#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using Google.ProtocolBuffers.Descriptors;
namespace Google.ProtocolBuffers.ProtoMunge
{
/// <summary>
/// Utility console application which takes a message descriptor and a corresponding message,
/// and produces a new message with similar but random data. The data is the same length
/// as the original, but with random values within appropriate bands. (For instance, a compressed
/// integer in the range 0-127 will end up as another integer in the same range, to keep the length
/// the same.)
/// TODO(jonskeet): Potentially refactor to use an instance instead, making it simpler to
/// be thread-safe for external use.
/// </summary>
public sealed class Program
{
private static readonly Random rng = new Random();
private static int Main(string[] args)
{
if (args.Length != 3)
{
Console.Error.WriteLine("Usage: ProtoMunge <descriptor type name> <input data> <output file>");
Console.Error.WriteLine(
"The descriptor type name is the fully-qualified message name, including assembly.");
Console.Error.WriteLine(
"(At a future date it may be possible to do this without building the .NET assembly at all.)");
return 1;
}
IMessage defaultMessage;
try
{
defaultMessage = MessageUtil.GetDefaultMessage(args[0]);
}
catch (ArgumentException e)
{
Console.Error.WriteLine(e.Message);
return 1;
}
try
{
IBuilder builder = defaultMessage.WeakCreateBuilderForType();
byte[] inputData = File.ReadAllBytes(args[1]);
builder.WeakMergeFrom(ByteString.CopyFrom(inputData));
IMessage original = builder.WeakBuild();
IMessage munged = Munge(original);
if (original.SerializedSize != munged.SerializedSize)
{
throw new Exception("Serialized sizes don't match");
}
File.WriteAllBytes(args[2], munged.ToByteArray());
return 0;
}
catch (Exception e)
{
Console.Error.WriteLine("Error: {0}", e.Message);
Console.Error.WriteLine();
Console.Error.WriteLine("Detailed exception information: {0}", e);
return 1;
}
}
/// <summary>
/// Munges a message recursively.
/// </summary>
/// <returns>A new message of the same type as the original message,
/// but munged so that all the data is desensitised.</returns>
private static IMessage Munge(IMessage message)
{
IBuilder builder = message.WeakCreateBuilderForType();
foreach (var pair in message.AllFields)
{
if (pair.Key.IsRepeated)
{
foreach (object singleValue in (IEnumerable) pair.Value)
{
builder.WeakAddRepeatedField(pair.Key, CheckedMungeValue(pair.Key, singleValue));
}
}
else
{
builder[pair.Key] = CheckedMungeValue(pair.Key, pair.Value);
}
}
IMessage munged = builder.WeakBuild();
if (message.SerializedSize != munged.SerializedSize)
{
Console.WriteLine("Sub message sizes: {0}/{1}", message.SerializedSize, munged.SerializedSize);
}
return munged;
}
/// <summary>
/// Munges a single value and checks that the length ends up the same as it was before.
/// </summary>
private static object CheckedMungeValue(FieldDescriptor fieldDescriptor, object value)
{
int currentSize = CodedOutputStream.ComputeFieldSize(fieldDescriptor.FieldType, fieldDescriptor.FieldNumber,
value);
object mungedValue = MungeValue(fieldDescriptor, value);
int mungedSize = CodedOutputStream.ComputeFieldSize(fieldDescriptor.FieldType, fieldDescriptor.FieldNumber,
mungedValue);
// Exceptions log more easily than assertions
if (currentSize != mungedSize)
{
throw new Exception("Munged value had wrong size. Field type: " + fieldDescriptor.FieldType
+ "; old value: " + value + "; new value: " + mungedValue);
}
return mungedValue;
}
/// <summary>
/// Munges a single value of the specified field descriptor. (i.e. if the field is
/// actually a repeated int, this method receives a single int value to munge, and
/// is called multiple times).
/// </summary>
private static object MungeValue(FieldDescriptor fieldDescriptor, object value)
{
switch (fieldDescriptor.FieldType)
{
case FieldType.SInt64:
case FieldType.Int64:
return (long) MungeVarint64((ulong) (long) value);
case FieldType.UInt64:
return MungeVarint64((ulong) value);
case FieldType.SInt32:
return (int) MungeVarint32((uint) (int) value);
case FieldType.Int32:
return MungeInt32((int) value);
case FieldType.UInt32:
return MungeVarint32((uint) value);
case FieldType.Double:
return rng.NextDouble();
case FieldType.Float:
return (float) rng.NextDouble();
case FieldType.Fixed64:
{
byte[] data = new byte[8];
rng.NextBytes(data);
return BitConverter.ToUInt64(data, 0);
}
case FieldType.Fixed32:
{
byte[] data = new byte[4];
rng.NextBytes(data);
return BitConverter.ToUInt32(data, 0);
}
case FieldType.Bool:
return rng.Next(2) == 1;
case FieldType.String:
return MungeString((string) value);
case FieldType.Group:
case FieldType.Message:
return Munge((IMessage) value);
case FieldType.Bytes:
return MungeByteString((ByteString) value);
case FieldType.SFixed64:
{
byte[] data = new byte[8];
rng.NextBytes(data);
return BitConverter.ToInt64(data, 0);
}
case FieldType.SFixed32:
{
byte[] data = new byte[4];
rng.NextBytes(data);
return BitConverter.ToInt32(data, 0);
}
case FieldType.Enum:
return MungeEnum(fieldDescriptor, (EnumValueDescriptor) value);
default:
// TODO(jonskeet): Different exception?
throw new ArgumentException("Invalid field descriptor");
}
}
private static object MungeString(string original)
{
foreach (char c in original)
{
if (c > 127)
{
throw new ArgumentException("Can't handle non-ascii yet");
}
}
char[] chars = new char[original.Length];
// Convert to pure ASCII - no control characters.
for (int i = 0; i < chars.Length; i++)
{
chars[i] = (char) rng.Next(32, 127);
}
return new string(chars);
}
/// <summary>
/// Int32 fields are slightly strange - we need to keep the sign the same way it is:
/// negative numbers can munge to any other negative number (it'll always take
/// 10 bytes) but positive numbers have to stay positive, so we can't use the
/// full range of 32 bits.
/// </summary>
private static int MungeInt32(int value)
{
if (value < 0)
{
return rng.Next(int.MinValue, 0);
}
int length = CodedOutputStream.ComputeRawVarint32Size((uint) value);
uint min = length == 1 ? 0 : 1U << ((length - 1)*7);
uint max = length == 5 ? int.MaxValue : (1U << (length*7)) - 1;
return (int) NextRandomUInt64(min, max);
}
private static uint MungeVarint32(uint original)
{
int length = CodedOutputStream.ComputeRawVarint32Size(original);
uint min = length == 1 ? 0 : 1U << ((length - 1)*7);
uint max = length == 5 ? uint.MaxValue : (1U << (length*7)) - 1;
return (uint) NextRandomUInt64(min, max);
}
private static ulong MungeVarint64(ulong original)
{
int length = CodedOutputStream.ComputeRawVarint64Size(original);
ulong min = length == 1 ? 0 : 1UL << ((length - 1)*7);
ulong max = length == 10 ? ulong.MaxValue : (1UL << (length*7)) - 1;
return NextRandomUInt64(min, max);
}
/// <summary>
/// Returns a random number in the range [min, max] (both inclusive).
/// </summary>
private static ulong NextRandomUInt64(ulong min, ulong max)
{
if (min > max)
{
throw new ArgumentException("min must be <= max; min=" + min + "; max = " + max);
}
ulong range = max - min;
// This isn't actually terribly good at very large ranges - but it doesn't really matter for the sake
// of this program.
return min + (ulong) (range*rng.NextDouble());
}
private static object MungeEnum(FieldDescriptor fieldDescriptor, EnumValueDescriptor original)
{
// Find all the values which get encoded to the same size as the current value, and pick one at random
int originalSize = CodedOutputStream.ComputeRawVarint32Size((uint) original.Number);
List<EnumValueDescriptor> sameSizeValues = new List<EnumValueDescriptor>();
foreach (EnumValueDescriptor candidate in fieldDescriptor.EnumType.Values)
{
if (CodedOutputStream.ComputeRawVarint32Size((uint) candidate.Number) == originalSize)
{
sameSizeValues.Add(candidate);
}
}
return sameSizeValues[rng.Next(sameSizeValues.Count)];
}
private static object MungeByteString(ByteString byteString)
{
byte[] data = new byte[byteString.Length];
rng.NextBytes(data);
return ByteString.CopyFrom(data);
}
}
}
