get_id_token.sh

#!/bin/bash
# get_id_token.sh
# A shell script which demonstrates how to get an OpenID Connect id_token from from Okta using the OAuth 2.0 "Implicit Flow"
# Author: Joel Franusic <joel.franusic@okta.com>
# 
#   Copyright 2016, Okta Inc
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.

base_url=""
client_id=""
origin=""
password=""
username=""
verbose=0

# http://stackoverflow.com/questions/8175000/parsing-arguments-options-flags-in-a-bash-script
while getopts ":b:c:o:u:p:v" OPTION
do
    case $OPTION in
    b)
        base_url="$OPTARG"
    ;;
    c)
        client_id="$OPTARG"
    ;;
    o)
        origin="$OPTARG"
    ;;
    u)
        username="$OPTARG"
    ;;
    p)
        password="$OPTARG"
    ;;
    v)
        verbose=1
    ;;
    [?])
        echo "Usage: $0 -b base_url -c client_id -o origin -u username -p password" >&2
	echo ""
	echo "Example:"
	echo "$0 -b 'https://example.okta.com' -c aBCdEf0GhiJkLMno1pq2 -u AzureDiamond -p hunter2 -o 'https://example.net/you_app'"
        exit 1
    ;;
    esac
done

# redirect_uri="https%3A%2F%2Fexample.com"
redirect_uri=$(curl --silent --output /dev/null --write-out %{url_effective} --get --data-urlencode "$origin" "" | cut -d '?' -f 2)

rv=$(curl --silent "${base_url}/api/v1/authn" \
	  -H "Origin: ${origin}" \
	  -H 'Content-Type: application/json' \
	  -H 'Accept: application/json' \
	  --data-binary $(printf '{"username":"%s","password":"%s"}' $username $password) )
if [ $verbose -eq 1 ]; then
    echo $rv
fi
session_token=$(echo $rv | /usr/local/bin/jq '.sessionToken' | tr -d \")
if [ $verbose -eq 1 ]; then
    echo "Session token: '${session_token}'"
fi

url=$(printf "%s/oauth2/v1/authorize?sessionToken=%s&client_id=%s&scope=openid+email+profile+groups&response_type=id_token&response_mode=fragment&nonce=%s&redirect_uri=%s&state=%s" \
      $base_url \
      $session_token \
      $client_id \
      "staticNonce" \
      $redirect_uri \
      "staticState")
if [ $verbose -eq 1 ]; then
    echo "Here is the URL: '${url}'"
    curl -v $url;
    exit
fi

rv=$(curl --silent -v $url 2>&1)

id_token=$(echo "$rv" | egrep '^< Location: .*id_token=' | cut -d '=' -f 2 | egrep -o '[[:alnum:]_\.\-]*')
echo $id_token