Create a public/private key pair

The private_key_jwt client authentication method is the only supported method for OAuth service apps that want to get access tokens with Okta scopes.

The private key that you use to sign the JWT must have the corresponding public key registered in the JWKSet of the OAuth service app. We recommend generating the public/private key pair first before creating the OAuth service app.

  1. Use a tool such as this JSON Web Key Generator to generate a JWKS public/private key pair for testing. Okta supports both RSA and Elliptic Curve (EC) keys. In this example, we are selecting RSA as the encryption algorithm. Select the following values:

    • Key size — 2048
    • Key use — signature
    • Algorithm — RSA256
    • Key ID — (Optional) This can be any random value.

Note: Use the JSON Web Key Generator link to generate a JWKS public/private key pair for testing purposes only. For a production use case, use your own internal instance of the key pair generator.

  1. The JSON Web Key Generator tool extracts the public key from the key pair automatically. For testing purposes, copy the Public Key that is provided.

Note: Some Okta SDKs require that keys be in Privacy Enhanced Mail (PEM) format. If you are working with an Okta SDK that requires that the key be in PEM format, after you have generated the key pair, copy the public/private key pair into a JWK to PEM Convertor tool and copy the private key to use when signing the JWT.

The JWKS should look something like this:

"keys": [
      {
    "kty": "RSA",
    "e": "AQAB",
    "use": "sig",
    "kid": "my_key_id",
    "alg": "RS256",
    "n": "u0VYW2-76A_lYg5NQihhcPJYYU9-NHbNaO6LFERWnOUbU7l3MJdmCailwSzjO76O-2GdLE-Hn2kx04jWCCPofnQ8xNmFScNo8UQ1dKVq0UkFK-sl-Z0Uu19GiZa2fxSWwg_1g2t-ZpNtKCI279xGBi_hTnupqciUonWe6CIvTv0FfX0LiMqQqjARxPS-6fdBZq8WN9qLGDwpjHK81CoYuzASOezVFYDDyXYzV0X3X_kFVt2sqL5DVN684bEbTsWl91vV-bGmswrlQ0UVUq6t78VdgMrj0RZBD-lFNJcY7CwyugpgLbnm4HEJmCOWJOdjVLj3hFxVVblNJQQ1Z15UXw"
      }
    ]