{
    "mode": "man",
    "parameter": "EVP_MAC-BLAKE2BMAC",
    "section": "7ssl",
    "url": "https://www.chedong.com/phpMan.php/man/EVP_MAC-BLAKE2BMAC/7ssl/json",
    "generated": "2026-10-04T14:57:21Z",
    "sections": {
        "NAME": {
            "content": "EVPMAC-BLAKE2, EVPMAC-BLAKE2BMAC, EVPMAC-BLAKE2SMAC - The BLAKE2 EVPMAC implementations\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "Support for computing BLAKE2 MACs through the EVPMAC API.\n",
            "subsections": [
                {
                    "name": "Identity",
                    "content": "These implementations are identified with one of these names and properties, to be used with\nEVPMACfetch():\n\n\"BLAKE2BMAC\", \"provider=default\"\n\"BLAKE2SMAC\", \"provider=default\"\n"
                },
                {
                    "name": "Supported parameters",
                    "content": "The general description of these parameters can be found in \"PARAMETERS\" in EVPMAC(3).\n\nAll  these  parameters  (except  for  \"block-size\") can be set with EVPMACCTXsetparams().\nFurthermore, the \"size\" parameter can be retrieved  with  EVPMACCTXgetparams(),  or  with\nEVPMACCTXgetmacsize().   The  length of the \"size\" parameter should not exceed that of a\nsizet.  Likewise, the \"block-size\" parameter can be retrieved with EVPMACCTXgetparams(),\nor with EVPMACCTXgetblocksize().\n\n\"key\" (OSSLMACPARAMKEY) <octet string>\nSets the MAC key.  It may be at most 64 bytes for BLAKE2BMAC or 32 for BLAKE2SMAC and  at\nleast  1  byte  in  both  cases.  Setting this parameter is identical to passing a key to\nEVPMACinit(3).\n\n\"custom\" (OSSLMACPARAMCUSTOM) <octet string>\nSets the customization/personalization string.  It is an optional value  of  at  most  16\nbytes for BLAKE2BMAC or 8 for BLAKE2SMAC, and is empty by default.\n\n\"salt\" (OSSLMACPARAMSALT) <octet string>\nSets  the  salt.   It  is  an  optional value of at most 16 bytes for BLAKE2BMAC or 8 for\nBLAKE2SMAC, and is empty by default.\n\n\"size\" (OSSLMACPARAMSIZE) <unsigned integer>\nSets the MAC size.  It can be any number between 1 and 32 for EVPMACBLAKE2S or  between\n1 and 64 for EVPMACBLAKE2B.  It is 32 and 64 respectively by default.\n\n\"block-size\" (OSSLMACPARAMBLOCKSIZE) <unsigned integer>\nGets the MAC block size.  It is 64 for EVPMACBLAKE2S and 128 for EVPMACBLAKE2B.\n"
                }
            ]
        },
        "SEE ALSO": {
            "content": "EVPMACCTXgetparams(3),    EVPMACCTXsetparams(3),    \"PARAMETERS\"    in    EVPMAC(3),\nOSSLPARAM(3)\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "The macros and functions described here were added to OpenSSL 3.0.\n",
            "subsections": []
        },
        "COPYRIGHT": {
            "content": "Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.\n\nLicensed under the Apache License 2.0 (the \"License\").  You may not use this file  except  in\ncompliance  with  the  License.   You  can  obtain  a  copy in the file LICENSE in the source\ndistribution or at <https://www.openssl.org/source/license.html>.\n\n3.0.13                                       2026-07-29                         EVPMAC-BLAKE2(7SSL)",
            "subsections": []
        }
    },
    "summary": "EVPMAC-BLAKE2, EVPMAC-BLAKE2BMAC, EVPMAC-BLAKE2SMAC - The BLAKE2 EVPMAC implementations",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "EVPMACCTXgetparams",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/EVPMACCTXgetparams/3/json"
        },
        {
            "name": "EVPMACCTXsetparams",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/EVPMACCTXsetparams/3/json"
        },
        {
            "name": "EVPMAC",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/EVPMAC/3/json"
        },
        {
            "name": "OSSLPARAM",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/OSSLPARAM/3/json"
        }
    ]
}