redhat man page for dgst

DGST(1) 							      OpenSSL								   DGST(1)

NAME
       dgst, md5, md4, md2, sha1, sha, mdc2, ripemd160 - message digests

SYNOPSIS
       openssl dgst [-md5|-md4|-md2|-sha1|-sha|-mdc2|-ripemd160|-dss1] [-c] [-d] [-hex] [-binary] [-out filename] [-sign filename] [-verify file-
       name] [-prverify filename] [-signature filename] [file...]

       [md5|md4|md2|sha1|sha|mdc2|ripemd160] [-c] [-d] [file...]

DESCRIPTION
       The digest functions output the message digest of a supplied file or files in hexadecimal form. They can also be used for digital signing
       and verification.

OPTIONS
       -c  print out the digest in two digit groups separated by colons, only relevant if hex format output is used.

       -d  print out BIO debugging information.

       -hex
	   digest is to be output as a hex dump. This is the default case for a "normal" digest as opposed to a digital signature.

       -binary
	   output the digest or signature in binary form.

       -out filename
	   filename to output to, or standard output by default.

       -sign filename
	   digitally sign the digest using the private key in "filename".

       -verify filename
	   verify the signature using the the public key in "filename".  The output is either "Verification OK" or "Verification Failure".

       -prverify filename
	   verify the signature using the  the private key in "filename".

       -signature filename
	   the actual signature to verify.

       -rand file(s)
	   a file or files containing random data used to seed the random number generator, or an EGD socket (see RAND_egd(3)).  Multiple files
	   can be specified separated by a OS-dependent character.  The separator is ; for MS-Windows, , for OpenVMS, and : for all others.

       file...
	   file or files to digest. If no files are specified then standard input is used.

NOTES
       The digest of choice for all new applications is SHA1. Other digests are however still widely used.

       If you wish to sign or verify data using the DSA algorithm then the dss1 digest must be used.

       A source of random numbers is required for certain signing algorithms, in particular DSA.

       The signing and verify options should only be used if a single file is being signed or verified.

0.9.7a								    2000-09-04								   DGST(1)