| Index: xz/src/liblzma/common/stream_flags_decoder.c
|
| ===================================================================
|
| --- xz/src/liblzma/common/stream_flags_decoder.c (revision 0)
|
| +++ xz/src/liblzma/common/stream_flags_decoder.c (revision 0)
|
| @@ -0,0 +1,82 @@
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +//
|
| +/// \file stream_flags_decoder.c
|
| +/// \brief Decodes Stream Header and Stream Footer from .xz files
|
| +//
|
| +// Author: Lasse Collin
|
| +//
|
| +// This file has been put into the public domain.
|
| +// You can do whatever you want with this file.
|
| +//
|
| +///////////////////////////////////////////////////////////////////////////////
|
| +
|
| +#include "stream_flags_common.h"
|
| +
|
| +
|
| +static bool
|
| +stream_flags_decode(lzma_stream_flags *options, const uint8_t *in)
|
| +{
|
| + // Reserved bits must be unset.
|
| + if (in[0] != 0x00 || (in[1] & 0xF0))
|
| + return true;
|
| +
|
| + options->version = 0;
|
| + options->check = in[1] & 0x0F;
|
| +
|
| + return false;
|
| +}
|
| +
|
| +
|
| +extern LZMA_API(lzma_ret)
|
| +lzma_stream_header_decode(lzma_stream_flags *options, const uint8_t *in)
|
| +{
|
| + // Magic
|
| + if (memcmp(in, lzma_header_magic, sizeof(lzma_header_magic)) != 0)
|
| + return LZMA_FORMAT_ERROR;
|
| +
|
| + // Verify the CRC32 so we can distinguish between corrupt
|
| + // and unsupported files.
|
| + const uint32_t crc = lzma_crc32(in + sizeof(lzma_header_magic),
|
| + LZMA_STREAM_FLAGS_SIZE, 0);
|
| + if (crc != unaligned_read32le(in + sizeof(lzma_header_magic)
|
| + + LZMA_STREAM_FLAGS_SIZE))
|
| + return LZMA_DATA_ERROR;
|
| +
|
| + // Stream Flags
|
| + if (stream_flags_decode(options, in + sizeof(lzma_header_magic)))
|
| + return LZMA_OPTIONS_ERROR;
|
| +
|
| + // Set Backward Size to indicate unknown value. That way
|
| + // lzma_stream_flags_compare() can be used to compare Stream Header
|
| + // and Stream Footer while keeping it useful also for comparing
|
| + // two Stream Footers.
|
| + options->backward_size = LZMA_VLI_UNKNOWN;
|
| +
|
| + return LZMA_OK;
|
| +}
|
| +
|
| +
|
| +extern LZMA_API(lzma_ret)
|
| +lzma_stream_footer_decode(lzma_stream_flags *options, const uint8_t *in)
|
| +{
|
| + // Magic
|
| + if (memcmp(in + sizeof(uint32_t) * 2 + LZMA_STREAM_FLAGS_SIZE,
|
| + lzma_footer_magic, sizeof(lzma_footer_magic)) != 0)
|
| + return LZMA_FORMAT_ERROR;
|
| +
|
| + // CRC32
|
| + const uint32_t crc = lzma_crc32(in + sizeof(uint32_t),
|
| + sizeof(uint32_t) + LZMA_STREAM_FLAGS_SIZE, 0);
|
| + if (crc != unaligned_read32le(in))
|
| + return LZMA_DATA_ERROR;
|
| +
|
| + // Stream Flags
|
| + if (stream_flags_decode(options, in + sizeof(uint32_t) * 2))
|
| + return LZMA_OPTIONS_ERROR;
|
| +
|
| + // Backward Size
|
| + options->backward_size = unaligned_read32le(in + sizeof(uint32_t));
|
| + options->backward_size = (options->backward_size + 1) * 4;
|
| +
|
| + return LZMA_OK;
|
| +}
|
|
|
| Property changes on: xz/src/liblzma/common/stream_flags_decoder.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|