SHA1(1)                 System General Commands Manual                 SHA1(1)

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

SYNOPSIS
     sha1 [-p | -t | -x | -c [checklist ...] | -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 under a public-key cryptosystem
     such as RSA.

     The options are as follows:

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

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

     -s string
             Prints a checksum of the given string.

     -t      Runs a built-in time trial.

     -x      Runs a built-in test script.

     The SHA-1 sum of each file listed on the command line is printed after
     the options are processed.

     The sha1 command is shorthand for

           cksum -a sha1

     The cksum(1) command can also be used to compute digests from the SHA-2
     family: sha256, sha384 and sha512.

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

     J. Burrows, The Secure Hash Standard, FIPS PUB 180-1.

     D. Eastlake and P. Jones, US Secure Hash Algorithm 1, RFC 3174.

Interix                          June 12, 2006                         Interix