You can use openssl commands to check a certificate against a key and against a certificate authority.
For example:
#Check if key matches certificate, these modulus would match.
openssl rsa -noout -modulus -in server.key
openssl x509 -noout -modulus -in server.crt
# Check if a certificate is valid for a given CA/Intermediate.
openssl verify -CAfile root.crt -untrusted intermediate.crt server.crt
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Greg Wootton | Principal Systems Technical Support Engineer