https://github.com/sheagcraig/macsesh
Tools for letting the macOS Keychain verify certs for python requests
https://github.com/sheagcraig/macsesh
https macos python-requests requests tacos
Last synced: about 2 months ago
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Tools for letting the macOS Keychain verify certs for python requests
- Host: GitHub
- URL: https://github.com/sheagcraig/macsesh
- Owner: sheagcraig
- License: other
- Created: 2020-04-25T12:06:36.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-12-01T18:31:06.000Z (almost 2 years ago)
- Last Synced: 2025-07-29T05:52:03.249Z (3 months ago)
- Topics: https, macos, python-requests, requests, tacos
- Language: Python
- Homepage:
- Size: 78.1 KB
- Stars: 28
- Watchers: 2
- Forks: 2
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# MacSesh
This package allows the popular requests library to use the macOS
keychain for validating a server, and for doing client cert auth.
Its original use-case was for Mac admins wanting to use python requests
and certs provided by an MDM for TLS, Specifically, client cert auth
using SCEP profiles, and x509 payloads for server validation.
### Installing
```
pip install MacSesh
```
If you want to install from a source distribution, clone and run below.
```
pip install .
```
## Example Usage:
Validate using a trusted cert from the keychain:
```
>>> import macsesh
>>> sesh = macsesh.Session()
>>> response = sesh.get('https://nethack.org')
```
If you want to use the "basic" requests API without creating a session:
```
>>> macsesh.inject_into_requests()
>>> requests.get('https://en.wikipedia.org/wiki/Taco') # Uses keychain
```
Client cert auth:
```
>>> import macsesh
>>> sesh = macsesh.Session()
>>> response = sesh.get('https://nethack.org', cert='My Identity Cert')
```
## Validating a server
macsesh uses any of the _trusted_ certs from keychains included in the
current user's keychain search list, as well as the system roots.
Typically, this search list consists of:
- The user's default keychain at `~/Library/Keychains/login.keychain`
- The system keychain at `/Library/Keychains/System.keychain`
- The System Roots keychain at
`/System/Library/Keychains/SystemRootCertificates.keychain`.
Certs in the system roots are implicitly trusted. Certs from other
keychains must be marked as trusted for this purpose or they won't be
included.
When using macsesh, just leave the requests `verify` at its default of
`True` and macsesh will do the rest.
## Client cert auth
macsesh can also do client cert auth from the keychain, currently only
with the `SecureTransportAdapter`. The other adapter types can do client
cert auth as well of course, but they require the identity to be
available on the filesystem just like regular requests.
To specify a certificate to use, provide the Common Name of the cert to
requests' normal `cert` argument as in the example above. As the
keychain may have multiple certs which match , macsesh performs some
additional filtering.
1. The query does a "subject contains" search with the CN provided, so
for exmaple `cert='taco'` could match a CN of `taco truck` or `taco
party`.
2. After the "subject contains" search, macsesh will drop anything that
is not an exact string match.
3. The resulting certs may have been renewed, and the old certs are
still in the keychain. macsesh sorts them by "not valid after" date
and picks the one with the longest lifespan.
## Advanced
### Cleanup
If for some reason you want to revert to "normal" requests (probably
using certifi), in the same python process, you'll need to remove this
module's injected stuff from urllib3 or requests.
Remove the `SSLContext` if you used any of the Sessions:
```macsesh.extract_from_urllib3()```
Clean up after using the "basic" API:
```macsesh.extract_from_requests()```
Any certs added to the keychains after starting a session will
not be available. Digging down in and updating the SSLContext is rough;
just make a new session if you have this need!
### Choosing a session type
macsesh provides three different types of requests `Session` classes.
While we probably only need the `Session`, the other two are included
for posterity since they are interesting and potentially useful.
1. If in doubt, use `Session` It uses the securetransport module
contributed to urllib3 as a base SSLContext. Pip, for example, uses
this on macOS. The securetransport module uses an entirely different
`SSLContext`, using ctypes to connect to the macOS `Security`
framework. macsesh then injects additional code into the urllib3
code to use the keychain instead of conforming to the OpenSSL
approach of using paths to files. If you need to do client cert auth
from keychain identities, this is the one you want.
1. `KeychainSession` uses a custom SSLContext, requests Adapter, and
requests Session, and injects the SSLContext into urllib3. The certs
for validation are dumped from the keychain and held in memory. The
goal of this approach is to use the minimum amount of messing about
to achieve cert validation.
3. `SimpleKeychainSession` circumvents the normal flow of session
startup, and tells the SSLContext to load its trust information
up front rather than waiting for a bunch of internal checks to decide
the context needs to load the trust store. It uses the same method
as the `KeychainSession` and functionally shouldn't be any different.
### What about cert auth for `SimpleKeychainSession` and
`KeychainSession`?
I can try implementing looking up and retrieving certs by name for the
other "strategies", but I'm not sure how much utility there is for that,
as the keys would have to be exportable. At that point, just export them
and use regular old requests.