Building a Secure RedHat Apache Server HOWTO: Troubleshooting

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## 5. Troubleshooting

Here are some common problems that may arise.

## 5.1 Server Appears to start, but you cannot access the secure site

Check the `error_log` file. If you did not set your virtual host to write to an error log, you may want to reconsider. The example SSL virtual host writes to an error log file. Most likely you will have a few warnings and an error at the end of the log that basically say that the private key does not match the certificate.

Example:

> `

>     [Tue Nov 21 09:09:02 2000] [notice] Apache/1.3.14 (Unix) mod_ssl/2.7.1
>     OpenSSL/0.9.6 configured -- resuming normal operations
>     [Tue Nov 21 09:09:16 2000] [notice] caught SIGTERM, shutting down
>     [Tue Nov 21 14:39:54 2000] [notice] Apache/1.3.14 (Unix) mod_ssl/2.7.1
>     OpenSSL/0.9.6 configured -- resuming normal operations
>     [Tue Nov 21 14:40:31 2000] [notice] caught SIGTERM, shutting down
>     [Tue Nov 21 14:43:53 2000] [error] mod_ssl: Init: (esi.fin.equifax.com:443)
>     Unable to configure RSA server private key (OpenSSL library error follows)
>     [Tue Nov 21 14:43:53 2000] [error] OpenSSL: error:0B080074:x509 certificate
>     routines:X509_check_private_key:key values mismatch

> `

If you get the error messages above, chances are the key and certificate do not match. Make sure you aren't using the default `server.key` file. You should also check the `httpd.conf` file to make sure that the directives are pointing to the correct private key and certificate.

You can check to make sure that you your private key and certificate are in the correct format and match each other. To do this, give the commands below to decrypt the private key in one terminal window and decrypt the certificate in the other. What you will be comparing are the Modulus and the Exponent of each key. If the modulus and exponent from the key matches the set from the certificate, you have just confirmed that your certificate and key are correctly paired.

If all else fails, create a new private key, CSR or self-signed certificate. Before you do this, check your CA's re-issue policy. You may be charged for a re-issue.

To view the contents of the certificate:

> `

>     openssl x509 -noout -text -in filename.crt

> `

To view the contents of the private key:

> `

>     openssl rsa -noout -text -in filename.key

> `

## 5.2 Certificate Name Check Warning is issued by the client's browser

The most common cause for this is omitting the "www" at the beginning of the domain name when creating the CSR. The name defined by the "ServerName" directive for that virtual host must match the domain name presented by the certificate exactly or the browser will let the client know. The exception is a wild card certificate. A wild card certificate's domain name field would look like *.somedomain.com. This enables you to use one certificate for any number of sub-domains of somedomain.com (e.g. host1.somedomain.com and host2.somedomain.com).

## 5.3 Certificate was Signed by an Untrusted Certificate Authority Warning is issued by the client's browser

If you are using a self-signed certificate, you will get this warning. Your clients will be given the option to trust your certificate or not. If you have a CA signed certificate and are getting the untrusted warning, you probably need to install their intermediate (root) certificate.

## 5.4 SSLEngine on is an un-recognized command (when starting Apache)

This error message is issued if you do not have ModSSL compiled with Apache. Some SSL packages use a different directive to start SSL within a virtual host. If you are using a package that does use a different directive, you will also receive this error message.

## 5.5 You have forgotten your "PEM Passphrase" and you would like to know how to reset it

There is no way to reset this passphrase. The only solution is to remember the passphrase or create a new private key. You will then need to obtain a new certificate or create a new self-signed certificate.

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