SHA1(1)                    OpenBSD Reference Manual                    SHA1(1)

NAME
     sha1 - calculate a message-digest fingerprint (checksum) for a file



SYNOPSIS
     sha1 [-ptx] [-s string] [file ...]

DESCRIPTION
     sha1 takes as input a message of arbitrary length and produces as output
     a 160-bit "fingerprint" or "message digest" of the input.  It is conjec-
     tured that it is computationally infeasible to produce two messages hav-
     ing the same message digest, or to produce any message having a given
     prespecified target message digest.  The SHA-1 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 un-
     der a public-key cryptosystem such as RSA.

OPTIONS
     The following four options may be used in any combination and must pre-
     cede any files named on the command line.  The SHA-1 sum of each file
     listed on the command line is printed after the options are processed.

     -s string   Prints a checksum of the given string.

     -p          Echos stdin to stdout and appends the SHA-1 sum to stdout.

     -t          Runs a built-in time trial.

     -x          Runs a built-in test script.

SEE ALSO
     cksum(1),  md5(1),  rmd160(1)

     NIST FIPS PUB 180-1 describes the SHA-1 message-digest algorithm in de-
     tail.

ACKNOWLEDGEMENTS
     This program is placed in the public domain for free general use by RSA
     Data Security.

OpenBSD 2.6                      July 12, 1997                               1