A fast, safe, and efficient CBOR serialization library for Swift on any platform.
swiftpackageindex.com/thecoolwinter/CBOR/1.1.1/documentation/cbor
khanwinter.com
atproto
swift
cbor
1//
2// fuzz.swift
3// CBOR
4//
5// Created by Khan Winter on 8/29/25.
6//
7
8import CBOR
9#if canImport(FoundationEssentials)
10import FoundationEssentials
11#else
12import Foundation
13#endif
14
15@_optimize(none)
16func blackhole(_ val: some Any) { }
17
18/// Fuzzing entry point
19@_cdecl("LLVMFuzzerTestOneInput")
20public func fuzz(_ start: UnsafeRawPointer, _ count: Int) -> CInt {
21 let bytes = UnsafeRawBufferPointer(start: start, count: count)
22 let data = Data(bytes)
23
24 // Try decoding against a bunch of standard types.
25 // Each attempt is independent — errors are ignored, crashes are what fuzzing is for.
26 func tryDecode<T: Decodable>(_ type: T.Type) {
27 do {
28 blackhole(try CBORDecoder(rejectIndeterminateLengths: false).decode(T.self, from: data))
29 } catch {
30 // ignore decode errors
31 }
32 }
33
34 // Scalars
35 tryDecode(Bool.self)
36 tryDecode(Int.self)
37 tryDecode(Int8.self)
38 tryDecode(Int16.self)
39 tryDecode(Int32.self)
40 tryDecode(Int64.self)
41 tryDecode(UInt.self)
42 tryDecode(UInt8.self)
43 tryDecode(UInt16.self)
44 tryDecode(UInt32.self)
45 tryDecode(UInt64.self)
46 tryDecode(Float.self)
47 tryDecode(Double.self)
48 tryDecode(String.self)
49 tryDecode(Data.self)
50
51 // Optionals
52 tryDecode(Optional<Int>.self)
53 tryDecode(Optional<String>.self)
54 tryDecode(Optional<Data>.self)
55
56 // Collections
57 tryDecode([Int].self)
58 tryDecode([String].self)
59 tryDecode([Data].self)
60 tryDecode([String: Int].self)
61 tryDecode([String: String].self)
62
63 // Nested combinations
64 tryDecode([[Int]].self)
65 tryDecode([String: [String: Int]].self)
66
67 // Any decodable
68 tryDecode(AnyDecodable.self)
69
70 return 0
71}