OCSP Response Linter is a command line tool for fetching, linting, and verifying OCSP responses.
This is not an officially supported Google product.
We distinguish between lints and verifications as follows:
- A lint is a requirement that can be checked using only the OCSP response (e.g. ensuring that the producedAt date field of a response is no more than four days in the past)
- A verification is a requirement that necessitates querying an outside service and may run while in the process of fetching the OCSP Response (e.g. checking that an OCSP response is delivered in 10 seconds after sending the request)
The lints and verifications implemented come primarily from Apple's OCSP Lints and Test Cases and IETF standards set out in RFC 6960.
The OCSP Response Linter allows users to specify three different types of input. The first (default) method is to supply server URL(s)
./ocsp_status [url1] [url2] ...
The second method is to supply ASN.1 DER encoded certificate file(s) that should be sent to an OCSP responder. Please note that the certificate must contain an OCSP responder URL and issuer certificate URL or else the tool will not be able to generate the OCSP request.
./ocsp_status -incert [certfile1] [certfile2] ...
The third method is to supply the OCSP response file(s) itself. If this method is chosen, verifications checking to see if fetching the OCSP Response meets IETF standards cannot be run.
./ocsp_status -inresp [respfile1] [respfile2] ...
The OCSP Response Linter will loop through all inputs provided and lint/verify each resulting OCSP response.
A complete table of available flags:
| Flag | Description | Example |
|---|---|---|
| inresp | Read in OCSP response(s) files | ./ocsp_status -inresp google_resp google_resp2 |
| incert | Read in certificate files (must be ASN.1 DER encoded) | ./ocsp_status -incert google_cert.der google_cert2.der |
| issuercert | Read in space separated issuer certificate files (must be ASN.1 DER encoded) | ./ocsp_status -issuercert="googleissuer_cert.der googleissuer_cert2.der" -incert google_cert.der google_cert2.der |
| ocspurl | Read in space separated urls to send the OCSP request to | ./ocsp_status -ocspurl=http://ocsp1.com http://ocsp2.com google.com:443 google2.com:443 |
| usepost | Use POST to send the OCSP request (default is GET) | ./ocsp_status -post google.com:443 |
| dir | Write the OCSP response to a file | ./ocsp_status -dir=google_resp google.com:443 |
| nostaple | Don't use the stapled OCSP response (only use with server URLs) | ./ocsp_status -nostaple google.com:443 |
| verbose | Print information on all lints (default is only printing failed/errored lints) | ./ocsp_status -verbose google.com:443 |
Note you can also do ./ocsp_status -help to see a list of all possible flags and their descriptions.