200多个常见的VC++加密算法源码

				// files.cpp - written and placed in the public domain by Wei Dai
				
				#include "pch.h"
				#include "files.h"
				
				NAMESPACE_BEGIN(CryptoPP)
				
				static const unsigned int BUFFER_SIZE = 1024;
				
				FileSource::FileSource (std::istream &i, bool pumpAndClose, BufferedTransformation *outQueue)
					: Source(outQueue), in(i)
				{
					if (pumpAndClose)
					{
						PumpAll();
						Close();
					}
				}
				
				FileSource::FileSource (const char *filename, bool pumpAndClose, BufferedTransformation *outQueue)
					: Source(outQueue), file(filename, std::ios::in | std::ios::binary), in(file)
				{
					if (!file)
					{
						std::string message = "FileSource: error opening file for reading: ";
						message += filename;
						throw OpenErr(message.c_str());
					}
				
					if (pumpAndClose)
					{
						PumpAll();
						Close();
					}
				}
				
				unsigned int FileSource::Pump(unsigned int size)
				{
					unsigned int total=0;
					SecByteBlock buffer(STDMIN(size, BUFFER_SIZE));
				
					while (size && in.good())
					{
						in.read((char *)buffer.ptr, STDMIN(size, BUFFER_SIZE));
						unsigned l = in.gcount();
						outQueue->Put(buffer, l);
						size -= l;
						total += l;
					}
				
					if (!in.good() && !in.eof())
						throw ReadErr();
				
					return total;
				}
				
				unsigned long FileSource::PumpAll()
				{
					unsigned long total=0;
					unsigned int l;
				
					while ((l=Pump(BUFFER_SIZE)) != 0)
						total += l;
				
					return total;
				}
				
				FileSink::FileSink(std::ostream &o)
					: out(o)
				{
				}
				
				FileSink::FileSink(const char *filename)
					: file(filename, std::ios::out | std::ios::binary | std::ios::trunc), out(file)
				{
					if (!file)
					{
						std::string message = "FileSource: error opening file for writing: ";
						message += filename;
						throw OpenErr(message.c_str());
					}
				}
				
				void FileSink::InputFinished()
				{
					out.flush();
					if (!out.good())
					  throw WriteErr();
				}
				
				void FileSink::Put(const byte *inString, unsigned int length)
				{
					out.write((const char *)inString, length);
					if (!out.good())
					  throw WriteErr();
				}
				
				NAMESPACE_END