Problems installing SSL certificate on nginx with intermediate key

Question

I am trying to install an SSL certificate on my Ubuntu server. I have purchased the certificate from my CA and have downloaded the certificate itself and an intermediate certificate. As so:

my certificate: mydomain.crt
intermediate certificate: GandiStandardSSLCA.pem

I also have (made using openssl)

my private key (?): mydomain.key
and signing request: mydomain.csr

I have uploaded all these files to my server and followed a guide to combine my certificate with the intermediate:

cat mydomain.crt GandiStandardSSLCA.pem > mydomain-bundle.crt

I then add the following to my vhost's config:

listen   443 ssl;
ssl_certificate       /etc/nginx/ssl/mydomain-bundle.crt;
ssl_certificate_key   /etc/nginx/ssl/mydomain.key;

But when I go to restart nginx I get this error:

* Restarting nginx
* Stopping nginx nginx [ OK ]
nginx: [emerg] SSL_CTX_use_PrivateKey_file("/etc/nginx/ssl/mydomain.key") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch) nginx: configuration file /etc/nginx/nginx.conf test failed

Any ideas why and how to solve?

Answer 1

Does your key list ok:

openssl rsa -in /etc/nginx/ssl/mydomain.key

Do the modulus of the key and the cert match:

openssl x509  -in mydomain.crt -modulus 

openssl rsa  -in qa.server.key  -modulus

These numbers must match.