» Active Directory Secrets Engine (API)

This is the API documentation for the Vault AD secrets engine. For general information about the usage and operation of the AD secrets engine, please see the Vault Active Directory documentation.

This documentation assumes the AD secrets engine is enabled at the /ad path in Vault. Since it is possible to enable secrets engines at any location, please update your API calls accordingly.

» Configuration

The config endpoint configures the LDAP connection and binding parameters, as well as the password rotation configuration.

» Password parameters

  • ttl (string, optional) - The default password time-to-live in seconds. Once the ttl has passed, a password will be rotated the next time it's requested.
  • max_ttl (string, optional) - The maximum password time-to-live in seconds. No role will be allowed to set a custom ttl greater than the max_ttl.
  • length (string, optional) - The desired password length. Defaults to 64. Minimum is 14.
  • formatter (string, optional) - Text into which the base64 password should be inserted, formatted like so: mycustom{{PASSWORD}}.

To meet Microsoft's password complexity requirements, all passwords begin with "?@09AZ" unless a formatter is provided. The formatter is for organizations with different, custom password requirements. It allows an organization to supply text that fulfills those requirements. {{PASSWORD}} must appear exactly once and can be anywhere in the text.

» Connection parameters

  • url (string, required) - The LDAP server to connect to. Examples: ldaps://ldap.myorg.com, ldaps://ldap.myorg.com:636. This can also be a comma-delineated list of URLs, e.g. ldaps://ldap.myorg.com,ldaps://ldap.myorg.com:636, in which case the servers will be tried in-order if there are errors during the connection process.
  • starttls (bool, optional) - If true, issues a StartTLS command after establishing an unencrypted connection.
  • insecure_tls - (bool, optional) - If true, skips LDAP server SSL certificate verification - insecure, use with caution!
  • certificate - (string, optional) - CA certificate to use when verifying LDAP server certificate, must be x509 PEM encoded.

» Binding parameters

  • binddn (string, required) - Distinguished name of object to bind when performing user and group search. Example: cn=vault,ou=Users,dc=example,dc=com
  • bindpass (string, required) - Password to use along with binddn when performing user search.
  • userdn (string, optional) - Base DN under which to perform user search. Example: ou=Users,dc=example,dc=com
  • upndomain (string, optional) - userPrincipalDomain used to construct the UPN string for the authenticating user. The constructed UPN will appear as [username]@UPNDomain. Example: example.com, which will cause vault to bind as username@example.com.

» Other parameters

  • last_rotation_tolerance (string, optional) - Tolerance duration to use when checking the last rotation time. Active Directory often shows a "pwdLastSet" time after Vault's because it takes a while for password updates to be propagated across a large cluster. By default, if Active Directory's last rotation time is within 5 seconds of Vault's, Vault considers itself to have been the last entity that rotated the password. However, if it's been more than 5 seconds, Vault thinks that something rotated the password out-of-band, and re-rotates it so it will "know" it and be able to continue returning it. This may be too low for larger Active Directory clusters, and too high for smaller ones.

» Config management

At present, this endpoint does not confirm that the provided AD credentials are valid AD credentials with proper permissions.

Method Path
POST /ad/config
GET /ad/config
DELETE /ad/config

» Sample Post Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request POST \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/config

» Sample Post Payload

{
  "binddn": "domain-admin",
  "bindpass": "pa$$w0rd",
  "url": "ldaps://127.0.0.11",
  "userdn": "dc=example,dc=com"
}

» Sample Get Response Data

{
  "binddn": "domain-admin",
  "certificate": "",
  "insecure_tls": false,
  "length": 64,
  "max_ttl": 2764800,
  "starttls": false,
  "tls_max_version": "tls12",
  "tls_min_version": "tls12",
  "ttl": 2764800,
  "upndomain": "",
  "url": "ldaps://127.0.0.11",
  "userdn": "dc=example,dc=com"
}

» Role management

The roles endpoint configures how Vault will manage the passwords for individual service accounts.

» Parameters

  • service_account_name (string, required) - The name of a pre-existing service account in Active Directory that maps to this role.
  • ttl (string, optional) - The password time-to-live in seconds. Defaults to the configuration ttl if not provided.

When adding a role, Vault verifies its associated service account exists.

Method Path
GET /ad/roles
POST /ad/roles/:role_name
GET /ad/roles/:role_name
DELETE /ad/roles/:role_name

» Sample Post Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request POST \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/roles/my-application

» Sample Post Payload

{
  "service_account_name": "my-application@example.com",
  "ttl": 100
}

» Sample Get Role Response

{
  "last_vault_rotation": "2018-05-24T17:14:38.677370855Z",
  "password_last_set": "2018-05-24T17:14:38.6038495Z",
  "service_account_name": "my-application@example.com",
  "ttl": 100
}

» Sample List Roles Response

Performing a LIST on the /ad/roles endpoint will list the names of all the roles Vault contains.

[
  "my-application"
]

» Retrieving passwords

The creds endpoint offers the credential information for a given role.

Method Path
GET /ad/creds/:role_name

» Sample Get Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request GET \
    http://127.0.0.1:8200/v1/ad/creds/my-application

» Sample Get Response

{
  "current_password": "?@09AZnh4Q5N4O5zdLk/4F8aIMgsnpDM6tSQEZCge3Mz1wXcZEgZhOa6OR748F96",
  "last_password": "?@09AZSen9TzUwK7ZhafS7B0GuWGraQjfWEna5SwnmF/tVaKFqjXhhGV/Z0v/pBJ",
  "username": "my-application"
}

» Library management

The library endpoint configures the sets of service accounts that Vault will offer for check-out.

» Parameters

  • name (string: "", required): The name of the set of service accounts.
  • service_account_names (string: "", or list: [] required): The names of all the service accounts that can be checked out from this set. These service accounts must only be used by Vault, and may only be in one set. These service accounts must already exist in Active Directory.
  • ttl (duration: "24h", optional): The maximum amount of time a single check-out lasts before Vault automatically checks it back in. Defaults to 24 hours. Setting it to zero reflects an unlimited lending period.
  • max_ttl (duration: "24h", optional): The maximum amount of time a check-out last with renewal before Vault automatically checks it back in. Defaults to 24 hours. Setting it to zero reflects an unlimited lending period.
  • disable_check_in_enforcement (bool: false, optional): Disable enforcing that service accounts must be checked in by the entity or client token that checked them out. Defaults to false.

When adding a service account to the library, Vault verifies it already exists in Active Directory.

Method Path
LIST /ad/library
POST /ad/library/:set_name
GET /ad/library/:set_name
DELETE /ad/library/:set_name

» Sample Post Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request POST \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/library/accounting-team

» Sample Post Payload

{
  "service_account_names": ["fizz@example.com", "buzz@example.com"],
  "ttl": "10h",
  "max_ttl": "20h",
  "disable_check_in_enforcement": false
}

» Sample Get Response

{
  "service_account_names": ["fizz@example.com", "buzz@example.com"],
  "ttl": "10h",
  "max_ttl": "20h",
  "disable_check_in_enforcement": false
}

» Sample List Response

Performing a LIST on the /ad/library endpoint will list the names of all the sets of service accounts Vault contains.

[
  "accounting-team"
]

» Check-out management

These endpoints help manage check-outs.

» Check a credential out

Returns a 200 if a credential is available, and a 400 if no credential is available.

  • name (string: "", required): The name of the set of service accounts.
  • ttl (duration: "", optional): The maximum amount of time a check-out lasts before Vault automatically checks it back in. Setting it to zero reflects an unlimited lending period. Defaults to the set's ttl. If the requested ttl is higher than the set's, the set's will be used.
Method Path
POST /ad/library/:set_name/check-out

» Sample Post Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request POST \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/library/accounting-team/check-out

» Sample Post Payload

{
  "ttl": "1h"
}

» Sample Post Response

{
  "request_id": "364a17d4-e5ab-998b-ceee-b49929229e0c",
  "lease_id": "ad/library/accounting-team/check-out/aoBsaBEI4PK96VnukubvYDlZ",
  "renewable": true,
  "lease_duration": 36000,
  "data": {
    "password": "?@09QW0KZ8DSBu3deIu7XLY1NZqzwhozmMAZ6v0IcZJGOjs5GvpVMvOeW7/duls2",
    "service_account_name": "fizz@example.com"
  },
  "wrap_info": null,
  "warnings": null,
  "auth": null
}

» Check a credential in

By default, check-in must be called by the same entity or client token used for check-out. To disable this behavior, use the disable_check_in_enforcement toggle on the library set. Or, use the ad/library/manage/:set_name/check-in behavior to force check-in of the account. Access to the "manage" endpoint should only be granted to highly privileged Vault users, like Vault operators.

If a caller attempts to check in a service account they're not authorized to check in, they will receive an error response. If they attempt to check in a service account they are authorized to check in, but it's already checked in, they will receive a successful response but the account will not be included in the check_ins listed. check_ins shows which service accounts were checked in by this particular call.

  • name (string: "", required): The name of the set of service accounts.
  • service_account_names (string: "", or list: [] optional): The names of all the service accounts to be checked in. May be omitted if only one is checked out.
Method Path
POST /ad/library/:set_name/check-in
POST /ad/library/manage/:set_name/check-in

» Sample Post Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request POST \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/library/accounting-team/check-in

» Sample Post Payload

{
  "service_account_names": ["fizz@example.com"]
}

» Sample Post Response

{
  "request_id": "db45c714-3f68-b748-95bc-8f7467637a52",
  "lease_id": "",
  "renewable": false,
  "lease_duration": 0,
  "data": {
    "check_ins": ["fizz@example.com"]
  },
  "wrap_info": null,
  "warnings": null,
  "auth": null
}

» Check the status of service accounts

Method Path
GET /ad/library/:set_name/status

» Sample Get Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request GET \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/library/accounting-team/status

» Sample Get Response

{
  "request_id": "9e44c8b5-d142-5867-2a11-49f3ba71215a",
  "lease_id": "",
  "renewable": false,
  "lease_duration": 0,
  "data": {
    "buzz@example.com": {
      "available": true
    },
    "fizz@example.com": {
      "available": false,
      "borrower_client_token": "4c653e473bf7e27c6759fccc3def20c44d776279",
      "borrower_entity_id": "631256b1-8523-9838-5501-d0a1e2cdad9c"
    }
  },
  "wrap_info": null,
  "warnings": null,
  "auth": null
}

» Rotate Root Credentials

Rotate the bindpass to a new one known only to Vault.

» Risks

  1. When the bindpass is rotated, it successfully gets rotated in Active Directory but Vault can't store it so it becomes unknown.
  2. If the binddn in use applies to more than one entity in Active Directory, root credential rotation will fail because it's unclear which entity to perform the operation for.

» Mitigating Risks

  1. Always have another account that can provision a new binddn and bindpass to replace one whose password becomes unknown.
  2. Ensure the binddn in use only applies to one entity by including all distinguished name parameters possible. For example, use "CN=vault-ad-test,CN=Users,DC=example,DC=com" instead of "CN=vault-ad-test".

» Endpoints

Method Path
GET /ad/rotate-root

Generally, rotate-root returns a 204. However, if rotate-root is already in progress, it may return a 200 with a warning that root credential rotation is already in progress.

» Sample Get Request

$ curl \
    --header "X-Vault-Token: ..." \
    --request GET \
    --data @payload.json \
    http://127.0.0.1:8200/v1/ad/rotate-root