SSL and certificate validation¶
All SSL configuration is done per-storage.
Pinning by fingerprint¶
To pin the certificate by fingerprint:
[storage foo]
type = caldav
...
verify_fingerprint = "94:FD:7A:CB:50:75:A4:69:82:0A:F8:23:DF:07:FC:69:3E:CD:90:CA"
#verify = false # Optional: Disable CA validation, useful for self-signed certs
SHA1-, SHA256- or MD5-Fingerprints can be used. They’re detected by their length.
You can use the following command for obtaining a SHA-1 fingerprint:
echo -n | openssl s_client -connect unterwaditzer.net:443 | openssl x509 -noout -fingerprint
Custom root CAs¶
To point vdirsyncer to a custom set of root CAs:
[storage foo]
type = caldav
...
verify = "/path/to/cert.pem"
Vdirsyncer uses the requests library, which, by default, uses its own set of trusted CAs.
However, the actual behavior depends on how you have installed it. Some Linux distributions, such as Debian, patch their python-requests package to use the system certificate CAs. Normally these two stores are similar enough for you to not care.
But there are cases where certificate validation fails even though you can access the server fine through e.g. your browser. This usually indicates that your installation of the requests library is somehow broken. In such cases, it makes sense to explicitly set verify or verify_fingerprint as shown above.
Client Certificates¶
Client certificates may be specified with the auth_cert parameter. If the key and certificate are stored in the same file, it may be a string:
[storage foo]
type = caldav
...
auth_cert = "/path/to/certificate.pem"
If the key and certificate are separate, a list may be used:
[storage foo]
type = caldav
...
auth_cert = ["/path/to/certificate.crt", "/path/to/key.key"]