How to open .CRL files on Mac
To open .CRL files on Mac, if you have OpenSSL available, inspect the CRL in Terminal: openssl crl -in file.crl -noout -text.
Step-by-step instructions
- If you have OpenSSL available, inspect the CRL in Terminal: openssl crl -in file.crl -noout -text
- If the file is DER and OpenSSL reports input format issues, retry by specifying the format (for example: openssl crl -inform DER -in file.crl -noout -text)
Recommended software
- VS Code
- Notepad++/TextEdit
- jq (CLI)
Alternative methods
- Open .CRL in a browser-based viewer if desktop apps fail.
- Try opening .CRL on Mac with a secondary app to rule out app-specific issues.
- Convert .CRL only with trusted tools when direct opening is not possible.
Common issues
OpenSSL says it cannot read the CRL (PEM/DER mismatch)
CRLs are commonly stored as either DER (binary) or PEM (Base64). If the tool assumes the wrong encoding, it may fail to parse the file.
- Try OpenSSL with an explicit input format: openssl crl -inform DER -in file.crl -noout -text
- If it’s PEM, ensure the file contains a PEM header/footer (often begins with '-----BEGIN X509 CRL-----') and rerun without -inform DER
Windows import/view fails or shows unexpected results
The CRL may be corrupted/incomplete, or you may be importing it into the wrong store/context (for example, expecting it to apply to a different CA).
- Re-download the .crl from its official distribution source (for example, the CA’s published CRL URL) and try again.
- Confirm the CRL issuer matches the CA you expect by inspecting it (e.g., with OpenSSL text output) before importing.
The CRL appears “expired” or not yet valid
CRLs include update timing fields; if the system clock is wrong, or the CRL is older than expected, validation tooling may treat it as stale.
- Check your device date/time settings and correct them if necessary.
- Obtain the latest base/delta CRL from the official CA distribution location and re-check.
Security note
A CRL is signed PKI data; treat it as untrusted input until parsed by reputable tooling—malformed ASN.1/DER data can trigger vulnerabilities in buggy parsers.