Refactor KDB cipher and better tests

app/src/main/java/com/kunzisoft/keepass/database/crypto/AesEngine.kt

@@ -20,7 +20,7 @@
 package com.kunzisoft.keepass.database.crypto
 
 
-import com.kunzisoft.encrypt.CipherEngineFactory
+import com.kunzisoft.encrypt.CipherFactory
 import java.security.InvalidAlgorithmParameterException
 import java.security.InvalidKeyException
 import java.security.NoSuchAlgorithmException
@@ -31,7 +31,7 @@ class AesEngine : CipherEngine() {
 
     @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
     override fun getCipher(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-        return CipherEngineFactory.getAES(opmode, key, IV)
+        return CipherFactory.getAES(opmode, key, IV)
     }
 
     override fun getEncryptionAlgorithm(): EncryptionAlgorithm {

app/src/main/java/com/kunzisoft/keepass/database/crypto/ChaCha20Engine.kt

@@ -19,7 +19,7 @@
  */
 package com.kunzisoft.keepass.database.crypto
 
-import com.kunzisoft.encrypt.CipherEngineFactory
+import com.kunzisoft.encrypt.CipherFactory
 import java.security.InvalidAlgorithmParameterException
 import java.security.InvalidKeyException
 import java.security.NoSuchAlgorithmException
@@ -34,7 +34,7 @@ class ChaCha20Engine : CipherEngine() {
 
     @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
     override fun getCipher(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-        return CipherEngineFactory.getChacha20(opmode, key, IV)
+        return CipherFactory.getChacha20(opmode, key, IV)
     }
 
     override fun getEncryptionAlgorithm(): EncryptionAlgorithm {

app/src/main/java/com/kunzisoft/keepass/database/crypto/TwofishEngine.kt

@@ -19,7 +19,7 @@
  */
 package com.kunzisoft.keepass.database.crypto
 
-import com.kunzisoft.encrypt.CipherEngineFactory
+import com.kunzisoft.encrypt.CipherFactory
 import java.security.InvalidAlgorithmParameterException
 import java.security.InvalidKeyException
 import java.security.NoSuchAlgorithmException
@@ -30,7 +30,7 @@ class TwofishEngine : CipherEngine() {
 
     @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
     override fun getCipher(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-        return CipherEngineFactory.getTwofish(opmode, key, IV)
+        return CipherFactory.getTwofish(opmode, key, IV)
     }
 
     override fun getEncryptionAlgorithm(): EncryptionAlgorithm {

app/src/main/java/com/kunzisoft/keepass/database/file/input/DatabaseInputKDB.kt

@@ -20,7 +20,6 @@
 
 package com.kunzisoft.keepass.database.file.input
 
-import com.kunzisoft.encrypt.CipherFactory
 import com.kunzisoft.keepass.R
 import com.kunzisoft.keepass.database.crypto.EncryptionAlgorithm
 import com.kunzisoft.keepass.database.element.Database
@@ -35,12 +34,11 @@ import com.kunzisoft.keepass.database.file.DatabaseHeaderKDB
 import com.kunzisoft.keepass.stream.*
 import com.kunzisoft.keepass.tasks.ProgressTaskUpdater
 import java.io.*
-import java.security.*
+import java.security.DigestInputStream
+import java.security.MessageDigest
+import java.security.NoSuchAlgorithmException
 import java.util.*
 import javax.crypto.Cipher
-import javax.crypto.NoSuchPaddingException
-import javax.crypto.spec.IvParameterSpec
-import javax.crypto.spec.SecretKeySpec
 
 
 /**
@@ -131,32 +129,14 @@ class DatabaseInputKDB(cacheDirectory: File)
                     mDatabase.numberKeyEncryptionRounds)
 
             progressTaskUpdater?.updateMessage(R.string.decrypting_db)
-            // Initialize Rijndael algorithm
-            val cipher: Cipher = try {
-                // TODO Encapsulate
-                when {
-                    mDatabase.encryptionAlgorithm === EncryptionAlgorithm.AESRijndael -> {
-                        CipherFactory.getInstance("AES/CBC/PKCS5Padding")
-                    }
-                    mDatabase.encryptionAlgorithm === EncryptionAlgorithm.Twofish -> {
-                        CipherFactory.getInstance("Twofish/CBC/PKCS7PADDING")
-                    }
-                    else -> throw IOException("Encryption algorithm is not supported")
-                }
-            } catch (e1: NoSuchAlgorithmException) {
-                throw IOException("No such algorithm")
-            } catch (e1: NoSuchPaddingException) {
-                throw IOException("No such pdading")
-            }
 
-            try {
-                cipher.init(Cipher.DECRYPT_MODE,
-                        SecretKeySpec(mDatabase.finalKey, "AES"),
-                        IvParameterSpec(header.encryptionIV))
-            } catch (e1: InvalidKeyException) {
-                throw IOException("Invalid key")
-            } catch (e1: InvalidAlgorithmParameterException) {
-                throw IOException("Invalid algorithm parameter.")
+            val cipher: Cipher = try {
+                mDatabase.encryptionAlgorithm
+                        .cipherEngine.getCipher(Cipher.DECRYPT_MODE,
+                                mDatabase.finalKey ?: ByteArray(0),
+                                header.encryptionIV)
+            } catch (e: Exception) {
+                throw IOException("Algorithm not supported.", e)
             }
 
             val messageDigest: MessageDigest

app/src/main/java/com/kunzisoft/keepass/database/file/input/DatabaseInputKDBX.kt

@@ -156,7 +156,7 @@ class DatabaseInputKDBX(cacheDirectory: File)
             val isPlain: InputStream
             if (mDatabase.kdbxVersion.toKotlinLong() < DatabaseHeaderKDBX.FILE_VERSION_32_4.toKotlinLong()) {
 
-                val decrypted = attachCipherStream(databaseInputStream, cipher)
+                val decrypted = CipherInputStream(databaseInputStream, cipher)
                 val dataDecrypted = LittleEndianDataInputStream(decrypted)
                 val storedStartBytes: ByteArray?
                 try {
@@ -193,11 +193,10 @@ class DatabaseInputKDBX(cacheDirectory: File)
 
                 val hmIs = HmacBlockInputStream(isData, true, hmacKey)
 
-                isPlain = attachCipherStream(hmIs, cipher)
+                isPlain = CipherInputStream(hmIs, cipher)
             }
 
-            val inputStreamXml: InputStream
-            inputStreamXml = when (mDatabase.compressionAlgorithm) {
+            val inputStreamXml: InputStream = when (mDatabase.compressionAlgorithm) {
                 CompressionAlgorithm.GZip -> GZIPInputStream(isPlain)
                 else -> isPlain
             }
@@ -232,10 +231,6 @@ class DatabaseInputKDBX(cacheDirectory: File)
         return mDatabase
     }
 
-    private fun attachCipherStream(inputStream: InputStream, cipher: Cipher): InputStream {
-        return CipherInputStream(inputStream, cipher)
-    }
-
     @Throws(IOException::class)
     private fun loadInnerHeader(inputStream: InputStream, header: DatabaseHeaderKDBX) {
         val lis = LittleEndianDataInputStream(inputStream)

app/src/main/java/com/kunzisoft/keepass/database/file/output/DatabaseOutputKDB.kt

@@ -19,7 +19,6 @@
  */
 package com.kunzisoft.keepass.database.file.output
 
-import com.kunzisoft.encrypt.CipherFactory
 import com.kunzisoft.encrypt.UnsignedInt
 import com.kunzisoft.encrypt.stream.LittleEndianDataOutputStream
 import com.kunzisoft.encrypt.stream.NullOutputStream
@@ -37,8 +36,7 @@ import java.security.*
 import java.util.*
 import javax.crypto.Cipher
 import javax.crypto.CipherOutputStream
-import javax.crypto.spec.IvParameterSpec
-import javax.crypto.spec.SecretKeySpec
+import javax.crypto.NoSuchPaddingException
 
 class DatabaseOutputKDB(private val mDatabaseKDB: DatabaseKDB,
                         outputStream: OutputStream)
@@ -67,31 +65,27 @@ class DatabaseOutputKDB(private val mDatabaseKDB: DatabaseKDB,
 
         val finalKey = getFinalKey(header)
 
-        val cipher: Cipher
-        cipher = try {
-            when {
-                // TODO Encapsulate
-                mDatabaseKDB.encryptionAlgorithm === EncryptionAlgorithm.AESRijndael->
-                    CipherFactory.getInstance("AES/CBC/PKCS5Padding")
-                mDatabaseKDB.encryptionAlgorithm === EncryptionAlgorithm.Twofish ->
-                    CipherFactory.getInstance("Twofish/CBC/PKCS7PADDING")
-                else ->
-                    throw Exception()
-            }
-        } catch (e: Exception) {
-            throw DatabaseOutputException("Algorithm not supported.", e)
+        val cipher: Cipher = try {
+            mDatabaseKDB.encryptionAlgorithm
+                    .cipherEngine.getCipher(Cipher.ENCRYPT_MODE,
+                            finalKey ?: ByteArray(0),
+                            header.encryptionIV)
+        } catch (e1: NoSuchAlgorithmException) {
+            throw IOException("No such algorithm")
+        } catch (e1: NoSuchPaddingException) {
+            throw IOException("No such padding")
+        } catch (e1: InvalidKeyException) {
+            throw IOException("Invalid key")
+        } catch (e1: InvalidAlgorithmParameterException) {
+            throw IOException("Invalid algorithm parameter.")
         }
 
         try {
-            cipher.init(Cipher.ENCRYPT_MODE,
-                    SecretKeySpec(finalKey, "AES"),
-                    IvParameterSpec(header.encryptionIV))
             val cos = CipherOutputStream(mOutputStream, cipher)
             val bos = BufferedOutputStream(cos)
             outputPlanGroupAndEntries(bos)
             bos.flush()
             bos.close()
-
         } catch (e: InvalidKeyException) {
             throw DatabaseOutputException("Invalid key", e)
         } catch (e: InvalidAlgorithmParameterException) {

encrypt/src/androidTest/java/com/kunzisoft/encrypt/AESTest.kt

@@ -23,23 +23,82 @@ import com.kunzisoft.encrypt.aes.AndroidAESKeyTransformer
 import com.kunzisoft.encrypt.aes.NativeAESKeyTransformer
 import org.junit.Assert.assertArrayEquals
 import org.junit.Test
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
 import java.util.*
 import javax.crypto.Cipher
-import javax.crypto.spec.IvParameterSpec
-import javax.crypto.spec.SecretKeySpec
+import javax.crypto.CipherInputStream
+import javax.crypto.CipherOutputStream
 
 class AESTest {
 
     private val mRand = Random()
 
     @Test
-    fun testAES() {
-        // Test both an old and an even number to test my flip variable
-        testAESFinalKey(5)
-        testAESFinalKey(6)
+    fun testAESByteArray() {
+        // Generate random input
+        val input = ByteArray(mRand.nextInt(494) + 18)
+        mRand.nextBytes(input)
+        // Generate key
+        val keyArray = ByteArray(32)
+        mRand.nextBytes(keyArray)
+        // Generate IV
+        val ivArray = ByteArray(16)
+        mRand.nextBytes(ivArray)
+
+        val androidEncrypt = CipherFactory.getAES(Cipher.ENCRYPT_MODE, keyArray, ivArray).doFinal(input)
+        val nativeEncrypt = CipherFactory.getAES(Cipher.ENCRYPT_MODE, keyArray, ivArray, true).doFinal(input)
+
+        assertArrayEquals("Check AES encryption", androidEncrypt, nativeEncrypt)
+
+        val androidDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray).doFinal(androidEncrypt)
+        val nativeDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray, true).doFinal(nativeEncrypt)
+
+        assertArrayEquals("Check AES encryption/decryption", androidDecrypt, nativeDecrypt)
+
+        val androidMixDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray).doFinal(nativeEncrypt)
+        val nativeMixDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray, true).doFinal(androidEncrypt)
+
+        assertArrayEquals("Check AES mix encryption/decryption", androidMixDecrypt, nativeMixDecrypt)
     }
 
-    private fun testAESFinalKey(rounds: Long) {
+    @Test
+    fun testAESStream() {
+        // Generate random input
+        val input = ByteArray(mRand.nextInt(494) + 18)
+        mRand.nextBytes(input)
+        // Generate key
+        val keyArray = ByteArray(32)
+        mRand.nextBytes(keyArray)
+        // Generate IV
+        val ivArray = ByteArray(16)
+        mRand.nextBytes(ivArray)
+
+        val androidEncrypt = CipherFactory.getAES(Cipher.ENCRYPT_MODE, keyArray, ivArray)
+        val androidDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray)
+        val androidOutputStream = ByteArrayOutputStream()
+        CipherInputStream(ByteArrayInputStream(input), androidEncrypt).use { cipherInputStream ->
+            CipherOutputStream(androidOutputStream, androidDecrypt).use { outputStream ->
+                outputStream.write(cipherInputStream.readBytes())
+            }
+        }
+        val androidOut = androidOutputStream.toByteArray()
+
+        val nativeEncrypt = CipherFactory.getAES(Cipher.ENCRYPT_MODE, keyArray, ivArray)
+        val nativeDecrypt = CipherFactory.getAES(Cipher.DECRYPT_MODE, keyArray, ivArray)
+        val nativeOutputStream = ByteArrayOutputStream()
+        CipherInputStream(ByteArrayInputStream(input), nativeEncrypt).use { cipherInputStream ->
+            CipherOutputStream(nativeOutputStream, nativeDecrypt).use { outputStream ->
+                outputStream.write(cipherInputStream.readBytes())
+            }
+        }
+        val nativeOut = nativeOutputStream.toByteArray()
+
+        assertArrayEquals("Check AES encryption/decryption", androidOut, nativeOut)
+    }
+
+    @Test
+    fun testAESKDF() {
         val seed = ByteArray(32)
         val key = ByteArray(32)
         val nativeKey: ByteArray?
@@ -49,49 +108,11 @@ class AESTest {
         mRand.nextBytes(key)
 
         val androidAESKey = AndroidAESKeyTransformer()
-        androidKey = androidAESKey.transformMasterKey(seed, key, rounds)
+        androidKey = androidAESKey.transformMasterKey(seed, key, 60000)
 
         val nativeAESKey = NativeAESKeyTransformer()
-        nativeKey = nativeAESKey.transformMasterKey(seed, key, rounds)
+        nativeKey = nativeAESKey.transformMasterKey(seed, key, 60000)
 
         assertArrayEquals("Does not match", androidKey, nativeKey)
     }
-
-    @Test
-    fun testEncrypt() {
-        // Test above below and at the blocksize
-        testFinal(15)
-        testFinal(16)
-        testFinal(17)
-
-        // Test random larger sizes
-        val size = mRand.nextInt(494) + 18
-        testFinal(size)
-    }
-
-    private fun testFinal(dataSize: Int) {
-        // Generate some input
-        val input = ByteArray(dataSize)
-        mRand.nextBytes(input)
-
-        // Generate key
-        val keyArray = ByteArray(32)
-        mRand.nextBytes(keyArray)
-        val key = SecretKeySpec(keyArray, "AES")
-
-        // Generate IV
-        val ivArray = ByteArray(16)
-        mRand.nextBytes(ivArray)
-        val iv = IvParameterSpec(ivArray)
-
-        val android = CipherFactory.getInstance("AES/CBC/PKCS5Padding", true)
-        android.init(Cipher.ENCRYPT_MODE, key, iv)
-        val outAndroid = android.doFinal(input, 0, dataSize)
-
-        val nat = CipherFactory.getInstance("AES/CBC/PKCS5Padding")
-        nat.init(Cipher.ENCRYPT_MODE, key, iv)
-        val outNative = nat.doFinal(input, 0, dataSize)
-
-        assertArrayEquals("Arrays differ on size: $dataSize", outAndroid, outNative)
-    }
 }

encrypt/src/main/java/com/kunzisoft/encrypt/CipherEngineFactory.kt

@@ -1,45 +0,0 @@
-package com.kunzisoft.encrypt
-
-import org.bouncycastle.jce.provider.BouncyCastleProvider
-import java.security.InvalidAlgorithmParameterException
-import java.security.InvalidKeyException
-import java.security.NoSuchAlgorithmException
-import javax.crypto.Cipher
-import javax.crypto.NoSuchPaddingException
-import javax.crypto.spec.IvParameterSpec
-import javax.crypto.spec.SecretKeySpec
-
-class CipherEngineFactory {
-
-    companion object {
-
-        @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
-        fun getAES(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-            // TODO native
-            val androidOverride = false
-            val cipher = CipherFactory.getInstance("AES/CBC/PKCS5Padding", androidOverride)
-            cipher.init(opmode, SecretKeySpec(key, "AES"), IvParameterSpec(IV))
-            return cipher
-        }
-
-        @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
-        fun getTwofish(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-            // TODO native
-            val androidOverride = false
-            val cipher: Cipher = if (opmode == Cipher.ENCRYPT_MODE) {
-                CipherFactory.getInstance("Twofish/CBC/ZeroBytePadding", androidOverride)
-            } else {
-                CipherFactory.getInstance("Twofish/CBC/NoPadding", androidOverride)
-            }
-            cipher.init(opmode, SecretKeySpec(key, "AES"), IvParameterSpec(IV))
-            return cipher
-        }
-
-        @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
-        fun getChacha20(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
-            val cipher = Cipher.getInstance("Chacha7539", BouncyCastleProvider())
-            cipher.init(opmode, SecretKeySpec(key, "ChaCha7539"), IvParameterSpec(IV))
-            return cipher
-        }
-    }
-}

encrypt/src/main/java/com/kunzisoft/encrypt/CipherFactory.kt

@@ -1,61 +1,51 @@
-/*
- * Copyright 2019 Jeremy Jamet / Kunzisoft.
- *
- * This file is part of KeePassDX.
- *
- *  KeePassDX is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation, either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  KeePassDX is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with KeePassDX.  If not, see <http://www.gnu.org/licenses/>.
- *
- */
 package com.kunzisoft.encrypt
 
-import android.os.Build
 import org.bouncycastle.jce.provider.BouncyCastleProvider
+import java.security.InvalidAlgorithmParameterException
+import java.security.InvalidKeyException
 import java.security.NoSuchAlgorithmException
 import java.security.Security
 import javax.crypto.Cipher
 import javax.crypto.NoSuchPaddingException
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
 
 object CipherFactory {
 
-    private var blacklistInit = false
-    private var blacklisted: Boolean = false
-
     init {
         Security.removeProvider(BouncyCastleProvider.PROVIDER_NAME)
         Security.addProvider(BouncyCastleProvider())
     }
 
-    fun deviceBlacklisted(): Boolean {
-        if (!blacklistInit) {
-            blacklistInit = true
-            // The Acer Iconia A500 is special and seems to always crash in the native crypto libraries
-            blacklisted = Build.MODEL == "A500"
-        }
-        return blacklisted
-    }
-
-    private fun hasNativeImplementation(transformation: String): Boolean {
-        return transformation == "AES/CBC/PKCS5Padding"
-    }
-
-    @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class)
-    fun getInstance(transformation: String, androidOverride: Boolean = false): Cipher {
-        // Return the native AES if it is possible
-        return if (!deviceBlacklisted() && !androidOverride && hasNativeImplementation(transformation) && NativeLib.loaded()) {
+    @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
+    fun getAES(opmode: Int, key: ByteArray, IV: ByteArray, forceNative: Boolean = false): Cipher {
+        val transformation = "AES/CBC/PKCS5Padding"
+        val cipher = if (forceNative || (!NativeBlockList.isBlocked && NativeLib.loaded())) {
             Cipher.getInstance(transformation, AESProvider())
         } else {
             Cipher.getInstance(transformation)
         }
+        cipher.init(opmode, SecretKeySpec(key, "AES"), IvParameterSpec(IV))
+        return cipher
+    }
+
+    @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
+    fun getTwofish(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
+        val cipher: Cipher = if (opmode == Cipher.ENCRYPT_MODE) {
+            Cipher.getInstance("Twofish/CBC/ZeroBytePadding")
+        } else {
+            Cipher.getInstance("Twofish/CBC/NoPadding")
+        }
+        // TODO Verify KDB TwoFish
+        // CipherFactory.getInstance("Twofish/CBC/PKCS7PADDING")
+        cipher.init(opmode, SecretKeySpec(key, "AES"), IvParameterSpec(IV))
+        return cipher
+    }
+
+    @Throws(NoSuchAlgorithmException::class, NoSuchPaddingException::class, InvalidKeyException::class, InvalidAlgorithmParameterException::class)
+    fun getChacha20(opmode: Int, key: ByteArray, IV: ByteArray): Cipher {
+        val cipher = Cipher.getInstance("Chacha7539", BouncyCastleProvider())
+        cipher.init(opmode, SecretKeySpec(key, "ChaCha7539"), IvParameterSpec(IV))
+        return cipher
     }
 }

encrypt/src/main/java/com/kunzisoft/encrypt/NativeBlock.kt

@@ -0,0 +1,9 @@
+package com.kunzisoft.encrypt
+
+import android.os.Build
+
+object NativeBlockList {
+    val isBlocked: Boolean by lazy {
+        Build.MODEL == "A500"
+    }
+}

encrypt/src/main/java/com/kunzisoft/encrypt/aes/AESKeyTransformerFactory.kt

@@ -19,13 +19,12 @@
  */
 package com.kunzisoft.encrypt.aes
 
-import com.kunzisoft.encrypt.CipherFactory.deviceBlacklisted
+import com.kunzisoft.encrypt.NativeBlockList
 
 object AESKeyTransformerFactory : KeyTransformer() {
     override fun transformMasterKey(seed: ByteArray?, key: ByteArray?, rounds: Long?): ByteArray? {
         // Prefer the native final key implementation
-        val keyTransformer = if (!deviceBlacklisted()
-                && NativeAESKeyTransformer.available()) {
+        val keyTransformer = if (!NativeBlockList.isBlocked && NativeAESKeyTransformer.available()) {
             NativeAESKeyTransformer()
         } else {
             // Fall back on the android crypto implementation