NAME

       openssl-mac - perform Message Authentication Code operations

SYNOPSIS

       openssl mac [-help] [-cipher] [-digest] [-macopt] [-in filename] [-out filename] [-binary] [-provider
       name] [-provider-path path] [-propquery propq] mac_name

DESCRIPTION

       The message authentication code functions output the MAC of a supplied input file.

OPTIONS

       -help
           Print a usage message.

       -in filename
           Input  filename  to calculate a MAC for, or standard input by default.  Standard input is used if the
           filename is '-'.  Files are expected to be in binary format, standard  input  uses  hexadecimal  text
           format.

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

       -binary
           Output the MAC in binary form. Uses hexadecimal text format if not specified.

       -cipher name
           Used  by  CMAC  and  GMAC  to  specify the cipher algorithm.  For CMAC it must be one of AES-128-CBC,
           AES-192-CBC, AES-256-CBC or DES-EDE3-CBC.  For GMAC it should be a GCM mode cipher e.g. AES-128-GCM.

       -digest name
           Used by HMAC as an alphanumeric string (use if the key  contains  printable  characters  only).   The
           string  length  must  conform to any restrictions of the MAC algorithm.  To see the list of supported
           digests, use "openssl list -digest-commands".

       -macopt nm:v
           Passes options to the MAC algorithm.  A comprehensive list of controls can be found  in  the  EVP_MAC
           implementation documentation.  Common parameter names used by EVP_MAC_CTX_get_params() are:

           key:string
               Specifies  the  MAC  key  as an alphanumeric string (use if the key contains printable characters
               only).  The string length must conform to any restrictions of the MAC algorithm.  A key  must  be
               specified for every MAC algorithm.

           hexkey:string
               Specifies the MAC key in hexadecimal form (two hex digits per byte).  The key length must conform
               to any restrictions of the MAC algorithm.  A key must be specified for every MAC algorithm.

           iv:string
               Used  by  GMAC  to  specify  an  IV  as  an alphanumeric string (use if the IV contains printable
               characters only).

           hexiv:string
               Used by GMAC to specify an IV in hexadecimal form (two hex digits per byte).

           size:int
               Used by KMAC128 or KMAC256 to specify an output length.  The default sizes are  32  or  64  bytes
               respectively.

           custom:string
               Used  by  KMAC128  or KMAC256 to specify a customization string.  The default is the empty string
               "".

           digest:string
               This option is identical to the -digest option.

           cipher:string
               This option is identical to the -cipher option.

       -provider name
       -provider-path path
       -propquery propq
           See "Provider Options" in openssl(1), provider(7), and property(7).

       mac_name
           Specifies the name of a supported MAC algorithm which will be used.  To see  the  list  of  supported
           MAC's use the command "openssl list -mac-algorithms".

EXAMPLES

       To create a hex-encoded HMAC-SHA1 MAC of a file and write to stdout: \
        openssl mac -digest SHA1 \
                -macopt hexkey:000102030405060708090A0B0C0D0E0F10111213 \
                -in msg.bin HMAC

       To create a SipHash MAC from a file with a binary file output: \
        openssl mac -macopt hexkey:000102030405060708090A0B0C0D0E0F \
                -in msg.bin -out out.bin -binary SipHash

       To create a hex-encoded CMAC-AES-128-CBC MAC from a file:\
        openssl mac -cipher AES-128-CBC \
                -macopt hexkey:77A77FAF290C1FA30C683DF16BA7A77B \
                -in msg.bin CMAC

       To  create  a  hex-encoded KMAC128 MAC from a file with a Customisation String 'Tag' and output length of
       16: \
        openssl mac -macopt custom:Tag -macopt hexkey:40414243444546 \
                -macopt size:16 -in msg.bin KMAC128

       To create a hex-encoded GMAC-AES-128-GCM with a IV from a file: \
        openssl mac -cipher AES-128-GCM -macopt hexiv:E0E00F19FED7BA0136A797F3 \
                -macopt hexkey:77A77FAF290C1FA30C683DF16BA7A77B -in msg.bin GMAC

NOTES

       The MAC mechanisms that are available will depend  on  the  options  used  when  building  OpenSSL.   Use
       "openssl list -mac-algorithms" to list them.

SEE ALSO

       openssl(1),    EVP_MAC(3),    EVP_MAC-CMAC(7),    EVP_MAC-GMAC(7),    EVP_MAC-HMAC(7),   EVP_MAC-KMAC(7),
       EVP_MAC-Siphash(7), EVP_MAC-Poly1305(7)

COPYRIGHT

       Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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>.

3.0.2                                              2025-02-05                                  OPENSSL-MAC(1SSL)