Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
MD5(1)			FreeBSD	General	Commands Manual			MD5(1)

     md5, sha1,	rmd160 -- calculate a message-digest fingerprint (checksum)
     for a file

     md5 [-pqrtx] [-s string] [file ...]
     sha1 [-pqrtx] [-s string] [file ...]
     rmd160 [-pqrtx] [-s string] [file ...]

     The md5, sha1 and rmd160 utilities	take as	input a	message	of arbitrary
     length and	produce	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,
     SHA-1 and RIPEMD-160 algorithms are intended for digital signature	appli-
     cations, 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

     -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.

     The md5, sha1 and rmd160 utilities	exit 0 on success, and 1 if at least
     one of the	input files could not be read.

     cksum(1), md5(3), ripemd(3), sha(3)

     R.	Rivest,	The MD5	Message-Digest Algorithm, RFC1321.

     J.	Burrows, The Secure Hash Standard, FIPS	PUB 180-1.

     D.	Eastlake and P.	Jones, US Secure Hash Algorithm	1, RFC 3174.

     RIPEMD-160	is part	of the ISO draft standard "ISO/IEC DIS 10118-3"	on
     dedicated hash functions.

     Secure Hash Standard (SHS):

     The RIPEMD-160 page:

     This program is placed in the public domain for free general use by RSA
     Data Security.

     Support for SHA-1 and RIPEMD-160 has been added by	Oliver Eikemeier

FreeBSD	5.3			 June 6, 2004			   FreeBSD 5.3


Want to link to this manual page? Use this URL:

home | help