Client Assertion

This page must be considered part of the iSHARE Framework

This page is considered normative and is therefore compliant with RFC 2119.

This page defines the JWT payload that should be provided to generate an iSHARE JWT client assertion for the access token endpoint.

JWT Payload

Instead of the default iSHARE JWT payload requirements, the following apply:

• The iss and sub claims MUST contain a valid Party Identifier of the client that wishes to authenticate.

• The aud The claim MUST contain only a valid Party Identifier of the party that authenticates the client. Including multiple audiences creates a risk of impersonation and is therefore not allowed.

In OAuth 2.0, clients are generally pre-registered. Since in iSHARE servers interact with clients that may have been previously unknown, this is not a workable requirement. Therefore, iSHARE implements a generic client identification and authentication scheme, based on iSHARE whitelisted PKIs.

Since OAuth 2.0 doesn’t specify a PKI-based authentication scheme, but OpenID Connect 1.0 does, iSHARE chooses to use the scheme specified by OpenID Connect in all use cases. This is preferred over defining a new proprietary scheme.

Example Client Assertion JWT Payload:

{
  "iss": "did:ishare:EU.NL.NTRNL-10000001",
  "sub": "did:ishare:EU.NL.NTRNL-10000001",
  "aud": "did:ishare:EU.NL.NTRNL-10000000",
  "jti": "378a47c4-2822-4ca5-a49a-7e5a1cc7ea59",
  "exp": 1504683475,
  "iat": 1504683445
}