In Java we will call this method with byte array buffers we use to read from a stream. Java does not
guarantee to completely fill the buffer (and can't at the end of a stream). Passing the number of bytes
to read from the array to NativeCrypto avoids copying bytes between arrays of various lengths.
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extra : commitid : 7Vp3hqUE08T
extra : amend_source : 89845bccc20cfe36b421a568e52bdaa1be2f2800