md5.1 revision 32074 
1.Dd February 14, 1994
2.Dt MD5 1
3.Os
4.Sh NAME
5.Nm md5
6.Nd calculate a message-digest fingerprint (checksum) for a file
7.Sh SYNOPSIS
8.Nm
9.Op Fl ptx
10.Op Fl s Ar string
11.Op Ar file ...
12.Sh DESCRIPTION
13.Nm
14takes as input a message of arbitrary length and produces
15as output a 128-bit
16.Dq fingerprint
17or
18.Dq message digest
19of the input.  It is conjectured that it is computationally infeasible to
20produce two messages having the same message digest, or to produce any
21message having a given prespecified target message digest.
22The MD5 algorithm is intended for digital signature applications, where a
23large file must be
24.Dq compressed
25in a secure manner before being encrypted with a private
26.Pq secret
27key under a public-key cryptosystem such as
28.Em RSA .
29.Pp
30The following four options may be used in any combination and must
31precede any files named on the command line.  The MD5
32sum of each file listed on the command line is printed after the options
33are processed.
34.Bl -tag -width Fl
35.It Fl s Ar string
36prints a checksum of the given
37.Ar string .
38.It Fl p
39echos stdin to stdout and appends the MD5 sum to stdout.
40.It Fl t
41runs a built-in time trial.
42.It Fl x
43runs a built-in test script.
44.El
45.Sh SEE ALSO
46.Xr cksum 1
47.Rs
48.%A R. Rivest
49.%T The MD5 Message-Digest Algorithm
50.%O RFC1321
51.Re
52.Sh ACKNOWLEDGEMENTS
53This program is placed in the public domain for free general use by
54RSA Data Security.
55