From: "Aaron D. Gifford" <astounding@...>
Date: 2012-04-28T08:02:10+09:00
Subject: Re: why does this return 255 bits instead of 256 (and general bit byte hex string array crypt mayhem

Remember, when you convert an integer to a string (#to_s) that leading
zeros are trimmed off.  So if a 256-bit hash happens to be an integer
that, when converted to a binary string representation, that string
may be from 1 to 256.  If the hash was the integer zero (possible,
though unlikely), the length would be 1.

That may explain your results IF your hash input to SHA-256 was
something other than "anything" (which hash, since the the highest bit
at position 256 is a one, should produce a length of 256 when #to_s(2)
is called).

Aaron out.