CODEWITHSUNDEEP
pythonrestauthenticationcertificate
Carlo-Rodriguez
Carlo-Rodriguez

Reputation: 176

python certificate based authentication in REST request

I tried to send a REST request in python with a certificate based authentication to a given server that is providing the REST api's but after hours of searching and trying I think I need help.

I have a signed certificate from the mentioned server and the key for that cert. The Server itselfs does also provide a certificate for https.

I tried the library httplib.HTTPSConnection:


    import httplib
    import urllib

    clientCert = "client.crt"
    clientKey = "client.key"
    serverCert = 'server.crt'
    serverApi = "/api/getExample"
    serverHost = "restapi.example.com"
    serverPort = 443
    requestMethod = "POST"
    params = urllib.urlencode({'someId': 'myId'})
    headers = {"Content-type": "application/x-www-form-urlencoded","Accept": "application/json"}

    conn = httplib.HTTPSConnection(serverHost, serverPort, key_file=clientKey, cert_file=clientCert)
    conn.request(requestMethod, serverApi, params, headers)
    response = conn.getresponse()
    conn.getresponse()
    conn.close()

I get ssl.SSLError: SSL: CERTIFICATE_VERIFY_FAILED
Is it possible to get a cert based auth running with that library?

Upvotes: 4

Views: 36179

Answers (2)

reinies
reinies

Reputation: 1

Thank you, Carlo,

I managed to get it working by using a single file for the certificate chain, certificate, and private key. Before this, I was encountering the error: HTTPSConnectionPool(host='host, port=4443): Max retries exceeded with url: /api/endpoint (Caused by SSLError(SSLError(9, '[SSL] PEM lib (_ssl.c:3921)'))).

Here's the adapted code I used:

import json
import requests

clientCertsAndKey = 'certChainAndCertAndKey.pem'
url = 'https://example.com/api'
payload = { 'someId': 'myID' }
certServer = 'cs.crt'
headers = {'content-type': 'application/json'}

try:
    r = requests.post(url, data=json.dumps(payload), verify=certServer, 
                      headers=headers, cert=clientCertsAndKey)
    print(r.status_code)
    print(r.json())
except requests.exceptions.SSLError as ssl_error:
    print(f'SSL error: {ssl_error}')

Just remember, for anyone using a single file for your client certificate + private key, ensure that the certificate chain (certificates of the entities that issued your certificate) is also included in the file. This helped me to overcome the aforementioned SSL error.

Upvotes: -1

Carlo-Rodriguez
Carlo-Rodriguez

Reputation: 176

I was able to get it running with the aid of the "requests" library.

import json
import requests
    
clientCrt = "cc.crt"
clientKey = "ck.key"
url = "https://example.com/api"
payload = { "someId": "myID" }
certServer = 'cs.crt'
headers = {'content-type': 'application/json'}
r = requests.post(url, data=json.dumps(payload), verify=certServer, 
                  headers=headers, cert=(clientCrt, clientKey))
print(r.status_code)
print(r.json())

Simple as that

Upvotes: 9

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