Merge pull request #8900 from element-hq/feature/bma/testScanEncryptorUtils

Add unit test on ScanEncryptorUtils.

Author: bmarty

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/internal/session/contentscanner/ScanEncryptorUtilsTest.kt

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2024 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.session.contentscanner
+
+import okio.ByteString.Companion.decodeBase64
+import org.amshove.kluent.shouldBe
+import org.amshove.kluent.shouldBeEqualTo
+import org.amshove.kluent.shouldNotBe
+import org.junit.Test
+import org.matrix.android.sdk.api.session.crypto.attachments.ElementToDecrypt
+import org.matrix.android.sdk.api.session.crypto.model.EncryptedFileInfo
+import org.matrix.android.sdk.api.session.crypto.model.EncryptedFileKey
+import org.matrix.android.sdk.internal.crypto.tools.withOlmDecryption
+import org.matrix.android.sdk.internal.di.MoshiProvider
+import org.matrix.android.sdk.internal.session.contentscanner.model.DownloadBody
+import org.matrix.android.sdk.internal.session.contentscanner.model.EncryptedBody
+import org.matrix.olm.OlmPkMessage
+
+class ScanEncryptorUtilsTest {
+    private val anMxcUrl = "mxc://matrix.org/123456"
+    private val anElementToDecrypt = ElementToDecrypt(
+            k = "key",
+            iv = "iv",
+            sha256 = "sha256"
+    )
+    private val aPublicKey = "6n3l15JqsNhpM1OwRIoDCL/3c1B5idcwvy07Y5qFRyw="
+    private val aPrivateKey = "CLYwNaeA9d0KHE0DniO1bxGgmNsPJ/pyanF4b4tcK1M="
+
+    @Test
+    fun whenNoServerKeyIsProvidedTheContentIsNotEncrypted() {
+        val result = ScanEncryptorUtils.getDownloadBodyAndEncryptIfNeeded(
+                publicServerKey = null,
+                mxcUrl = anMxcUrl,
+                elementToDecrypt = anElementToDecrypt
+        )
+        result shouldBeEqualTo DownloadBody(
+                file = EncryptedFileInfo(
+                        url = anMxcUrl,
+                        iv = anElementToDecrypt.iv,
+                        hashes = mapOf("sha256" to anElementToDecrypt.sha256),
+                        key = EncryptedFileKey(
+                                k = anElementToDecrypt.k,
+                                alg = "A256CTR",
+                                keyOps = listOf("encrypt", "decrypt"),
+                                kty = "oct",
+                                ext = true
+                        ),
+                        v = "v2"
+                ),
+                encryptedBody = null
+        )
+    }
+
+    @Test
+    fun whenServerKeyIsProvidedTheContentIsEncrypted() {
+        System.loadLibrary("olm")
+        val result = ScanEncryptorUtils.getDownloadBodyAndEncryptIfNeeded(
+                publicServerKey = aPublicKey,
+                mxcUrl = anMxcUrl,
+                elementToDecrypt = anElementToDecrypt
+        )
+        result.file shouldBe null
+        // Note: we cannot check the members of EncryptedBody because they change on each call.
+        result.encryptedBody shouldNotBe null
+    }
+
+    @Test
+    fun checkThatTheCodeIsAbleToDecryptContent() {
+        System.loadLibrary("olm")
+        val clearInfo = ScanEncryptorUtils.getDownloadBodyAndEncryptIfNeeded(
+                publicServerKey = null,
+                mxcUrl = anMxcUrl,
+                elementToDecrypt = anElementToDecrypt
+        )
+        // Uncomment to get a new encrypted body
+        // val encryptedBody = ScanEncryptorUtils.getDownloadBodyAndEncryptIfNeeded(
+        //         publicServerKey = aPublicKey,
+        //         mxcUrl = anMxcUrl,
+        //         elementToDecrypt = anElementToDecrypt
+        // ).encryptedBody!!
+        // println("libolmEncryptedBody: $encryptedBody")
+        val libolmEncryptedBody = EncryptedBody(
+                cipherText = "GTnDhm6xe5fPe/QCr6fyGcZXheFhZlPG" +
+                        "nJZiCK8Xwq6qTg71vSUGWtLdt3uaTmK7" +
+                        "F7fB3PBKchHu2VVv6MMgo8fpUQ7KBbmu" +
+                        "NWTrNmf3QdhXuRwUwz/q4GxsbGR2zjSX" +
+                        "/UoE5S4ymVtOVhvSfXQfssN56wVIzC6S" +
+                        "dy57y6b1IXPihlCUdvb8LMkMvViHYeNf" +
+                        "beFrAfMlsyr1+jdZEXZF5Q7iruhsH2iu" +
+                        "k7+Ayl9rdILCD5tjE9pezwe1V6uc/Agb",
+                mac = "Wk77HRg50oM",
+                ephemeral = "rMTK6/CGASinfX4USFS5qmD3r4meffxKc/jCSFIBczw"
+        )
+        // Try to decrypt the body
+        val result = withOlmDecryption { olmPkDecryption ->
+            olmPkDecryption.setPrivateKey(aPrivateKey.decodeBase64()!!.toByteArray())
+            olmPkDecryption.decrypt(
+                    OlmPkMessage().apply {
+                        mCipherText = libolmEncryptedBody.cipherText
+                        mMac = libolmEncryptedBody.mac
+                        mEphemeralKey = libolmEncryptedBody.ephemeral
+                    }
+            )
+        }
+        val parseResult = MoshiProvider.providesMoshi()
+                .adapter(DownloadBody::class.java)
+                .fromJson(result)
+        parseResult shouldBeEqualTo clearInfo
+    }
+}