int upx_decompress ( const upx_bytep src, unsigned src_len,
upx_bytep dst, unsigned* dst_len,
int method,
const upx_compress_result_t *cresult )
{
int r = UPX_E_ERROR;
assert(*dst_len > 0);
assert(src_len < *dst_len); // must be compressed
if (cresult && cresult->method == 0)
cresult = NULL;
if (0) {
}
#if (WITH_LZMA)
else if (M_IS_LZMA(method))
r = upx_lzma_decompress(src, src_len, dst, dst_len, method, cresult);
#endif
#if (WITH_NRV)
else if (M_IS_NRV2B(method) || M_IS_NRV2D(method) || M_IS_NRV2E(method))
r = upx_nrv_decompress(src, src_len, dst, dst_len, method, cresult);
#endif
#if (WITH_UCL)
else if (M_IS_NRV2B(method) || M_IS_NRV2D(method) || M_IS_NRV2E(method))
r = upx_ucl_decompress(src, src_len, dst, dst_len, method, cresult);
#endif
#if (WITH_ZLIB)
else if (M_IS_DEFLATE(method))
r = upx_zlib_decompress(src, src_len, dst, dst_len, method, cresult);
#endif
else {
throwInternalError("unknown decompression method");
}
return r;
}
int upx_zlib_test_overlap ( const upx_bytep buf,
const upx_bytep tbuf,
unsigned src_off, unsigned src_len,
unsigned* dst_len,
int method,
const upx_compress_result_t *cresult )
{
assert(method == M_DEFLATE);
MemBuffer b(src_off + src_len);
memcpy(b + src_off, buf + src_off, src_len);
unsigned saved_dst_len = *dst_len;
int r = upx_zlib_decompress(b + src_off, src_len, b, dst_len, method, cresult);
if (r != UPX_E_OK)
return r;
if (*dst_len != saved_dst_len)
return UPX_E_ERROR;
// NOTE: there is a very tiny possibility that decompression has
// succeeded but the data is not restored correctly because of
// in-place buffer overlapping, so we use an extra memcmp().
if (tbuf != NULL && memcmp(tbuf, b, *dst_len) != 0)
return UPX_E_ERROR;
return UPX_E_OK;
}
