Implement Noise XX Handshake Protocol for Direct Messages (#180)

* noise

* works?

* noise

* temporary

* better

* wip: use subnet

* better

* barely working

* werk

* subnet

* fix peer ID

* 8 byte peer ID

* wip noise

* wip fixes for noise

* std lib for noise

* noise handshake one step further

* buffers

* use fork

* fix imports

* simplify counter

* remove trash

* hashing

* no prologue

* nice

* wip, use noise encryption

* peer ID hex

* simplify session manager

* heavy logging

* use singleton

* Fix Noise session race condition with elegant per-peer actor serialization

- Use Kotlin coroutine actors for per-peer packet processing
- Each peer gets dedicated actor that processes packets sequentially
- Eliminates race conditions in session management without complex locking
- Single surgical change in PacketProcessor - minimal, maintainable
- Leverages Kotlin's native concurrency primitives

* decrypt correctly

* iniator works now

* clean code and fix signature to null

* better

* no signature in private message

* small fixes

* refactor ack

* refactor but untested

* messages working

* wip ack

* wip fix ack

* more logging

* pending tracker

* keep pending connections on errors

* less logging

* refactor model

* refactor frombinarydata

* idendityannouncement refactor and update to new binary protocol

* fix keys

* refix keys

* dms work

* revert to mainnet

* do not change bluetooth adapter name

* keep code but uncomment

* clean up comments

* cleanup comments
This commit is contained in:
callebtc
2025-07-24 12:01:46 +02:00
committed by GitHub
parent 9e9231353b
commit c3c395832c
58 changed files with 15209 additions and 517 deletions
@@ -0,0 +1,289 @@
package com.bitchat.android.identity
import android.content.Context
import android.content.SharedPreferences
import androidx.security.crypto.EncryptedSharedPreferences
import androidx.security.crypto.MasterKey
import java.security.MessageDigest
import java.security.SecureRandom
import android.util.Log
/**
* Manages persistent identity storage and peer ID rotation - 100% compatible with iOS implementation
*
* Handles:
* - Static identity key persistence across app sessions
* - Peer ID rotation timing (5-15 minute random intervals)
* - Secure storage using Android EncryptedSharedPreferences
* - Fingerprint calculation and identity validation
*/
class SecureIdentityStateManager(private val context: Context) {
companion object {
private const val TAG = "SecureIdentityStateManager"
private const val PREFS_NAME = "bitchat_identity"
private const val KEY_STATIC_PRIVATE_KEY = "static_private_key"
private const val KEY_STATIC_PUBLIC_KEY = "static_public_key"
private const val KEY_LAST_ROTATION = "last_rotation"
private const val KEY_NEXT_ROTATION_INTERVAL = "next_rotation_interval"
// Rotation intervals (same as iOS)
private const val MIN_ROTATION_INTERVAL = 5 * 60 * 1000L // 5 minutes
private const val MAX_ROTATION_INTERVAL = 15 * 60 * 1000L // 15 minutes
}
private val prefs: SharedPreferences
private val random = SecureRandom()
init {
// Create master key for encryption
val masterKey = MasterKey.Builder(context, MasterKey.DEFAULT_MASTER_KEY_ALIAS)
.setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
.build()
// Create encrypted shared preferences
prefs = EncryptedSharedPreferences.create(
context,
PREFS_NAME,
masterKey,
EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
)
}
// MARK: - Static Key Management
/**
* Load saved static key pair
* Returns (privateKey, publicKey) or null if none exists
*/
fun loadStaticKey(): Pair<ByteArray, ByteArray>? {
return try {
val privateKeyString = prefs.getString(KEY_STATIC_PRIVATE_KEY, null)
val publicKeyString = prefs.getString(KEY_STATIC_PUBLIC_KEY, null)
if (privateKeyString != null && publicKeyString != null) {
val privateKey = android.util.Base64.decode(privateKeyString, android.util.Base64.DEFAULT)
val publicKey = android.util.Base64.decode(publicKeyString, android.util.Base64.DEFAULT)
// Validate key sizes
if (privateKey.size == 32 && publicKey.size == 32) {
Log.d(TAG, "Loaded static identity key from secure storage")
Pair(privateKey, publicKey)
} else {
Log.w(TAG, "Invalid key sizes in storage, returning null")
null
}
} else {
Log.d(TAG, "No static identity key found in storage")
null
}
} catch (e: Exception) {
Log.e(TAG, "Failed to load static key: ${e.message}")
null
}
}
/**
* Save static key pair to secure storage
*/
fun saveStaticKey(privateKey: ByteArray, publicKey: ByteArray) {
try {
// Validate key sizes
if (privateKey.size != 32 || publicKey.size != 32) {
throw IllegalArgumentException("Invalid key sizes: private=${privateKey.size}, public=${publicKey.size}")
}
val privateKeyString = android.util.Base64.encodeToString(privateKey, android.util.Base64.DEFAULT)
val publicKeyString = android.util.Base64.encodeToString(publicKey, android.util.Base64.DEFAULT)
prefs.edit()
.putString(KEY_STATIC_PRIVATE_KEY, privateKeyString)
.putString(KEY_STATIC_PUBLIC_KEY, publicKeyString)
.apply()
Log.d(TAG, "Saved static identity key to secure storage")
} catch (e: Exception) {
Log.e(TAG, "Failed to save static key: ${e.message}")
throw e
}
}
// MARK: - Fingerprint Generation
/**
* Generate fingerprint from public key (SHA-256 hash)
*/
fun generateFingerprint(publicKeyData: ByteArray): String {
val digest = MessageDigest.getInstance("SHA-256")
val hash = digest.digest(publicKeyData)
return hash.joinToString("") { "%02x".format(it) }
}
/**
* Validate fingerprint format
*/
fun isValidFingerprint(fingerprint: String): Boolean {
// SHA-256 fingerprint should be 64 hex characters
return fingerprint.matches(Regex("^[a-fA-F0-9]{64}$"))
}
// MARK: - Peer ID Rotation Management
/**
* Check if peer ID should be rotated based on random interval
*/
fun shouldRotatePeerID(): Boolean {
val lastRotation = prefs.getLong(KEY_LAST_ROTATION, 0L)
val nextInterval = prefs.getLong(KEY_NEXT_ROTATION_INTERVAL, 0L)
val now = System.currentTimeMillis()
if (lastRotation == 0L || nextInterval == 0L) {
// First run or missing data - schedule next rotation and don't rotate now
scheduleNextRotation()
return false
}
val shouldRotate = (now - lastRotation) >= nextInterval
if (shouldRotate) {
Log.d(TAG, "Peer ID rotation due: ${(now - lastRotation) / 1000}s since last rotation")
}
return shouldRotate
}
/**
* Mark rotation as completed and schedule next one
*/
fun markRotationCompleted() {
val now = System.currentTimeMillis()
prefs.edit()
.putLong(KEY_LAST_ROTATION, now)
.apply()
scheduleNextRotation()
Log.d(TAG, "Peer ID rotation marked as completed")
}
/**
* Schedule the next rotation with random interval (5-15 minutes)
*/
private fun scheduleNextRotation() {
val nextInterval = MIN_ROTATION_INTERVAL + random.nextLong(MAX_ROTATION_INTERVAL - MIN_ROTATION_INTERVAL)
prefs.edit()
.putLong(KEY_NEXT_ROTATION_INTERVAL, nextInterval)
.apply()
Log.d(TAG, "Next peer ID rotation scheduled in ${nextInterval / 60000} minutes")
}
/**
* Get time until next rotation (for debugging)
*/
fun getTimeUntilNextRotation(): Long {
val lastRotation = prefs.getLong(KEY_LAST_ROTATION, 0L)
val nextInterval = prefs.getLong(KEY_NEXT_ROTATION_INTERVAL, 0L)
val now = System.currentTimeMillis()
if (lastRotation == 0L || nextInterval == 0L) return -1
val elapsed = now - lastRotation
return maxOf(0L, nextInterval - elapsed)
}
// MARK: - Identity Validation
/**
* Validate that a public key is valid for Curve25519
*/
fun validatePublicKey(publicKey: ByteArray): Boolean {
if (publicKey.size != 32) return false
// Check for all-zero key (invalid point)
if (publicKey.all { it == 0.toByte() }) return false
// Check for other known invalid points
val invalidPoints = setOf(
ByteArray(32) { 0x00.toByte() }, // All zeros
ByteArray(32) { 0xFF.toByte() }, // All ones
// Add other known invalid Curve25519 points if needed
)
return !invalidPoints.any { it.contentEquals(publicKey) }
}
/**
* Validate that a private key is valid for Curve25519
*/
fun validatePrivateKey(privateKey: ByteArray): Boolean {
if (privateKey.size != 32) return false
// Check for all-zero key
if (privateKey.all { it == 0.toByte() }) return false
// Check that clamping bits are correct for Curve25519
val clampedKey = privateKey.clone()
clampedKey[0] = (clampedKey[0].toInt() and 248).toByte()
clampedKey[31] = (clampedKey[31].toInt() and 127).toByte()
clampedKey[31] = (clampedKey[31].toInt() or 64).toByte()
// After clamping, the key should not be all zeros
return !clampedKey.all { it == 0.toByte() }
}
// MARK: - Debug Information
/**
* Get debug information about identity state
*/
fun getDebugInfo(): String = buildString {
appendLine("=== Identity State Manager Debug ===")
val hasIdentity = prefs.contains(KEY_STATIC_PRIVATE_KEY)
appendLine("Has identity: $hasIdentity")
if (hasIdentity) {
val lastRotation = prefs.getLong(KEY_LAST_ROTATION, 0L)
val nextInterval = prefs.getLong(KEY_NEXT_ROTATION_INTERVAL, 0L)
val timeUntilNext = getTimeUntilNextRotation()
appendLine("Last rotation: ${if (lastRotation > 0) "${(System.currentTimeMillis() - lastRotation) / 1000}s ago" else "never"}")
appendLine("Next rotation in: ${if (timeUntilNext >= 0) "${timeUntilNext / 1000}s" else "not scheduled"}")
appendLine("Rotation interval: ${nextInterval / 1000}s")
try {
val keyPair = loadStaticKey()
if (keyPair != null) {
val fingerprint = generateFingerprint(keyPair.second)
appendLine("Identity fingerprint: ${fingerprint.take(16)}...")
appendLine("Key validation: private=${validatePrivateKey(keyPair.first)}, public=${validatePublicKey(keyPair.second)}")
}
} catch (e: Exception) {
appendLine("Key validation failed: ${e.message}")
}
}
}
// MARK: - Emergency Clear
/**
* Clear all identity data (for panic mode)
*/
fun clearIdentityData() {
try {
prefs.edit().clear().apply()
Log.w(TAG, "All identity data cleared")
} catch (e: Exception) {
Log.e(TAG, "Failed to clear identity data: ${e.message}")
}
}
/**
* Check if identity data exists
*/
fun hasIdentityData(): Boolean {
return prefs.contains(KEY_STATIC_PRIVATE_KEY) && prefs.contains(KEY_STATIC_PUBLIC_KEY)
}
}