fix(security): apply iOS audit parity fixes (#709)

Co-authored-by: CC <cc@ggg.local>
2026-07-27 08:45:20 +00:00 · 2026-06-15 08:35:37 -05:00
parent 13585a9a9c
commit 6189f0cb84
6 changed files with 133 additions and 4 deletions
@@ -0,0 +1,23 @@
+@file:JvmName("Base64")
+
+package android.util
+
+const val DEFAULT: Int = 0
+const val NO_WRAP: Int = 2
+
+fun encodeToString(input: ByteArray, flags: Int): String {
+    val encoder = if (flags and NO_WRAP != 0) {
+        java.util.Base64.getEncoder()
+    } else {
+        java.util.Base64.getMimeEncoder()
+    }
+    return encoder.encodeToString(input)
+}
+
+fun decode(input: String, flags: Int): ByteArray {
+    return if (flags and NO_WRAP != 0) {
+        java.util.Base64.getDecoder().decode(input)
+    } else {
+        java.util.Base64.getMimeDecoder().decode(input)
+    }
+}
@@ -0,0 +1,85 @@
+package com.bitchat.android.nostr
+
+import com.google.gson.Gson
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class NostrProtocolTest {
+    private val gson = Gson()
+
+    @Test
+    fun decryptPrivateMessage_acceptsAuthenticatedSeal() {
+        val sender = NostrIdentity.generate()
+        val recipient = NostrIdentity.generate()
+        val giftWrap = NostrProtocol.createPrivateMessage(
+            content = "bitchat1:test",
+            recipientPubkey = recipient.publicKeyHex,
+            senderIdentity = sender
+        ).single()
+
+        val decrypted = NostrProtocol.decryptPrivateMessage(giftWrap, recipient)
+
+        assertEquals("bitchat1:test", decrypted?.first)
+        assertEquals(sender.publicKeyHex, decrypted?.second)
+    }
+
+    @Test
+    fun decryptPrivateMessage_rejectsSealWhoseSignerDoesNotMatchRumor() {
+        val claimedSender = NostrIdentity.generate()
+        val attacker = NostrIdentity.generate()
+        val recipient = NostrIdentity.generate()
+        val giftWrap = forgedGiftWrap(
+            content = "bitchat1:forged",
+            claimedSender = claimedSender,
+            sealSigner = attacker,
+            recipient = recipient
+        )
+
+        val decrypted = NostrProtocol.decryptPrivateMessage(giftWrap, recipient)
+
+        assertNull(decrypted)
+    }
+
+    private fun forgedGiftWrap(
+        content: String,
+        claimedSender: NostrIdentity,
+        sealSigner: NostrIdentity,
+        recipient: NostrIdentity
+    ): NostrEvent {
+        val rumorBase = NostrEvent(
+            pubkey = claimedSender.publicKeyHex,
+            createdAt = (System.currentTimeMillis() / 1000).toInt(),
+            kind = NostrKind.DIRECT_MESSAGE,
+            tags = listOf(listOf("p", recipient.publicKeyHex)),
+            content = content
+        )
+        val rumor = rumorBase.copy(id = rumorBase.computeEventIdHex())
+        val sealContent = NostrCrypto.encryptNIP44(
+            plaintext = gson.toJson(rumor),
+            recipientPublicKeyHex = recipient.publicKeyHex,
+            senderPrivateKeyHex = sealSigner.privateKeyHex
+        )
+        val seal = NostrEvent(
+            pubkey = sealSigner.publicKeyHex,
+            createdAt = NostrCrypto.randomizeTimestampUpToPast(),
+            kind = NostrKind.SEAL,
+            tags = emptyList(),
+            content = sealContent
+        ).sign(sealSigner.privateKeyHex)
+
+        val (wrapPrivateKey, wrapPublicKey) = NostrCrypto.generateKeyPair()
+        val giftWrapContent = NostrCrypto.encryptNIP44(
+            plaintext = gson.toJson(seal),
+            recipientPublicKeyHex = recipient.publicKeyHex,
+            senderPrivateKeyHex = wrapPrivateKey
+        )
+        return NostrEvent(
+            pubkey = wrapPublicKey,
+            createdAt = NostrCrypto.randomizeTimestampUpToPast(),
+            kind = NostrKind.GIFT_WRAP,
+            tags = listOf(listOf("p", recipient.publicKeyHex)),
+            content = giftWrapContent
+        ).sign(wrapPrivateKey)
+    }
+}