Created
August 10, 2022 22:06
-
-
Save mygzi/8633044f86e0610824963cdc59ac5d1c to your computer and use it in GitHub Desktop.
Epic on FHIR backend system (sandbox) authentication sample
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
from datetime import datetime | |
from datetime import timezone | |
from datetime import timedelta | |
import requests | |
import jwt | |
import os | |
import uuid | |
from cryptography.hazmat.backends import default_backend | |
from cryptography.hazmat.primitives.serialization import load_pem_private_key | |
from cryptography.x509 import load_pem_x509_certificate | |
# load key pair created by following https://fhir.epic.com/Documentation?docId=oauth2§ion=Creating-Key-Pair | |
os.chdir('replace-with-path-to-key-files') | |
with open('epic-on-fhir-private-key.pem', 'rb') as private_key_file: | |
lines = private_key_file.read() | |
private_key = load_pem_private_key(lines, None, default_backend()) | |
with open('epic-on-fhir-public-key-509.pem', 'rb') as cert_file: | |
cert_str = cert_file.read() | |
cert_obj = load_pem_x509_certificate(cert_str) | |
public_key = cert_obj.public_key() | |
# build the JWT | |
algorithm = "RS384" | |
client_id = "replace-with-non-production-client-id-from-epic-app-listing" | |
endpoint = "https://fhir.epic.com/interconnect-fhir-oauth/oauth2/token" | |
payload = { | |
"iss": client_id, | |
"sub": client_id, | |
"aud": endpoint, | |
"jti": str(uuid.uuid4()), | |
"exp": datetime.now(tz=timezone.utc) + timedelta(minutes=+1), | |
} | |
token = jwt.encode( | |
payload, | |
private_key, | |
algorithm=algorithm, | |
headers={"alg": "RS384", "typ": "JWT"}, | |
) | |
print(f"headers {jwt.get_unverified_header(token)}") | |
decoded = jwt.decode(token, public_key, audience=endpoint, algorithms=[algorithm]) | |
print(f"payload {decoded}") | |
payload = { | |
"grant_type": "client_credentials", | |
"client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer", | |
"client_assertion": token | |
} | |
r = requests.post('https://fhir.epic.com/interconnect-fhir-oauth/oauth2/token', data=payload) | |
print(r.status_code) # is everything 200 OK? |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment