permissionlesstech/bitchat
1
0
Fork 0
mirror of https://github.com/permissionlesstech/bitchat.git synced 2026-07-26 13:45:22 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'main' into refactor/extract-command-coordinator

Browse Source
This commit is contained in:
jack
2025-11-24 11:06:32 -10:00
committed by GitHub
parent 477cc7fa05 6888bfa351
commit c538837300
2 changed files with 250 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bitchat/Nostr/XChaCha20Poly1305Compat.swift
+28 -9
View File
@@ -5,16 +5,27 @@ import CryptoKit
/// Implements HChaCha20 to derive a subkey and reduces the 24-byte nonce to a 12-byte nonce
/// as per XChaCha20 construction.
enum XChaCha20Poly1305Compat {
/// Errors that can occur during XChaCha20-Poly1305 operations
enum Error: Swift.Error {
case invalidKeyLength(expected: Int, got: Int)
case invalidNonceLength(expected: Int, got: Int)
}
struct SealBox {
let ciphertext: Data
let tag: Data
}
static func seal(plaintext: Data, key: Data, nonce24: Data, aad: Data? = nil) throws -> SealBox {
precondition(key.count == 32, "XChaCha20 key must be 32 bytes")
precondition(nonce24.count == 24, "XChaCha20 nonce must be 24 bytes")
guard key.count == 32 else {
throw Error.invalidKeyLength(expected: 32, got: key.count)
}
guard nonce24.count == 24 else {
throw Error.invalidNonceLength(expected: 24, got: nonce24.count)
}
let subkey = hchacha20(key: key, nonce16: nonce24.prefix(16))
let subkey = try hchacha20(key: key, nonce16: Data(nonce24.prefix(16)))
let nonce12 = derive12ByteNonce(from24: nonce24)
let chachaKey = SymmetricKey(data: subkey)
let nonce = try ChaChaPoly.Nonce(data: nonce12)
@@ -23,10 +34,14 @@ enum XChaCha20Poly1305Compat {
}
static func open(ciphertext: Data, tag: Data, key: Data, nonce24: Data, aad: Data? = nil) throws -> Data {
precondition(key.count == 32, "XChaCha20 key must be 32 bytes")
precondition(nonce24.count == 24, "XChaCha20 nonce must be 24 bytes")
guard key.count == 32 else {
throw Error.invalidKeyLength(expected: 32, got: key.count)
}
guard nonce24.count == 24 else {
throw Error.invalidNonceLength(expected: 24, got: nonce24.count)
}
let subkey = hchacha20(key: key, nonce16: nonce24.prefix(16))
let subkey = try hchacha20(key: key, nonce16: Data(nonce24.prefix(16)))
let nonce12 = derive12ByteNonce(from24: nonce24)
let chachaKey = SymmetricKey(data: subkey)
let box = try ChaChaPoly.SealedBox(nonce: ChaChaPoly.Nonce(data: nonce12), ciphertext: ciphertext, tag: tag)
@@ -43,10 +58,14 @@ enum XChaCha20Poly1305Compat {
return out
}
private static func hchacha20(key: Data, nonce16: Data) -> Data {
private static func hchacha20(key: Data, nonce16: Data) throws -> Data {
// HChaCha20 based on the original ChaCha20 core with a 16-byte nonce.
precondition(key.count == 32)
precondition(nonce16.count == 16)
guard key.count == 32 else {
throw Error.invalidKeyLength(expected: 32, got: key.count)
}
guard nonce16.count == 16 else {
throw Error.invalidNonceLength(expected: 16, got: nonce16.count)
}
// Constants "expand 32-byte k"
var state: [UInt32] = [