Python certificate chain resolver

Resolve / obtain the certificate intermediates of a x509 certificate using the CLI or python API.

The CLI writes the full bundle to stdout. The Python API can be used to iterate over the certificates and get additional information on the bundle.

from cert_chain_resolver.api import resolve
with open('cert.pem', 'rb') as f:
   fb = f.read()
   chain = resolve(fb)
>>>
for cert in chain:
  print(cert)
<Cert common_name="cert-chain-resolver.remcokoopmans.com" subject="CN=cert-chain-resolver.remcokoopmans.com" issuer="CN=R3,O=Let's Encrypt,C=US">
<Cert common_name="R3" subject="CN=R3,O=Let's Encrypt,C=US" issuer="CN=DST Root CA X3,O=Digital Signature Trust Co.">
<Cert common_name="DST Root CA X3" subject="CN=DST Root CA X3,O=Digital Signature Trust Co." issuer="CN=DST Root CA X3,O=Digital Signature Trust Co.">

Support

• PKCS7, PEM and DER formats
• LetsEncrypt certificates

Dependencies

• cryptography

Documentation

Read more on readthedocs

Install

Pypi

$ pip install cert-chain-resolver

Usage

Installed using PIP

$ cert_chain_resolver certificate.crt > bundle.crt

Or read from stdin

$ cat certificate.crt | cert_chain_resolver > bundle.crt

After cloning the repository

Install dependencies

$ make

from file:

$ python -m cert_chain_resolver.cli certificate.crt > bundle.crt

from stdin:

$ cat certificate.crt | python -m cert_chain_resolver.cli > bundle.crt

Print the details of each certificate in resolved chain

$ cert_chain_resolver cert.pem --info

Development

bootstrap

$ make

Testing

Unit testing

$ make tests

Re-run tests on file changes:

$ make tests TEST_ARGS="-- -f"