mirror of
https://github.com/permissionlesstech/bitchat-android.git
synced 2026-07-24 22:25:19 +00:00
callebtcandGitHub
73c91b9509
* wip plumtree * sync works * fix logging * ttl to 0 * fix send packet to one peer * spec * wip GCS instead of bloom * remove bloom filter remainders * clean * prune old announcements * remove announcements from sync after LEAVE * sync after 1 second * pruning * track own announcement and prune messages without announcements * fix pruning * getGcsMaxFilterBytes default value 400 bytes * parameters
32 lines
1.0 KiB
Kotlin
32 lines
1.0 KiB
Kotlin
package com.bitchat.android.sync
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import com.bitchat.android.protocol.BitchatPacket
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import java.security.MessageDigest
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/**
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* Deterministic packet ID helper for sync purposes.
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* Uses SHA-256 over a canonical subset of packet fields:
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* [type | senderID | timestamp | payload] to generate a stable ID.
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* Returns a 16-byte (128-bit) truncated hash for compactness.
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*/
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object PacketIdUtil {
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fun computeIdBytes(packet: BitchatPacket): ByteArray {
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val md = MessageDigest.getInstance("SHA-256")
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md.update(packet.type.toByte())
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md.update(packet.senderID)
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// Timestamp as 8 bytes big-endian
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val ts = packet.timestamp.toLong()
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for (i in 7 downTo 0) {
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md.update(((ts ushr (i * 8)) and 0xFF).toByte())
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}
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md.update(packet.payload)
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val digest = md.digest()
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return digest.copyOf(16) // 128-bit ID
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}
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fun computeIdHex(packet: BitchatPacket): String {
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return computeIdBytes(packet).joinToString("") { b -> "%02x".format(b) }
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}
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}
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