openssl-dgst

DGST(1SSL)                          OpenSSL                         DGST(1SSL)

NAME
       openssl-dgst, dgst - perform digest operations

SYNOPSIS
       openssl dgst [-digest] [-help] [-c] [-d] [-list] [-hex] [-binary] [-r]
       [-out filename] [-sign filename] [-keyform arg] [-passin arg] [-verify
       filename] [-prverify filename] [-signature filename] [-sigopt nm:v]
       [-hmac key] [-fips-fingerprint] [-rand file...]  [-engine id]
       [-engine_impl] [file...]

       openssl digest [...]

DESCRIPTION
       The digest functions output the message digest of a supplied file or
       files in hexadecimal.  The digest functions also generate and verify
       digital signatures using message digests.

       The generic name, dgst, may be used with an option specifying the
       algorithm to be used.  The default digest is sha256.  A supported
       digest name may also be used as the command name.  To see the list of
       supported algorithms, use the list --digest-commands command.

OPTIONS
       -help
           Print out a usage message.

       -digest
           Specifies name of a supported digest to be used. To see the list of
           supported digests, use the command list --digest-commands.

       -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.

       -list
           Prints out a list of supported message digests.

       -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.  See NOTES
           below for digital signatures using -hex.

       -binary
           Output the digest or signature in binary form.

       -r  Output the digest in the "coreutils" format, including newlines.
           Used by programs like sha1sum.

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

       -sign filename
           Digitally sign the digest using the private key in "filename". Note
           this option does not support Ed25519 or Ed448 private keys. Use the
           pkeyutl command instead for this.

       -keyform arg
           Specifies the key format to sign digest with. The DER, PEM, P12,
           and ENGINE formats are supported.

       -sigopt nm:v
           Pass options to the signature algorithm during sign or verify
           operations.  Names and values of these options are algorithm-
           specific.

       -passin arg
           The private key password source. For more information about the
           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).

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

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

       -signature filename
           The actual signature to verify.

       -hmac key
           Create a hashed MAC using "key".

       -mac alg
           Create MAC (keyed Message Authentication Code). The most popular
           MAC algorithm is HMAC (hash-based MAC), but there are other MAC
           algorithms which are not based on hash, for instance gost-mac
           algorithm, supported by ccgost engine. MAC keys and other options
           should be set via -macopt parameter.

       -macopt nm:v
           Passes options to MAC algorithm, specified by -mac key.  Following
           options are supported by both by HMAC and gost-mac:

           key:string
               Specifies MAC key as alphanumeric string (use if key contain
               printable characters only). String length must conform to any
               restrictions of the MAC algorithm for example exactly 32 chars
               for gost-mac.

           hexkey:string
               Specifies MAC key in hexadecimal form (two hex digits per
               byte).  Key length must conform to any restrictions of the MAC
               algorithm for example exactly 32 chars for gost-mac.

       -rand file...
           A file or files containing random data used to seed the random
           number generator.  Multiple files can be specified separated by an
           OS-dependent character.  The separator is ; for MS-Windows, , for
           OpenVMS, and : for all others.

       [-writerand file]
           Writes random data to the specified file upon exit.  This can be
           used with a subsequent -rand flag.

       -fips-fingerprint
           Compute HMAC using a specific key for certain OpenSSL-FIPS
           operations.

       -engine id
           Use engine id for operations (including private key storage).  This
           engine is not used as source for digest algorithms, unless it is
           also specified in the configuration file or -engine_impl is also
           specified.

       -engine_impl
           When used with the -engine option, it specifies to also use engine
           id for digest operations.

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

EXAMPLES
       To create a hex-encoded message digest of a file:
        openssl dgst -md5 -hex file.txt

       To sign a file using SHA-256 with binary file output:
        openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt

       To verify a signature:
        openssl dgst -sha256 -verify publickey.pem \
        -signature signature.sign \
        file.txt

NOTES
       The digest mechanisms that are available will depend on the options
       used when building OpenSSL.  The list digest-commands command can be
       used to list them.

       New or agile applications should use probably use SHA-256. Other
       digests, particularly SHA-1 and MD5, are still widely used for
       interoperating with existing formats and protocols.

       When signing a file, dgst will automatically determine the algorithm
       (RSA, ECC, etc) to use for signing based on the private key's ASN.1
       info.  When verifying signatures, it only handles the RSA, DSA, or
       ECDSA signature itself, not the related data to identify the signer and
       algorithm used in formats such as x.509, CMS, and S/MIME.

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

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

       Hex signatures cannot be verified using openssl.  Instead, use "xxd -r"
       or similar program to transform the hex signature into a binary
       signature prior to verification.

HISTORY
       The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
       The FIPS-related options were removed in OpenSSL 1.1.0.

COPYRIGHT
       Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

1.1.1f                            2023-10-10                        DGST(1SSL)