Fix unbounded inflate parsing binary fragments#76
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When parsing a binary fragment, the library attempted to decompress the patch data before checking the expected size and without specifying any limit. This allowed a malicious patch to include an "inflate bomb" as a binary fragment, forcing the library to allocate excessive memory during parsing. The BinaryFragment type now stores the raw compressed data at parse time and provides a separate method to get a reader for the decompressed data. The reader limits the decompressed size to the declared size in the fragment. This is an API break, but I expect very few clients interact with binary fragment data directly. This fixes the unbounded inflate during parsing and also limits the memory allocated by the library during an apply to a copy buffer. However, applying a patch can still write large amounts of data to the client-provided writer in ways the client can't easily prevent. A future commit will enforce limits at apply time to fix this.
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When parsing a binary fragment, the library attempted to decompress the patch data before checking the expected size and without specifying any limit. This allowed a malicious patch to include an "inflate bomb" as a binary fragment, forcing the library to allocate excessive memory during parsing.
The BinaryFragment type now stores the raw compressed data at parse time and provides a separate method to get a reader for the decompressed data. The reader limits the decompressed size to the declared size in the fragment. This is an API break, but I expect very few clients interact with binary fragment data directly.
This fixes the unbounded inflate during parsing and also limits the memory allocated by the library during an apply to a copy buffer. However, applying a patch can still write large amounts of data to the client-provided writer in ways the client can't easily prevent. A future commit will enforce limits at apply time to fix this.