Verify SSL Certificate matches Private Key
From Leo's Notes
This page was last edited on 8 May 2019, at 20:18.
When given a private key and a signed SSL certificate, to validate whether the private key matches that of the certificate:
# openssl x509 -modulus -noout -in server.crt
Modulus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
# openssl rsa -modulus -noout -in server.key
Modulus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
If the two modulus matches, the private key is for the certificate.