1.\" $FreeBSD$ 2.Dd February 14, 1994 3.Dt MD5 1 4.Os 5.Sh NAME 6.Nm md5 7.Nd calculate a message-digest fingerprint (checksum) for a file 8.Sh SYNOPSIS 9.Nm 10.Op Fl pqrtx 11.Op Fl s Ar string 12.Op Ar 13.Sh DESCRIPTION 14.Nm Md5 15takes as input a message of arbitrary length and produces 16as output a 128-bit 17.Dq fingerprint 18or 19.Dq message digest 20of the input. It is conjectured that it is computationally infeasible to 21produce two messages having the same message digest, or to produce any 22message having a given prespecified target message digest. 23The MD5 algorithm is intended for digital signature applications, where a 24large file must be 25.Dq compressed 26in a secure manner before being encrypted with a private 27.Pq secret 28key under a public-key cryptosystem such as 29.Em RSA . 30.Pp 31The following options may be used in any combination and must 32precede any files named on the command line. The MD5 33sum of each file listed on the command line is printed after the options 34are processed. 35.Bl -tag -width indent 36.It Fl s Ar string 37Print a checksum of the given 38.Ar string . 39.It Fl p 40Echo stdin to stdout and appends the MD5 sum to stdout. 41.It Fl q 42Quiet mode - only the MD5 sum is printed out. Overrides the 43.Fl r 44option. 45.It Fl r 46Reverses the format of the output. This helps with visual diffs. Does nothing 47when combined with the 48.Fl ptx 49options. 50.It Fl t 51Run a built-in time trial. 52.It Fl x 53Run a built-in test script. 54.El 55.Sh SEE ALSO 56.Xr cksum 1 57.Rs 58.%A R. Rivest 59.%T The MD5 Message-Digest Algorithm 60.%O RFC1321 61.Re 62.Sh ACKNOWLEDGMENTS 63This program is placed in the public domain for free general use by 64RSA Data Security. 65