pdbreader

gistfile1.txt

using System;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace newtonsoft_snupkg_core
{
    static class BinaryReaderExtensions
    {
        public static string ReadNullTerminatedString(this BinaryReader stream)
        {
            var builder = new StringBuilder();
            char ch;
            while ((ch = stream.ReadChar()) != 0)
                builder.Append(ch);
            return builder.ToString();
        }
    }

    class Program
    {
        const string pdbStreamName = "#Pdb";
        const uint pdbIdSize = 20;
        private readonly string _pdbFileName;

        public Program(string pdbFileName)
        {
            _pdbFileName = pdbFileName;
        }

        uint GetPdbIdOffset()
        {
            var stream = File.OpenRead(_pdbFileName);

            using (var reader = new BinaryReader(stream))
            {
                uint signature = reader.ReadUInt32();
                stream.Seek(4 + // Signature
                   2 + // Version Major
                   2 + // Version Minor
                   4,  // Reserved)
                   SeekOrigin.Begin);

                // skip the version string
                uint versionStringSize = 0;
                versionStringSize = reader.ReadUInt32();

                stream.Seek(versionStringSize, SeekOrigin.Current);

                // storage header
                stream.Seek(2, SeekOrigin.Current);

                // read the stream headers
                ushort streamCount = reader.ReadUInt16();
                uint streamOffset;
                string streamName;

                for (int i = 0; i < streamCount; i++)
                {
                    var pos = stream.Position;
                    streamOffset = reader.ReadUInt32();
                    // stream size
                    stream.Seek(4, SeekOrigin.Current);
                    streamName = reader.ReadNullTerminatedString();

                    Console.WriteLine($"{i}: {streamName}");
                    if (streamName == pdbStreamName)
                    {
                        // We found it!
                        return streamOffset;
                    }

                    // streams headers are on a four byte alignment
                    if (stream.Position % 4 != 0)
                    {
                        stream.Seek(4 - stream.Position % 4, SeekOrigin.Current);
                    }
                }
            }

            throw new ArgumentException("We have a file with a metadata pdb signature but no pdb stream");
        }

        static void Main(string[] args)
        {
            var fileName = "/Users/jasonimison/Newtonsoft.Json.pdb";
            var program = new Program(fileName);
            var offset = program.GetPdbIdOffset();
            var bytes = File.ReadAllBytes(fileName);
            for (var i = 0; i <= pdbIdSize; i++)
            {
                bytes[i + offset] = 0;
            }

            var algorithm = HashAlgorithm.Create("SHA256");
            if (algorithm != null)
            {
                var hash = algorithm.ComputeHash(bytes);
                var checksum = ToHexString(hash);
                Console.WriteLine(checksum);
            }
            else
            {
                throw new ArgumentException("Unknown hash algorithm");
            }
        }

        /// <summary>
        /// Convert an array of bytes to a lower case hex string.
        /// </summary>
        /// <param name="bytes">array of bytes</param>
        /// <returns>hex string</returns>
        private static string ToHexString(byte[] bytes)
        {
            if (bytes == null)
            {
                throw new ArgumentNullException(nameof(bytes));
            }
            return string.Concat(bytes.Select(b => b.ToString("x2")));
        }
    }
}