---
title: "Subject directory attributes (SDA)"
source_url: https://dev.digicert.com/iot-trust-manager-api/tutorials/subject-directory-attributes-sda.html
---

When requesting a certificate using DigiCert® IoT Trust Manager, you can use the subject directory attributes (SDA) certificate extension to store information supplemental to the certificate’s standard fields and extensions. To use the SDA extension, create a JSON-formatted object describing the attributes and information you want to store. You must include this JSON object as part of your certificate request.


> **Info**
>
> To store data in the SDA extension, you must request a certificate using an enrollment profile that supports subject directory attributes. This enrollment profile must use a certificate profile created with a template that includes the subject directory field. To get a certificate template that supports the SDA extension, contact your DigiCert ONE account representative.


## SDA JSON object

The SDA JSON object contains a sequence of elements, where each element describes a non-standard attribute you want to add to the certificate. There is no limit to the number of elements this sequence can contain.

- Each element in the top-level sequence contains another sequence of objects.
- The first element in each sub-sequence describes the object identifier (OID) of a supplemental attribute.
- The elements following the OID describe the SDA data structure and the information you want it to contain.

Each element in the SDA JSON object requires these two fields:

- `type`: Data type of the content in the corresponding `value` field.
  **Allowed values:** See the [SDA data types](#section-idm33286818036460) table below. Each `type` corresponds with an ASN.1 type under the DER serialization format. Case-sensitive.
- `value`: Value of the element. Must match the defined `type` for the element.

## Examples

The structure of the SDA JSON object is the same for both REST API and UI console requests.

- **REST API**: Submit the JSON data in the `certificate_profile_attributes` section of the [Request certificate payload](https://one.digicert.com/iot/api-docs/index.html#/Certificates/requestCertificate).
  - The `id` is `extensions.subject_directory`.
  - The `value` is the SDA data, formatted as a JSON string.
- **UI console**: Submit the JSON object in the **Subject directory** field of the certificate request form.

**REST API requests**

```json
{
  "certificate_profile_attributes": [
    ...
    {
      "id": "extensions.subject_directory",
      "value": "{\"type\": \"SEQUENCE\", \"value\": [{\"type\": \"SEQUENCE\", \"value\": [{\"type\": \"OBJECT_IDENTIFIER\", \"value\": \"1.3.6.1.4.1.51552.9.1\"}, {\"type\": \"SET\", \"value\": [{\"type\": \"INTEGER\", \"value\": \"614\"},{\"type\": \"INTEGER\", \"value\": \"202\"}]}]}]}"
    }
   ...
  ],
...
}
```

**UI console requests**

```
{
  "type": "SEQUENCE",
  "value": [
    {
      "type": "SEQUENCE",
      "value": [
        {
          "type": "OBJECT_IDENTIFIER",
          "value": "1.3.6.1.4.1.51552.9.1"
        },
        {
          "type": "SET",
          "value": [
            {
              "type": "INTEGER",
              "value": "202"
            }
          ]
        }
      ]
    }, {
      "type": "SEQUENCE",
      "value": [
        {
          "type": "OBJECT_IDENTIFIER",
          "value": "1.3.6.1.4.1.51552.92.5"
        },
        {
          "type": "BOOLEAN",
          "value": true
        }, 
        {
          "type": "STRING",
          "value": "Example string"
        }
      ]
    }
  ]
}
```


## Properties

| Name | Type | Req/Opt | Description |
| --- | --- | --- | --- |
| type | string | required | Data type of the content in the corresponding `value` field.<br>**Note:** The `type` value for the top-level object should be `SEQUENCE` (case-sensitive). |
| value | array | required | Ordered list of objects. Each object contains a sequence with details about a specific attribute. Include as many elements as needed. |
| .. type | string | required | Data type of the content in the `value` field.<br>**Note:** The `type` value for each element in the top-level sequence should also be `SEQUENCE` (case sensitive). |
| .. value | array | required | Ordered list of objects that describe the SDA data structure and information to store for the attribute. |
| .. .. type | string | required | Data type of the content in the corresponding `value` field.<br>**Allowed values:** See the [SDA data types](#section-idm33286818036460) table below. Each allowed value corresponds with an ASN.1 type under the DER serialization format. Case-sensitive. |
| .. .. value | Set by `type` value | required | Value to store in the SDA. |
{.params-table}

## SDA data types

| Type | ASN.1 Type | Description |
| --- | --- | --- |
| SEQUENCE | DERSequence | Ordered collection of one or more elements. |
| SET | DERSet | Unordered collection of one or more elements. |
| OBJECT_IDENTIFIER | DERObjectIdentifier | String of positive integers, separated by dots, that identifies an object. |
| STRING | DERUTF8String | UTF-8 encoded string. |
| INTEGER | DERInteger | Positive or negative integer. |
| BOOLEAN | DERBoolean | Boolean value (`true` or `false`). |