C3-PRO Sample Resources

This repository contains 🔥FHIR sample resources, as used by the C3-PRO libraries.

Since FHIR is still evolving there are different versions of the resources:

• the master branch contains STU-3 (v3.0.0) resources
• the develop branch may contain resources of a newer FHIR version

Questionnaire

The Questionnaire subfolder contains simple questionnaires that demonstrate usage of certain data types with questionnaires.

QuestionnaireResponse

Example QuestionnaireResponse files with responses to the respective questionnaires. Usually, those are encrypted when going over the wire, see below.

Encryption

C3-PRO uses RSA and AES encryption with OAEP (optimal asymmetric encryption padding), which was standardized in PKCS#1 v2 and uses SHA-1/MGF1 by default. We use our own simple JSON format to transmit both the RSA-encrypted random AES key as well as the AES-encrypted FHIR resource:

{
    "message": "{{ AES-encrypted fhir resource, base64 encoded }}",
    "symmetric_key": "{{ RSA-encrypted AES key used to encrypt `message`, base64 encoded }}",
    "key_id": "{{ RSA key id used to encrypt `symmetric_key` }}",
    "version": "{{ FHIR version, `dstu2-1.0.2` or `stu3-3.0.0` }}"
}

Use of JWE is being discussed.

The enc directory contains encryption-related files that can be used for unit testing:

• private.pem: private RSA 2048 key
• public.crt: the corresponding public RSA key as X509 certificate

AES

AES encryption uses a 32 bit key by default. To achieve correct padding these settings can be used on the mobile platforms:

• iOS: kSecPaddingOAEP
• Java: RSA/ECB/OAEPWithSHA1AndMGF1Padding

RSA

To follow.

JWE

To follow.