RMD160(1)                  OpenBSD Reference Manual                  RMD160(1)

NAME
     rmd160 - calculate a message-digest fingerprint (checksum) for a file

SYNOPSIS
     rmd160 [-bpqrtx] [-c [checklist ...]] [-s string] [file ...]

DESCRIPTION
     rmd160 takes as input a message of arbitrary length and produces as out-
     put a 160-bit "fingerprint" or "message digest" of the input.  It is con-
     jectured 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 RMD-160 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      Output checksums in base64 notation, not hexadecimal.

     -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 support-
             ed checksums (see cksum(1)).  If no file is given, stdin is used.

     -p      Echoes stdin to stdout and appends the RMD-160 sum to stdout.

     -q      Only print the checksum (quiet mode).

     -r      Reverse the format of the hash algorithm output, making it match
             the output format used by cksum(1).

     -s string
             Prints a checksum of the given string.

     -t      Runs a built-in time trial.  Specifying -t multiple times results
             in the number of rounds being multiplied by 10 for each addition-
             al flag.

     -x      Runs a built-in test script.

     The RMD-160 sum of each file listed on the command line is printed after
     the options are processed.

     The rmd160 utility exits 0 on success, and >0 if an error occurs.

SEE ALSO
     cksum(1), md5(1), sha1(1)

     RMD-160 is part of the ISO draft standard "ISO/IEC DIS 10118-3" on dedi-
     cated hash functions.

OpenBSD 4.7                      May 31, 2007                                1
