Simple command line script that creates an LTI signed url based on input params. Useful for generating utls to test an LTI provider.

lti_signer.py

#!/usr/bin/env python

import sys
import argparse
import requests

from oauth2 import Consumer
from oauth2 import Request
from oauth2 import SignatureMethod_HMAC_SHA1
from oauth2 import generate_nonce
from time import time

KEY = u'12345'
SECRET = u'secret'
BASE_URL = 'http://localhost:8080/'


def generate_signed_lti_request(url, key, secret, params={}, method="POST"):
    """
    Emulate a tool consumer by creating signed LTI postdata.

    :param url: url endpoint (in mediacore) for the request.
    :param key: oauth consumer key
    :param secret: oauth secret key
    :param params: (optional) extra post params for the reqest
    """
    request_params = dict(
        oauth_version = '1.0',
        oauth_nonce = generate_nonce(),
        oauth_timestamp = int(time()),
        oauth_consumer_key = key,
        lti_message_type = 'basic-lti-launch-request',
        lti_version = 'LTI-1p0',
    )
    request_params.update(params)
    if not request_params.get('resource_link_id', None):
        request_params['resource_link_id'] = 'abc-defghi-j'
    consumer = Consumer(key=key, secret=secret)
    req = Request(method=method, url=url, parameters=request_params)
    sig_method = SignatureMethod_HMAC_SHA1()
    req.sign_request(sig_method, consumer, None)
    return req



if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('-u', '--url', default=BASE_URL)
    parser.add_argument('-k', '--key', default=KEY)
    parser.add_argument('-s', '--secret', default=KEY)
    parser.add_argument('-m', '--method', default="POST")
    parser.add_argument('-p', '--post-data', action='store_true')
    parser.add_argument('--url-out', action='store_true')
    parser.add_argument('params', nargs='*')

    args = parser.parse_args()

    d_params = {}
    for p in args.params:
        s = p.split('=')
        d_params[s[0]] = s[1]

    req = generate_signed_lti_request(
        args.url,
        args.key,
        args.secret,
        d_params,
        args.method
    )

    if args.url_out:
        sys.stdout.write(args.url + '?' + req.to_postdata())
        sys.exit(0)

    if args.post_data:
        sys.stdout.write(req.to_postdata())
        sys.exit(0)

    if args.method == 'POST':
        resp = requests.post(args.url, req)
    elif args.method == 'GET':
        resp = requests.get(args.url, req)
    print resp.text

Updated the script with some output options.

pip install httpie
http `./lti-signer -k abc -s abc --url-out`