diff --git a/Foundation/include/Poco/DigestEngine.h b/Foundation/include/Poco/DigestEngine.h
index 3de5b08c9..28562c2a6 100644
--- a/Foundation/include/Poco/DigestEngine.h
+++ b/Foundation/include/Poco/DigestEngine.h
@@ -1,125 +1,128 @@
-//
-// DigestEngine.h
-//
-// $Id: //poco/1.4/Foundation/include/Poco/DigestEngine.h#1 $
-//
-// Library: Foundation
-// Package: Crypt
-// Module:  DigestEngine
-//
-// Definition of class DigestEngine.
-//
-// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
-// and Contributors.
-//
-// Permission is hereby granted, free of charge, to any person or organization
-// obtaining a copy of the software and accompanying documentation covered by
-// this license (the "Software") to use, reproduce, display, distribute,
-// execute, and transmit the Software, and to prepare derivative works of the
-// Software, and to permit third-parties to whom the Software is furnished to
-// do so, all subject to the following:
-// 
-// The copyright notices in the Software and this entire statement, including
-// the above license grant, this restriction and the following disclaimer,
-// must be included in all copies of the Software, in whole or in part, and
-// all derivative works of the Software, unless such copies or derivative
-// works are solely in the form of machine-executable object code generated by
-// a source language processor.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
-// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
-// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
-// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-//
-
-
-#ifndef Foundation_DigestEngine_INCLUDED
-#define Foundation_DigestEngine_INCLUDED
-
-
-#include "Poco/Foundation.h"
-#include <vector>
-
-
-namespace Poco {
-
-
-class Foundation_API DigestEngine
-	/// This class is an abstract base class
-	/// for all classes implementing a message
-	/// digest algorithm, like MD5Engine
-	/// and SHA1Engine.
-	/// Call update() repeatedly with data to
-	/// compute the digest from. When done,
-	/// call digest() to obtain the message
-	/// digest.
-{
-public:
-	typedef std::vector<unsigned char> Digest;
-
-	DigestEngine();
-	virtual ~DigestEngine();
-		
-	void update(const void* data, unsigned length);
-	void update(char data);
-	void update(const std::string& data);
-		/// Updates the digest with the given data.
-		
-	virtual unsigned digestLength() const = 0;
-		/// Returns the length of the digest in bytes.
-
-	virtual void reset() = 0;
-		/// Resets the engine so that a new
-		/// digest can be computed.
-		
-	virtual const Digest& digest() = 0;
-		/// Finishes the computation of the digest and
-		/// returns the message digest. Resets the engine
-		/// and can thus only be called once for every digest.
-		/// The returned reference is valid until the next
-		/// time digest() is called, or the engine object is destroyed.
-
-	static std::string digestToHex(const Digest& bytes);
-		/// Converts a message digest into a string of hexadecimal numbers.
-
-protected:
-	virtual void updateImpl(const void* data, unsigned length) = 0;
-		/// Updates the digest with the given data. Must be implemented
-		/// by subclasses.
-		
-private:
-	DigestEngine(const DigestEngine&);
-	DigestEngine& operator = (const DigestEngine&);
-};
-
-
-//
-// inlines
-//
-
-
-inline void DigestEngine::update(const void* data, unsigned length)
-{
-	updateImpl(data, length);
-}
-
-
-inline void DigestEngine::update(char data)
-{
-	updateImpl(&data, 1);
-}
-
-
-inline void DigestEngine::update(const std::string& data)
-{
-	updateImpl(data.data(), (unsigned) data.size());	
-}
-
-
-} // namespace Poco
-
-
-#endif // Foundation_DigestEngine_INCLUDED
+//
+// DigestEngine.h
+//
+// $Id: //poco/1.4/Foundation/include/Poco/DigestEngine.h#1 $
+//
+// Library: Foundation
+// Package: Crypt
+// Module:  DigestEngine
+//
+// Definition of class DigestEngine.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// Permission is hereby granted, free of charge, to any person or organization
+// obtaining a copy of the software and accompanying documentation covered by
+// this license (the "Software") to use, reproduce, display, distribute,
+// execute, and transmit the Software, and to prepare derivative works of the
+// Software, and to permit third-parties to whom the Software is furnished to
+// do so, all subject to the following:
+// 
+// The copyright notices in the Software and this entire statement, including
+// the above license grant, this restriction and the following disclaimer,
+// must be included in all copies of the Software, in whole or in part, and
+// all derivative works of the Software, unless such copies or derivative
+// works are solely in the form of machine-executable object code generated by
+// a source language processor.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+
+#ifndef Foundation_DigestEngine_INCLUDED
+#define Foundation_DigestEngine_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include <vector>
+
+
+namespace Poco {
+
+
+class Foundation_API DigestEngine
+	/// This class is an abstract base class
+	/// for all classes implementing a message
+	/// digest algorithm, like MD5Engine
+	/// and SHA1Engine.
+	/// Call update() repeatedly with data to
+	/// compute the digest from. When done,
+	/// call digest() to obtain the message
+	/// digest.
+{
+public:
+	typedef std::vector<unsigned char> Digest;
+
+	DigestEngine();
+	virtual ~DigestEngine();
+		
+	void update(const void* data, unsigned length);
+	void update(char data);
+	void update(const std::string& data);
+		/// Updates the digest with the given data.
+		
+	virtual unsigned digestLength() const = 0;
+		/// Returns the length of the digest in bytes.
+
+	virtual void reset() = 0;
+		/// Resets the engine so that a new
+		/// digest can be computed.
+		
+	virtual const Digest& digest() = 0;
+		/// Finishes the computation of the digest and
+		/// returns the message digest. Resets the engine
+		/// and can thus only be called once for every digest.
+		/// The returned reference is valid until the next
+		/// time digest() is called, or the engine object is destroyed.
+
+        static std::string digestToHex(const Digest& bytes);
+                /// Converts a message digest into a string of hexadecimal numbers.
+
+        static Digest digestFromHex(const std::string& digest);
+                /// Converts a string created by digestToHex back to its Digest presentation
+
+protected:
+        virtual void updateImpl(const void* data, unsigned length) = 0;
+                /// Updates the digest with the given data. Must be implemented
+		/// by subclasses.
+		
+private:
+	DigestEngine(const DigestEngine&);
+	DigestEngine& operator = (const DigestEngine&);
+};
+
+
+//
+// inlines
+//
+
+
+inline void DigestEngine::update(const void* data, unsigned length)
+{
+	updateImpl(data, length);
+}
+
+
+inline void DigestEngine::update(char data)
+{
+	updateImpl(&data, 1);
+}
+
+
+inline void DigestEngine::update(const std::string& data)
+{
+	updateImpl(data.data(), (unsigned) data.size());	
+}
+
+
+} // namespace Poco
+
+
+#endif // Foundation_DigestEngine_INCLUDED
diff --git a/Foundation/src/DigestEngine.cpp b/Foundation/src/DigestEngine.cpp
index 9ee745659..7d606a8e1 100644
--- a/Foundation/src/DigestEngine.cpp
+++ b/Foundation/src/DigestEngine.cpp
@@ -1,68 +1,104 @@
-//
-// DigestEngine.cpp
-//
-// $Id: //poco/1.4/Foundation/src/DigestEngine.cpp#1 $
-//
-// Library: Foundation
-// Package: Crypt
-// Module:  DigestEngine
-//
-// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
-// and Contributors.
-//
-// Permission is hereby granted, free of charge, to any person or organization
-// obtaining a copy of the software and accompanying documentation covered by
-// this license (the "Software") to use, reproduce, display, distribute,
-// execute, and transmit the Software, and to prepare derivative works of the
-// Software, and to permit third-parties to whom the Software is furnished to
-// do so, all subject to the following:
-// 
-// The copyright notices in the Software and this entire statement, including
-// the above license grant, this restriction and the following disclaimer,
-// must be included in all copies of the Software, in whole or in part, and
-// all derivative works of the Software, unless such copies or derivative
-// works are solely in the form of machine-executable object code generated by
-// a source language processor.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
-// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
-// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
-// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-//
-
-
-#include "Poco/DigestEngine.h"
-
-
-namespace Poco {
-
-
-DigestEngine::DigestEngine()
-{
-}
-
-
-DigestEngine::~DigestEngine()
-{
-}
-
-
-std::string DigestEngine::digestToHex(const Digest& bytes)
-{
-	static const char digits[] = "0123456789abcdef";
-	std::string result;
-	result.reserve(bytes.size()*2);
-	for (Digest::const_iterator it = bytes.begin(); it != bytes.end(); ++it)
-	{
-		unsigned char c = *it;
-		result += digits[(c >> 4) & 0xF];
-		result += digits[c & 0xF];
-	}
-	return result;
-}
-
-
-} // namespace Poco
+//
+// DigestEngine.cpp
+//
+// $Id: //poco/1.4/Foundation/src/DigestEngine.cpp#1 $
+//
+// Library: Foundation
+// Package: Crypt
+// Module:  DigestEngine
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// Permission is hereby granted, free of charge, to any person or organization
+// obtaining a copy of the software and accompanying documentation covered by
+// this license (the "Software") to use, reproduce, display, distribute,
+// execute, and transmit the Software, and to prepare derivative works of the
+// Software, and to permit third-parties to whom the Software is furnished to
+// do so, all subject to the following:
+// 
+// The copyright notices in the Software and this entire statement, including
+// the above license grant, this restriction and the following disclaimer,
+// must be included in all copies of the Software, in whole or in part, and
+// all derivative works of the Software, unless such copies or derivative
+// works are solely in the form of machine-executable object code generated by
+// a source language processor.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+
+#include "Poco/DigestEngine.h"
+#include "Poco/Exception.h"
+
+
+namespace Poco {
+
+
+DigestEngine::DigestEngine()
+{
+}
+
+
+DigestEngine::~DigestEngine()
+{
+}
+
+
+std::string DigestEngine::digestToHex(const Digest& bytes)
+{
+	static const char digits[] = "0123456789abcdef";
+	std::string result;
+	result.reserve(bytes.size()*2);
+	for (Digest::const_iterator it = bytes.begin(); it != bytes.end(); ++it)
+	{
+		unsigned char c = *it;
+		result += digits[(c >> 4) & 0xF];
+		result += digits[c & 0xF];
+        }
+        return result;
+}
+
+
+DigestEngine::Digest DigestEngine::digestFromHex(const std::string& digest)
+{
+        if (digest.size() % 2 != 0)
+                throw DataFormatException();
+        Digest result;
+        result.reserve(digest.size()/2);
+        for (std::size_t i = 0; i < digest.size(); ++i)
+        {
+                int c = 0;
+                // first upper 4 bits
+                if (digest[i] >= '0' && digest[i] <= '9')
+                        c = digest[i] - '0';
+                else if (digest[i] >= 'a' && digest[i] <= 'f')
+                        c = digest[i] - 'a'+10;
+                else if (digest[i] >= 'A' && digest[i] <= 'F')
+                        c = digest[i] - 'A'+10;
+                else
+                        throw DataFormatException();
+                c <<= 4;
+                ++i;
+                if (digest[i] >= '0' && digest[i] <= '9')
+                        c += digest[i] - '0';
+                else if (digest[i] >= 'a' && digest[i] <= 'f')
+                        c += digest[i] - 'a'+10;
+                else if (digest[i] >= 'A' && digest[i] <= 'F')
+                        c += digest[i] - 'A'+10;
+                else
+                        throw DataFormatException();
+
+                result.push_back(static_cast<unsigned char>(c));
+        }
+        return result;
+}
+
+
+} // namespace Poco