From 7768bc1fdb4bdf2b44ba09e2b814c0e7c4dcc3ac Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris+github@qwirx.com>
Date: Fri, 18 Nov 2016 22:20:29 +0000
Subject: [PATCH] Add MD5DigestStream and test

---
 lib/crypto/MD5Digest.h             | 115 ++++++++++++++++++++++++++++-
 test/httpserver/testhttpserver.cpp |  11 +++
 2 files changed, 123 insertions(+), 3 deletions(-)

diff --git a/lib/crypto/MD5Digest.h b/lib/crypto/MD5Digest.h
index 1be01ea93..a83ffb002 100644
--- a/lib/crypto/MD5Digest.h
+++ b/lib/crypto/MD5Digest.h
@@ -21,7 +21,7 @@
 //		Created: 8/12/03
 //
 // --------------------------------------------------------------------------
-class MD5Digest  
+class MD5Digest
 {
 public:
 	MD5Digest();
@@ -45,13 +45,122 @@ class MD5Digest
 	};
 
 	int CopyDigestTo(uint8_t *to);
-
 	bool DigestMatches(uint8_t *pCompareWith) const;
 
 private:
-	MD5_CTX	md5;
+	MD5_CTX md5;
 	uint8_t mDigest[MD5_DIGEST_LENGTH];
 };
 
+class MD5DigestStream : public IOStream
+{
+private:
+	MD5Digest mDigest;
+	MD5DigestStream(const MD5DigestStream &rToCopy); /* forbidden */
+	MD5DigestStream& operator=(const MD5DigestStream &rToCopy); /* forbidden */
+	bool mClosed;
+
+public:
+	MD5DigestStream()
+	: mClosed(false)
+	{ }
+
+	virtual int Read(void *pBuffer, int NBytes,
+		int Timeout = IOStream::TimeOutInfinite)
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	virtual pos_type BytesLeftToRead()
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	virtual void Write(const void *pBuffer, int NBytes,
+		int Timeout = IOStream::TimeOutInfinite)
+	{
+		mDigest.Add(pBuffer, NBytes);
+	}
+	virtual void Write(const std::string& rBuffer,
+		int Timeout = IOStream::TimeOutInfinite)
+	{
+		mDigest.Add(rBuffer);
+	}
+	virtual void WriteAllBuffered(int Timeout = IOStream::TimeOutInfinite) { }
+	virtual pos_type GetPosition() const
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	virtual void Seek(pos_type Offset, int SeekType)
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	virtual void Close()
+	{
+		mDigest.Finish();
+		mClosed = true;
+	}
+
+	// Has all data that can be read been read?
+	virtual bool StreamDataLeft()
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	// Has the stream been closed (writing not possible)
+	virtual bool StreamClosed()
+	{
+		return mClosed;
+	}
+
+	// Utility functions
+	bool ReadFullBuffer(void *pBuffer, int NBytes, int *pNBytesRead,
+		int Timeout = IOStream::TimeOutInfinite)
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	IOStream::pos_type CopyStreamTo(IOStream &rCopyTo,
+		int Timeout = IOStream::TimeOutInfinite, int BufferSize = 1024)
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	void Flush(int Timeout = IOStream::TimeOutInfinite)
+	{ }
+	static int ConvertSeekTypeToOSWhence(int SeekType)
+	{
+		THROW_EXCEPTION(CommonException, NotSupported);
+	}
+	virtual std::string ToString() const
+	{
+		return "MD5DigestStream";
+	}
+
+	std::string DigestAsString()
+	{
+		// You can only get a digest when the stream has been closed, because this
+		// finalises the underlying MD5Digest object.
+		ASSERT(mClosed);
+		return mDigest.DigestAsString();
+	}
+	uint8_t *DigestAsData(int *pLength = 0)
+	{
+		// You can only get a digest when the stream has been closed, because this
+		// finalises the underlying MD5Digest object.
+		ASSERT(mClosed);
+		return mDigest.DigestAsData(pLength);
+	}
+	int CopyDigestTo(uint8_t *to)
+	{
+		// You can only get a digest when the stream has been closed, because this
+		// finalises the underlying MD5Digest object.
+		ASSERT(mClosed);
+		return mDigest.CopyDigestTo(to);
+	}
+	bool DigestMatches(uint8_t *pCompareWith) const
+	{
+		// You can only get a digest when the stream has been closed, because this
+		// finalises the underlying MD5Digest object.
+		ASSERT(mClosed);
+		return mDigest.DigestMatches(pCompareWith);
+	}
+};
+
 #endif // MD5DIGEST_H
 
diff --git a/test/httpserver/testhttpserver.cpp b/test/httpserver/testhttpserver.cpp
index 7bdfaf693..335ccd3ae 100644
--- a/test/httpserver/testhttpserver.cpp
+++ b/test/httpserver/testhttpserver.cpp
@@ -27,6 +27,7 @@
 #include "HTTPServer.h"
 #include "HTTPTest.h"
 #include "IOStreamGetLine.h"
+#include "MD5Digest.h"
 #include "S3Client.h"
 #include "S3Simulator.h"
 #include "ServerControl.h"
@@ -237,6 +238,16 @@ bool test_httpserver()
 {
 	SETUP();
 
+	{
+		FileStream fs("testfiles/dsfdsfs98.fd");
+		MD5DigestStream digester;
+		fs.CopyStreamTo(digester);
+		fs.Seek(0, IOStream::SeekType_Absolute);
+		digester.Close();
+		std::string digest = digester.DigestAsString();
+		TEST_EQUAL("dc3b8c5e57e71d31a0a9d7cbeee2e011", digest);
+	}
+
 	// Test that HTTPRequest can be written to and read from a stream.
 	{
 		HTTPRequest request(HTTPRequest::Method_PUT, "/newfile");