Section: OpenSSL (1SSL)
The CA.pl script is a perl script that supplies the relevant command line arguments to the openssl command for some common certificate operations. It is intended to simplify the process of certificate creation and management by the use of some simple options.
- ?, -h, -help
- prints a usage message.:
- creates a new self signed certificate. The private key is written to the file ``newkey.pem and the request written to the file ``newreq.pem.:
- creates a new certificate request. The private key is written to the file ``newkey.pem and the request written to the file ``newreq.pem.:
- is like -newreq except that the private key will not be encrypted.:
- creates a new CA hierarchy for use with the ca program (or the -signcert and -xsign options). The user is prompted to enter the filename of the CA certificates (which should also contain the private key) or by hitting ENTER details of the CA will be prompted for. The relevant files and directories are created in a directory called ``demoCA'' in the current directory.:
- create a PKCS#12 file containing the user certificate, private key and CA certificate. It expects the user certificate and private key to be in the file ``newcert.pem and the CA certificate to be in the file demoCA/cacert.pem, it creates a file ``newcert.p12. This command can thus be called after the -sign option. The PKCS#12 file can be imported directly into a browser. If there is an additional argument on the command line it will be used as the ``friendly name for the certificate (which is typically displayed in the browser list box), otherwise the name ``My Certificate is used.:
- -sign, -signreq, -xsign
- calls the ca program to sign a certificate request. It expects the request to be in the file ``newreq.pem. The new certificate is written to the file ``newcert.pem except in the case of the -xsign option when it is written to standard output.:
- this option is the same as the -signreq option except it uses the configuration file section v3_ca and so makes the signed request a valid CA certificate. This is useful when creating intermediate CA from a root CA.:
- this option is the same as -sign except it expects a self signed certificate to be present in the file ``newreq.pem''.:
- verifies certificates against the CA certificate for ``demoCA. If no certificates are specified on the command line it tries to verify the file ``newcert.pem.:
- one or more optional certificate file names for use with the -verify command.:
Create a CA hierarchy:
Complete certificate creation example: create a CA, create a request, sign the request and finally create a PKCS#12 file containing it.
CA.pl -newca CA.pl -newreq CA.pl -signreq CA.pl -pkcs12 "My Test Certificate"
Although the CA.pl creates RSA CAs and requests it is still possible to use it with DSA certificates and requests using the req?(1) command directly. The following example shows the steps that would typically be taken.
Create some DSA parameters:
openssl dsaparam -out dsap.pem 1024
Create a DSA CA certificate and private key:
openssl req -x509 -newkey dsa:dsap.pem -keyout cacert.pem -out cacert.pem
Create the CA directories and files:
enter cacert.pem when prompted for the CA file name.
Create a DSA certificate request and private key (a different set of parameters can optionally be created first):
openssl req -out newreq.pem -newkey dsa:dsap.pem
Sign the request:
Most of the filenames mentioned can be modified by editing the CA.pl script.
If the demoCA directory already exists then the -newca command will not overwrite it and will do nothing. This can happen if a previous call using the -newca option terminated abnormally. To get the correct behaviour delete the demoCA directory if it already exists.
Under some environments it may not be possible to run the CA.pl script directly (for example Win32) and the default configuration file location may be wrong. In this case the command:
perl -S CA.pl
can be used and the OPENSSL_CONF environment variable changed to point to the correct path of the configuration file ``openssl.cnf''.
The script is intended as a simple front end for the openssl program for use by a beginner. Its behaviour isn't always what is wanted. For more control over the behaviour of the certificate commands call the openssl command directly.