# man > openssl-mac(1) [_OPENSSL-MAC_(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-MAC/1SSL/markdown) OpenSSL [_OPENSSL-MAC_(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-MAC/1SSL/markdown) ## 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 _ 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 to output to, or standard output by default. ### -binary Output the MAC in binary form. Uses hexadecimal text format if not specified. ### -cipher _ 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 _ 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 _ 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 _ ### -provider-path _ ### -propquery _ See "Provider Options" in [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**provider**(7)](https://www.chedong.com/phpMan.php/man/provider/7/markdown), and [**property**(7)](https://www.chedong.com/phpMan.php/man/property/7/markdown). _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)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**EVP_MAC**(3)](https://www.chedong.com/phpMan.php/man/EVPMAC/3/markdown), [**EVP_MAC-CMAC**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-CMAC/7/markdown), [**EVP_MAC-GMAC**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-GMAC/7/markdown), [**EVP_MAC-HMAC**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-HMAC/7/markdown), [**EVP_MAC-KMAC**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-KMAC/7/markdown), [**EVP_MAC-Siphash**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-Siphash/7/markdown), [**EVP_MAC-Poly1305**(7)](https://www.chedong.com/phpMan.php/man/EVPMAC-Poly1305/7/markdown) ## COPYRIGHT Copyright 2018-2022 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 <>. 3.0.13 2026-07-29 [_OPENSSL-MAC_(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-MAC/1SSL/markdown)