UA-.NETStandard/fuzzing/Opc.Ua.Encoders.Fuzz/FuzzableCode.cs

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 *
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using System;
using System.IO;
using Microsoft.Extensions.Logging.Abstractions;
using Opc.Ua.Bindings;

namespace Opc.Ua.Fuzzing
{
    public static partial class FuzzableCode
    {
        public static ServiceMessageContext MessageContext { get; } =
            ServiceMessageContext.Create(new FuzzTelemetryContext());

        /// <summary>
        /// Print information about the fuzzer target.
        /// </summary>
        public static void FuzzInfo()
        {
            Console.WriteLine("OPC UA Core Encoder Fuzzer for afl-fuzz and libfuzzer.");
            Console.WriteLine("Fuzzing targets for various aspects of the Binary, Json and Xml encoders.");
        }

        /// <summary>
        /// Prepare a seekable memory stream from the input stream.
        /// </summary>
        private static MemoryStream PrepareArraySegmentStream(Stream stream)
        {
            const int segmentSize = 0x40;

            // afl-fuzz uses a non seekable stream, causing false positives
            // use ArraySegmentStream in combination with fuzz target...
            MemoryStream memoryStream;
            using (var binaryStream = new BinaryReader(stream))
            {
                var bufferCollection = new BufferCollection();
                byte[] buffer;
                do
                {
                    buffer = binaryStream.ReadBytes(segmentSize);
                    bufferCollection.Add(new ArraySegment<byte>(buffer));
                } while (buffer.Length == segmentSize);
                memoryStream = new ArraySegmentStream(bufferCollection);
            }

            return memoryStream;
        }

        private sealed class FuzzTelemetryContext : TelemetryContextBase
        {
            public FuzzTelemetryContext()
                : base(NullLoggerFactory.Instance)
            {
            }
        }
    }
}