Add encrypted notification log storage foundation

2026-07-23 08:03:19 +00:00
parent 022fb5220f
commit 23af171c29
6 changed files with 271 additions and 0 deletions
@@ -0,0 +1,29 @@
+package se.ajpanton.notificationlog.data
+
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.security.SecureRandom
+import javax.crypto.KeyGenerator
+
+class AesGcmCipherTest {
+    @Test
+    fun roundTripsDataWithoutLeavingItInCipherText() {
+        val key = KeyGenerator.getInstance("AES").apply { init(256) }.generateKey()
+        val plainText = "private notification content".encodeToByteArray()
+
+        val encrypted = AesGcmCipher(key).encrypt(plainText)
+
+        assertFalse(encrypted.cipherText.decodeToString().contains("private notification content"))
+        assertTrue(AesGcmCipher(key).decrypt(encrypted).contentEquals(plainText))
+    }
+
+    @Test(expected = javax.crypto.AEADBadTagException::class)
+    fun rejectsTamperedCipherText() {
+        val key = KeyGenerator.getInstance("AES").apply { init(256) }.generateKey()
+        val encrypted = AesGcmCipher(key, SecureRandom()).encrypt("message".encodeToByteArray())
+        encrypted.cipherText[0] = (encrypted.cipherText[0].toInt() xor 1).toByte()
+
+        AesGcmCipher(key).decrypt(encrypted)
+    }
+}