JWT using RS256

createToken.py

import base64
import rsa
import hashlib

(pubkey, privkey) = rsa.newkeys(512)

with open('private.key','wb') as keyfile:
    keyfile.write(privkey._save_pkcs1_pem())
with open('public.key','wb') as keyfile:
    keyfile.write(pubkey._save_pkcs1_pem())

file = open('private.key')
key = file.read()

header = '{"typ": "JWT", "alg": "RS256"}'
payload = '{"iss":"joe", "exp":1300819380, "http://example.com/is_root":true}'

urlSafeEncodedBytes = base64.urlsafe_b64encode(header.encode("utf-8")) 
urlSafeEncodedHeader = str(urlSafeEncodedBytes,"utf-8").split('=')[0]

urlSafeEncodedBytes = base64.urlsafe_b64encode(payload.encode("utf-8")) 
urlSafeEncodedPayload = str(urlSafeEncodedBytes,"utf-8").split('=')[0]

token = urlSafeEncodedHeader + '.' + urlSafeEncodedPayload

sign = base64.urlsafe_b64encode(rsa.sign(token.encode("utf-8"), rsa.PrivateKey._load_pkcs1_pem(bytes(key,'utf-8')), 'SHA-256')).decode('utf-8').rstrip('=')
token = token + '.' + sign

print(token)