Added support for decryption of RAR files #1
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@@ -6,4 +6,5 @@ bin/ | |
| *.user | ||
| TestArchives/Scratch/ | ||
| TestArchives/Scratch2/ | ||
| TestResults/ | ||
| *.nupkg | ||
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| @@ -0,0 +1,65 @@ | ||
| using System; | ||
| using System.IO; | ||
| using System.Net.Security; | ||
| using System.Text; | ||
| using System.Collections.Generic; | ||
| using System.Linq; | ||
| using Microsoft.VisualStudio.TestTools.UnitTesting; | ||
| using SharpCompress.Common; | ||
| using SharpCompress.Common.Rar.Headers; | ||
| using SharpCompress.IO; | ||
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| namespace SharpCompress.Test.Rar.Unit | ||
| { | ||
| /// <summary> | ||
| /// Summary description for RarFactoryReaderTest | ||
| /// </summary> | ||
| [TestClass] | ||
| public class RarHeaderFactoryTest : TestBase | ||
| { | ||
| private RarHeaderFactory rarHeaderFactory; | ||
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| [TestInitialize] | ||
| public void Initialize() | ||
| { | ||
| ResetScratch(); | ||
| rarHeaderFactory = new RarHeaderFactory(StreamingMode.Seekable, Options.KeepStreamsOpen); | ||
| } | ||
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| [TestMethod] | ||
| public void ReadHeaders_RecognizeEncryptedFlag() | ||
| { | ||
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| ReadEncryptedFlag("Rar.Encrypted_filesAndHeader.rar", true); | ||
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| } | ||
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| private void ReadEncryptedFlag(string testArchive, bool isEncrypted) | ||
| { | ||
| using (var stream = GetReaderStream(testArchive)) | ||
| foreach (var header in rarHeaderFactory.ReadHeaders(stream)) | ||
| { | ||
| if (header.HeaderType == HeaderType.ArchiveHeader) | ||
| { | ||
| Assert.AreEqual(isEncrypted, rarHeaderFactory.IsEncrypted); | ||
| break; | ||
| } | ||
| } | ||
| } | ||
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| [TestMethod] | ||
| public void ReadHeaders_RecognizeNoEncryptedFlag() | ||
| { | ||
| ReadEncryptedFlag("Rar.rar", false); | ||
| } | ||
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| private FileStream GetReaderStream(string testArchive) | ||
| { | ||
| return new FileStream(Path.Combine(TEST_ARCHIVES_PATH, testArchive), | ||
| FileMode.Open); | ||
| } | ||
| } | ||
| } |
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| @@ -0,0 +1,116 @@ | ||
| using System; | ||
| using System.Collections.Generic; | ||
| using System.IO; | ||
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| namespace SharpCompress.Common.Rar | ||
| { | ||
| internal class RarCryptoWrapper : Stream | ||
| { | ||
| private readonly Stream _actualStream; | ||
| private byte[] _salt; | ||
| private RarRijndael _rijndael; | ||
| private readonly string _password; | ||
| private readonly Queue<byte> _data = new Queue<byte>(); | ||
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| public RarCryptoWrapper(Stream actualStream, string password) | ||
| { | ||
| _actualStream = actualStream; | ||
| _password = password; | ||
| } | ||
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| internal byte[] Salt | ||
| { | ||
| get { return _salt; } | ||
| set | ||
| { | ||
| _salt = value; | ||
| if (value != null) InitializeAes(); | ||
| } | ||
| } | ||
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| private void InitializeAes() | ||
| { | ||
| _rijndael = RarRijndael.InitializeFrom(_password, _salt); | ||
| } | ||
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| public override void Flush() | ||
| { | ||
| throw new NotImplementedException(); | ||
| } | ||
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| public override long Seek(long offset, SeekOrigin origin) | ||
| { | ||
| throw new NotImplementedException(); | ||
| } | ||
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| public override void SetLength(long value) | ||
| { | ||
| throw new NotImplementedException(); | ||
| } | ||
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| public override int Read(byte[] buffer, int offset, int count) | ||
| { | ||
| if (Salt == null) return _actualStream.Read(buffer, offset, count); | ||
| return ReadAndDecrypt(buffer, offset, count); | ||
| } | ||
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| public int ReadAndDecrypt(byte[] buffer, int offset, int count) | ||
| { | ||
| int queueSize = _data.Count; | ||
| int sizeToRead = count - queueSize; | ||
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| if (sizeToRead > 0) | ||
| { | ||
| int alignedSize = sizeToRead + ((~sizeToRead + 1) & 0xf); | ||
| for (int i = 0; i < alignedSize/16; i++) | ||
| { | ||
| //long ax = System.currentTimeMillis(); | ||
| byte[] cipherText = new byte[RarRijndael.CryptoBlockSize]; | ||
| _actualStream.Read(cipherText, 0, RarRijndael.CryptoBlockSize); | ||
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| var readBytes = _rijndael.ProcessBlock(cipherText); | ||
| foreach(var readByte in readBytes) | ||
| _data.Enqueue(readByte); | ||
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Owner
There was a problem hiding this comment. Would using a queue like this be a source of performance problems? Also, please nest everything with braces. Even if it's just a single line under an foreach for if statement.
Contributor
Author
There was a problem hiding this comment. The queue is necessary because we can only decrypt 16 bytes at a time, but the client of this code does not necessarily read 16 block at a time. As a solution for this, all 16 bytes will go to a queue, and if for instance the client only reads 2 bytes, the other 14 will stay in the queue and will be directly read (without decrypting) the next time. Also, performance wise I don't think there's an issue, because generarlly, queues only involve in-memory access without any difficult calculation. I checked, the performance culprit in this class is the SHA1 calculation.
Contributor
Author
There was a problem hiding this comment. About braces, don't additional braces make the code look more verbose? If you're worried that people might add another line and forget to use braces, I think with IDEs like Visual studio it won't happen because the indentation will make it look obvious
Owner
There was a problem hiding this comment. It does add more lines yes. However, there are two reasons I do it. First, it just makes it perfectly clear on a quick skim of the code that a line is nested. Second, and probably more important, merging goes a lot smoother with the nesting. I've shot myself in the foot with merging because the tool couldn't see the differences with the single line versus the nested approach. Having a couple of extra lines because of braces never hurt anyone :) Of course, you can write some nasty code because of too many levels of nesting in a method, but that's a different story.
Contributor
Author
There was a problem hiding this comment. ok.. updated to use braces On 16 July 2013 22:22, Adam Hathcock notifications@github.com wrote:
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| } | ||
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| for (int i = 0; i < count; i++) | ||
| buffer[offset+i] = _data.Dequeue(); | ||
| } | ||
| return count; | ||
| } | ||
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| public override void Write(byte[] buffer, int offset, int count) | ||
| { | ||
| throw new NotImplementedException(); | ||
| } | ||
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| public override bool CanRead | ||
| { | ||
| get { throw new NotImplementedException(); } | ||
| } | ||
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| public override bool CanSeek | ||
| { | ||
| get { throw new NotImplementedException(); } | ||
| } | ||
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| public override bool CanWrite | ||
| { | ||
| get { throw new NotImplementedException(); } | ||
| } | ||
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| public override long Length | ||
| { | ||
| get { throw new NotImplementedException(); } | ||
| } | ||
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| public override long Position { get; set; } | ||
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| protected override void Dispose(bool disposing) | ||
| { | ||
| if(_rijndael!= null) _rijndael.Dispose(); | ||
| base.Dispose(disposing); | ||
| } | ||
| } | ||
| } | ||
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Revert this please.