The R Project SVN – R – Diff – /trunk/src/extra/xz/common/block_buffer_encoder.c

 extern LZMA_API(lzma_ret)
 lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator,
 		const uint8_t *in, size_t in_size,
 		uint8_t *out, size_t *out_pos, size_t out_size)
+{
-	// Sanity checks
+	// Validate the arguments.
-	if (block == NULL || block->filters == NULL
-			|| (in == NULL && in_size != 0) || out == NULL
+	if (block == NULL || (in == NULL && in_size != 0) || out == NULL
 			|| out_pos == NULL || *out_pos > out_size)
 		return LZMA_PROG_ERROR;
+	// The contents of the structure may depend on the version so
-	// Check the version field.
+	// check the version before validating the contents of *block.
 	if (block->version != 0)
 		return LZMA_OPTIONS_ERROR;
+	if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX
+			|| block->filters == NULL)
+		return LZMA_PROG_ERROR;
+	if (!lzma_check_is_supported(block->check))
+		return LZMA_UNSUPPORTED_CHECK;
 	// Size of a Block has to be a multiple of four, so limit the size
 	// here already. This way we don't need to check it again when adding
 	// Block Padding.
 	out_size -= (out_size - *out_pos) & 3;
 	// Get the size of the Check field.
 	const size_t check_size = lzma_check_size(block->check);
-	if (check_size == UINT32_MAX)
+	assert(check_size != UINT32_MAX);
-		return LZMA_PROG_ERROR;
 	// Reserve space for the Check field.
 	if (out_size - *out_pos <= check_size)
 		return LZMA_BUF_ERROR;

The R Project SVN R