diff --git a/src/ICSharpCode.SharpZipLib/Core/StreamUtils.cs b/src/ICSharpCode.SharpZipLib/Core/StreamUtils.cs
index 6d0d9b304..f4feeb2b3 100644
--- a/src/ICSharpCode.SharpZipLib/Core/StreamUtils.cs
+++ b/src/ICSharpCode.SharpZipLib/Core/StreamUtils.cs
@@ -1,5 +1,6 @@
using System;
using System.IO;
+using System.Threading.Tasks;
namespace ICSharpCode.SharpZipLib.Core
{
@@ -64,16 +65,8 @@ static public void ReadFully(Stream stream, byte[] buffer, int offset, int count
}
}
- /// <summary>
- /// Read as much data as possible from a <see cref="Stream"/>", up to the requested number of bytes
- /// </summary>
- /// <param name="stream">The stream to read data from.</param>
- /// <param name="buffer">The buffer to store data in.</param>
- /// <param name="offset">The offset at which to begin storing data.</param>
- /// <param name="count">The number of bytes of data to store.</param>
- /// <exception cref="ArgumentNullException">Required parameter is null</exception>
- /// <exception cref="ArgumentOutOfRangeException"><paramref name="offset"/> and or <paramref name="count"/> are invalid.</exception>
- static public int ReadRequestedBytes(Stream stream, byte[] buffer, int offset, int count)
+ // A helper function to share between the async and sync versions of ReadRequestedBytes
+ private static void ValidateArgumentsForRead(Stream stream, byte[] buffer, int offset, int count)
{
if (stream == null)
{
@@ -95,7 +88,23 @@ static public int ReadRequestedBytes(Stream stream, byte[] buffer, int offset, i
{
throw new ArgumentOutOfRangeException(nameof(count));
}
+ }
+ /// <summary>
+ /// Read as much data as possible from a <see cref="Stream"/>", up to the requested number of bytes
+ /// </summary>
+ /// <param name="stream">The stream to read data from.</param>
+ /// <param name="buffer">The buffer to store data in.</param>
+ /// <param name="offset">The offset at which to begin storing data.</param>
+ /// <param name="count">The number of bytes of data to store.</param>
+ /// <exception cref="ArgumentNullException">Required parameter is null</exception>
+ /// <exception cref="ArgumentOutOfRangeException"><paramref name="offset"/> and or <paramref name="count"/> are invalid.</exception>
+ static public int ReadRequestedBytes(Stream stream, byte[] buffer, int offset, int count)
+ {
+ // Common validation function
+ ValidateArgumentsForRead(stream, buffer, offset, count);
+
+ // read the data using Read
int totalReadCount = 0;
while (count > 0)
{
@@ -112,6 +121,37 @@ static public int ReadRequestedBytes(Stream stream, byte[] buffer, int offset, i
return totalReadCount;
}
+ /// <summary>
+ /// Read as much data as possible from a <see cref="Stream"/>", up to the requested number of bytes
+ /// </summary>
+ /// <param name="stream">The stream to read data from.</param>
+ /// <param name="buffer">The buffer to store data in.</param>
+ /// <param name="offset">The offset at which to begin storing data.</param>
+ /// <param name="count">The number of bytes of data to store.</param>
+ /// <exception cref="ArgumentNullException">Required parameter is null</exception>
+ /// <exception cref="ArgumentOutOfRangeException"><paramref name="offset"/> and or <paramref name="count"/> are invalid.</exception>
+ static public async Task<int> ReadRequestedBytesAsync(Stream stream, byte[] buffer, int offset, int count)
+ {
+ // Common validation function
+ ValidateArgumentsForRead(stream, buffer, offset, count);
+
+ // read the data using ReadAsync
+ int totalReadCount = 0;
+ while (count > 0)
+ {
+ int readCount = await stream.ReadAsync(buffer, offset, count);
+ if (readCount <= 0)
+ {
+ break;
+ }
+ offset += readCount;
+ count -= readCount;
+ totalReadCount += readCount;
+ }
+
+ return totalReadCount;
+ }
+
/// <summary>
/// Copy the contents of one <see cref="Stream"/> to another.
/// </summary>
diff --git a/src/ICSharpCode.SharpZipLib/Encryption/ZipAESStream.cs b/src/ICSharpCode.SharpZipLib/Encryption/ZipAESStream.cs
index 4f649e8a9..f06f35a75 100644
--- a/src/ICSharpCode.SharpZipLib/Encryption/ZipAESStream.cs
+++ b/src/ICSharpCode.SharpZipLib/Encryption/ZipAESStream.cs
@@ -1,6 +1,8 @@
using System;
using System.IO;
using System.Security.Cryptography;
+using System.Threading;
+using System.Threading.Tasks;
using ICSharpCode.SharpZipLib.Core;
namespace ICSharpCode.SharpZipLib.Encryption
@@ -70,18 +72,11 @@ public override int Read(byte[] buffer, int offset, int count)
return 0;
// If we have buffered data, read that first
- int nBytes = 0;
- if (HasBufferedData)
- {
- nBytes = ReadBufferedData(buffer, offset, count);
+ int nBytes = ReadBufferedData(buffer, ref offset, ref count);
- // Read all requested data from the buffer
- if (nBytes == count)
- return nBytes;
-
- offset += nBytes;
- count -= nBytes;
- }
+ // Read all requested data from the buffer
+ if (nBytes == count)
+ return nBytes;
// Read more data from the input, if available
if (_slideBuffer != null)
@@ -90,6 +85,27 @@ public override int Read(byte[] buffer, int offset, int count)
return nBytes;
}
+ /// <inheritdoc/>
+ public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+ {
+ // Nothing to do
+ if (count == 0)
+ return 0;
+
+ // If we have buffered data, read that first
+ int nBytes = ReadBufferedData(buffer, ref offset, ref count);
+
+ // Read all requested data from the buffer
+ if (nBytes == count)
+ return nBytes;
+
+ // Read more data from the input, if available
+ if (_slideBuffer != null)
+ nBytes += await ReadAndTransformAsync(buffer, offset, count);
+
+ return nBytes;
+ }
+
// Read data from the underlying stream and decrypt it
private int ReadAndTransform(byte[] buffer, int offset, int count)
{
@@ -105,68 +121,127 @@ private int ReadAndTransform(byte[] buffer, int offset, int count)
// Maintain a read-ahead equal to the length of (crypto block + Auth Code).
// When that runs out we can detect these final sections.
int lengthToRead = BLOCK_AND_AUTH - byteCount;
- if (_slideBuffer.Length - _slideBufFreePos < lengthToRead)
+ UpdateSlideBufferIfNeeded(lengthToRead);
+
+ int obtained = StreamUtils.ReadRequestedBytes(_stream, _slideBuffer, _slideBufFreePos, lengthToRead);
+ _slideBufFreePos += obtained;
+
+ // Transform data from the slide buffer
+ if (TransformFromSlideBuffer(buffer, ref offset, bytesLeftToRead, ref nBytes))
{
- // Shift the data to the beginning of the buffer
- int iTo = 0;
- for (int iFrom = _slideBufStartPos; iFrom < _slideBufFreePos; iFrom++, iTo++)
- {
- _slideBuffer[iTo] = _slideBuffer[iFrom];
- }
- _slideBufFreePos -= _slideBufStartPos; // Note the -=
- _slideBufStartPos = 0;
+ // Reached the auth code
+ break;
}
- int obtained = StreamUtils.ReadRequestedBytes(_stream, _slideBuffer, _slideBufFreePos, lengthToRead);
+ }
+ return nBytes;
+ }
+
+ // Read data from the underlying stream asynchronously and decrypt it
+ private async Task<int> ReadAndTransformAsync(byte[] buffer, int offset, int count)
+ {
+ int nBytes = 0;
+ while (nBytes < count)
+ {
+ int bytesLeftToRead = count - nBytes;
+
+ // Calculate buffer quantities vs read-ahead size, and check for sufficient free space
+ int byteCount = _slideBufFreePos - _slideBufStartPos;
+
+ // Need to handle final block and Auth Code specially, but don't know total data length.
+ // Maintain a read-ahead equal to the length of (crypto block + Auth Code).
+ // When that runs out we can detect these final sections.
+ int lengthToRead = BLOCK_AND_AUTH - byteCount;
+ UpdateSlideBufferIfNeeded(lengthToRead);
+
+ int obtained = await StreamUtils.ReadRequestedBytesAsync(_stream, _slideBuffer, _slideBufFreePos, lengthToRead);
_slideBufFreePos += obtained;
- // Recalculate how much data we now have
- byteCount = _slideBufFreePos - _slideBufStartPos;
- if (byteCount >= BLOCK_AND_AUTH)
+ // Transform data from the slide buffer
+ if (TransformFromSlideBuffer(buffer, ref offset, bytesLeftToRead, ref nBytes))
{
- var read = TransformAndBufferBlock(buffer, offset, bytesLeftToRead, CRYPTO_BLOCK_SIZE);
- nBytes += read;
- offset += read;
+ // Reached the auth code
+ break;
}
- else
+ }
+ return nBytes;
+ }
+
+ // Helper function to update the slide buffer, if we need to
+ private void UpdateSlideBufferIfNeeded(int lengthToRead)
+ {
+ if (_slideBuffer.Length - _slideBufFreePos < lengthToRead)
+ {
+ // Shift the data to the beginning of the buffer
+ int iTo = 0;
+ for (int iFrom = _slideBufStartPos; iFrom < _slideBufFreePos; iFrom++, iTo++)
{
- // Last round.
- if (byteCount > AUTH_CODE_LENGTH)
- {
- // At least one byte of data plus auth code
- int finalBlock = byteCount - AUTH_CODE_LENGTH;
- nBytes += TransformAndBufferBlock(buffer, offset, bytesLeftToRead, finalBlock);
- }
- else if (byteCount < AUTH_CODE_LENGTH)
- throw new Exception("Internal error missed auth code"); // Coding bug
- // Final block done. Check Auth code.
- byte[] calcAuthCode = _transform.GetAuthCode();
- for (int i = 0; i < AUTH_CODE_LENGTH; i++)
+ _slideBuffer[iTo] = _slideBuffer[iFrom];
+ }
+ _slideBufFreePos -= _slideBufStartPos; // Note the -=
+ _slideBufStartPos = 0;
+ }
+ }
+
+ // A helper to do the non-async crypto transform, using data from the in-memory slide buffer
+ // Returns true if the auth code has been reached, false if not.
+ private bool TransformFromSlideBuffer(byte[] buffer, ref int offset, int bytesLeftToRead, ref int nBytes)
+ {
+ // Recalculate how much data we now have
+ int byteCount = _slideBufFreePos - _slideBufStartPos;
+ if (byteCount >= BLOCK_AND_AUTH)
+ {
+ var read = TransformAndBufferBlock(buffer, offset, bytesLeftToRead, CRYPTO_BLOCK_SIZE);
+ nBytes += read;
+ offset += read;
+
+ return false;
+ }
+ else
+ {
+ // Last round.
+ if (byteCount > AUTH_CODE_LENGTH)
+ {
+ // At least one byte of data plus auth code
+ int finalBlock = byteCount - AUTH_CODE_LENGTH;
+ nBytes += TransformAndBufferBlock(buffer, offset, bytesLeftToRead, finalBlock);
+ }
+ else if (byteCount < AUTH_CODE_LENGTH)
+ throw new Exception("Internal error missed auth code"); // Coding bug
+ // Final block done. Check Auth code.
+ byte[] calcAuthCode = _transform.GetAuthCode();
+ for (int i = 0; i < AUTH_CODE_LENGTH; i++)
+ {
+ if (calcAuthCode[i] != _slideBuffer[_slideBufStartPos + i])
{
- if (calcAuthCode[i] != _slideBuffer[_slideBufStartPos + i])
- {
- throw new Exception("AES Authentication Code does not match. This is a super-CRC check on the data in the file after compression and encryption. \r\n"
- + "The file may be damaged.");
- }
+ throw new Exception("AES Authentication Code does not match. This is a super-CRC check on the data in the file after compression and encryption. \r\n"
+ + "The file may be damaged.");
}
+ }
- // don't need this any more, so use it as a 'complete' flag
- _slideBuffer = null;
+ // don't need this any more, so use it as a 'complete' flag
+ _slideBuffer = null;
- break; // Reached the auth code
- }
+ return true; // Reached the auth code
}
- return nBytes;
}
// read some buffered data
- private int ReadBufferedData(byte[] buffer, int offset, int count)
+ private int ReadBufferedData(byte[] buffer, ref int offset, ref int count)
{
- int copyCount = Math.Min(count, _transformBufferFreePos - _transformBufferStartPos);
+ if (HasBufferedData)
+ {
+ int copyCount = Math.Min(count, _transformBufferFreePos - _transformBufferStartPos);
+
+ Array.Copy(_transformBuffer, _transformBufferStartPos, buffer, offset, copyCount);
+ _transformBufferStartPos += copyCount;
- Array.Copy(_transformBuffer, _transformBufferStartPos, buffer, offset, copyCount);
- _transformBufferStartPos += copyCount;
+ offset += copyCount;
+ count -= copyCount;
+
+ return copyCount;
+ }
- return copyCount;
+ return 0;
}
// Perform the crypto transform, and buffer the data if less than one block has been requested.
diff --git a/test/ICSharpCode.SharpZipLib.Tests/Zip/ZipEncryptionHandling.cs b/test/ICSharpCode.SharpZipLib.Tests/Zip/ZipEncryptionHandling.cs
index 34dde202b..15247f1d3 100644
--- a/test/ICSharpCode.SharpZipLib.Tests/Zip/ZipEncryptionHandling.cs
+++ b/test/ICSharpCode.SharpZipLib.Tests/Zip/ZipEncryptionHandling.cs
@@ -4,6 +4,7 @@
using System.IO;
using System.Text;
using ICSharpCode.SharpZipLib.Tests.TestSupport;
+using System.Threading.Tasks;
namespace ICSharpCode.SharpZipLib.Tests.Zip
{
@@ -180,6 +181,53 @@ public void ZipFileStoreAes()
}
}
+ /// <summary>
+ /// As <see cref="ZipFileStoreAes"/>, but with Async reads
+ /// </summary>
+ [Test]
+ [Category("Encryption")]
+ [Category("Zip")]
+ public async Task ZipFileStoreAesAsync()
+ {
+ string password = "password";
+
+ using (var memoryStream = new MemoryStream())
+ {
+ // Try to create a zip stream
+ WriteEncryptedZipToStream(memoryStream, password, 256, CompressionMethod.Stored);
+
+ // reset
+ memoryStream.Seek(0, SeekOrigin.Begin);
+
+ // try to read it
+ var zipFile = new ZipFile(memoryStream, leaveOpen: true)
+ {
+ Password = password
+ };
+
+ foreach (ZipEntry entry in zipFile)
+ {
+ if (!entry.IsFile) continue;
+
+ // Should be stored rather than deflated
+ Assert.That(entry.CompressionMethod, Is.EqualTo(CompressionMethod.Stored), "Entry should be stored");
+
+ using (var zis = zipFile.GetInputStream(entry))
+ {
+ var buffer = new byte[entry.Size];
+
+ using (var inputStream = zipFile.GetInputStream(entry))
+ {
+ await zis.ReadAsync(buffer, 0, buffer.Length);
+ }
+
+ var content = Encoding.UTF8.GetString(buffer);
+ Assert.That(content, Is.EqualTo(DummyDataString), "Decompressed content does not match input data");
+ }
+ }
+ }
+ }
+
/// <summary>
/// Test using AES encryption on a file whose contents are Stored rather than deflated
/// </summary>