diff options
Diffstat (limited to 'wx+/zlib_wrap.h')
| -rw-r--r-- | wx+/zlib_wrap.h | 95 |
1 files changed, 51 insertions, 44 deletions
diff --git a/wx+/zlib_wrap.h b/wx+/zlib_wrap.h index c229a589..9fa50240 100644 --- a/wx+/zlib_wrap.h +++ b/wx+/zlib_wrap.h @@ -1,7 +1,7 @@ // ************************************************************************** // * This file is part of the FreeFileSync project. It is distributed under * // * GNU General Public License: http://www.gnu.org/licenses/gpl.html * -// * Copyright (C) ZenJu (zhnmju123 AT gmx DOT de) - All Rights Reserved * +// * Copyright (C) ZenJu (zenju AT gmx DOT de) - All Rights Reserved * // ************************************************************************** #ifndef SIMPLE_H_INCLUDED_18134135134135345489 @@ -55,27 +55,28 @@ template <class BinContainer> BinContainer compress(const BinContainer& stream, int level) //throw ZlibInternalError { BinContainer contOut; - - //save uncompressed stream size for decompression - const std::uint64_t uncompressedSize = stream.size(); //use portable number type! - contOut.resize(sizeof(uncompressedSize)); - std::copy(reinterpret_cast<const char*>(&uncompressedSize), - reinterpret_cast<const char*>(&uncompressedSize) + sizeof(uncompressedSize), - &*contOut.begin()); - - const size_t bufferEstimate = impl::zlib_compressBound(stream.size()); //upper limit for buffer size, larger than input size!!! - - contOut.resize(contOut.size() + bufferEstimate); - - const size_t bytesWritten = impl::zlib_compress(&*stream.begin(), - stream.size(), - &*contOut.begin() + contOut.size() - bufferEstimate, - bufferEstimate, - level); //throw ZlibInternalError - if (bytesWritten < bufferEstimate) - contOut.resize(contOut.size() - (bufferEstimate - bytesWritten)); //caveat: unsigned arithmetics - //caveat: physical memory consumption still *unchanged*! - + if (!stream.empty()) //don't dereference iterator into empty container! + { + //save uncompressed stream size for decompression + const std::uint64_t uncompressedSize = stream.size(); //use portable number type! + contOut.resize(sizeof(uncompressedSize)); + std::copy(reinterpret_cast<const char*>(&uncompressedSize), + reinterpret_cast<const char*>(&uncompressedSize) + sizeof(uncompressedSize), + &*contOut.begin()); + + const size_t bufferEstimate = impl::zlib_compressBound(stream.size()); //upper limit for buffer size, larger than input size!!! + + contOut.resize(contOut.size() + bufferEstimate); + + const size_t bytesWritten = impl::zlib_compress(&*stream.begin(), + stream.size(), + &*contOut.begin() + contOut.size() - bufferEstimate, + bufferEstimate, + level); //throw ZlibInternalError + if (bytesWritten < bufferEstimate) + contOut.resize(contOut.size() - (bufferEstimate - bytesWritten)); //caveat: unsigned arithmetics + //caveat: physical memory consumption still *unchanged*! + } return contOut; } @@ -83,31 +84,37 @@ BinContainer compress(const BinContainer& stream, int level) //throw ZlibInterna template <class BinContainer> BinContainer decompress(const BinContainer& stream) //throw ZlibInternalError { - //retrieve size of uncompressed data - std::uint64_t uncompressedSize = 0; //use portable number type! - if (stream.size() < sizeof(uncompressedSize)) - throw ZlibInternalError(); - std::copy(&*stream.begin(), - &*stream.begin() + sizeof(uncompressedSize), - reinterpret_cast<char*>(&uncompressedSize)); - BinContainer contOut; - try - { - contOut.resize(uncompressedSize); //throw std::bad_alloc - } - catch (std::bad_alloc&) //most likely due to data corruption! + if (!stream.empty()) //don't dereference iterator into empty container! { - throw ZlibInternalError(); + //retrieve size of uncompressed data + std::uint64_t uncompressedSize = 0; //use portable number type! + if (stream.size() < sizeof(uncompressedSize)) + throw ZlibInternalError(); + std::copy(&*stream.begin(), + &*stream.begin() + sizeof(uncompressedSize), + reinterpret_cast<char*>(&uncompressedSize)); + try + { + //attention: contOut MUST NOT be empty! Else it will pass a nullptr to zlib_decompress() => Z_STREAM_ERROR although "uncompressedSize == 0"!!! + //secondary bug: don't dereference iterator into empty container! + if (uncompressedSize == 0) //cannot be 0: compress() directly maps empty -> empty container skipping zlib! + throw ZlibInternalError(); + + contOut.resize(uncompressedSize); //throw std::bad_alloc + } + catch (std::bad_alloc&) //most likely due to data corruption! + { + throw ZlibInternalError(); + } + + const size_t bytesWritten = impl::zlib_decompress(&*stream.begin() + sizeof(uncompressedSize), + stream.size() - sizeof(uncompressedSize), + &*contOut.begin(), + uncompressedSize); //throw ZlibInternalError + if (bytesWritten != uncompressedSize) + throw ZlibInternalError(); } - - const size_t bytesWritten = impl::zlib_decompress(&*stream.begin() + sizeof(uncompressedSize), - stream.size() - sizeof(uncompressedSize), - &*contOut.begin(), - uncompressedSize); //throw ZlibInternalError - if (bytesWritten != uncompressedSize) - throw ZlibInternalError(); - return contOut; } } |