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; }
lzma_stream_footer_decode(lzma_stream_flags *options, const uint8_t *in) { uint32_t crc; // 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 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; }