> ## Documentation Index
> Fetch the complete documentation index at: https://support.fortanix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Compute a message authentication code (HMAC or CMAC). The key being used
should have the `MACGENERATE` key operation.

> A key of type `HMAC` needs to be used for computing an HMAC, and the hash
algorithm should be present in the request.

AES, ARIA, DES3, and SEED keys can be used for computing a CMAC. No hash
algorithm should be specified for CMAC computation.
The digest algorithm shouldn't be specified in case of CMAC.

## OpenAPI

````json POST /crypto/v1/mac
{
  "openapi": "3.0.0",
  "info": {
    "title": "Fortanix DSM REST API",
    "description": "This is a set of REST APIs for accessing the Fortanix Data Security Manager. This includes APIs for managing accounts, and for performing cryptographic and key management operations. \n\n **Note:** \n- All binary input should be base64-encoded. These fields are marked with `format: byte`. \n- For forward compatibility, any API client is expected to ignore any fields in the response not explicitly mentioned in the documentation. We reserve the right to add new fields at any time to provide new functionality without affecting existing API clients.",
    "termsOfService": "https://www.fortanix.com/legal/terms/",
    "contact": {
      "name": "Fortanix Support",
      "url": "https://support.fortanix.com/",
      "email": "support@fortanix.com"
    },
    "license": {
      "name": "Apache 2.0",
      "url": "http://www.apache.org/licenses/LICENSE-2.0.html"
    },
    "version": "0.1.0-20260526"
  },
  "servers": [
    {
      "url": "https://amer.smartkey.io"
    }
  ],
  "paths": {
    "/crypto/v1/mac": {
      "post": {
        "operationId": "Mac",
        "tags": [
          "Crypto"
        ],
        "security": [
          {
            "bearerToken": []
          },
          {
            "apiKeyAuth": []
          }
        ],
        "summary": "Compute a message authentication code (HMAC or CMAC). The key being used\nshould have the `MACGENERATE` key operation.",
        "description": "A key of type `HMAC` needs to be used for computing an HMAC, and the hash\nalgorithm should be present in the request.\n\nAES, ARIA, DES3, and SEED keys can be used for computing a CMAC. No hash\nalgorithm should be specified for CMAC computation.\nThe digest algorithm shouldn't be specified in case of CMAC.",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/MacRequest"
              }
            }
          }
        },
        "responses": {
          "2XX": {
            "description": "Success result",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/MacResponse"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MacRequest": {
        "allOf": [
          {
            "type": "object",
            "description": "Request to compute a MAC.",
            "properties": {
              "key": {
                "$ref": "#/components/schemas/SobjectDescriptor"
              },
              "alg": {
                "$ref": "#/components/schemas/DigestAlgorithm"
              },
              "data": {
                "type": "string",
                "format": "byte",
                "description": "The data for which to generate a MAC"
              }
            },
            "required": [
              "data"
            ]
          }
        ]
      },
      "MacResponse": {
        "allOf": [
          {
            "type": "object",
            "description": "Response of a MAC computation request.",
            "properties": {
              "kid": {
                "type": "string",
                "format": "uuid",
                "nullable": true,
                "description": "The ID of the key used to compute the MAC. Returned for\nnon-transient keys"
              },
              "mac": {
                "type": "string",
                "format": "byte",
                "description": "MAC generated for the input data"
              }
            },
            "required": [
              "mac"
            ]
          }
        ]
      },
      "SobjectDescriptor": {
        "description": "Uniquely identifies a persisted or transient sobject.",
        "oneOf": [
          {
            "title": "SobjectDescriptorVariantKid",
            "type": "object",
            "properties": {
              "kid": {
                "type": "string",
                "format": "uuid"
              }
            },
            "required": [
              "kid"
            ]
          },
          {
            "title": "SobjectDescriptorVariantName",
            "type": "object",
            "properties": {
              "name": {
                "type": "string",
                "maxLength": 4096,
                "pattern": "^[^\\n]*[^\\s\\n][^\\n]*$"
              }
            },
            "required": [
              "name"
            ]
          },
          {
            "title": "SobjectDescriptorVariantTransientKey",
            "type": "object",
            "properties": {
              "transient_key": {
                "type": "string",
                "format": "byte"
              }
            },
            "required": [
              "transient_key"
            ]
          },
          {
            "title": "SobjectDescriptorVariantInline",
            "type": "object",
            "properties": {
              "inline": {
                "$ref": "#/components/schemas/SobjectDescriptorInline"
              }
            },
            "required": [
              "inline"
            ]
          }
        ]
      },
      "DigestAlgorithm": {
        "description": "A hash algorithm.",
        "type": "string",
        "enum": [
          "BLAKE2B256",
          "BLAKE2B384",
          "BLAKE2B512",
          "BLAKE2S256",
          "RIPEMD160",
          "SSL3",
          "SHA1",
          "SHA224",
          "SHA256",
          "SHA384",
          "SHA512",
          "STREEBOG256",
          "STREEBOG512",
          "SHA3_224",
          "SHA3_256",
          "SHA3_384",
          "SHA3_512"
        ]
      },
      "SobjectDescriptorInline": {
        "allOf": [
          {
            "type": "object",
            "properties": {
              "value": {
                "type": "string",
                "format": "byte"
              },
              "obj_type": {
                "$ref": "#/components/schemas/ObjectType"
              }
            },
            "required": [
              "value",
              "obj_type"
            ]
          }
        ]
      },
      "ObjectType": {
        "description": "Type of security object.",
        "type": "string",
        "enum": [
          "AES",
          "ARIA",
          "DES",
          "DES3",
          "SEED",
          "RSA",
          "DSA",
          "EC",
          "KCDSA",
          "ECKCDSA",
          "BIP32",
          "SLIP10",
          "BLS",
          "OPAQUE",
          "HMAC",
          "LEDABETA",
          "ROUND5BETA",
          "SECRET",
          "LMS",
          "XMSS",
          "MLDSA",
          "MLDSABETA",
          "MLKEM",
          "MLKEMBETA",
          "CERTIFICATE",
          "PBE"
        ]
      }
    }
  }
}
````