = pbkdf2(password!!, salt!!, keyLength!!, iteration!!, algorithm!!)
-
-            if (key.isNotEmpty()) {
-                result.success(key)
-            } else {
-                result.error("PBKDF2ERROR", "PBKDF2 KEY IS NULL.", null)
-            }
-        } else if (call.method == "symKeygen") {
-            val keySize = call.argument<Int>("size") // 128, 192, 256
-
-            val aesKey = symKeygen(keySize!!) // Collection<ByteArray>
-
-            if (aesKey.isNotEmpty()) {
-                result.success(aesKey)
-            } else {
-                result.error("SYMKEYGENERROR", "GENERATED KEY IS NULL.", null)
-            }
-        } else if (call.method == "symEncrypt") {
-            val payload = call.argument<ByteArray>("payload") // ByteArray
-            val aesKey = call.argument<ByteArray>("aesKey") // ByteArray
-
-            val encryptedPayload = symEncrypt(payload!!, aesKey!!) // Collection<ByteArray>
-
-            if (encryptedPayload.isNotEmpty()) {
-                result.success(encryptedPayload)
-            } else {
-                result.error("ENCRYPTIONERROR", "ENCRYPTED PAYLOAD IS NULL.", null)
-            }
-        } else if (call.method == "symDecrypt") {
-            val payload = call.argument<Collection<ByteArray>>("payload") // Collection<ByteArray>
-            val aesKey = call.argument<ByteArray>("aesKey") // ByteArray
-            var decryptedPayload : ByteArray? = null
-
-            try {
-                decryptedPayload = symDecrypt(payload!!, aesKey!!)
-                if (decryptedPayload != null && decryptedPayload.isNotEmpty()) {
-                    result.success(decryptedPayload)
-                } else {
-                    result.error("DECRYPTIONERROR", "DECRYPTED PAYLOAD IS NULL. MAYBE VERIFICATION MAC IS UNVALID.", null)
+                try {
+                    val d = Hash().digest(message, algorithm!!)
+                    if (d.isNotEmpty()) {
+                        result.success(d)
+                    } else {
+                        result.error("DIGESTERROR", "DIGEST IS NULL.", null)
+                    }
+                } catch (e : Exception) {
+                    result.error("DIGESTEXCEPTION", e.message, null)
                 }
-            } catch (e : Exception) {
-                result.error("DECRYPTIONERROR", "AN ERROR OCCURED WHILE DECRYPTING.", null)
             }
-            
-        } else {
-            result.notImplemented()
+            "pbkdf2" -> {
+                val password = call.argument<String>("password")
+                val salt = call.argument<String>("salt")
+                val keyLength = call.argument<Int>("keyLength")
+                val iteration = call.argument<Int>("iteration")
+                val algorithm = call.argument<String>("algorithm")
+
+                try {
+                    val key = KeyDerivation().pbkdf2(password!!, salt!!, keyLength!!, iteration!!, algorithm!!)
+                    if (key.isNotEmpty()) {
+                        result.success(key)
+                    } else {
+                        result.error("PBKDF2ERROR", "PBKDF2 KEY IS NULL.", null)
+                    }
+                } catch (e : Exception) {
+                    result.error("PBKDF2EXCEPTION", e.message, null)
+                }
+            }
+            "keygen" -> {
+                val size = call.argument<Int>("size") // 128, 192, 256
+                try {
+                    val key = KeyGeneration().keygen(size!!)
+
+                    if (key.isNotEmpty()) {
+                        result.success(key)
+                    } else {
+                        result.error("KEYGENERROR", "GENERATED KEY IS NULL.", null)
+                    }
+                } catch (e : Exception) {
+                    result.error("KEYGENEXCEPTION", e.message, null)
+                }
+            }
+            "rsaKeypairGen" -> {
+                val size = call.argument<Int>("size")
+                try {
+                    val keypair = KeyGeneration().rsaKeypairGen(size!!)
+
+                    if (keypair.isNotEmpty()) {
+                        result.success(keypair)
+                    } else {
+                        result.error("KEYPAIRGENERROR", "GENERATED KEYPAIR IS EMPTY.", null)
+                    }
+                } catch (e : Exception) {
+                    result.error("KEYPAIRGENEXCEPTION", e.message, null)
+                }
+            }
+            "encrypt" -> {
+                val data = call.argument<ByteArray>("data")
+                val key = call.argument<ByteArray>("key")
+                val algorithm = call.argument<String>("algorithm")
+                val mode = call.argument<String>("mode")
+                val padding = call.argument<String>("padding")
+
+                try {
+                    val payload = Cipher().encrypt(data!!, key!!, algorithm!!, mode!!, padding!!)
+
+                    if (payload.isNotEmpty()) {
+                        result.success(payload)
+                    } else {
+                        result.error("ENCRYPTIONERROR", "ENCRYPTED PAYLOAD IS EMPTY.", null)
+                    }
+                } catch (e: Exception) {
+                    result.error("ENCRYPTIONEXCEPTION", e.message, null)
+                }
+
+            }
+            "decrypt" -> {
+                val payload = call.argument<Collection<ByteArray>>("payload") // Collection<ByteArray>
+
+                val key = call.argument<ByteArray>("key")
+                val algorithm = call.argument<String>("algorithm")
+                val mode = call.argument<String>("mode")
+                val padding = call.argument<String>("padding")
+
+                var decryptedPayload : ByteArray? = null
+
+                try {
+                    decryptedPayload = Cipher().decrypt(payload!!, key!!, algorithm!!, mode!!, padding!!)
+                    if (decryptedPayload != null && decryptedPayload.isNotEmpty()) {
+                        result.success(decryptedPayload)
+                    } else {
+                        result.error("DECRYPTIONERROR", "DECRYPTED PAYLOAD IS NULL. MAYBE VERIFICATION MAC IS UNVALID.", null)
+                    }
+                } catch (e : Exception) {
+                    result.error("DECRYPTIONEXCEPTION", e.message, null)
+                }
+            }
+            else -> result.notImplemented()
         }
     }
 
     override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
     }
-
-    // CRYPTO NATIVE FUNCTIONS
-
-    private fun digest(obj: ByteArray?): ByteArray {
-        val md = MessageDigest.getInstance(HASH_FUNC)
-        return md.digest(obj)
-    }
-
-    private fun pbkdf2(password : String, salt : String, keyLength : Int, iteration : Int, algorithm : String) : ByteArray {
-        val chars: CharArray = password.toCharArray()
-
-        val spec = PBEKeySpec(chars, salt.toByteArray(), iteration, keyLength * 8)
-        val skf: SecretKeyFactory = if (algorithm == "sha1") {
-            SecretKeyFactory.getInstance("PBKDF2withHmacSHA1")
-        } else if (algorithm == "sha256") {
-            SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256")
-        } else {
-            SecretKeyFactory.getInstance("PBKDF2withHmacSHA512")
-        }
-        return skf.generateSecret(spec).encoded
-    }
-
-    private fun symKeygen(keySize : Int): ByteArray {
-
-        val SYM_CRYPTO_BITS = keySize
-
-        val secureRandom = SecureRandom()
-        val keyGenerator = KeyGenerator.getInstance(SYM_CRYPTO_METHOD)
-        keyGenerator?.init(SYM_CRYPTO_BITS, secureRandom)
-        val skey = keyGenerator?.generateKey()
-
-        return skey!!.encoded
-    }
-
-    private fun symEncrypt(payload: ByteArray, aesKey: ByteArray): Collection<ByteArray> {
-
-        val mac = digest(aesKey + payload)
-        val key: SecretKey = SecretKeySpec(aesKey, SYM_CRYPTO_METHOD)
-
-        val cipher = Cipher.getInstance(SYM_CRYPTO_PADDING)
-        cipher.init(Cipher.ENCRYPT_MODE, key)
-
-        val encryptedBytes = cipher.doFinal(mac + payload)
-        val iv = cipher.iv
-
-        return listOf(encryptedBytes, iv);
-    }
-
-    private fun symDecrypt(payload: Collection<ByteArray>, aesKey: ByteArray): ByteArray? {
-
-        val key: SecretKey = SecretKeySpec(aesKey, SYM_CRYPTO_METHOD)
-        val cipher = Cipher.getInstance(SYM_CRYPTO_PADDING);
-        val iv = payload.last();
-        val ivSpec = IvParameterSpec(iv)
-        cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
-
-        val decryptedBytes = cipher.doFinal(payload.first());
-
-        val mac = decryptedBytes.copyOfRange(0, 32)
-        val decryptedContent = decryptedBytes.copyOfRange(32, decryptedBytes.size)
-        val verificationMac = digest(aesKey + decryptedContent)
-
-        if (mac.contentEquals(verificationMac)) return decryptedContent
-
-        return null;
-    }
-
 }

android/src/main/kotlin/fr/pointcheval/native_crypto/PlatformVersionException.kt

@@ -0,0 +1,5 @@
+package fr.pointcheval.native_crypto
+
+import java.lang.Exception
+
+class PlatformVersionException(message : String) : Exception(message)