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jackandGitHub
78a81e5b57
Replaces destroy-then-rebuild Noise re-handshakes with an atomic reconnect protocol: prepared XX message-1 handoff tokens (claim-once, invalidated by crossed inbound initiations), receive-only quarantine of the established transport while an inbound replacement proves identity (promote on success, rollback+cooldown on failure/timeout), deterministic lower-peerID-wins crossed-initiator resolution, and a per-link-epoch BLE revalidation policy that re-proves cached sessions inside the same bleQueue critical section as the link rebind. On main, a fresh msg1 simply destroys an established session and rekey spans two non-atomic barriers. Includes the review fix: timeout-restores defer outbound queue draining until the convergence retry completes (restore reason plumbed end-to-end), so DMs are never drained under keys a restarted peer already discarded — with a deterministic interleaving test. Identity-mismatch restores drain immediately. Full local suite 1768 tests green.
78 lines
3.3 KiB
Swift
78 lines
3.3 KiB
Swift
//
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// NoiseSecurityConstants.swift
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// bitchat
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//
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// This is free and unencumbered software released into the public domain.
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// For more information, see <https://unlicense.org>
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//
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import BitFoundation
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import Foundation
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enum NoiseSecurityConstants {
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// Maximum message size to prevent memory exhaustion
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static let maxMessageSize = 65535 // 64KB as per Noise spec
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/// The extracted transport nonce (4 bytes) and Poly1305 tag (16 bytes)
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/// added by `NoiseCipherState` around every transport plaintext.
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static let transportCiphertextOverhead = 20
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/// Private files are an explicit BitChat extension to the ordinary Noise
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/// message-size ceiling. They remain bounded by the same framed-file cap
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/// used by the binary and fragment decoders. Only the `.privateFile`
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/// typed-payload path is allowed to use this larger budget.
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private static let privateFileOuterPacketOverhead =
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(BinaryProtocol.v1HeaderSize + 2) // v2 adds two length bytes
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+ BinaryProtocol.senderIDSize
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+ BinaryProtocol.recipientIDSize
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static let maxPrivateFilePlaintextSize = FileTransferLimits.maxFramedFileBytes
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- privateFileOuterPacketOverhead
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- transportCiphertextOverhead
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static let maxPrivateFileCiphertextSize =
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maxPrivateFilePlaintextSize + transportCiphertextOverhead
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// Maximum handshake message size
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static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
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// Noise XX message 1 contains only the initiator's 32-byte ephemeral key.
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static let xxInitialMessageSize = 32
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// Bounds an ordinary initiator whose message 1 or 2 is lost.
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static let ordinaryHandshakeTimeout: TimeInterval = 10
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// Bounds the receive-only rollback quarantine created by an unauthenticated
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// inbound message 1. A lost message 3 must not strand outbound traffic.
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static let ordinaryResponderHandshakeTimeout: TimeInterval = 20
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// A released client may immediately retry after both crossed initiators
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// yielded. Give that unilateral retry a brief head start before the
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// patched side spends its one bounded recovery.
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static let handshakeCollisionRecoveryDelay: TimeInterval = 0.2
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// Rate-limited recovery remains actionable without spinning.
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static let handshakeRateLimitRecoveryDelay: TimeInterval = 60
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// Covers only reordering between a winning message 3 and the losing
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// crossed message 1.
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static let recentInitiatorCompletionGracePeriod: TimeInterval = 1
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// After unauthenticated responder rollback, reject another attempt long
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// enough that paced message 1 traffic cannot keep outbound paused. A
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// legitimate peer converges through the one manager-owned local retry.
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static let ordinaryReconnectRollbackCooldown: TimeInterval = 60
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// Session timeout - sessions older than this should be renegotiated
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static let sessionTimeout: TimeInterval = 86400 // 24 hours
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// Maximum number of messages before rekey (2^64 - 1 is the nonce limit)
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static let maxMessagesPerSession: UInt64 = 1_000_000_000 // 1 billion messages
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// Rate limiting
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static let maxHandshakesPerMinute = 10
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static let maxMessagesPerSecond = 100
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// Global rate limiting (across all peers)
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static let maxGlobalHandshakesPerMinute = 30
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static let maxGlobalMessagesPerSecond = 500
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}
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