Before you start
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Before you can begin integrating with BankID OIDC platform, you need to make sure you have:
We strongly recommend that you make use of an OpenID Connect client library applicable for your platform. Check out the officially certified implementations. |
OpenID Connect with Authorization Code flow
OpenID Connect is a protocol for authentication that builds on the OAuth 2.0 authorization framework. This getting started guide describes how to integrate BankID in your application using authorization code flow.
The steps necessary to perform an OpenID Connect authentication request is:
- Redirect the end-user to the authorization endpoint with applicable parameters.
- The end user authenticates using BankID and is redirected back to your web application.
- Handle the redirect request by checking parameters and handle potential errors.
- Exchange the code parameter for tokens by making a request to the token endpoint.
- Use the ID token to identify the user.
- Use the Access token to access resource servers, for example in the context of signing documents online.
- Use the Refresh token to retrieve new access tokens.
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Authorization Code flow with Proof Key for Code Exchange (PKCE)
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Warning |
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Note that implicit flow is not supported as recommended by IETF (https://tools.ietf.org/html/draft-ietf-oauth-security-topics-13). |
Implementation
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Authorization Request
- Connect to the appropriate OIDC discovery endpoint using your preferred framework and store the JSON response in your applicationto get the OpenID configuration.
Note: Make sure to keep the response updated every so often (at least daily).
For the public test environment (CURRENT) the Discovery endpoint is:
https://auth.current.bankid.no/auth/realms/current/.well-known/openid-configuration.
See all environments. - Use the
authorization_endpoint
found in the Discovery endpoint response.
Note: Do not hard code theauthorization_endpoint
this value. Always retrieve it from the OpenID Connect configurationRetrieve the config regularly from the OIDC discovery endpoint, as it may change. - Generate a random string value for
state
and store it in a variable calledstate
your user session.- The value must be non-guessable (e.g. GUID) and unique for each request.
- This value will be used to mitigate cross-site request forgery, but it can also be used by your application to link the callback request to the
- end-user session alongside a cookie.
- Generate a random string value for
nonce
and store it in a variable callednonce
your user session.- The value must
- be non-guessable, cryptographically random (your framework/language most likely have support for this)
- and unique for each request.
- This will be used to verify integrity of ID token and mitigate replay attacks.
state
andnonce
value in your application so they can be retrieved later, i.e. using your preferred session mechanism. These values should be stored together.
Build - Generate
code_verifier
for PKCE flow and store this in your user session.- This 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.
- This will be used to generate a code challenge (6) and during Token exchange later.
- Generate
code_challenge
from thecode_verifier
by generating a Base64-URL-encoded string of the SHA256 hash of the code verifier. - (Optional) Add any
login_hint
to the request to pre-select IDP or pre-fill user information. If user information is used we recommend using an encrypted request object. - Finally, we can build the authorization URL by adding the following query parameters (see see Authorize for more options and details):
client_id
: Unique client identifier provided when provisioning the clientYour assigned client ID with BankID OIDC.scope
: Specify Comma separated list of scopes that indicate which information (see ID token) and resources you request access to. In the example below, we useopenid
andprofile
to get a regular ID token.redirect_uri
: URI to your server-side callback endpoint where you want to receive the callback response from the BankID OIDC service. This URL must be pre-registered with BankID OIDC.response_type
: Determines message flow. Only "code" is supported.state
: Your generated value forstate
.nonce
: Your generated value fornonce
.code_challenge
: Your generatedcode_challenge
.code_challenge_method=S256
- (optional)
login_hint
: Addlogin_hint
here if applicable
Code Block title Example authorization requestAuthorization Request GET authorization_endpoint ?client_id=myclientyour-bankidclient-currentid &scope=openid+profile &redirect_uri=https%3A%2F%2Fmywebapp.example.org%2Fcallback &response_type=code &state=01e3ac8e-4a26-4dfb-79ca-2631394c4144 &nonce=1fb72f68-1bea-2ba2-12d7-24df1c999d1b &code_challenge=ixDBJg7pc3yT2h65DRvhjIbGko7U-t3cYVJmdMF-hTU &code_challenge_method=S256 &login_hint=BID
- Redirect end-user to the completed built authorization URL to start BankID Authentication.
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Authorization Code callback
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If authentication is successful, the end-user will be redirected to your application at the given redirect_uri
with state
and code
as parameters.
- Verify that the
state
parameter returned corresponds to thestate
parameter for your user session. Do a POST request to the token_endpoint with the provided code to get the ID token, Access token and Refresh token.
Example request
Code Block title Example Token Request POST /auth/realms/current/protocol/openid-connect/token HTTP/1.1 Host: auth.current.bankid.no Authorization: Basic b2lkYy10ZXN0Y2xpZW50OjAxMjM0NTY3LTg5YWItY2RlZi0wMTIzLTQ1Njc4OWFiY2RlZg== Content-Type: application/x-www-form-urlencoded grant_type=authorization_code &client_id=your-client-id &code=code=authorization-code-from-callback &redirect_uri=https%3A%2F%2Fmywebapp.example.org%2Fcallback &code_verifier=your-code-verifier
- Important: Perform Token validation
Verify the signature of the JWS tokens received and check the certificate chain of the signing key used by following this guide.
- Check claims by following this guide.
- Once validation is complete, you can access the claims in the various tokens:
- The ID token contains claims that can be used to identify the end-user. See ID token for available claims.
- The Access token can be used to access additional services such as document signing or additional user information (5).
- (optional) Fetch additional Userinfo through userinfo_endpoint.
- Use the access token you received in the previous step as Bearer token in the userinfo request
- Use the
userinfo_endpoint
found in the Discovery endpoint response. - The Userinfo response comes in JWS format so you need to perform signature validation here as well.
If authentication is cancelled (due to user action or errors)
If error
is part of the query parameters, the authentication was not completed, you need to handle the error.
- The possible ASCII values for the
error
query parameter is defined in the specification for OIDC (§3.1.4.6) or OAuth 2.0 (RFC 6749, §4.1.2.1). - If the end-user cancels an authentication request in the BankID OIDC client,
error
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- will have the value
access_denied
. - In addition to
error
, the response parametererror_description
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- may include BankID error codes the end-user experienced.
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Next steps
It is recommended to take a look at Session handling to get a better understanding of the session lifetime.
Next steps
Read up on how we do Key rotation and how you can do Token verification.
Our APIs are continuously adding new changes and features in API Versions and Changelog.
The list of error codes displayed to the end-user is useful for troubleshooting.
Known issues contains a list of restrictions, caveats and known problems.
The Deprecations list is also interesting to keep an eye on.The list of error codes displayed to the end-user is useful for troubleshooting.