reset method
Reset the digest to its original state.
Implementation
@override
void reset() {
_a.set(0x01234567, 0x89ABCDEF);
_b.set(0xFEDCBA98, 0x76543210);
_c.set(0xF096A5B4, 0xC3B2E187);
_bufferOffset = 0;
_buffer.fillRange(0, _buffer.length, 0);
_wordBufferOffset = 0;
_wordBuffer.fillRange(0, _wordBuffer.length, 0);
_byteCount.set(0);
}