Re: Move sha1 to C?

[Leo <sdl.web@gmail.com>]

On 2011-05-24 06:10 +0800, Paul Eggert wrote:
> My guess is that's due to a bit of unportable code in gnulib-tool,
> which I just fixed as follows.  Could you please try it again?  If
> that doesn't work, I can push the sha1 gnulib code into the Emacs
> trunk myself, but I'd rather get it working for everybody.  Thanks.

It works smoothly now. BTW, md5sum is not available on OSX. I alias md5
to md5sum and the script seems to run without any problem.

man md5:

----------------

SYNOPSIS
     md5 [-pqrtx] [-s string] [file ...]

DESCRIPTION
     The md5 utility takes as input a message of arbitrary length and produces
     as output a ``fingerprint'' or ``message digest'' of the input.  It is
     conjectured that it is computationally infeasible to produce two messages
     having the same message digest, or to produce any message having a given
     prespecified target message digest.  The MD5 algorithm is intended for
     digital signature applications, where a large file must be ``compressed''
     in a secure manner before being encrypted with a private (secret) key
     under a public-key cryptosystem such as RSA.

     MD5 has not yet (2001-09-03) been broken, but sufficient attacks have
     been made that its security is in some doubt.  The attacks on MD5 are in
     the nature of finding ``collisions'' -- that is, multiple inputs which
     hash to the same value; it is still unlikely for an attacker to be able
     to determine the exact original input given a hash value.

     The following options may be used in any combination and must precede any
     files named on the command line.  The hexadecimal checksum of each file
     listed on the command line is printed after the options are processed.

     -s string
             Print a checksum of the given string.

     -p      Echo stdin to stdout and append the checksum to stdout.

     -q      Quiet mode - only the checksum is printed out.  Overrides the -r
             option.

     -r      Reverses the format of the output.  This helps with visual diffs.
             Does nothing when combined with the -ptx options.

     -t      Run a built-in time trial.

     -x      Run a built-in test script.