1 .\" $FreeBSD: src/sbin/md5/md5.1,v 1.10.2.7 2002/06/20 23:09:06 charnier Exp $
2 .\" $DragonFly: src/sbin/md5/md5.1,v 1.2 2003/06/17 04:27:33 dillon Exp $
8 .Nd calculate a message-digest fingerprint (checksum) for a file
17 utility takes as input a message of arbitrary length and produces
23 It is conjectured that it is computationally infeasible to
24 produce two messages having the same message digest, or to produce any
25 message having a given prespecified target message digest.
26 The MD5 algorithm is intended for digital signature applications, where a
29 in a secure manner before being encrypted with a private
31 key under a public-key cryptosystem such as
34 MD5 has not yet (2001-09-03) been broken, but sufficient attacks have been
35 made that its security is in some doubt.
37 are in the nature of finding
39 \(em that is, multiple
40 inputs which hash to the same value; it is still unlikely for an attacker
41 to be able to determine the exact original input given a hash value.
43 The following options may be used in any combination and must
44 precede any files named on the command line.
46 sum of each file listed on the command line is printed after the options
48 .Bl -tag -width indent
50 Print a checksum of the given
53 Echo stdin to stdout and appends the MD5 sum to stdout.
55 Quiet mode - only the MD5 sum is printed out.
60 Reverses the format of the output.
61 This helps with visual diffs.
63 when combined with the
67 Run a built-in time trial.
69 Run a built-in test script.
75 .%T The MD5 Message-Digest Algorithm
79 This program is placed in the public domain for free general use by