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3b34851de1
broken. API has changed a lot and it will still change a little more here and there. The command line tool doesn't have all the required changes to reflect the API changes, so it's easy to get "internal error" or trigger assertions.
89 lines
2.6 KiB
C
89 lines
2.6 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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/// \file stream_flags_decoder.c
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/// \brief Decodes Stream Header and Stream Footer from .lzma files
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//
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// Copyright (C) 2007 Lasse Collin
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 2.1 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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///////////////////////////////////////////////////////////////////////////////
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#include "stream_flags_common.h"
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static bool
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stream_flags_decode(lzma_stream_flags *options, const uint8_t *in)
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{
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// Reserved bits must be unset.
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if (in[0] != 0x00 || (in[1] & 0xF0))
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return true;
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options->check = in[1] & 0x0F;
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return false;
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}
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extern LZMA_API lzma_ret
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lzma_stream_header_decode(lzma_stream_flags *options, const uint8_t *in)
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{
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// Magic
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if (memcmp(in, lzma_header_magic, sizeof(lzma_header_magic)) != 0)
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return LZMA_FORMAT_ERROR;
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// Verify the CRC32 so we can distinguish between corrupt
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// and unsupported files.
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const uint32_t crc = lzma_crc32(in + sizeof(lzma_header_magic),
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LZMA_STREAM_FLAGS_SIZE, 0);
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if (crc != integer_read_32(in + sizeof(lzma_header_magic)
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+ LZMA_STREAM_FLAGS_SIZE))
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return LZMA_DATA_ERROR;
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// Stream Flags
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if (stream_flags_decode(options, in + sizeof(lzma_header_magic)))
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return LZMA_HEADER_ERROR;
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// Set Backward Size to indicate unknown value. That way
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// lzma_stream_flags_equal can be used to compare Stream Header
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// and Stream Footer while keeping it useful also for comparing
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// two Stream Footers.
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options->backward_size = LZMA_VLI_VALUE_UNKNOWN;
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return LZMA_OK;
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}
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extern LZMA_API lzma_ret
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lzma_stream_footer_decode(lzma_stream_flags *options, const uint8_t *in)
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{
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// Magic
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if (memcmp(in + sizeof(uint32_t) * 2 + LZMA_STREAM_FLAGS_SIZE,
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lzma_footer_magic, sizeof(lzma_footer_magic)) != 0)
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return LZMA_FORMAT_ERROR;
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// CRC32
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const uint32_t crc = lzma_crc32(in + sizeof(uint32_t),
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sizeof(uint32_t) + LZMA_STREAM_FLAGS_SIZE, 0);
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if (crc != integer_read_32(in))
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return LZMA_DATA_ERROR;
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// Stream Flags
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if (stream_flags_decode(options, in + sizeof(uint32_t) * 2))
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return LZMA_HEADER_ERROR;
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// Backward Size
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options->backward_size = integer_read_32(in + sizeof(uint32_t));
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options->backward_size = (options->backward_size + 1) * 4;
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return LZMA_OK;
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}
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