MirBSD manpage: md5(1)

MD5(1)                       BSD Reference Manual                       MD5(1)

NAME

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

SYNOPSIS

     md5 [-b] [-p | -s string | file ...]
     md5 -G [file ...]
     md5 -t | -x | -c [checklist ...]
     md5sum [-b | -t] [file ...]

DESCRIPTION

     md5 takes as input a message of arbitrary length and produces as output a
     128-bit "fingerprint" or "message digest" of the input. It was conjec-
     tured that it would be computationally infeasible to produce two messages
     having the same message digest (a collision), or to produce any message
     having a given prespecified target message digest. However, collisions
     have now been produced for MD5, so the use of other message digest func-
     tions is now preferred.

     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.

     The options are as follows:

     -b      Print the checksum as binary to stdout. Ignored in GNU mode.

     -c [checklist ...]
             Compares all checksums contained in the file checklist with newly
             computed checksums for the corresponding files. Output consists
             of the digest used, the file name, and an OK or FAILED for the
             result of the comparison. This will validate any of the supported
             checksums (see cksum(1)). If no file is given, stdin is used.

     -G      Enable GNU md5sum compatible output mode. Can also be enabled by
             calling this program as md5sum.

     -p      Echoes stdin to stdout and appends the MD5 sum to stdout.

     -s string
             Prints a checksum of the given string.

     -t      Runs a built-in time trial. Ignored in GNU mode.

     -x      Runs a built-in test script.

     The MD5 sum of each file listed on the command line is printed after the
     options are processed.

SEE ALSO

     cksum(1), rmd160(1), sha1(1)

     R. Rivest, The MD5 Message-Digest Algorithm, RFC 1321.

BUGS

     Since collisions have been found for MD5, the use of rmd160(1) or sha1(1)
     is recommended instead.

MirBSD #10-current            September 4, 2020                              1