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/*
* Zlib Compressor
* (C) 2001 Peter J Jones
* 2001-2007,2014 Jack Lloyd
* 2006 Matt Johnston
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/zlib.h>
#include <botan/internal/compress_utils.h>
#include <botan/exceptn.h>
#include <zlib.h>
namespace Botan {
namespace {
class Zlib_Stream : public Zlib_Style_Stream<z_stream, Bytef>
{
public:
Zlib_Stream()
{
streamp()->opaque = alloc();
streamp()->zalloc = Compression_Alloc_Info::malloc<unsigned int>;
streamp()->zfree = Compression_Alloc_Info::free;
}
uint32_t run_flag() const override { return Z_NO_FLUSH; }
uint32_t flush_flag() const override { return Z_SYNC_FLUSH; }
uint32_t finish_flag() const override { return Z_FINISH; }
int compute_window_bits(int wbits, int wbits_offset) const
{
if(wbits_offset == -1)
return -wbits;
else
return wbits + wbits_offset;
}
};
class Zlib_Compression_Stream : public Zlib_Stream
{
public:
Zlib_Compression_Stream(size_t level, int wbits, int wbits_offset = 0)
{
wbits = compute_window_bits(wbits, wbits_offset);
if(level >= 9)
level = 9;
else if(level == 0)
level = 6;
int rc = ::deflateInit2(streamp(), level, Z_DEFLATED, wbits, 8, Z_DEFAULT_STRATEGY);
if(rc != Z_OK)
throw Compression_Error("deflateInit2", ErrorType::ZlibError, rc);
}
~Zlib_Compression_Stream()
{
::deflateEnd(streamp());
}
bool run(uint32_t flags) override
{
int rc = ::deflate(streamp(), flags);
if(rc != Z_OK && rc != Z_STREAM_END && rc != Z_BUF_ERROR)
throw Compression_Error("zlib deflate", ErrorType::ZlibError, rc);
return (rc == Z_STREAM_END);
}
};
class Zlib_Decompression_Stream : public Zlib_Stream
{
public:
Zlib_Decompression_Stream(int wbits, int wbits_offset = 0)
{
int rc = ::inflateInit2(streamp(), compute_window_bits(wbits, wbits_offset));
if(rc != Z_OK)
throw Compression_Error("inflateInit2", ErrorType::ZlibError, rc);
}
~Zlib_Decompression_Stream()
{
::inflateEnd(streamp());
}
bool run(uint32_t flags) override
{
int rc = ::inflate(streamp(), flags);
if(rc != Z_OK && rc != Z_STREAM_END && rc != Z_BUF_ERROR)
throw Compression_Error("zlib inflate", ErrorType::ZlibError, rc);
return (rc == Z_STREAM_END);
}
};
class Deflate_Compression_Stream final : public Zlib_Compression_Stream
{
public:
Deflate_Compression_Stream(size_t level, int wbits) :
Zlib_Compression_Stream(level, wbits, -1) {}
};
class Deflate_Decompression_Stream final : public Zlib_Decompression_Stream
{
public:
explicit Deflate_Decompression_Stream(int wbits) : Zlib_Decompression_Stream(wbits, -1) {}
};
class Gzip_Compression_Stream final : public Zlib_Compression_Stream
{
public:
Gzip_Compression_Stream(size_t level, int wbits, uint8_t os_code, uint64_t hdr_time) :
Zlib_Compression_Stream(level, wbits, 16)
{
clear_mem(&m_header, 1);
m_header.os = os_code;
m_header.time = static_cast<uLong>(hdr_time);
int rc = deflateSetHeader(streamp(), &m_header);
if(rc != Z_OK)
throw Compression_Error("deflateSetHeader", ErrorType::ZlibError, rc);
}
private:
::gz_header m_header;
};
class Gzip_Decompression_Stream final : public Zlib_Decompression_Stream
{
public:
explicit Gzip_Decompression_Stream(int wbits) : Zlib_Decompression_Stream(wbits, 16) {}
};
}
Compression_Stream* Zlib_Compression::make_stream(size_t level) const
{
return new Zlib_Compression_Stream(level, 15);
}
Compression_Stream* Zlib_Decompression::make_stream() const
{
return new Zlib_Decompression_Stream(15);
}
Compression_Stream* Deflate_Compression::make_stream(size_t level) const
{
return new Deflate_Compression_Stream(level, 15);
}
Compression_Stream* Deflate_Decompression::make_stream() const
{
return new Deflate_Decompression_Stream(15);
}
Compression_Stream* Gzip_Compression::make_stream(size_t level) const
{
return new Gzip_Compression_Stream(level, 15, m_os_code, m_hdr_time);
}
Compression_Stream* Gzip_Decompression::make_stream() const
{
return new Gzip_Decompression_Stream(15);
}
}