OpenSSL certificate checking
Check a certificate Information about it (signing authority, expiration date, etc.): openssl x509 -in server.crt -text -noout Check a key Check the SSL key and verify the consistency: openssl rsa -in server.key -check Check a CSR Verify the CSR and print CSR data filled in when generating the CSR: openssl req -text -noout -verify -in server.csr Verify a certificate and key matches The checksums can be compared to verify that the certificate and key match. openssl x509 -noout -modulus -in server.crt | openssl md5 openssl rsa -noout -modulus -in server.key | openssl md5 Verifying that a Certificate is issued by a CA Verify that a certificate was issued by a specific CA, given that CA's certificate openssl verify -verbose -CAfile cacert.pem server.crt server.crt: OK