Pushed Authorization Request (PAR)¶

The Pushed Authorization Request (PAR) is a method for the client to send the authorization request parameters to the OIDC Provider server in a backchannel request.

This is useful for several reasons:

The client can send sensitive information directly to the authorization server, without exposing it to the user agent.
The OIDC Provider can ensure that the request parameters is not tampered with. E.g. when using private_key_jwt the JWT signature can be verified.
URL length limitations are avoided, as the request is sent in the body of the request.

Steps¶

The client sends a backchannel request with the standard authorization parameters to the OIDC Provider.
The OIDC Provider validates the request and returns a reference to the client.
The client sends the reference to the user agent through the regular Authorize request.
The Authorization Code flow continues as normal and end-user authenticates...

API¶

Note

You will always find the up-to-date URL for the PAR endpoint in the OpenID Configuration - as pushed_authorization_request_endpoint.

1. Create Pushed Authorization Request¶

Request¶

POST [pushed_authorization_request_endpoint]

Headers¶

Content-Type: application/x-www-form-urlencoded

Authentication¶

Client authentication according to supported methods.

Body¶

The body of the request contains the parameters of the authorization request, form encoded.

client_id=myclient-bankid-current
&scope=openid+profile
&redirect_uri=https%3A%2F%2Fmywebapp.example.org%2Fcallback
&response_type=code
&login_hint=:12345678901
&acr_values=urn:bankid:bid
&state=01e3ac8e-4a26-4dfb-79ca-2631394c4144
&nonce=1fb72f68-1bea-2ba2-12d7-24df1c999d1b
&code_challenge=rMU4NcLC3_O_tsTZ3gQE1ONoXD6OMZph_2zRuobajhQ
&code_challenge_method=S256

Parameters¶

The content of the body parameters is the same as authorize parameters.

Name	Description
client_id	Unique ID (arbitrary string) for the OIDC Client in question. This is created as part of the provisioning process.
redirect_uri	Redirect URI to which the Authorize response will be sent. This URI must exactly match one of the Redirect URI values for the OIDC Client pre-registered at the OpenID Provider.
scope	List of scope values specifying what kind of resources (dataset) the OIDC Client requests access to. The value openid must always be included in the list. Each scope value must be separated by space. Scope values are case-sensitive.
response_type	Determines the message flow to be used, thus also governing the content and type of the response from the Authorize endpoint. Only `code` (Authorization code flow) is supported.
response_mode	The response mode to be used for returning parameters from the Authorization Endpoint via redirect_uri. The following values are supported: `query`, `fragment`, `form_post`.
acr_values	Allows you to determine the a Level of Assurance (LoA) and ACR (Authentication Context Class Reference) value by selecting the Identity provider (IDP) used for authentication. The value is a space-separated list of ACR values, and we support the following values: - `urn:bankid:bis` - Biometric authentication using WebAuthn at LoA 3. - `urn:bankid:bid` - Authentication using BankID at LoA 4. If none of these parameters are set, the default LoA is 4 (BankID High). Note: This parameter has no effect if the `login_hint` parameter contains a reference to any particular IDP. Nor does it have any effect if the `id_token_hint` parameter is set.
login_hint (request objects/PAR only)	This parameter can be used to prefill the user ID in the login form. The value is a colon (:) followed by NNIN (Norwegian National Identity Number). Example: `:01010112345` Do not send login_hint as query parameter. Use PAR or encrypted request objects. Note: Previously, `login_hint` was used to select IDP or LoA; you should instead use the `acr_values` parameter for that purpose. Warning: Specifying nnin in an unencrypted query param login_hint is deprecated in API Version 4.
code_challenge	Base64-URL-encoded string of the SHA256 hash of a "code verifier" value generated on merchant side. A code verifier is a cryptographically random string using the characters A-Z, a-z, 0-9, and the punctuation characters -._~ (hyphen, period, underscore, and tilde), between 43 and 128 characters long.
code_challenge_method	Method used to encode the code verifier. Only "S256" (SHA256) is supported.
state	Opaque value used to maintain state between the request and the callback. It is strongly recommended that merchants provide this value to mitigate Cross-Site Request Forgery.
nonce	String value used to associate a ODIC Client session with an ID Token, and to mitigate replay attacks. The value is passed through unmodified from the Authentication Request to the resulting ID Token as `nonce` claim.
api_version	The version of the API of the BankID OpenID Provider to be used. Integer value. See API versions for more information.
ui_locales	May be used to set a language preference for GUI handling. The default GUI experience supports: `nb` (Norsk Bokmål), `nn` (Norsk Nynorsk) and 'en' (English). If ui_locales is not set, the first (if any) `Accept-Language` header of the request is used to determine preferred locale. Otherwise `nb` is used by default.
prompt	Support for the standardized values `none` and `login`. The former can be used to check for an existing (still valid) authentication session with the OIDC provider. The latter can be used to force a re-authentication, possibly with a different `login_hint` and/or `acr_values`. Optional.
display	The display parameter allows Clients to adjust the user interface displayed to end-users to make it more consistent with the device type and viewport size. We support: `page` (default) - standard responsive view (desktops, tablets). `touch` - suitable for integration in mobile apps. `wap` - same as `touch` above. `popup` - suitable for popup or iframe integrations.
request	This parameter may be used to group and send several query parameters as one. The standard specifies guidelines on how to use it. BankID supports both plaintext and encrypted request objects. Encrypted and signed objects are in certain cases possible. If the request parameter contains personal information, it should be encrypted. See encryption.
request_uri	Only supported when using with Pushed Authorization Requests (PAR) to reference previously pushed request parameters.
id_token_hint	JWT value for an ID Token previously issued by the OIDC Provider used as a hint about the end user's existing session with the OIDC provider. Note that this parameter has precedence before both `acr_values` and `login_hint`, but precedence after the `prompt` parameter. If the ID Token has expired, a new authentication is triggered for the IDP option that was used when the ID Token was first issued. Otherwise, the authentication is still valid and the OIDC Provider proceeds directly to consent handling.

Response¶

Status¶

201 Created

Headers¶

Content-Type: application/json

Body¶

The response is a JSON structure containing the reference to the request object.

{
  "request_uri": "urn:ietf:params:oauth:request_uri:12627496-8a05-4e3d-a04c-9478fc9c456b",
  "expires_in": 300
}

2. Authorization Request with Request URI¶

Start end-user BankID authentication by redirecting the user to the below URL:

Request¶

GET [authorization_endpoint]
?client_id=myclient-bankid-current
&request_uri=urn:ietf:params:oauth:request_uri:12627496-8a05-4e3d-a04c-9478fc9c456b

Response¶

After BankID authentication, we will return the end-user to the redirect_uri you specified in the initial request.

This is following the Authorization Code flow.

3. Token exchange¶

Do the token request for grant_type=authorization_code.