Manual: openssl-mac

OPENSSL-MAC(1SSL)					   OpenSSL					   OPENSSL-MAC(1SSL)

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] [-provparam [name:]key=value] [-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 and standard input are expected to be in binary 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 should be a CBC mode cipher e.g. AES-128-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
       -provparam [name:]key=value
       -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 2018-2024 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
       .

3.5.5							 2026-01-27					   OPENSSL-MAC(1SSL)