OpenSSL
Useful commands for OpenSSL
CRLs
Parsing a CRL: openssl crl -inform DER -text -noout -in mycrl.crl
PKCS12
Reading a PKCS12 file: openssl pkcs12 -info -in some_file.p12
X.509
- Parsing a PEM file:
openssl x509 -text -in some_file -inform pem - Download and parse certificate:
echo | openssl s_client -starttls=smtp -connect some_domain.tld:25 2>/dev/null | openssl x509 -text
Connect with TLS
- Connect to SMTP:
openssl s_client -connect some_domain.tld:587 -starttls smtp - Download certificate (HTTPS w/o SNI):
openssl s_client -showcerts -connect some_domain.tld:443 </dev/null - Download certificate (HTTPS w/ SNI):
openssl s_client -showcerts -servername some_domain.tld -connect some_domain.tld:443 </dev/null