Openssl req: certificate request generating utility-new: generates a new certificate request-key: specifies the file to read the private key from-out: specifies the output filename-subj: sets certificate subject.
Name
config - OpenSSL CONF library configuration files
Description
The OpenSSL CONF library can be used to read configuration files. It is used for the OpenSSL master configuration file openssl.cnf andin a few other places like SPKAC files and certificate extension files for the x509 utility. OpenSSL applications can also use theCONF library for their own purposes.
A configuration file is divided into a number of sections. Each section starts with a line [ section_name ] and ends when a new section is started orend of file is reached. A section name can consist of alphanumeric characters and underscores.
The first section of a configuration file is special and is referred to as the default section this is usually unnamed and is from the start of fileuntil the first named section. When a name is being looked up it is first looked up in a named section (if any) and then the default section.
The environment is mapped onto a section called ENV .
Comments can be included by preceding them with the # character
Each section in a configuration file consists of a number of name and value pairs of the form name=value
The name string can contain any alphanumeric characters as well as a few punctuation symbols such as . , ; and _.
The value string consists of the string following the = character until end of line with any leading and trailing white space removed.
The value string undergoes variable expansion. This can be done by including the form $var or ${var}: this will substitute the valueof the named variable in the current section. It is also possible to substitute a value from another section using the syntax $section::name or${section::name}. By using the form $ENV::name environment variables can be substituted. It is also possible to assign values toenvironment variables by using the name ENV::name, this will work if the program looks up environment variables using the CONFlibrary instead of calling getenv() directly.
It is possible to escape certain characters by using any kind of quote or the character. By making the last character of a line a avalue string can be spread across multiple lines. In addition the sequences n, r, b and t arerecognized.
Openssl Library Configuration
In OpenSSL 0.9.7 and later applications can automatically configure certain aspects of OpenSSL using the master OpenSSL configuration file, or optionally analternative configuration file. The openssl utility includes this functionality: any sub command uses the master OpenSSL configuration file unless anoption is used in the sub command to use an alternative configuration file.
To enable library configuration the default section needs to contain an appropriate line which points to the main configuration section. The default name isopenssl_conf which is used by the openssl utility. Other applications may use an alternative name such as myapplicaton_conf.
The configuration section should consist of a set of name value pairs which contain specific module configuration information. The name representsthe name of the configuration module the meaning of the value is module specific: it may, for example, represent a further configuration sectioncontaining configuration module specific information. E.g.Currently there are two configuration modules. One for ASN1 objects another for ENGINE configuration.
ASN1 OBJECT CONFIGURATION MODULE
The command init determines whether to initialize the ENGINE . If the value is 0 the ENGINE will not beinitialized, if 1 and attempt it made to initialized the ENGINE immediately. If the init command is not present then an attemptwill be made to initialize the ENGINE after all commands in its section have been processed.
The command default_algorithms sets the default algorithms an ENGINE will supply using the functionsENGINE_set_default_string()
If the name matches none of the above command names it is assumed to be a ctrl command which is sent to the ENGINE . The value of the commandis the argument to the ctrl command. If the value is the string EMPTY then no value is sent to the command.
For example:
Notes
If a configuration file attempts to expand a variable that doesn't exist then an error is flagged and the file will not load. This can happen if an attemptis made to expand an environment variable that doesn't exist. For example in a previous version of OpenSSL the default OpenSSL master configuration file usedthe value of HOME which may not be defined on non Unix systems and would cause an error.
This can be worked around by including a default section to provide a default value: then if the environment lookup fails the default value will beused instead. For this to work properly the default value must be defined earlier in the configuration file than the expansion. See theEXAMPLES section for an example of how to do this.
If the same variable exists in the same section then all but the last value will be silently ignored. In certain circumstances such as with DNs the samefield may occur multiple times. This is usually worked around by ignoring any characters before an initial . e.g.
Examples
Here is a sample configuration file using some of the features mentioned above.This next example shows how to expand environment variables safely.
Suppose you want a variable called tmpfile to refer to a temporary filename. The directory it is placed in can determined by the theTEMP or TMP environment variables but they may not be set to any value at all. If you just include the environmentvariable names and the variable doesn't exist then this will cause an error when an attempt is made to load the configuration file. By making use of thedefault section both values can be looked up with TEMP taking priority and /tmp used if neither is defined:
Bugs
Currently there is no way to include characters using the octal nnn form. Strings are all null terminated so nulls cannot form part of the value.
The escaping isn't quite right: if you want to use sequences like n you can't use any quote escaping on the same line.
Files are loaded in a single pass. This means that an variable expansion will only work if the variables referenced are defined earlier in thefile.
See Also
x509(1), req(1), ca(1)
Referenced By
ca.pl(1),openssl(1)Create the OpenSSL Configuration File
This sample was created for Ubuntu and Debian servers, Red Hat and CentOS have a different path for Apache files.
The Apache path for Ubuntu and Debian is /etc/apache2, on Red Hat and CentOS it is /etc/httpd.
Edit file /etc/ssl/openssl.cnf
Create the Certification Authority (CA)
Create the folder structure to hold certificates:
$ mkdir /opt/met-ca
$ mkdir /opt/met-ca/certs
$ mkdir /opt/met-ca/crl
$ mkdir /opt/met-ca/newcerts
$ mkdir /opt/met-ca/private
$ mkdir /opt/met-ca/requests
$ touch /opt/met-ca/index.txt
$ echo “01” > /opt/ca/serial
$ echo “01” > /opt/ca/crlnumber
$ chmod 700 /opt/ca
$ mkdir /opt/met-ca/certs
$ mkdir /opt/met-ca/crl
$ mkdir /opt/met-ca/newcerts
$ mkdir /opt/met-ca/private
$ mkdir /opt/met-ca/requests
$ touch /opt/met-ca/index.txt
$ echo “01” > /opt/ca/serial
$ echo “01” > /opt/ca/crlnumber
$ chmod 700 /opt/ca
Create public and private auto signed keys of our own Certification Authority (in the example it is valid for 10 years). We will need to specify certificate data, the password for encryption and the process will generate two files:
$ openssl req -config /etc/ssl/openssl.cnf -new -x509 -days 3650 -sha1 -newkey rsa:2048 -keyout /opt/ca/private/ca.key -out /opt/ca/ca.crt
Change key grants:
Create Apache Certification
Create a pair of keys. We will need to specify the password and certification data. A file key (server.key) and certification request (server.pem) will be created.
$ openssl req -new -sha1 -newkey rsa:2048 -nodes -keyout server.key -out server.pem
CA should sign the certification request. Copy server.pem to certification request and sign.
$ openssl ca -config /etc/ssl/openssl.cnf -policy policy_anything -extensions ssl_server -out requests/server-signed.pem -infiles requests/server.pem
Apache will need a PEM format, is mandatory to convert to this format:
$ openssl x509 -in requests/server-signed.pem -out requests/server.crt
Apache Configuration
Copy server.crt and the server.key into /etc/apache2/ssl (if no SSL folder exists, create it). Change files grants (server.key should only be read by the root user, server.crt should have read permission granted to everyone):
If Apache is not listening to the SSL port, enable it configuring /etc/apache2/ports.conf:
Enable Apache SSL support:
$ apt-get install libapache-mod-ssl
Set Apache to load SSL modules:
Configure the website:
Link the default-ssl file to enable SSL:
$ ln -s /etc/apache2/sites-available/default-ssl /etc/apache2/sites-enabled/default-ssl
Edit /etc/apache2/sites-availables/default-ssl (enable SSL engine and set SSLCertificateFile and SSLCertificateKeyFile)
Create user certificates:
To create certificates and sign with CA, first create the pair of keys. We will need to specify the password and certification data. A key (user.key) and certification request (user.pem) will be created:
$ openssl req -new -sha1 -newkey rsa:2048 -nodes -keyout user.key -out user.pem
Sign certificates with CA:
$ cp /tmp/usuario.pem /opt/ca/requests
$ openssl ca -config /etc/ssl/openssl.cnf -policy policy_anything -extensions [b]ssl_client[/b] -out requests/user-signed.pem -infiles requests/user.pem
$ openssl ca -config /etc/ssl/openssl.cnf -policy policy_anything -extensions [b]ssl_client[/b] -out requests/user-signed.pem -infiles requests/user.pem
Convert certificate to PKCS12 to be recognized by the browser:
$ openssl pkcs12 -export -clcerts -in user-signed.pem -inkey usuario.key -out user.p12
The files user-signed.pem, user.pem and user.key can be deleted
The user.p12 should be installed to allow browser use.
Certification Revocation
If the server has been compromised the CA should be revocated. To revocate a certificate find the serial number at /opt/ca/index.txt.
$ openssl ca -config /etc/ssl/openssl.cnf -revoke newcerts/<serial-number>.pem
Creat a list of certificates (CRL) to be revocated.
$ openssl ca -config /etc/ssl/openssl.cnf -gencrl -crlexts crl_ext -md sha1 -out crl.pem
To send it to the browser the list should be converted to DER format:
$ openssl crl -in crl.pem -out ca.crl -outform DER
Now send the list to the browser.
Add CRL to Apache
Copy the CRL file to the Apache SSL folder:
Modify /etc/apache2/sites-available/default-ssl file, add SSLCARevocationFile:
Restart Apache service.