encryption

Signed-off-by: ale <ale@manalejandro.com>

app/src/main/java/com/manalejandro/alejabber/MainActivity.kt

@@ -6,7 +6,9 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Forum
 import androidx.compose.material.icons.filled.ManageAccounts
@@ -127,11 +129,13 @@ fun MainAppContent() {
                 }
             }
         }
-    ) { _ ->
-        AleJabberNavGraph(
-            navController    = navController,
-            startDestination = Screen.Accounts.route
-        )
+    ) { paddingValues ->
+        Box(modifier = Modifier.padding(paddingValues)) {
+            AleJabberNavGraph(
+                navController    = navController,
+                startDestination = Screen.Accounts.route
+            )
+        }
     }
 }
 

app/src/main/java/com/manalejandro/alejabber/data/remote/EncryptionManager.kt

@@ -0,0 +1,324 @@
+package com.manalejandro.alejabber.data.remote
+
+import android.content.Context
+import android.util.Log
+import com.manalejandro.alejabber.domain.model.EncryptionType
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import org.jivesoftware.smack.packet.Message
+import org.jivesoftware.smackx.carbons.packet.CarbonExtension
+import org.jivesoftware.smackx.omemo.OmemoManager
+import org.jivesoftware.smackx.omemo.OmemoMessage
+import org.jivesoftware.smackx.omemo.exceptions.CryptoFailedException
+import org.jivesoftware.smackx.omemo.exceptions.UndecidedOmemoIdentityException
+import org.jivesoftware.smackx.omemo.listener.OmemoMessageListener
+import org.jivesoftware.smackx.omemo.signal.SignalOmemoService
+import org.jivesoftware.smackx.omemo.trust.OmemoFingerprint
+import org.jivesoftware.smackx.omemo.trust.OmemoTrustCallback
+import org.jivesoftware.smackx.omemo.trust.TrustState
+import org.jxmpp.jid.impl.JidCreate
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Manages OMEMO, OTR and OpenPGP encryption for outgoing messages and
+ * decryption of incoming OMEMO-encrypted messages.
+ *
+ * - OMEMO  : implemented via smack-omemo-signal (Signal Protocol / XEP-0384).
+ *            Uses TOFU trust model — all new identities are trusted on first use.
+ *            `initializeAsync` is used so the UI thread is never blocked.
+ * - OTR    : implemented from scratch with BouncyCastle ECDH + AES-256-CTR.
+ *            Session state is kept in memory. Keys are ephemeral per session.
+ * - OpenPGP: encrypt with the recipient's public key stored via the Settings screen.
+ *            Signing is done with the user's own private key (also in Settings).
+ */
+@Singleton
+class EncryptionManager @Inject constructor(
+    @param:ApplicationContext private val context: Context,
+    private val xmppManager: XmppConnectionManager
+) {
+    private val TAG = "EncryptionManager"
+    private val scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
+
+    // ── OMEMO state per account ───────────────────────────────────────────
+    enum class OmemoState { IDLE, INITIALISING, READY, FAILED }
+
+    private val _omemoState = MutableStateFlow<Map<Long, OmemoState>>(emptyMap())
+    val omemoState: StateFlow<Map<Long, OmemoState>> = _omemoState.asStateFlow()
+
+    private var omemoServiceSetup = false
+
+    // ── OTR sessions: (accountId, bareJid) → OtrSession ──────────────────
+    private val otrSessions = mutableMapOf<Pair<Long, String>, OtrSession>()
+
+    // ── OpenPGP manager ───────────────────────────────────────────────────
+    private val pgpManager = PgpManager(context)
+
+    // ─────────────────────────────────────────────────────────────────────
+    // OMEMO
+    // ─────────────────────────────────────────────────────────────────────
+
+    /** Initialise OMEMO asynchronously for [accountId]. */
+    fun initOmemo(accountId: Long) {
+        val state = _omemoState.value[accountId]
+        if (state == OmemoState.READY || state == OmemoState.INITIALISING) return
+        val connection = xmppManager.getConnection(accountId) ?: return
+        if (!connection.isAuthenticated) return
+
+        _omemoState.update { it + (accountId to OmemoState.INITIALISING) }
+        scope.launch {
+            try {
+                if (!omemoServiceSetup) {
+                    SignalOmemoService.acknowledgeLicense()
+                    SignalOmemoService.setup()
+                    omemoServiceSetup = true
+                }
+                val omemoManager = OmemoManager.getInstanceFor(connection)
+                // TOFU trust callback — trust every new identity on first encounter
+                omemoManager.setTrustCallback(object : OmemoTrustCallback {
+                    override fun getTrust(
+                        device: org.jivesoftware.smackx.omemo.internal.OmemoDevice,
+                        fingerprint: OmemoFingerprint
+                    ): TrustState = TrustState.trusted
+
+                    override fun setTrust(
+                        device: org.jivesoftware.smackx.omemo.internal.OmemoDevice,
+                        fingerprint: OmemoFingerprint,
+                        state: TrustState
+                    ) { /* TOFU: ignore */ }
+                })
+                // Register incoming OMEMO message listener
+                omemoManager.addOmemoMessageListener(object : OmemoMessageListener {
+                    override fun onOmemoMessageReceived(
+                        stanza: org.jivesoftware.smack.packet.Stanza,
+                        decryptedMessage: OmemoMessage.Received
+                    ) {
+                        val from = stanza.from?.asBareJid()?.toString() ?: return
+                        val body = decryptedMessage.body ?: return
+                        scope.launch {
+                            xmppManager.dispatchDecryptedOmemoMessage(accountId, from, body)
+                        }
+                    }
+
+                    override fun onOmemoCarbonCopyReceived(
+                        direction: CarbonExtension.Direction,
+                        carbonCopy: Message,
+                        wrappingMessage: Message,
+                        decryptedCarbonCopy: OmemoMessage.Received
+                    ) {
+                        val from = carbonCopy.from?.asBareJid()?.toString() ?: return
+                        val body = decryptedCarbonCopy.body ?: return
+                        scope.launch {
+                            xmppManager.dispatchDecryptedOmemoMessage(accountId, from, body)
+                        }
+                    }
+                })
+                // Use async initialisation so we never block the IO thread during PubSub
+                omemoManager.initializeAsync(object : OmemoManager.InitializationFinishedCallback {
+                    override fun initializationFinished(manager: OmemoManager) {
+                        _omemoState.update { it + (accountId to OmemoState.READY) }
+                        Log.i(TAG, "OMEMO ready for account $accountId")
+                    }
+                    override fun initializationFailed(cause: Exception) {
+                        _omemoState.update { it + (accountId to OmemoState.FAILED) }
+                        Log.e(TAG, "OMEMO init failed for account $accountId", cause)
+                    }
+                })
+            } catch (e: Exception) {
+                _omemoState.update { it + (accountId to OmemoState.FAILED) }
+                Log.e(TAG, "OMEMO setup error for account $accountId", e)
+            }
+        }
+    }
+
+    fun isOmemoReady(accountId: Long) = _omemoState.value[accountId] == OmemoState.READY
+
+    fun getOmemoStateLabel(accountId: Long): String = when (_omemoState.value[accountId]) {
+        OmemoState.READY        -> "✓ Ready"
+        OmemoState.INITIALISING -> "⏳ Initialising…"
+        OmemoState.FAILED       -> "✗ Init failed"
+        else                    -> "⏳ Not started"
+    }
+
+    fun getOwnOmemoFingerprint(accountId: Long): String? {
+        if (!isOmemoReady(accountId)) return null
+        return try {
+            val connection = xmppManager.getConnection(accountId) ?: return null
+            OmemoManager.getInstanceFor(connection).ownFingerprint.toString()
+        } catch (e: Exception) { null }
+    }
+
+    // ─────────────────────────────────────────────────────────────────────
+    // OTR
+    // ─────────────────────────────────────────────────────────────────────
+
+    /** Start or resume an OTR session with [toJid]. */
+    fun startOtrSession(accountId: Long, toJid: String) {
+        val key = accountId to toJid
+        if (otrSessions.containsKey(key)) return
+        otrSessions[key] = OtrSession()
+        Log.i(TAG, "OTR session started with $toJid")
+    }
+
+    fun endOtrSession(accountId: Long, toJid: String) {
+        otrSessions.remove(accountId to toJid)
+        Log.i(TAG, "OTR session ended with $toJid")
+    }
+
+    fun isOtrSessionActive(accountId: Long, toJid: String) =
+        otrSessions.containsKey(accountId to toJid)
+
+    // ─────────────────────────────────────────────────────────────────────
+    // OpenPGP
+    // ─────────────────────────────────────────────────────────────────────
+
+    fun pgpManager() = pgpManager
+
+    // ─────────────────────────────────────────────────────────────────────
+    // Unified send
+    // ─────────────────────────────────────────────────────────────────────
+
+    /**
+     * Sends [body] to [toJid] with the specified [encryptionType].
+     * Returns (success: Boolean, notice: String?) where notice is a
+     * non-null informational message when the call partially succeeded
+     * (e.g. degraded to plain text).
+     */
+    fun sendMessage(
+        accountId: Long,
+        toJid: String,
+        body: String,
+        encryptionType: EncryptionType
+    ): Pair<Boolean, String?> {
+        val connection = xmppManager.getConnection(accountId)
+            ?: return false to "Not connected"
+        if (!connection.isConnected || !connection.isAuthenticated)
+            return false to "Not authenticated"
+
+        return when (encryptionType) {
+            EncryptionType.NONE    -> xmppManager.sendMessage(accountId, toJid, body) to null
+            EncryptionType.OMEMO   -> sendOmemo(accountId, toJid, body)
+            EncryptionType.OTR     -> sendOtr(accountId, toJid, body)
+            EncryptionType.OPENPGP -> sendPgp(accountId, toJid, body)
+        }
+    }
+
+    // ── OMEMO send ────────────────────────────────────────────────────────
+
+    private fun sendOmemo(accountId: Long, toJid: String, body: String): Pair<Boolean, String?> {
+        if (!isOmemoReady(accountId)) {
+            val notice = when (_omemoState.value[accountId]) {
+                OmemoState.INITIALISING -> "OMEMO is still initialising — sent as plain text."
+                OmemoState.FAILED       -> "OMEMO failed to initialise — sent as plain text."
+                else                    -> "OMEMO not ready — sent as plain text."
+            }
+            return if (xmppManager.sendMessage(accountId, toJid, body)) true to notice
+            else false to "Send failed"
+        }
+        return try {
+            val connection   = xmppManager.getConnection(accountId)!!
+            val omemoManager = OmemoManager.getInstanceFor(connection)
+            val recipientJid = JidCreate.entityBareFrom(toJid)
+            val encrypted    = omemoManager.encrypt(recipientJid, body)
+            // OmemoMessage.Sent — obtain the smack Message via reflection to avoid
+            // depending on the exact method name which differs between smack versions.
+            val stanza = omemoSentToMessage(encrypted, toJid)
+            connection.sendStanza(stanza)
+            true to null
+        } catch (e: UndecidedOmemoIdentityException) {
+            // TOFU: trust all undecided identities then retry — the trust callback
+            // already trusts everything on get(), but the exception might still be
+            // thrown if devices were added mid-flight. Just degrade gracefully.
+            Log.w(TAG, "OMEMO undecided identities — degrading to plain text: ${e.message}")
+            val sent = xmppManager.sendMessage(accountId, toJid, body)
+            if (sent) true to "OMEMO: undecided devices — sent as plain text. Open Settings to manage trust."
+            else false to "Send failed"
+        } catch (e: CryptoFailedException) {
+            Log.e(TAG, "OMEMO crypto failed", e)
+            false to "OMEMO encryption failed: ${e.message}"
+        } catch (e: Exception) {
+            Log.e(TAG, "OMEMO send error", e)
+            false to "OMEMO error: ${e.message}"
+        }
+    }
+
+    /**
+     * Converts an [OmemoMessage.Sent] to a [Message] stanza ready to send.
+     *
+     * Smack 4.4.x exposes the wrapped Message via one of several method names
+     * depending on the exact patch version. We try known names via reflection
+     * so the code compiles and runs regardless of minor API changes.
+     */
+    private fun omemoSentToMessage(sent: OmemoMessage.Sent, toJid: String): Message {
+        val bareJid = JidCreate.entityBareFrom(toJid)
+        // Try method names used in different smack 4.4.x versions
+        for (methodName in listOf("asMessage", "buildMessage", "toMessage", "getMessage")) {
+            try {
+                val m = sent.javaClass.getMethod(methodName,
+                    org.jxmpp.jid.BareJid::class.java)
+                val result = m.invoke(sent, bareJid)
+                if (result is Message) return result
+            } catch (_: NoSuchMethodException) {}
+            try {
+                val m = sent.javaClass.getMethod(methodName)
+                val result = m.invoke(sent)
+                if (result is Message) return result
+            } catch (_: NoSuchMethodException) {}
+        }
+        // Last resort: look for any method returning Message
+        for (m in sent.javaClass.methods) {
+            if (Message::class.java.isAssignableFrom(m.returnType) && m.parameterCount <= 1) {
+                try {
+                    val result = if (m.parameterCount == 0) m.invoke(sent)
+                    else m.invoke(sent, bareJid)
+                    if (result is Message) return result
+                } catch (_: Exception) {}
+            }
+        }
+        throw IllegalStateException("Cannot extract Message from OmemoMessage.Sent")
+    }
+
+    // ── OTR send ──────────────────────────────────────────────────────────
+
+    private fun sendOtr(accountId: Long, toJid: String, body: String): Pair<Boolean, String?> {
+        val key = accountId to toJid
+        val session = otrSessions.getOrPut(key) { OtrSession() }
+        return try {
+            val ciphertext = session.encrypt(body)
+            val sent = xmppManager.sendMessage(accountId, toJid, ciphertext)
+            if (sent) true to null
+            else false to "Send failed"
+        } catch (e: Exception) {
+            Log.e(TAG, "OTR encrypt error", e)
+            false to "OTR error: ${e.message}"
+        }
+    }
+
+    // ── OpenPGP send ──────────────────────────────────────────────────────
+
+    private fun sendPgp(accountId: Long, toJid: String, body: String): Pair<Boolean, String?> {
+        return try {
+            val encrypted = pgpManager.encryptFor(toJid, body)
+            if (encrypted != null) {
+                val sent = xmppManager.sendMessage(accountId, toJid, encrypted)
+                if (sent) true to null
+                else false to "Send failed"
+            } else {
+                // No recipient key — fall back to plain
+                val sent = xmppManager.sendMessage(accountId, toJid, body)
+                if (sent) true to "OpenPGP: no key for $toJid — sent as plain text."
+                else false to "Send failed"
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "PGP encrypt error", e)
+            false to "PGP error: ${e.message}"
+        }
+    }
+}

app/src/main/java/com/manalejandro/alejabber/data/remote/OtrSession.kt

@@ -0,0 +1,185 @@
+package com.manalejandro.alejabber.data.remote
+
+import android.util.Base64
+import android.util.Log
+import org.bouncycastle.crypto.engines.AESEngine
+import org.bouncycastle.crypto.generators.ECKeyPairGenerator
+import org.bouncycastle.crypto.modes.SICBlockCipher
+import org.bouncycastle.crypto.params.AEADParameters
+import org.bouncycastle.crypto.params.ECDomainParameters
+import org.bouncycastle.crypto.params.ECKeyGenerationParameters
+import org.bouncycastle.crypto.params.ECPrivateKeyParameters
+import org.bouncycastle.crypto.params.ECPublicKeyParameters
+import org.bouncycastle.crypto.params.KeyParameter
+import org.bouncycastle.crypto.params.ParametersWithIV
+import org.bouncycastle.jce.ECNamedCurveTable
+import org.bouncycastle.jce.provider.BouncyCastleProvider
+import java.security.SecureRandom
+import javax.crypto.Cipher
+import javax.crypto.Mac
+import javax.crypto.SecretKey
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
+
+/**
+ * Lightweight OTR-inspired session using BouncyCastle.
+ *
+ * This implements the *symmetric encryption core* of OTR:
+ *  - Ephemeral ECDH key exchange on Curve25519 (via BouncyCastle named curve "curve25519")
+ *  - AES-256 in CTR mode for message encryption
+ *  - HMAC-SHA256 for message authentication
+ *  - A nonce counter to provide Forward Secrecy across messages within a session
+ *
+ * Protocol flow:
+ *  1. Both sides call [getPublicKeyBytes] to get their ephemeral public key.
+ *  2. When the peer's public key is received, call [setRemotePublicKey].
+ *     This derives the shared AES and MAC keys using ECDH.
+ *  3. [encrypt] / [decrypt] can then be called.
+ *
+ * The ciphertext format is:
+ *   BASE64( nonce(8 bytes) | ciphertext | hmac(32 bytes) )
+ * prefixed with the OTR-style header "?OTR:" so recipients can identify it.
+ *
+ * NOTE: True OTR (OTR v2/v3/v4) requires D-H ratcheting and a full AKE
+ * (Authenticated Key Exchange) negotiation via XMPP. That full protocol
+ * requires the otr4j library (MIT-licensed). This implementation provides
+ * session-level encryption that can be upgraded to full OTR when otr4j is
+ * added as a dependency.
+ */
+class OtrSession {
+
+    private val TAG = "OtrSession"
+    private val rng = SecureRandom()
+
+    // Curve25519 ECDH parameters
+    private val curveParams = ECNamedCurveTable.getParameterSpec("curve25519")
+    private val domainParams = ECDomainParameters(
+        curveParams.curve, curveParams.g, curveParams.n, curveParams.h
+    )
+
+    // Ephemeral local key pair
+    private val localKeyPair: Pair<ByteArray, ByteArray>  // (privateKey, publicKey)
+
+    // Shared secret derived after ECDH
+    private var sessionAesKey: ByteArray? = null
+    private var sessionMacKey: ByteArray? = null
+
+    // Monotonic counter used as IV for AES-CTR
+    private var sendCounter = 0L
+    private var recvCounter = 0L
+
+    init {
+        val keyGenParams = ECKeyGenerationParameters(domainParams, rng)
+        val generator = ECKeyPairGenerator()
+        generator.init(keyGenParams)
+        val keyPair = generator.generateKeyPair()
+        val privKey = keyPair.private as ECPrivateKeyParameters
+        val pubKey  = keyPair.public  as ECPublicKeyParameters
+        localKeyPair = privKey.d.toByteArray() to pubKey.q.getEncoded(true)
+        Log.d(TAG, "OTR ephemeral key pair generated")
+    }
+
+    /** Returns our ephemeral compressed public key (33 bytes for curve25519). */
+    fun getPublicKeyBytes(): ByteArray = localKeyPair.second
+
+    /** Returns our public key as a Base64 string for transport in a chat message. */
+    fun getPublicKeyBase64(): String =
+        Base64.encodeToString(localKeyPair.second, Base64.NO_WRAP)
+
+    /**
+     * Finalises the ECDH key exchange using the remote party's [publicKeyBytes].
+     * After this call, [encrypt] and [decrypt] are operational.
+     */
+    fun setRemotePublicKey(publicKeyBytes: ByteArray) {
+        try {
+            val remotePoint = curveParams.curve.decodePoint(publicKeyBytes)
+            val remoteKey   = ECPublicKeyParameters(remotePoint, domainParams)
+            val privD       = org.bouncycastle.math.ec.ECAlgorithms.referenceMultiply(
+                remoteKey.q, org.bouncycastle.util.BigIntegers.fromUnsignedByteArray(localKeyPair.first)
+            )
+            val sharedX = privD.xCoord.encoded   // 32 bytes
+            // Derive AES key (first 32 bytes of SHA-256(shared)) and MAC key (SHA-256 of AES key)
+            val sha256 = java.security.MessageDigest.getInstance("SHA-256")
+            val aesKey = sha256.digest(sharedX)
+            sessionAesKey = aesKey
+            sessionMacKey = sha256.digest(aesKey)
+            Log.i(TAG, "OTR ECDH complete — session keys derived")
+        } catch (e: Exception) {
+            Log.e(TAG, "ECDH key exchange failed", e)
+            throw e
+        }
+    }
+
+    /**
+     * Encrypts [plaintext] using AES-256-CTR and authenticates it with HMAC-SHA256.
+     * Returns the encoded ciphertext string suitable for XMPP transport.
+     * Throws [IllegalStateException] if [setRemotePublicKey] was not called yet.
+     */
+    fun encrypt(plaintext: String): String {
+        val aesKey = sessionAesKey ?: error("OTR session not established — call setRemotePublicKey first")
+        val macKey = sessionMacKey!!
+        val nonce  = longToBytes(sendCounter++)
+        val iv     = ByteArray(16).also { System.arraycopy(nonce, 0, it, 0, 8) }
+
+        // AES-256-CTR
+        val cipher = Cipher.getInstance("AES/CTR/NoPadding")
+        cipher.init(Cipher.ENCRYPT_MODE, SecretKeySpec(aesKey, "AES"), IvParameterSpec(iv))
+        val cipherBytes = cipher.doFinal(plaintext.toByteArray(Charsets.UTF_8))
+
+        // HMAC-SHA256 over nonce + ciphertext
+        val mac  = Mac.getInstance("HmacSHA256")
+        mac.init(SecretKeySpec(macKey, "HmacSHA256"))
+        mac.update(nonce)
+        val hmac = mac.doFinal(cipherBytes)
+
+        // Format: nonce(8) | ciphertext | hmac(32)
+        val payload = nonce + cipherBytes + hmac
+        return "?OTR:" + Base64.encodeToString(payload, Base64.NO_WRAP)
+    }
+
+    /**
+     * Decrypts an OTR-encoded [ciphertext] produced by [encrypt].
+     * Returns the plaintext, or null if authentication fails.
+     */
+    fun decrypt(ciphertext: String): String? {
+        val aesKey = sessionAesKey ?: return null
+        val macKey = sessionMacKey ?: return null
+
+        return try {
+            val stripped = ciphertext.removePrefix("?OTR:")
+            val payload  = Base64.decode(stripped, Base64.NO_WRAP)
+            if (payload.size < 8 + 32) return null
+
+            val nonce       = payload.slice(0..7).toByteArray()
+            val hmacStored  = payload.slice(payload.size - 32 until payload.size).toByteArray()
+            val cipherBytes = payload.slice(8 until payload.size - 32).toByteArray()
+
+            // Verify HMAC first
+            val mac = Mac.getInstance("HmacSHA256")
+            mac.init(SecretKeySpec(macKey, "HmacSHA256"))
+            mac.update(nonce)
+            val hmacCalc = mac.doFinal(cipherBytes)
+            if (!hmacCalc.contentEquals(hmacStored)) {
+                Log.w(TAG, "OTR HMAC verification failed")
+                return null
+            }
+
+            // Decrypt
+            val iv = ByteArray(16).also { System.arraycopy(nonce, 0, it, 0, 8) }
+            val cipher = Cipher.getInstance("AES/CTR/NoPadding")
+            cipher.init(Cipher.DECRYPT_MODE, SecretKeySpec(aesKey, "AES"), IvParameterSpec(iv))
+            cipher.doFinal(cipherBytes).toString(Charsets.UTF_8)
+        } catch (e: Exception) {
+            Log.e(TAG, "OTR decrypt error", e)
+            null
+        }
+    }
+
+    fun isEstablished(): Boolean = sessionAesKey != null
+
+    private fun longToBytes(l: Long): ByteArray = ByteArray(8) { i ->
+        ((l shr ((7 - i) * 8)) and 0xFF).toByte()
+    }
+}
+
+

app/src/main/java/com/manalejandro/alejabber/data/remote/PgpManager.kt

@@ -0,0 +1,206 @@
+package com.manalejandro.alejabber.data.remote
+
+import android.content.Context
+import android.util.Log
+import org.bouncycastle.bcpg.ArmoredInputStream
+import org.bouncycastle.bcpg.ArmoredOutputStream
+import org.bouncycastle.openpgp.PGPCompressedData
+import org.bouncycastle.openpgp.PGPEncryptedDataGenerator
+import org.bouncycastle.openpgp.PGPEncryptedDataList
+import org.bouncycastle.openpgp.PGPLiteralData
+import org.bouncycastle.openpgp.PGPLiteralDataGenerator
+import org.bouncycastle.openpgp.PGPObjectFactory
+import org.bouncycastle.openpgp.PGPPublicKey
+import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData
+import org.bouncycastle.openpgp.PGPPublicKeyRingCollection
+import org.bouncycastle.openpgp.PGPSecretKeyRing
+import org.bouncycastle.openpgp.PGPSecretKeyRingCollection
+import org.bouncycastle.openpgp.PGPUtil
+import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator
+import org.bouncycastle.openpgp.operator.bc.BcPGPDataEncryptorBuilder
+import org.bouncycastle.openpgp.operator.bc.BcPublicKeyDataDecryptorFactory
+import org.bouncycastle.openpgp.operator.bc.BcPublicKeyKeyEncryptionMethodGenerator
+import org.bouncycastle.openpgp.operator.jcajce.JcaKeyFingerprintCalculator
+import org.bouncycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.util.Date
+import java.security.SecureRandom
+
+/**
+ * Manages OpenPGP keys and message encryption/decryption using BouncyCastle.
+ *
+ * Public keys for contacts are stored as armored ASCII files in the app's
+ * files directory at  pgp/contacts/<jid>.asc
+ * The user's own key pair (if any) is stored at  pgp/own.asc (secret ring)
+ */
+class PgpManager(private val context: Context) {
+
+    private val TAG = "PgpManager"
+    private val pgpDir get() = File(context.filesDir, "pgp").also { it.mkdirs() }
+    private val contactDir get() = File(pgpDir, "contacts").also { it.mkdirs() }
+    private val ownKeyFile get() = File(pgpDir, "own.asc")
+
+    // ── Key storage ───────────────────────────────────────────────────────
+
+    /** Save an armored public key for [jid]. */
+    fun saveContactPublicKey(jid: String, armoredKey: String) {
+        File(contactDir, safeFileName(jid) + ".asc").writeText(armoredKey)
+        Log.i(TAG, "PGP public key saved for $jid")
+    }
+
+    /** Load the armored public key for [jid], or null if not stored. */
+    fun loadContactPublicKeyArmored(jid: String): String? {
+        val f = File(contactDir, safeFileName(jid) + ".asc")
+        return if (f.exists()) f.readText() else null
+    }
+
+    /** Delete the public key for [jid]. */
+    fun deleteContactPublicKey(jid: String) {
+        File(contactDir, safeFileName(jid) + ".asc").delete()
+    }
+
+    /** Returns the list of JIDs that have a stored public key. */
+    fun listContactsWithKeys(): List<String> =
+        contactDir.listFiles()
+            ?.filter { it.extension == "asc" }
+            ?.map { it.nameWithoutExtension }
+            ?: emptyList()
+
+    /** Save the user's own secret key ring (armored). */
+    fun saveOwnSecretKeyArmored(armoredKey: String) {
+        ownKeyFile.writeText(armoredKey)
+        Log.i(TAG, "Own PGP secret key saved")
+    }
+
+    /** Load the user's own secret key ring (armored), or null. */
+    fun loadOwnSecretKeyArmored(): String? =
+        if (ownKeyFile.exists()) ownKeyFile.readText() else null
+
+    fun hasOwnKey(): Boolean = ownKeyFile.exists()
+
+    /** Returns the fingerprint of the user's own primary key as a hex string. */
+    fun getOwnKeyFingerprint(): String? {
+        val armored = loadOwnSecretKeyArmored() ?: return null
+        return try {
+            val secretRing = readSecretKeyRing(armored) ?: return null
+            val fingerprint = secretRing.secretKey.publicKey.fingerprint
+            fingerprint.joinToString("") { "%02X".format(it) }
+        } catch (e: Exception) {
+            Log.e(TAG, "Error reading own key fingerprint", e)
+            null
+        }
+    }
+
+    // ── Encrypt ───────────────────────────────────────────────────────────
+
+    /**
+     * Encrypts [plaintext] for [jid].
+     * Returns the armored ciphertext, or null if no key is stored for [jid].
+     */
+    fun encryptFor(jid: String, plaintext: String): String? {
+        val armoredKey = loadContactPublicKeyArmored(jid) ?: return null
+        return try {
+            val pubKey = readFirstPublicEncryptionKey(armoredKey) ?: return null
+            encrypt(plaintext, pubKey)
+        } catch (e: Exception) {
+            Log.e(TAG, "PGP encrypt error for $jid", e)
+            null
+        }
+    }
+
+    private fun encrypt(plaintext: String, pubKey: PGPPublicKey): String {
+        val out = ByteArrayOutputStream()
+        val armoredOut = ArmoredOutputStream(out)
+
+        val encGen = PGPEncryptedDataGenerator(
+            BcPGPDataEncryptorBuilder(
+                org.bouncycastle.bcpg.SymmetricKeyAlgorithmTags.AES_256
+            ).setWithIntegrityPacket(true).setSecureRandom(SecureRandom())
+        )
+        encGen.addMethod(BcPublicKeyKeyEncryptionMethodGenerator(pubKey))
+
+        val encOut = encGen.open(armoredOut, ByteArray(1 shl 16))
+        val literalGen = PGPLiteralDataGenerator()
+        val literalOut: java.io.OutputStream = literalGen.open(
+            encOut, PGPLiteralData.BINARY, "", Date(), ByteArray(1 shl 16)
+        )
+        literalOut.write(plaintext.toByteArray(Charsets.UTF_8))
+        literalOut.close()
+        encOut.close()
+        armoredOut.close()
+        return String(out.toByteArray(), Charsets.UTF_8)
+    }
+
+    // ── Decrypt ───────────────────────────────────────────────────────────
+
+    /**
+     * Decrypts an armored PGP message using the user's own private key.
+     * [passphrase] is used to unlock the private key.
+     * Returns plaintext or null on failure.
+     */
+    fun decrypt(armoredCiphertext: String, passphrase: CharArray = CharArray(0)): String? {
+        val armoredOwnKey = loadOwnSecretKeyArmored() ?: return null
+        return try {
+            val secretRing = readSecretKeyRing(armoredOwnKey) ?: return null
+            val factory    = PGPObjectFactory(
+                PGPUtil.getDecoderStream(ByteArrayInputStream(armoredCiphertext.toByteArray())),
+                JcaKeyFingerprintCalculator()
+            )
+            val encDataList = factory.nextObject() as? PGPEncryptedDataList
+                ?: (factory.nextObject() as? PGPEncryptedDataList)
+                ?: return null
+
+            val encData = encDataList.encryptedDataObjects.asSequence()
+                .filterIsInstance<PGPPublicKeyEncryptedData>()
+                .firstOrNull() ?: return null
+
+            val secretKey = secretRing.getSecretKey(encData.keyID) ?: return null
+            val privateKey = secretKey.extractPrivateKey(
+                JcePBESecretKeyDecryptorBuilder()
+                    .setProvider("BC")
+                    .build(passphrase)
+            )
+            val plainStream = encData.getDataStream(BcPublicKeyDataDecryptorFactory(privateKey))
+            val plainFactory = PGPObjectFactory(plainStream, JcaKeyFingerprintCalculator())
+            var obj = plainFactory.nextObject()
+            if (obj is PGPCompressedData) {
+                obj = PGPObjectFactory(
+                    obj.dataStream, JcaKeyFingerprintCalculator()
+                ).nextObject()
+            }
+            val literalData = obj as? PGPLiteralData ?: return null
+            literalData.inputStream.readBytes().toString(Charsets.UTF_8)
+        } catch (e: Exception) {
+            Log.e(TAG, "PGP decrypt error", e)
+            null
+        }
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────────
+
+    private fun readFirstPublicEncryptionKey(armored: String): PGPPublicKey? {
+        val stream = ArmoredInputStream(ByteArrayInputStream(armored.toByteArray()))
+        val col    = PGPPublicKeyRingCollection(stream, BcKeyFingerprintCalculator())
+        for (ring in col.keyRings) {
+            for (key in ring.publicKeys) {
+                if (key.isEncryptionKey) return key
+            }
+        }
+        return null
+    }
+
+    private fun readSecretKeyRing(armored: String): PGPSecretKeyRing? {
+        val stream = ArmoredInputStream(ByteArrayInputStream(armored.toByteArray()))
+        val col    = PGPSecretKeyRingCollection(stream, BcKeyFingerprintCalculator())
+        return col.keyRings.asSequence().firstOrNull()
+    }
+
+    private fun safeFileName(jid: String): String =
+        jid.replace(Regex("[^a-zA-Z0-9._@-]"), "_")
+}
+
+
+
+

app/src/main/java/com/manalejandro/alejabber/data/remote/XmppConnectionManager.kt

@@ -47,6 +47,12 @@ data class PresenceUpdate(
     val statusMessage: String
 )
 
+/** A contact has requested subscription (wants to see our presence). */
+data class SubscriptionRequest(
+    val accountId: Long,
+    val fromJid: String
+)
+
 @Singleton
 class XmppConnectionManager @Inject constructor() {
 
@@ -76,6 +82,10 @@ class XmppConnectionManager @Inject constructor() {
     private val _presenceUpdates = MutableSharedFlow<PresenceUpdate>(extraBufferCapacity = 64)
     val presenceUpdates: SharedFlow<PresenceUpdate> = _presenceUpdates.asSharedFlow()
 
+    // ── Incoming subscription requests ───────────────────────────────────
+    private val _subscriptionRequests = MutableSharedFlow<SubscriptionRequest>(extraBufferCapacity = 32)
+    val subscriptionRequests: SharedFlow<SubscriptionRequest> = _subscriptionRequests.asSharedFlow()
+
     // ─────────────────────────────────────────────────────────────────────
 
     fun connect(account: Account) {
@@ -161,6 +171,54 @@ class XmppConnectionManager @Inject constructor() {
 
     fun getConnection(accountId: Long): AbstractXMPPConnection? = connections[accountId]
 
+    /**
+     * Called by [EncryptionManager] when an incoming OMEMO message has been
+     * decrypted. Re-emits it through the same [incomingMessages] flow so
+     * [XmppForegroundService] and the chat UI can handle it uniformly.
+     */
+    suspend fun dispatchDecryptedOmemoMessage(accountId: Long, from: String, body: String) {
+        _incomingMessages.emit(
+            IncomingMessage(accountId = accountId, from = from, body = body)
+        )
+    }
+
+    /** Accept a subscription request — send subscribed + subscribe back. */
+    fun acceptSubscription(accountId: Long, fromJid: String) {
+        scope.launch {
+            try {
+                val connection = connections[accountId] ?: return@launch
+                val jid = JidCreate.entityBareFrom(fromJid)
+                // Confirm subscription
+                val subscribed = Presence(Presence.Type.subscribed)
+                subscribed.to = jid
+                connection.sendStanza(subscribed)
+                // Subscribe back (mutual)
+                val subscribe = Presence(Presence.Type.subscribe)
+                subscribe.to = jid
+                connection.sendStanza(subscribe)
+                Log.i(TAG, "Accepted subscription from $fromJid")
+            } catch (e: Exception) {
+                Log.e(TAG, "Accept subscription error", e)
+            }
+        }
+    }
+
+    /** Deny/cancel a subscription request. */
+    fun denySubscription(accountId: Long, fromJid: String) {
+        scope.launch {
+            try {
+                val connection = connections[accountId] ?: return@launch
+                val jid = JidCreate.entityBareFrom(fromJid)
+                val unsubscribed = Presence(Presence.Type.unsubscribed)
+                unsubscribed.to = jid
+                connection.sendStanza(unsubscribed)
+                Log.i(TAG, "Denied subscription from $fromJid")
+            } catch (e: Exception) {
+                Log.e(TAG, "Deny subscription error", e)
+            }
+        }
+    }
+
     // ─────────────────────────────────────────────────────────────────────
 
     private fun buildConfig(account: Account): XMPPTCPConnectionConfiguration {
@@ -185,6 +243,23 @@ class XmppConnectionManager @Inject constructor() {
     private fun setupRoster(accountId: Long, connection: AbstractXMPPConnection) {
         val roster = Roster.getInstanceFor(connection)
         roster.isRosterLoadedAtLogin = true
+        // Manual subscription mode: we handle subscribe/unsubscribe stanzas ourselves
+        roster.subscriptionMode = Roster.SubscriptionMode.manual
+
+        // ── Subscription request listener ─────────────────────────────────
+        connection.addAsyncStanzaListener({ stanza ->
+            val presence = stanza as Presence
+            scope.launch {
+                when (presence.type) {
+                    Presence.Type.subscribe -> {
+                        val fromJid = presence.from?.asBareJid()?.toString() ?: return@launch
+                        Log.i(TAG, "Subscription request from $fromJid")
+                        _subscriptionRequests.emit(SubscriptionRequest(accountId, fromJid))
+                    }
+                    else -> { /* handled by roster listener */ }
+                }
+            }
+        }, org.jivesoftware.smack.filter.StanzaTypeFilter(Presence::class.java))
 
         // ── Snapshot all current presences once the roster is loaded ──────
         scope.launch {

app/src/main/java/com/manalejandro/alejabber/data/repository/MessageRepository.kt

@@ -70,5 +70,9 @@ class MessageRepository @Inject constructor(
 
     suspend fun clearConversation(accountId: Long, conversationJid: String) =
         messageDao.clearConversation(accountId, conversationJid)
+
+    /** Persists an already-sent outgoing message (e.g. encrypted via EncryptionManager). */
+    suspend fun saveOutgoingMessage(message: Message): Long =
+        messageDao.insertMessage(message.toEntity())
 }
 

app/src/main/java/com/manalejandro/alejabber/service/XmppForegroundService.kt

@@ -38,6 +38,7 @@ class XmppForegroundService : Service() {
         startForeground(AleJabberApp.NOTIFICATION_ID_SERVICE, buildForegroundNotification())
         listenForIncomingMessages()
         listenForPresenceUpdates()
+        listenForSubscriptionRequests()
         connectAllAccounts()
     }
 
@@ -87,6 +88,36 @@ class XmppForegroundService : Service() {
         }
     }
 
+    private fun listenForSubscriptionRequests() {
+        serviceScope.launch {
+            xmppManager.subscriptionRequests.collect { req ->
+                showSubscriptionNotification(req.accountId, req.fromJid)
+            }
+        }
+    }
+
+    private fun showSubscriptionNotification(accountId: Long, fromJid: String) {
+        val intent = Intent(this, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP
+            putExtra("subscription_account_id", accountId)
+            putExtra("subscription_from_jid", fromJid)
+        }
+        val pendingIntent = PendingIntent.getActivity(
+            this, fromJid.hashCode(), intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+        val notification = NotificationCompat.Builder(this, AleJabberApp.CHANNEL_MESSAGES)
+            .setSmallIcon(R.drawable.ic_launcher_foreground)
+            .setContentTitle("Contact request")
+            .setContentText("$fromJid wants to add you as a contact")
+            .setAutoCancel(true)
+            .setContentIntent(pendingIntent)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+            .build()
+        val nm = getSystemService(NotificationManager::class.java)
+        nm.notify("sub_${fromJid}".hashCode(), notification)
+    }
+
     private fun showMessageNotification(from: String, body: String) {
         val intent = Intent(this, MainActivity::class.java).apply {
             flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP

app/src/main/java/com/manalejandro/alejabber/ui/chat/ChatScreen.kt

@@ -58,6 +58,7 @@ import coil.compose.AsyncImage
 import com.google.accompanist.permissions.ExperimentalPermissionsApi
 import com.google.accompanist.permissions.isGranted
 import com.google.accompanist.permissions.rememberPermissionState
+import com.manalejandro.alejabber.data.remote.EncryptionManager
 import com.manalejandro.alejabber.R
 import com.manalejandro.alejabber.domain.model.*
 import com.manalejandro.alejabber.media.RecordingState
@@ -81,6 +82,8 @@ fun ChatScreen(
     val listState = rememberLazyListState()
     val micPermission = rememberPermissionState(Manifest.permission.RECORD_AUDIO)
     val clipboard = LocalClipboard.current
+    val snackbarHostState = remember { SnackbarHostState() }
+    val scope = rememberCoroutineScope()
 
     // Message selected via long-press → shows the action bottom sheet
     var selectedMessage by remember { mutableStateOf<Message?>(null) }
@@ -96,6 +99,21 @@ fun ChatScreen(
         viewModel.init(accountId, conversationJid)
     }
 
+    // Show error snackbar
+    LaunchedEffect(uiState.error) {
+        uiState.error?.let {
+            snackbarHostState.showSnackbar(it, duration = SnackbarDuration.Long)
+            viewModel.clearError()
+        }
+    }
+    // Show info snackbar
+    LaunchedEffect(uiState.info) {
+        uiState.info?.let {
+            snackbarHostState.showSnackbar(it, duration = SnackbarDuration.Long)
+            viewModel.clearInfo()
+        }
+    }
+
     // Scroll to bottom on new message
     LaunchedEffect(uiState.messages.size) {
         if (uiState.messages.isNotEmpty()) {
@@ -114,10 +132,10 @@ fun ChatScreen(
                 title = {
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         AvatarWithStatus(
-                            name = uiState.contactName,
-                            avatarUrl = null,
+                            name     = uiState.contactName,
+                            avatarUrl = uiState.contactAvatarUrl,
                             presence = uiState.contactPresence,
-                            size = 36.dp
+                            size     = 36.dp
                         )
                         Spacer(Modifier.width(10.dp))
                         Column {
@@ -151,7 +169,8 @@ fun ChatScreen(
                     containerColor = MaterialTheme.colorScheme.surface
                 )
             )
-        }
+        },
+        snackbarHost = { SnackbarHost(snackbarHostState) }
         // No bottomBar — input is placed inside the content column so imePadding works
     ) { padding ->
         // imePadding() here at the column level makes the whole content
@@ -270,9 +289,13 @@ fun ChatScreen(
     // ── Encryption picker ─────────────────────────────────────────────────
     if (uiState.showEncryptionPicker) {
         EncryptionPickerDialog(
-            current  = uiState.encryptionType,
-            onSelect = viewModel::setEncryption,
-            onDismiss = viewModel::toggleEncryptionPicker
+            current     = uiState.encryptionType,
+            omemoState  = uiState.omemoState,
+            pgpHasOwn   = uiState.pgpHasOwnKey,
+            pgpHasCont  = uiState.pgpHasContactKey,
+            otrActive   = uiState.otrActive,
+            onSelect    = viewModel::setEncryption,
+            onDismiss   = viewModel::toggleEncryptionPicker
         )
     }
 
@@ -861,6 +884,10 @@ fun ChatInput(
 @Composable
 fun EncryptionPickerDialog(
     current: EncryptionType,
+    omemoState: EncryptionManager.OmemoState,
+    pgpHasOwn: Boolean,
+    pgpHasCont: Boolean,
+    otrActive: Boolean,
     onSelect: (EncryptionType) -> Unit,
     onDismiss: () -> Unit
 ) {
@@ -870,21 +897,57 @@ fun EncryptionPickerDialog(
         text = {
             Column {
                 EncryptionType.entries.forEach { type ->
+                    val (statusLabel, statusColor, enabled) = when (type) {
+                        EncryptionType.NONE    -> Triple("", null, true)
+                        EncryptionType.OMEMO   -> when (omemoState) {
+                            EncryptionManager.OmemoState.READY        -> Triple("✓ Ready", MaterialTheme.colorScheme.primary, true)
+                            EncryptionManager.OmemoState.INITIALISING -> Triple("⏳ Initialising…", MaterialTheme.colorScheme.onSurfaceVariant, true)
+                            EncryptionManager.OmemoState.FAILED       -> Triple("✗ Failed", MaterialTheme.colorScheme.error, false)
+                            else                                       -> Triple("⏳ Not started", MaterialTheme.colorScheme.onSurfaceVariant, true)
+                        }
+                        EncryptionType.OTR     -> if (otrActive)
+                            Triple("✓ Session active", MaterialTheme.colorScheme.primary, true)
+                        else
+                            Triple("New session", MaterialTheme.colorScheme.onSurfaceVariant, true)
+                        EncryptionType.OPENPGP -> when {
+                            !pgpHasOwn  -> Triple("✗ No own key", MaterialTheme.colorScheme.error, false)
+                            !pgpHasCont -> Triple("⚠ No contact key", MaterialTheme.colorScheme.tertiary, true)
+                            else        -> Triple("✓ Keys available", MaterialTheme.colorScheme.primary, true)
+                        }
+                    }
                     Row(
                         modifier = Modifier
                             .fillMaxWidth()
                             .clip(RoundedCornerShape(8.dp))
                             .pointerInput(type) {
-                                detectTapGestures { onSelect(type) }
+                                detectTapGestures { if (enabled) onSelect(type) }
                             }
                             .padding(12.dp),
                         verticalAlignment = Alignment.CenterVertically
                     ) {
-                        RadioButton(selected = current == type, onClick = { onSelect(type) })
+                        RadioButton(
+                            selected = current == type,
+                            onClick  = { if (enabled) onSelect(type) },
+                            enabled  = enabled
+                        )
                         Spacer(Modifier.width(12.dp))
-                        Column {
-                            Text(type.toDisplayName(), fontWeight = FontWeight.Medium)
-                            Text(type.toDescription(), style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant)
+                        Column(modifier = Modifier.weight(1f)) {
+                            Row(verticalAlignment = Alignment.CenterVertically) {
+                                Text(type.toDisplayName(), fontWeight = FontWeight.Medium)
+                                if (statusLabel.isNotEmpty()) {
+                                    Spacer(Modifier.width(6.dp))
+                                    Text(
+                                        statusLabel,
+                                        style = MaterialTheme.typography.labelSmall,
+                                        color = statusColor ?: MaterialTheme.colorScheme.onSurfaceVariant
+                                    )
+                                }
+                            }
+                            Text(
+                                type.toDescription(),
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
                         }
                     }
                 }

app/src/main/java/com/manalejandro/alejabber/ui/chat/ChatViewModel.kt

@@ -3,6 +3,7 @@ package com.manalejandro.alejabber.ui.chat
 import android.net.Uri
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.manalejandro.alejabber.data.remote.EncryptionManager
 import com.manalejandro.alejabber.data.repository.ContactRepository
 import com.manalejandro.alejabber.data.repository.MessageRepository
 import com.manalejandro.alejabber.domain.model.*
@@ -18,6 +19,7 @@ data class ChatUiState(
     val messages: List<Message> = emptyList(),
     val contactName: String = "",
     val contactPresence: PresenceStatus = PresenceStatus.OFFLINE,
+    val contactAvatarUrl: String? = null,
     val inputText: String = "",
     val encryptionType: EncryptionType = EncryptionType.NONE,
     val isTyping: Boolean = false,
@@ -25,7 +27,12 @@ data class ChatUiState(
     val recordingState: RecordingState = RecordingState.IDLE,
     val recordingDurationMs: Long = 0,
     val showEncryptionPicker: Boolean = false,
-    val error: String? = null
+    val omemoState: EncryptionManager.OmemoState = EncryptionManager.OmemoState.IDLE,
+    val otrActive: Boolean = false,
+    val pgpHasOwnKey: Boolean = false,
+    val pgpHasContactKey: Boolean = false,
+    val error: String? = null,
+    val info: String? = null
 )
 
 @HiltViewModel
@@ -33,7 +40,8 @@ class ChatViewModel @Inject constructor(
     private val messageRepository: MessageRepository,
     private val contactRepository: ContactRepository,
     private val httpUploadManager: HttpUploadManager,
-    private val audioRecorder: AudioRecorder
+    private val audioRecorder: AudioRecorder,
+    private val encryptionManager: EncryptionManager
 ) : ViewModel() {
 
     private val _uiState = MutableStateFlow(ChatUiState())
@@ -47,30 +55,26 @@ class ChatViewModel @Inject constructor(
         currentJid = jid
 
         viewModelScope.launch {
-            // Load messages
             messageRepository.getMessages(accountId, jid).collect { messages ->
                 _uiState.update { it.copy(messages = messages) }
             }
         }
         viewModelScope.launch {
-            // Load contact info
-            contactRepository.getContacts(accountId)
-                .take(1)
-                .collect { contacts ->
-                    val contact = contacts.find { it.jid == jid }
-                    _uiState.update {
-                        it.copy(
-                            contactName = contact?.nickname?.ifBlank { jid } ?: jid,
-                            contactPresence = contact?.presence ?: PresenceStatus.OFFLINE
-                        )
-                    }
+            // Keep contact info (name, presence, avatar) live
+            contactRepository.getContacts(accountId).collect { contacts ->
+                val contact = contacts.find { it.jid == jid }
+                _uiState.update {
+                    it.copy(
+                        contactName       = contact?.nickname?.ifBlank { jid } ?: jid,
+                        contactPresence   = contact?.presence ?: PresenceStatus.OFFLINE,
+                        contactAvatarUrl  = contact?.avatarUrl
+                    )
                 }
+            }
         }
         viewModelScope.launch {
-            // Mark as read
             messageRepository.markAllAsRead(accountId, jid)
         }
-        // Observe recording state
         viewModelScope.launch {
             audioRecorder.state.collect { state ->
                 _uiState.update { it.copy(recordingState = state) }
@@ -81,6 +85,26 @@ class ChatViewModel @Inject constructor(
                 _uiState.update { it.copy(recordingDurationMs = ms) }
             }
         }
+        // Observe OMEMO state — updates UI badge in real time
+        viewModelScope.launch {
+            encryptionManager.omemoState.collect { stateMap ->
+                val s = stateMap[accountId] ?: EncryptionManager.OmemoState.IDLE
+                _uiState.update { it.copy(omemoState = s) }
+            }
+        }
+        // Initialise OMEMO if needed
+        viewModelScope.launch {
+            encryptionManager.initOmemo(accountId)
+        }
+        // Check PGP key availability
+        val pgp = encryptionManager.pgpManager()
+        _uiState.update {
+            it.copy(
+                pgpHasOwnKey     = pgp.hasOwnKey(),
+                pgpHasContactKey = pgp.loadContactPublicKeyArmored(jid) != null,
+                otrActive        = encryptionManager.isOtrSessionActive(accountId, jid)
+            )
+        }
     }
 
     fun onInputChange(text: String) = _uiState.update { it.copy(inputText = text) }
@@ -90,12 +114,50 @@ class ChatViewModel @Inject constructor(
         if (text.isBlank()) return
         _uiState.update { it.copy(inputText = "") }
         viewModelScope.launch {
+            sendWithEncryption(text)
+        }
+    }
+
+    private suspend fun sendWithEncryption(body: String) {
+        val encType = _uiState.value.encryptionType
+        if (encType == EncryptionType.NONE) {
+            // Fast path — plain text via MessageRepository
             messageRepository.sendMessage(
-                accountId = currentAccountId,
-                toJid = currentJid,
-                body = text,
-                encryptionType = _uiState.value.encryptionType
+                accountId      = currentAccountId,
+                toJid          = currentJid,
+                body           = body,
+                encryptionType = EncryptionType.NONE
             )
+            return
+        }
+        // Encrypted path — EncryptionManager handles sending the stanza;
+        // we still persist the message locally.
+        val (ok, errorMsg) = encryptionManager.sendMessage(
+            accountId      = currentAccountId,
+            toJid          = currentJid,
+            body           = body,
+            encryptionType = encType
+        )
+        if (ok) {
+            // Persist as sent (EncryptionManager already sent the stanza)
+            val msg = Message(
+                accountId       = currentAccountId,
+                conversationJid = currentJid,
+                fromJid         = "",
+                toJid           = currentJid,
+                body            = body,
+                direction       = MessageDirection.OUTGOING,
+                status          = MessageStatus.SENT,
+                encryptionType  = encType
+            )
+            messageRepository.saveOutgoingMessage(msg)
+            errorMsg?.let { notice ->
+                _uiState.update { it.copy(info = notice) }
+            }
+        } else {
+            _uiState.update { it.copy(error = errorMsg ?: "Send failed") }
+            // Revert input so user can retry
+            _uiState.update { it.copy(inputText = body) }
         }
     }
 
@@ -106,9 +168,9 @@ class ChatViewModel @Inject constructor(
                 val url = httpUploadManager.uploadFile(currentAccountId, uri)
                 if (url != null) {
                     messageRepository.sendMessage(
-                        accountId = currentAccountId,
-                        toJid = currentJid,
-                        body = url,
+                        accountId      = currentAccountId,
+                        toJid          = currentJid,
+                        body           = url,
                         encryptionType = _uiState.value.encryptionType
                     )
                 }
@@ -130,9 +192,9 @@ class ChatViewModel @Inject constructor(
                 val url = httpUploadManager.uploadFile(currentAccountId, file, "audio/mp4")
                 if (url != null) {
                     messageRepository.sendMessage(
-                        accountId = currentAccountId,
-                        toJid = currentJid,
-                        body = url,
+                        accountId      = currentAccountId,
+                        toJid          = currentJid,
+                        body           = url,
                         encryptionType = _uiState.value.encryptionType
                     )
                 }
@@ -147,8 +209,47 @@ class ChatViewModel @Inject constructor(
 
     fun cancelRecording() = audioRecorder.cancelRecording()
 
-    fun setEncryption(type: EncryptionType) = _uiState.update {
-        it.copy(encryptionType = type, showEncryptionPicker = false)
+    fun setEncryption(type: EncryptionType) {
+        val omemoState = _uiState.value.omemoState
+        val pgpHasOwn  = _uiState.value.pgpHasOwnKey
+        val pgpHasCont = _uiState.value.pgpHasContactKey
+
+        val (finalType, notice) = when (type) {
+            EncryptionType.OMEMO -> when (omemoState) {
+                EncryptionManager.OmemoState.READY -> type to null
+                EncryptionManager.OmemoState.INITIALISING ->
+                    type to "OMEMO is initialising — messages will be encrypted once ready."
+                EncryptionManager.OmemoState.FAILED ->
+                    EncryptionType.NONE to "OMEMO failed to initialise. Check server PubSub support."
+                else ->
+                    type to "OMEMO is starting up…"
+            }
+            EncryptionType.OTR -> {
+                // Start OTR session
+                encryptionManager.startOtrSession(currentAccountId, currentJid)
+                _uiState.update { it.copy(otrActive = true) }
+                type to "OTR session started. Messages are encrypted end-to-end."
+            }
+            EncryptionType.OPENPGP -> when {
+                !pgpHasOwn  -> EncryptionType.NONE to "OpenPGP: You don't have a key pair. Generate one in Settings → Encryption."
+                !pgpHasCont -> type to "OpenPGP: No public key for this contact. Ask them to share their key in Settings → Encryption."
+                else        -> type to null
+            }
+            EncryptionType.NONE -> {
+                if (_uiState.value.encryptionType == EncryptionType.OTR) {
+                    encryptionManager.endOtrSession(currentAccountId, currentJid)
+                    _uiState.update { it.copy(otrActive = false) }
+                }
+                type to null
+            }
+        }
+        _uiState.update {
+            it.copy(
+                encryptionType       = finalType,
+                showEncryptionPicker = false,
+                info                 = notice
+            )
+        }
     }
 
     fun toggleEncryptionPicker() = _uiState.update {
@@ -160,6 +261,5 @@ class ChatViewModel @Inject constructor(
     }
 
     fun clearError() = _uiState.update { it.copy(error = null) }
+    fun clearInfo()  = _uiState.update { it.copy(info  = null) }
 }
-
-

app/src/main/java/com/manalejandro/alejabber/ui/contacts/ContactsScreen.kt

@@ -1,10 +1,10 @@
 package com.manalejandro.alejabber.ui.contacts
 
 import androidx.compose.animation.animateContentSize
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.combinedClickable
-import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
@@ -187,6 +187,42 @@ fun ContactsScreen(
             }
         )
     }
+
+    // ── Subscription authorization dialog ─────────────────────────────────
+    uiState.pendingSubscriptionJid?.let { fromJid ->
+        AlertDialog(
+            onDismissRequest = { viewModel.denySubscription() },
+            icon  = { Icon(Icons.Default.PersonAdd, null, tint = MaterialTheme.colorScheme.primary) },
+            title = { Text("Contact request") },
+            text  = {
+                Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    Text(
+                        "$fromJid wants to add you as a contact and see your presence status.",
+                        style = MaterialTheme.typography.bodyMedium
+                    )
+                    Text(
+                        "Do you want to accept and add them to your contacts?",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                }
+            },
+            confirmButton = {
+                Button(onClick = { viewModel.acceptSubscription() }) {
+                    Icon(Icons.Default.Check, null)
+                    Spacer(Modifier.width(6.dp))
+                    Text("Accept")
+                }
+            },
+            dismissButton = {
+                OutlinedButton(onClick = { viewModel.denySubscription() }) {
+                    Icon(Icons.Default.Close, null)
+                    Spacer(Modifier.width(6.dp))
+                    Text("Deny")
+                }
+            }
+        )
+    }
 }
 
 // ── Contact Detail Bottom Sheet ───────────────────────────────────────────

app/src/main/java/com/manalejandro/alejabber/ui/contacts/ContactsViewModel.kt

@@ -2,6 +2,7 @@ package com.manalejandro.alejabber.ui.contacts
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.manalejandro.alejabber.data.remote.XmppConnectionManager
 import com.manalejandro.alejabber.data.repository.AccountRepository
 import com.manalejandro.alejabber.data.repository.ContactRepository
 import com.manalejandro.alejabber.domain.model.Contact
@@ -31,14 +32,18 @@ data class ContactsUiState(
     val isLoading: Boolean = true,
     val searchQuery: String = "",
     val showAddDialog: Boolean = false,
-    val error: String? = null
+    val error: String? = null,
+    /** JID of a contact requesting subscription (triggers the authorization dialog). */
+    val pendingSubscriptionJid: String? = null,
+    val pendingSubscriptionAccountId: Long = 0
 )
 
 @OptIn(ExperimentalCoroutinesApi::class, FlowPreview::class)
 @HiltViewModel
 class ContactsViewModel @Inject constructor(
     private val accountRepository: AccountRepository,
-    private val contactRepository: ContactRepository
+    private val contactRepository: ContactRepository,
+    private val xmppManager: XmppConnectionManager
 ) : ViewModel() {
 
     private val _uiState = MutableStateFlow(ContactsUiState())
@@ -46,6 +51,20 @@ class ContactsViewModel @Inject constructor(
 
     private val searchQuery = MutableStateFlow("")
 
+    init {
+        // Listen for incoming subscription requests from any account
+        viewModelScope.launch {
+            xmppManager.subscriptionRequests.collect { req ->
+                _uiState.update {
+                    it.copy(
+                        pendingSubscriptionJid       = req.fromJid,
+                        pendingSubscriptionAccountId = req.accountId
+                    )
+                }
+            }
+        }
+    }
+
     /**
      * Load contacts for the given [accountId].
      * Safe to call multiple times; cancels the previous collection.
@@ -141,5 +160,27 @@ class ContactsViewModel @Inject constructor(
             }
         }
     }
+
+    fun acceptSubscription() {
+        val jid       = _uiState.value.pendingSubscriptionJid ?: return
+        val accountId = _uiState.value.pendingSubscriptionAccountId
+        xmppManager.acceptSubscription(accountId, jid)
+        // Optionally add the contact to the roster locally
+        viewModelScope.launch {
+            try {
+                contactRepository.addContact(
+                    Contact(accountId = accountId, jid = jid, nickname = jid)
+                )
+            } catch (_: Exception) {}
+        }
+        _uiState.update { it.copy(pendingSubscriptionJid = null) }
+    }
+
+    fun denySubscription() {
+        val jid       = _uiState.value.pendingSubscriptionJid ?: return
+        val accountId = _uiState.value.pendingSubscriptionAccountId
+        xmppManager.denySubscription(accountId, jid)
+        _uiState.update { it.copy(pendingSubscriptionJid = null) }
+    }
 }
 

app/src/main/java/com/manalejandro/alejabber/ui/navigation/NavGraph.kt

@@ -63,7 +63,7 @@ fun AleJabberNavGraph(
     startDestination: String = Screen.Accounts.route
 ) {
     NavHost(
-        navController = navController,
+        navController    = navController,
         startDestination = startDestination,
         enterTransition = {
             slideIntoContainer(AnimatedContentTransitionScope.SlideDirection.Left, tween(280))

app/src/main/java/com/manalejandro/alejabber/ui/settings/SettingsScreen.kt

@@ -1,5 +1,8 @@
 package com.manalejandro.alejabber.ui.settings
 
+import android.net.Uri
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.rememberScrollState
@@ -12,6 +15,7 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
@@ -28,8 +32,40 @@ fun SettingsScreen(
     viewModel: SettingsViewModel = hiltViewModel()
 ) {
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
-    var showThemeDialog by remember { mutableStateOf(false) }
+    val context = LocalContext.current
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    var showThemeDialog     by remember { mutableStateOf(false) }
     var showEncryptionDialog by remember { mutableStateOf(false) }
+    // PGP dialogs
+    var showPgpImportOwnDialog     by remember { mutableStateOf(false) }
+    var showPgpImportContactDialog by remember { mutableStateOf(false) }
+    var pgpContactJid              by remember { mutableStateOf("") }
+    var pgpKeyText                 by remember { mutableStateOf("") }
+    var showPgpContactDeleteDialog by remember { mutableStateOf<String?>(null) }
+
+    // File picker for PGP key import
+    val keyFilePicker = rememberLauncherForActivityResult(
+        ActivityResultContracts.GetContent()
+    ) { uri: Uri? ->
+        uri?.let {
+            val text = context.contentResolver.openInputStream(it)?.bufferedReader()?.readText() ?: return@let
+            pgpKeyText = text
+        }
+    }
+
+    LaunchedEffect(uiState.pgpError) {
+        uiState.pgpError?.let {
+            snackbarHostState.showSnackbar(it, duration = SnackbarDuration.Long)
+            viewModel.clearPgpMessages()
+        }
+    }
+    LaunchedEffect(uiState.pgpInfo) {
+        uiState.pgpInfo?.let {
+            snackbarHostState.showSnackbar(it)
+            viewModel.clearPgpMessages()
+        }
+    }
 
     Scaffold(
         topBar = {
@@ -41,7 +77,8 @@ fun SettingsScreen(
                     }
                 }
             )
-        }
+        },
+        snackbarHost = { SnackbarHost(snackbarHostState) }
     ) { padding ->
         Column(
             modifier = Modifier
@@ -49,71 +86,213 @@ fun SettingsScreen(
                 .padding(padding)
                 .verticalScroll(rememberScrollState())
         ) {
-            // Appearance section
+            // ── Appearance ────────────────────────────────────────────────
             SettingsSectionHeader(stringResource(R.string.settings_appearance))
-
             SettingsItem(
-                icon = Icons.Default.Palette,
-                title = stringResource(R.string.settings_theme),
+                icon     = Icons.Default.Palette,
+                title    = stringResource(R.string.settings_theme),
                 subtitle = uiState.appTheme.toDisplayName(),
-                onClick = { showThemeDialog = true }
+                onClick  = { showThemeDialog = true }
             )
-
             HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
 
-            // Notifications section
+            // ── Notifications ─────────────────────────────────────────────
             SettingsSectionHeader(stringResource(R.string.settings_notifications))
-
             SettingsSwitchItem(
-                icon = Icons.Default.Notifications,
-                title = stringResource(R.string.settings_notifications_messages),
-                checked = uiState.notificationsEnabled,
+                icon           = Icons.Default.Notifications,
+                title          = stringResource(R.string.settings_notifications_messages),
+                checked        = uiState.notificationsEnabled,
                 onCheckedChange = viewModel::setNotifications
             )
-
             SettingsSwitchItem(
-                icon = Icons.Default.Vibration,
-                title = stringResource(R.string.settings_notifications_vibrate),
-                checked = uiState.vibrateEnabled,
+                icon           = Icons.Default.Vibration,
+                title          = stringResource(R.string.settings_notifications_vibrate),
+                checked        = uiState.vibrateEnabled,
                 onCheckedChange = viewModel::setVibrate
             )
-
             SettingsSwitchItem(
-                icon = Icons.AutoMirrored.Filled.VolumeUp,
-                title = stringResource(R.string.settings_notifications_sound),
-                checked = uiState.soundEnabled,
+                icon           = Icons.AutoMirrored.Filled.VolumeUp,
+                title          = stringResource(R.string.settings_notifications_sound),
+                checked        = uiState.soundEnabled,
                 onCheckedChange = viewModel::setSound
             )
-
             HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
 
-            // Encryption section
+            // ── Encryption — default ──────────────────────────────────────
             SettingsSectionHeader(stringResource(R.string.settings_encryption))
-
             SettingsItem(
-                icon = Icons.Default.Lock,
-                title = stringResource(R.string.settings_default_encryption),
+                icon     = Icons.Default.Lock,
+                title    = stringResource(R.string.settings_default_encryption),
                 subtitle = uiState.defaultEncryption.name,
-                onClick = { showEncryptionDialog = true }
+                onClick  = { showEncryptionDialog = true }
+            )
+            HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
+
+            // ── OMEMO ─────────────────────────────────────────────────────
+            SettingsSectionHeader("OMEMO (XEP-0384)")
+            ListItem(
+                headlineContent   = { Text("OMEMO Device Fingerprint") },
+                supportingContent = {
+                    Text(
+                        uiState.omemoFingerprint ?: "Not available — open a chat to initialise",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                },
+                leadingContent = { Icon(Icons.Default.Fingerprint, null) }
+            )
+            HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
+
+            // ── OTR ───────────────────────────────────────────────────────
+            SettingsSectionHeader("OTR (Off-The-Record)")
+            ListItem(
+                headlineContent   = { Text("OTR Sessions") },
+                supportingContent = {
+                    Text(
+                        "OTR sessions are established per conversation.\n" +
+                        "Select OTR encryption in any chat to start a session.\n" +
+                        "Sessions use ephemeral ECDH keys — perfect forward secrecy.",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                },
+                leadingContent = { Icon(Icons.Default.SwapHoriz, null) }
+            )
+            HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
+
+            // ── OpenPGP ───────────────────────────────────────────────────
+            SettingsSectionHeader("OpenPGP")
+
+            // Own key status
+            ListItem(
+                headlineContent   = { Text("My PGP Key Pair") },
+                supportingContent = {
+                    if (uiState.pgpHasOwnKey) {
+                        Column {
+                            Text("Fingerprint:", style = MaterialTheme.typography.labelSmall)
+                            Text(
+                                uiState.pgpOwnKeyFingerprint ?: "—",
+                                style = MaterialTheme.typography.bodySmall,
+                                fontFamily = androidx.compose.ui.text.font.FontFamily.Monospace,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
+                        }
+                    } else {
+                        Text(
+                            "No key pair. Import an armored secret key (.asc).",
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    }
+                },
+                leadingContent  = { Icon(Icons.Default.Key, null) },
+                trailingContent = {
+                    if (uiState.pgpHasOwnKey) {
+                        IconButton(onClick = { viewModel.deleteOwnPgpKey() }) {
+                            Icon(Icons.Default.Delete, "Delete own key",
+                                tint = MaterialTheme.colorScheme.error)
+                        }
+                    } else {
+                        TextButton(onClick = { showPgpImportOwnDialog = true }) {
+                            Text("Import")
+                        }
+                    }
+                }
             )
 
+            // Import own key button (also visible via trailing if no key)
+            if (!uiState.pgpHasOwnKey) {
+                Row(
+                    Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 16.dp, vertical = 4.dp),
+                    horizontalArrangement = Arrangement.spacedBy(8.dp)
+                ) {
+                    OutlinedButton(
+                        onClick   = { showPgpImportOwnDialog = true },
+                        modifier  = Modifier.weight(1f)
+                    ) {
+                        Icon(Icons.Default.Edit, null, Modifier.size(18.dp))
+                        Spacer(Modifier.width(6.dp))
+                        Text("Paste key")
+                    }
+                    OutlinedButton(
+                        onClick   = { keyFilePicker.launch("*/*") },
+                        modifier  = Modifier.weight(1f)
+                    ) {
+                        Icon(Icons.Default.FolderOpen, null, Modifier.size(18.dp))
+                        Spacer(Modifier.width(6.dp))
+                        Text("From file")
+                    }
+                }
+            }
+
+            // Contact public keys
+            Spacer(Modifier.height(8.dp))
+            ListItem(
+                headlineContent   = { Text("Contact Public Keys") },
+                supportingContent = {
+                    if (uiState.pgpContactKeys.isEmpty()) {
+                        Text(
+                            "No contact keys stored.",
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    } else {
+                        Column {
+                            uiState.pgpContactKeys.forEach { jid ->
+                                Row(
+                                    modifier = Modifier.fillMaxWidth(),
+                                    verticalAlignment = Alignment.CenterVertically
+                                ) {
+                                    Text(
+                                        jid,
+                                        style    = MaterialTheme.typography.bodySmall,
+                                        modifier = Modifier.weight(1f)
+                                    )
+                                    IconButton(
+                                        onClick  = { showPgpContactDeleteDialog = jid },
+                                        modifier = Modifier.size(32.dp)
+                                    ) {
+                                        Icon(
+                                            Icons.Default.Delete, "Remove",
+                                            tint = MaterialTheme.colorScheme.error,
+                                            modifier = Modifier.size(16.dp)
+                                        )
+                                    }
+                                }
+                            }
+                        }
+                    }
+                },
+                leadingContent = { Icon(Icons.Default.People, null) }
+            )
+            OutlinedButton(
+                onClick   = { showPgpImportContactDialog = true },
+                modifier  = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp, vertical = 4.dp)
+            ) {
+                Icon(Icons.Default.PersonAdd, null, Modifier.size(18.dp))
+                Spacer(Modifier.width(6.dp))
+                Text("Add contact public key")
+            }
+
             HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp))
 
-            // About section
+            // ── About ─────────────────────────────────────────────────────
             SettingsSectionHeader(stringResource(R.string.settings_about))
-
             SettingsItem(
-                icon = Icons.Default.Info,
-                title = stringResource(R.string.settings_version),
+                icon    = Icons.Default.Info,
+                title   = stringResource(R.string.settings_version),
                 subtitle = "1.0.0",
                 onClick = {}
             )
-
             Spacer(Modifier.height(32.dp))
         }
     }
 
-    // Theme dialog
+    // ── Theme dialog ──────────────────────────────────────────────────────
     if (showThemeDialog) {
         AlertDialog(
             onDismissRequest = { showThemeDialog = false },
@@ -124,17 +303,14 @@ fun SettingsScreen(
                         Row(
                             modifier = Modifier
                                 .fillMaxWidth()
-                                .clickable {
-                                    viewModel.setTheme(theme)
-                                    showThemeDialog = false
-                                }
+                                .clickable { viewModel.setTheme(theme); showThemeDialog = false }
                                 .padding(12.dp),
                             verticalAlignment = Alignment.CenterVertically
                         ) {
-                            RadioButton(selected = uiState.appTheme == theme, onClick = {
-                                viewModel.setTheme(theme)
-                                showThemeDialog = false
-                            })
+                            RadioButton(
+                                selected = uiState.appTheme == theme,
+                                onClick  = { viewModel.setTheme(theme); showThemeDialog = false }
+                            )
                             Spacer(Modifier.width(12.dp))
                             Text(theme.toDisplayName())
                         }
@@ -147,7 +323,7 @@ fun SettingsScreen(
         )
     }
 
-    // Encryption default dialog
+    // ── Default encryption dialog ─────────────────────────────────────────
     if (showEncryptionDialog) {
         AlertDialog(
             onDismissRequest = { showEncryptionDialog = false },
@@ -158,19 +334,18 @@ fun SettingsScreen(
                         Row(
                             modifier = Modifier
                                 .fillMaxWidth()
-                                .clickable {
-                                    viewModel.setDefaultEncryption(type)
-                                    showEncryptionDialog = false
-                                }
+                                .clickable { viewModel.setDefaultEncryption(type); showEncryptionDialog = false }
                                 .padding(12.dp),
                             verticalAlignment = Alignment.CenterVertically
                         ) {
-                            RadioButton(selected = uiState.defaultEncryption == type, onClick = {
-                                viewModel.setDefaultEncryption(type)
-                                showEncryptionDialog = false
-                            })
+                            RadioButton(
+                                selected = uiState.defaultEncryption == type,
+                                onClick  = { viewModel.setDefaultEncryption(type); showEncryptionDialog = false }
+                            )
                             Spacer(Modifier.width(12.dp))
-                            Text(type.name)
+                            Column {
+                                Text(type.name, fontWeight = FontWeight.Medium)
+                            }
                         }
                     }
                 }
@@ -180,14 +355,126 @@ fun SettingsScreen(
             }
         )
     }
+
+    // ── PGP import own key ────────────────────────────────────────────────
+    if (showPgpImportOwnDialog) {
+        AlertDialog(
+            onDismissRequest = { showPgpImportOwnDialog = false; pgpKeyText = "" },
+            title = { Text("Import My PGP Secret Key") },
+            text = {
+                Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    Text(
+                        "Paste your armored PGP secret key below (-----BEGIN PGP PRIVATE KEY BLOCK-----…).",
+                        style = MaterialTheme.typography.bodySmall
+                    )
+                    OutlinedTextField(
+                        value         = pgpKeyText,
+                        onValueChange = { pgpKeyText = it },
+                        label         = { Text("Armored PGP key") },
+                        modifier      = Modifier
+                            .fillMaxWidth()
+                            .height(160.dp),
+                        maxLines      = 8
+                    )
+                    TextButton(onClick = { keyFilePicker.launch("*/*") }) {
+                        Icon(Icons.Default.FolderOpen, null)
+                        Spacer(Modifier.width(4.dp))
+                        Text("Pick from file")
+                    }
+                }
+            },
+            confirmButton = {
+                Button(onClick = {
+                    viewModel.importOwnPgpKey(pgpKeyText)
+                    showPgpImportOwnDialog = false
+                    pgpKeyText = ""
+                }, enabled = pgpKeyText.isNotBlank()) {
+                    Text("Import")
+                }
+            },
+            dismissButton = {
+                TextButton(onClick = { showPgpImportOwnDialog = false; pgpKeyText = "" }) {
+                    Text(stringResource(R.string.cancel))
+                }
+            }
+        )
+    }
+
+    // ── PGP import contact key ────────────────────────────────────────────
+    if (showPgpImportContactDialog) {
+        AlertDialog(
+            onDismissRequest = { showPgpImportContactDialog = false; pgpKeyText = ""; pgpContactJid = "" },
+            title = { Text("Add Contact Public Key") },
+            text = {
+                Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    OutlinedTextField(
+                        value         = pgpContactJid,
+                        onValueChange = { pgpContactJid = it },
+                        label         = { Text("Contact JID") },
+                        modifier      = Modifier.fillMaxWidth(),
+                        singleLine    = true
+                    )
+                    OutlinedTextField(
+                        value         = pgpKeyText,
+                        onValueChange = { pgpKeyText = it },
+                        label         = { Text("Armored public key") },
+                        modifier      = Modifier
+                            .fillMaxWidth()
+                            .height(140.dp),
+                        maxLines      = 8
+                    )
+                    TextButton(onClick = { keyFilePicker.launch("*/*") }) {
+                        Icon(Icons.Default.FolderOpen, null)
+                        Spacer(Modifier.width(4.dp))
+                        Text("Pick from file")
+                    }
+                }
+            },
+            confirmButton = {
+                Button(
+                    onClick = {
+                        viewModel.importContactPgpKey(pgpContactJid.trim(), pgpKeyText)
+                        showPgpImportContactDialog = false
+                        pgpKeyText = ""; pgpContactJid = ""
+                    },
+                    enabled = pgpContactJid.isNotBlank() && pgpKeyText.isNotBlank()
+                ) { Text("Save") }
+            },
+            dismissButton = {
+                TextButton(onClick = { showPgpImportContactDialog = false; pgpKeyText = ""; pgpContactJid = "" }) {
+                    Text(stringResource(R.string.cancel))
+                }
+            }
+        )
+    }
+
+    // ── PGP delete contact key confirmation ───────────────────────────────
+    showPgpContactDeleteDialog?.let { jid ->
+        AlertDialog(
+            onDismissRequest = { showPgpContactDeleteDialog = null },
+            title = { Text("Remove key?") },
+            text  = { Text("Remove the PGP public key for $jid?") },
+            confirmButton = {
+                TextButton(onClick = {
+                    viewModel.deleteContactPgpKey(jid)
+                    showPgpContactDeleteDialog = null
+                }) { Text("Remove", color = MaterialTheme.colorScheme.error) }
+            },
+            dismissButton = {
+                TextButton(onClick = { showPgpContactDeleteDialog = null }) {
+                    Text(stringResource(R.string.cancel))
+                }
+            }
+        )
+    }
 }
 
 @Composable
 fun SettingsSectionHeader(title: String) {
     Text(
-        text = title,
-        style = MaterialTheme.typography.labelLarge,
-        color = MaterialTheme.colorScheme.primary,
+        text     = title,
+        style    = MaterialTheme.typography.labelLarge,
+        color    = MaterialTheme.colorScheme.primary,
         fontWeight = FontWeight.SemiBold,
         modifier = Modifier.padding(start = 16.dp, top = 20.dp, bottom = 4.dp)
     )
@@ -201,14 +488,12 @@ fun SettingsItem(
     onClick: () -> Unit
 ) {
     ListItem(
-        headlineContent = { Text(title) },
+        headlineContent   = { Text(title) },
         supportingContent = if (subtitle.isNotBlank()) {
             { Text(subtitle, style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant) }
         } else null,
-        leadingContent = {
-            Icon(icon, null, tint = MaterialTheme.colorScheme.onSurfaceVariant)
-        },
-        modifier = Modifier.clickable(onClick = onClick)
+        leadingContent    = { Icon(icon, null, tint = MaterialTheme.colorScheme.onSurfaceVariant) },
+        modifier          = Modifier.clickable(onClick = onClick)
     )
 }
 
@@ -221,20 +506,13 @@ fun SettingsSwitchItem(
 ) {
     ListItem(
         headlineContent = { Text(title) },
-        leadingContent = {
-            Icon(icon, null, tint = MaterialTheme.colorScheme.onSurfaceVariant)
-        },
-        trailingContent = {
-            Switch(checked = checked, onCheckedChange = onCheckedChange)
-        }
+        leadingContent  = { Icon(icon, null, tint = MaterialTheme.colorScheme.onSurfaceVariant) },
+        trailingContent = { Switch(checked = checked, onCheckedChange = onCheckedChange) }
     )
 }
 
 fun AppTheme.toDisplayName(): String = when (this) {
     AppTheme.SYSTEM -> "System Default"
-    AppTheme.LIGHT -> "Light"
-    AppTheme.DARK -> "Dark"
+    AppTheme.LIGHT  -> "Light"
+    AppTheme.DARK   -> "Dark"
 }
-
-
-

app/src/main/java/com/manalejandro/alejabber/ui/settings/SettingsViewModel.kt

@@ -7,6 +7,8 @@ import androidx.datastore.preferences.core.edit
 import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.manalejandro.alejabber.data.remote.EncryptionManager
+import com.manalejandro.alejabber.data.remote.PgpManager
 import com.manalejandro.alejabber.domain.model.EncryptionType
 import com.manalejandro.alejabber.ui.theme.AppTheme
 import dagger.hilt.android.lifecycle.HiltViewModel
@@ -19,12 +21,22 @@ data class SettingsUiState(
     val notificationsEnabled: Boolean = true,
     val vibrateEnabled: Boolean = true,
     val soundEnabled: Boolean = true,
-    val defaultEncryption: EncryptionType = EncryptionType.OMEMO
+    val defaultEncryption: EncryptionType = EncryptionType.OMEMO,
+    // OMEMO
+    val omemoFingerprint: String? = null,
+    // OTR (informational only — sessions are per-chat)
+    // OpenPGP
+    val pgpHasOwnKey: Boolean = false,
+    val pgpOwnKeyFingerprint: String? = null,
+    val pgpContactKeys: List<String> = emptyList(),    // JIDs with stored pub key
+    val pgpError: String? = null,
+    val pgpInfo: String? = null
 )
 
 @HiltViewModel
 class SettingsViewModel @Inject constructor(
-    private val dataStore: DataStore<Preferences>
+    private val dataStore: DataStore<Preferences>,
+    private val encryptionManager: EncryptionManager
 ) : ViewModel() {
 
     companion object {
@@ -43,45 +55,95 @@ class SettingsViewModel @Inject constructor(
             dataStore.data.collect { prefs ->
                 _uiState.update { state ->
                     state.copy(
-                        appTheme = try { AppTheme.valueOf(prefs[KEY_THEME] ?: "SYSTEM") } catch (e: Exception) { AppTheme.SYSTEM },
+                        appTheme = try { AppTheme.valueOf(prefs[KEY_THEME] ?: "SYSTEM") } catch (_: Exception) { AppTheme.SYSTEM },
                         notificationsEnabled = prefs[KEY_NOTIFICATIONS] ?: true,
                         vibrateEnabled = prefs[KEY_VIBRATE] ?: true,
                         soundEnabled = prefs[KEY_SOUND] ?: true,
-                        defaultEncryption = try { EncryptionType.valueOf(prefs[KEY_DEFAULT_ENCRYPTION] ?: "OMEMO") } catch (e: Exception) { EncryptionType.OMEMO }
+                        defaultEncryption = try { EncryptionType.valueOf(prefs[KEY_DEFAULT_ENCRYPTION] ?: "OMEMO") } catch (_: Exception) { EncryptionType.OMEMO }
                     )
                 }
             }
         }
+        refreshPgpState()
     }
 
+    private fun refreshPgpState() {
+        val pgp = encryptionManager.pgpManager()
+        _uiState.update {
+            it.copy(
+                pgpHasOwnKey        = pgp.hasOwnKey(),
+                pgpOwnKeyFingerprint = pgp.getOwnKeyFingerprint(),
+                pgpContactKeys      = pgp.listContactsWithKeys()
+            )
+        }
+    }
+
+    // ── Preferences ───────────────────────────────────────────────────────
+
     fun setTheme(theme: AppTheme) {
-        viewModelScope.launch {
-            dataStore.edit { it[KEY_THEME] = theme.name }
-        }
+        viewModelScope.launch { dataStore.edit { it[KEY_THEME] = theme.name } }
     }
-
     fun setNotifications(enabled: Boolean) {
-        viewModelScope.launch {
-            dataStore.edit { it[KEY_NOTIFICATIONS] = enabled }
-        }
+        viewModelScope.launch { dataStore.edit { it[KEY_NOTIFICATIONS] = enabled } }
     }
-
     fun setVibrate(enabled: Boolean) {
-        viewModelScope.launch {
-            dataStore.edit { it[KEY_VIBRATE] = enabled }
-        }
+        viewModelScope.launch { dataStore.edit { it[KEY_VIBRATE] = enabled } }
     }
-
     fun setSound(enabled: Boolean) {
-        viewModelScope.launch {
-            dataStore.edit { it[KEY_SOUND] = enabled }
-        }
+        viewModelScope.launch { dataStore.edit { it[KEY_SOUND] = enabled } }
     }
-
     fun setDefaultEncryption(type: EncryptionType) {
+        viewModelScope.launch { dataStore.edit { it[KEY_DEFAULT_ENCRYPTION] = type.name } }
+    }
+
+    // ── OMEMO ─────────────────────────────────────────────────────────────
+
+    fun refreshOmemoFingerprint(accountId: Long) {
+        val fp = encryptionManager.getOwnOmemoFingerprint(accountId)
+        _uiState.update { it.copy(omemoFingerprint = fp) }
+    }
+
+    // ── OpenPGP ───────────────────────────────────────────────────────────
+
+    /** Import the user's own armored secret key (from file or paste). */
+    fun importOwnPgpKey(armoredKey: String) {
         viewModelScope.launch {
-            dataStore.edit { it[KEY_DEFAULT_ENCRYPTION] = type.name }
+            try {
+                encryptionManager.pgpManager().saveOwnSecretKeyArmored(armoredKey)
+                refreshPgpState()
+                _uiState.update { it.copy(pgpInfo = "Own PGP key imported successfully.") }
+            } catch (e: Exception) {
+                _uiState.update { it.copy(pgpError = "Key import failed: ${e.message}") }
+            }
         }
     }
-}
 
+    /** Delete the user's own key pair. */
+    fun deleteOwnPgpKey() {
+        viewModelScope.launch {
+            encryptionManager.pgpManager().saveOwnSecretKeyArmored("") // overwrite with empty
+            refreshPgpState()
+        }
+    }
+
+    /** Import a contact's public key. */
+    fun importContactPgpKey(jid: String, armoredKey: String) {
+        viewModelScope.launch {
+            try {
+                encryptionManager.pgpManager().saveContactPublicKey(jid, armoredKey)
+                refreshPgpState()
+                _uiState.update { it.copy(pgpInfo = "Public key for $jid saved.") }
+            } catch (e: Exception) {
+                _uiState.update { it.copy(pgpError = "Key import failed: ${e.message}") }
+            }
+        }
+    }
+
+    /** Remove a contact's public key. */
+    fun deleteContactPgpKey(jid: String) {
+        encryptionManager.pgpManager().deleteContactPublicKey(jid)
+        refreshPgpState()
+    }
+
+    fun clearPgpMessages() = _uiState.update { it.copy(pgpError = null, pgpInfo = null) }
+}