Setting up (comodo) ssl for your website on aws

We have bought our ssl from comodo from as we got a better deal there. After sending them our signed key. comodo sent us following files via email, against my private key. Now I would blog about how I setted the whole thing up on AWS.

First of all, before purchasing I had to send them a key which I had generated using OpenSSL using following command:

openssl req \
       -newkey rsa:2048 -nodes -keyout domain.key \
       -out domain.csr

Which was pretty easy. And as we had bought Comodo Essential SSL Wildcard so we could buy it without verifying our company, in fairly easy in less than 5 min.

After our successful purchase comodo sent us following files as zip in my email:
domain_com.crt os our Primary Certificate, COMODORSAAddTrustCA.crt is our Intermediate Certificate, and AddTrustExternalCAROOT.crt is the The Root Certificate.

Now it gets a little bit tricky because currently our certificates are in .crt format, but we want it to be in *.pem format. So we would need to convert them in *.pem.

openssl x509 -in ./AddTrustExternalCARoot.crt -outform pem -out ./pem/AddTrustExternalCARoot.pem
openssl x509 -in ./COMODORSAAddTrustCA.crt -outform pem -out ./pem/COMODORSAAddTrustCA.pem
openssl x509 -in ./COMODORSADomainValidationSecureServerCA.crt -outform pem -out ./pem/COMODORSADomainValidationSecureServerCA.pem
openssl x509 -in ./domain_com.crt -outform pem -out ./domain.pem

We would also need to keys that was used to create these certificates by comodo.

openssl rsa -in ./domain.key -outform PEM -out domain.key.pem

Lets create the chain first:

$ cat ./COMODORSADomainValidationSecureServerCA.pem > ./CAChain.pem
$ cat ./COMODORSAAddTrustCA.pem >> ./CAChain.pem
$ cat ./AddTrustExternalCARoot.pem >> ./CAChain.pem

Now you need to login to your aws console and search for ACM (Amazon Certificate Manager). and if it is your first time you need to click on Provision certificates.

It is time to import your certificate to ACM. At the form where it says Certificate body* please paste domain.pem and domain.key.pem and at Certificate chain paste CAChain.pem.

So thats it we are done importing.

Now if you have a load balancer you can take advantages of this ssl. If you have an existing load balancer or feel free to create one, where at the place of listener add https instead of http and for certificate choose acm and your domain.

You are good to go.

ssl (https) from python flask

Basically here I am in this blog I am going share a code snippet, and I am going to describe what else stupid things I tried and did not work to do that. Well, don’t miss my point, when I am sharing my stupid ordeal, it does not mean, I am proving myself stupid but I am trying to save your time, I am basically telling what did not work in last couple of hour so that it could save your time.

So using flask when I shared a static file migrated directly from django, while working with django we have figured out that we actually don’t need powerful tool like django, instead we can use something very lightweight like flask and it is much easier to switch from django to flask as for both of them default front end templating is jinja. Now after this shift, I had to face a little bit trouble with https, because when I tried https, it is completely blank, I lost my mind, what the hell is going on here? Then I realized for flask probably I need to define my ssl. They got this nice documentation at their website (, I follwed them, and it did not work! Why it won’t work? Alright after couple of trial and google search I realized this is an old school way of doing this, fine, I need to go to new school, obviously! I got myself a new dress and now context looks more pretty {“cert.crt”,”key.key”}. I am impressed but what the hell? it did not work as well, why it won’t work? I lost my mind! hours of fighting, and I got this error:

Traceback (most recent call last):
  File "/usr/lib/python2.7/", line 810, in __bootstrap_inner
  File "/usr/lib/python2.7/", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/", line 602, in inner
    passthrough_errors, ssl_context).serve_forever()
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/", line 506, in make_server
    passthrough_errors, ssl_context)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/", line 450, in __init__
    self.socket = ssl_context.wrap_socket(self.socket,
AttributeError: 'OpenSSL.SSL.Context' object has no attribute 'wrap_socket'

It is because I am using a python 2.7 version below 2.7.9.

What else did I try? You won’t want to know, I tried to install pyopenssl on heroku using pip, but looks like it is a ported version and failed to compile on heroku. Now I will write about what I had to do to make it work.

I have to make my cirtificate and keys:

$ openssl genrsa -des3 -passout pass:x -out server.pass.key 2048
 openssl rsa -passin pass:x -in server.pass.key -out server.key
 rm server.pass.key
 openssl req -new -key server.key -out server.csr
openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

So now we have server.key and server.csr two files in our directory

Now python script:

from flask import Flask, request, send_from_directory
from flask import render_template

#from OpenSSL import SSL
#context = SSL.Context(SSL.SSLv23_METHOD)

import os

ASSETS_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), '/static')
app = Flask(__name__, static_url_path='/static')

def send_js(path):
    return send_from_directory('js', path)

def signup():
    return render_template('signup.html')

if __name__ == '__main__':
    context = ('server.crt', 'server.key'), threaded=True, debug=True)

Done! Up and running if you got a version >=2.7.9.!