Certificates

See the Objects section for related information on these screens.

Certificates Overview

The ZyWALL can use certificates (also called digital IDs) to authenticate users. Certificates are based on public-private key pairs. A certificate contains the certificate owner's identity and public key. Certificates provide a way to exchange public keys for use in authentication.

A Certification Authority (CA) issues certificates and guarantees the identity of each certificate owner. There are commercial certification authorities like CyberTrust or VeriSign and government certification authorities. You can use the ZyWALL to generate certification requests that contain identifying information and public keys and then send the certification requests to a certification authority.

When using public-key cryptology for authentication, each host has two keys. One key is public and can be made openly available; the other key is private and must be kept secure. Public-key encryption in general works as follows.

The ZyWALL uses certificates based on public-key cryptology to authenticate users attempting to establish a connection, not to encrypt the data that you send after establishing a connection. The method used to secure the data that you send through an established connection depends on the type of connection. For example, a VPN tunnel might use the triple DES encryption algorithm.

The certification authority uses its private key to sign certificates. Anyone can then use the certification authority's public key to verify the certificates.

A certification path is the hierarchy of certification authority certificates that validate a certificate. The ZyWALL does not trust a certificate if any certificate on its path has expired or been revoked.

Certification authorities maintain directory servers with databases of valid and revoked certificates. A directory of certificates that have been revoked before the scheduled expiration is called a CRL (Certificate Revocation List). The ZyWALL can check a peer's certificate against a directory server's list of revoked certificates. The framework of servers, software, procedures and policies that handles keys is called PKI (public-key infrastructure).

Advantages of Certificates

Certificates offer the following benefits.

Self-signed Certificates

Until public-key infrastructure becomes more mature, it may not be available in some areas. You can have the ZyWALL act as a certification authority and sign its own certificates.

Factory Default Certificate

The ZyWALL generates its own unique self-signed certificate when you first turn it on. This certificate is referred to in the GUI as the factory default certificate.

Certificate File Formats

Any certificate that you want to import has to be in one of these file formats:

Note: Be careful to not convert a binary file to text during the transfer process. It is easy for this to occur since many programs use text files by default.

Verifying a Certificate

Before you import a certificate into the ZyWALL, you should verify that you have the actual certificate. This is especially true of trusted certificates since the ZyWALL also trusts any valid certificate signed by any of the imported trusted certificates.

Checking the Fingerprint of a Certificate on Your Computer

A certificate's fingerprints are message digests calculated using the MD5 or SHA1 algorithms. The following procedure describes how to check a certificate's fingerprint to verify that you have the actual certificate.

My Certificates Screen

This is the ZyWALL's summary list of certificates and certification requests.

Object > Certificate > My Certificates 

Label
Description
PKI Storage Space in Use
This bar displays the percentage of the ZyWALL's PKI storage space that is currently in use. When the storage space is almost full, you should consider deleting expired or unnecessary certificates before adding more certificates.
#
This field displays the certificate index number. The certificates are listed in alphabetical order.
Name
This field displays the name used to identify this certificate. It is recommended that you give each certificate a unique name.
Type
This field displays what kind of certificate this is.
REQ represents a certification request and is not yet a valid certificate. Send a certification request to a certification authority, which then issues a certificate. Use the My Certificate Import screen to import the certificate and replace the request.
SELF represents a self-signed certificate.
CERT represents a certificate issued by a certification authority.
Subject
This field displays identifying information about the certificate's owner, such as CN (Common Name), OU (Organizational Unit or department), O (Organization or company) and C (Country). It is recommended that each certificate have unique subject information.
Issuer
This field displays identifying information about the certificate's issuing certification authority, such as a common name, organizational unit or department, organization or company and country. With self-signed certificates, this is the same information as in the Subject field.
Valid From
This field displays the date that the certificate becomes applicable.
Valid To
This field displays the date that the certificate expires. The text displays in red and includes an Expired! message if the certificate has expired.
Modify
Click the Add icon to go to the screen where you can have the ZyWALL generate a certificate or a certification request.
Click the Edit icon to open a screen with an in-depth list of information about the certificate.
The ZyWALL keeps all of your certificates unless you specifically delete them. Uploading a new firmware or default configuration file does not delete your certificates.
Click the Delete icon to remove a certificate. A window displays asking you to confirm that you want to delete the certificate. Subsequent certificates move up by one when you take this action.
You cannot delete certificates that any of the ZyWALL's features are configured to use.
Import
Click Import to open a screen where you can save a certificate to the ZyWALL.
Refresh
Click Refresh to display the current validity status of the certificates.

My Certificates Add Screen

Use this screen to have the ZyWALL create a self-signed certificate, enroll a certificate with a certification authority or generate a certification request.

Object > Certificate > My Certificates > Add 

Label
Description
Name
Type a name to identify this certificate. You can use up to 31 alphanumeric and ;`~!@#$%^&()_+[]{}',.=- characters.
Subject Information
Use these fields to record information that identifies the owner of the certificate. You do not have to fill in every field, although the Common Name is mandatory. The certification authority may add fields (such as a serial number) to the subject information when it issues a certificate. It is recommended that each certificate have unique subject information.
Common Name
Select a radio button to identify the certificate's owner by IP address, domain name or e-mail address. Type the IP address (in dotted decimal notation), domain name or e-mail address in the field provided. The domain name or e-mail address is for identification purposes only and can be any string.
A domain name can be up to 255 characters. You can use alphanumeric characters, the hyphen and periods.
An e-mail address can be up to 63 characters. You can use alphanumeric characters, the hyphen, the @ symbol, periods and the underscore.
Organizational Unit
Identify the organizational unit or department to which the certificate owner belongs. You can use up to 31 characters. You can use alphanumeric characters, the hyphen and the underscore.
Organization
Identify the company or group to which the certificate owner belongs. You can use up to 31 characters. You can use alphanumeric characters, the hyphen and the underscore.
Country
Identify the nation where the certificate owner is located. You can use up to 31 characters. You can use alphanumeric characters, the hyphen and the underscore.
Key Type
Select RSA to use the Rivest, Shamir and Adleman public-key algorithm.
Select DSA to use the Digital Signature Algorithm public-key algorithm.
Key Length
Select a number from the drop-down list box to determine how many bits the key should use (512 to 2048). The longer the key, the more secure it is. A longer key also uses more PKI storage space.
Enrollment Options
These radio buttons deal with how and when the certificate is to be generated.
Create a self-signed certificate
Select Create a self-signed certificate to have the ZyWALL generate the certificate and act as the Certification Authority (CA) itself. This way you do not need to apply to a certification authority for certificates.
Create a certification request and save it locally for later manual enrollment
Select Create a certification request and save it locally for later manual enrollment to have the ZyWALL generate and store a request for a certificate. Use the My Certificate Details screen to view the certification request and copy it to send to the certification authority.
Copy the certification request from the My Certificate Details screen and then send it to the certification authority.
Create a certification request and enroll for a certificate immediately online
Select Create a certification request and enroll for a certificate immediately online to have the ZyWALL generate a request for a certificate and apply to a certification authority for a certificate.
You must have the certification authority's certificate already imported in the Trusted Certificates screen.
When you select this option, you must select the certification authority's enrollment protocol and the certification authority's certificate from the drop-down list boxes and enter the certification authority's server address. You also need to fill in the Reference Number and Key if the certification authority requires them.
Enrollment Protocol
This field applies when you select Create a certification request and enroll for a certificate immediately online. Select the certification authority's enrollment protocol from the drop-down list box.
Simple Certificate Enrollment Protocol (SCEP) is a TCP-based enrollment protocol that was developed by VeriSign and Cisco.
Certificate Management Protocol (CMP) is a TCP-based enrollment protocol that was developed by the Public Key Infrastructure X.509 working group of the Internet Engineering Task Force (IETF) and is specified in RFC 2510.
CA Server Address
This field applies when you select Create a certification request and enroll for a certificate immediately online. Enter the IP address (or URL) of the certification authority server.
For a URL, you can use up to 511 of the following characters. a-zA-Z0-9'()+,/:.=?;!*#@$_%-
CA Certificate
This field applies when you select Create a certification request and enroll for a certificate immediately online. Select the certification authority's certificate from the CA Certificate drop-down list box.
You must have the certification authority's certificate already imported in the Trusted Certificates screen. Click Trusted CAs to go to the Trusted Certificates screen where you can view (and manage) the ZyWALL's list of certificates of trusted certification authorities.
Request Authentication
When you select Create a certification request and enroll for a certificate immediately online, the certification authority may want you to include a reference number and key to identify you when you send a certification request.
Fill in both the Reference Number and the Key fields if your certification authority uses CMP enrollment protocol. Just the Key field displays if your certification authority uses the SCEP enrollment protocol.
For the reference number, use 0 to 99999999.
For the key, use up to 31 of the following characters. a-zA-Z0-9;|`~!@#$%^&*()_+\{}':,./<>=-
OK
Click OK to begin certificate or certification request generation.
Cancel
Click Cancel to quit and return to the My Certificates screen.

If you configured the My Certificate Create screen to have the ZyWALL enroll a certificate and the certificate enrollment is not successful, you see a screen with a Return button that takes you back to the My Certificate Create screen. Click Return and check your information in the My Certificate Create screen. Make sure that the certification authority information is correct and that your Internet connection is working properly if you want the ZyWALL to enroll a certificate online.

My Certificate Edit Screen

You can use this screen to view in-depth certificate information and change the certificate's name.

Object > Certificate > My Certificates > Edit

Label
Description
Name
This field displays the identifying name of this certificate. You can use up to 31 alphanumeric and ;`~!@#$%^&()_+[]{}',.=- characters.
Certification Path
This field displays for a certificate, not a certification request.
Click the Refresh button to have this read-only text box display the hierarchy of certification authorities that validate the certificate (and the certificate itself).
If the issuing certification authority is one that you have imported as a trusted certification authority, it may be the only certification authority in the list (along with the certificate itself). If the certificate is a self-signed certificate, the certificate itself is the only one in the list. The ZyWALL does not trust the certificate and displays "Not trusted" in this field if any certificate on the path has expired or been revoked.
Refresh
Click Refresh to display the certification path.
Certificate Information
These read-only fields display detailed information about the certificate.
Type
This field displays general information about the certificate. CA-signed means that a Certification Authority signed the certificate. Self-signed means that the certificate's owner signed the certificate (not a certification authority). "X.509" means that this certificate was created and signed according to the ITU-T X.509 recommendation that defines the formats for public-key certificates.
Version
This field displays the X.509 version number. "
Serial Number
This field displays the certificate's identification number given by the certification authority or generated by the ZyWALL.
Subject
This field displays information that identifies the owner of the certificate, such as Common Name (CN), Organizational Unit (OU), Organization (O) and Country (C).
Issuer
This field displays identifying information about the certificate's issuing certification authority, such as Common Name, Organizational Unit, Organization and Country.
With self-signed certificates, this is the same as the Subject Name field.
"none" displays for a certification request.
Signature Algorithm
This field displays the type of algorithm that was used to sign the certificate. The ZyWALL uses rsa-pkcs1-sha1 (RSA public-private key encryption algorithm and the SHA1 hash algorithm). Some certification authorities may use rsa-pkcs1-md5 (RSA public-private key encryption algorithm and the MD5 hash algorithm).
Valid From
This field displays the date that the certificate becomes applicable. "none" displays for a certification request.
Valid To
This field displays the date that the certificate expires. The text displays in red and includes an Expired! message if the certificate has expired. "none" displays for a certification request.
Key Algorithm
This field displays the type of algorithm that was used to generate the certificate's key pair (the ZyWALL uses RSA encryption) and the length of the key set in bits (1024 bits for example).
Subject Alternative Name
This field displays the certificate owner`s IP address (IP), domain name (DNS) or e-mail address (EMAIL).
Key Usage
This field displays for what functions the certificate's key can be used. For example, "DigitalSignature" means that the key can be used to sign certificates and "KeyEncipherment" means that the key can be used to encrypt text.
Basic Constraint
This field displays general information about the certificate. For example, Subject Type=CA means that this is a certification authority's certificate and "Path Length Constraint=1" means that there can only be one certification authority in the certificate's path. This field does not display for a certification request.
MD5 Fingerprint
This is the certificate's message digest that the ZyWALL calculated using the MD5 algorithm.
SHA1 Fingerprint
This is the certificate's message digest that the ZyWALL calculated using the SHA1 algorithm.
Certificate in PEM (Base-64) Encoded Format
This read-only text box displays the certificate or certification request in Privacy Enhanced Mail (PEM) format. PEM uses 64 ASCII characters to convert the binary certificate into a printable form.
You can copy and paste a certification request into a certification authority's web page, an e-mail that you send to the certification authority or a text editor and save the file on a management computer for later manual enrollment.
You can copy and paste a certificate into an e-mail to send to friends or colleagues or you can copy and paste a certificate into a text editor and save the file on a management computer for later distribution (via floppy disk for example).
Export
This button displays for a certification request. Use this button to save a copy of the request without its private key. Click this button and then Save in the File Download screen. The Save As screen opens, browse to the location that you want to use and click Save.
Export Certificate Only
Use this button to save a copy of the certificate without its private key. Click this button and then Save in the File Download screen. The Save As screen opens, browse to the location that you want to use and click Save.
Password
If you want to export the certificate with its private key, create a password and type it here. Make sure you keep this password in a safe place. You will need to use it if you import the certificate to another device.
Export Certificate with Private Key
Use this button to save a copy of the certificate with its private key. Type the certificate's password and click this button. Click Save in the File Download screen. The Save As screen opens, browse to the location that you want to use and click Save.
OK
Click OK to save your changes back to the ZyWALL. You can only change the name.
Cancel
Click Cancel to quit and return to the My Certificates screen.

My Certificate Import Screen

Follow the instructions in this screen to save an existing certificate to the ZyWALL.

Note: You can import a certificate that matches a corresponding certification request that was generated by the ZyWALL. You can also import a certificate in PKCS#12 format, including the certificate's public and private keys.

The certificate you import replaces the corresponding request in the My Certificates screen.

You must remove any spaces from the certificate's filename before you can import it.

Object > Certificate > My Certificates > Import 

Label
Description
File Path
Type in the location of the file you want to upload in this field or click Browse to find it.
You cannot import a certificate with the same name as a certificate that is already in the ZyWALL.
Browse
Click Browse to find the certificate file you want to upload.
Password
This field only applies when you import a binary PKCS#12 format file. Type the file's password that was created when the PKCS #12 file was exported.

Trusted Certificates Screen

This screen displays a summary list of certificates that you have set the ZyWALL to accept as trusted. The ZyWALL also accepts any valid certificate signed by a certificate on this list as being trustworthy; thus you do not need to import any certificate that is signed by one of these certificates.

OCSP

OCSP (Online Certificate Status Protocol) allows an application or device to check whether a certificate is valid. With OCSP the ZyWALL checks the status of individual certificates instead of downloading a Certificate Revocation List (CRL). OCSP has two main advantages over a CRL. The first is real-time status information. The second is a reduction in network traffic since the ZyWALL only gets information on the certificates that it needs to verify, not a huge list. When the ZyWALL requests certificate status information, the OCSP server returns a "expired", "current" or "unknown" response.

Object > Certificate > Trusted Certificates 

Label
Description
PKI Storage Space in Use
This bar displays the percentage of the ZyWALL's PKI storage space that is currently in use. When the storage space is almost full, you should consider deleting expired or unnecessary certificates before adding more certificates.
#
This field displays the certificate index number. The certificates are listed in alphabetical order.
Name
This field displays the name used to identify this certificate.
Subject
This field displays identifying information about the certificate's owner, such as CN (Common Name), OU (Organizational Unit or department), O (Organization or company) and C (Country). It is recommended that each certificate have unique subject information.
Issuer
This field displays identifying information about the certificate's issuing certification authority, such as a common name, organizational unit or department, organization or company and country. With self-signed certificates, this is the same information as in the Subject field.
Valid From
This field displays the date that the certificate becomes applicable.
Valid To
This field displays the date that the certificate expires. The text displays in red and includes an Expired! message if the certificate has expired.
Modify
Click the Edit icon to open a screen with an in-depth list of information about the certificate.
The ZyWALL keeps all of your certificates unless you specifically delete them. Uploading a new firmware or default configuration file does not delete your certificates.
Click the Delete icon to remove a certificate. A window displays asking you to confirm that you want to delete the certificates. Note that subsequent certificates move up by one when you take this action.
Import
Click Import to open a screen where you can save the certificate of a certification authority that you trust, from your computer to the ZyWALL.
Refresh
Click this button to display the current validity status of the certificates.

Trusted Certificates Edit Screen

Use this screen to view in-depth information about the certificate, change the certificate's name and set whether or not you want the ZyWALL to check a certification authority's list of revoked certificates before trusting a certificate issued by the certification authority.

Object > Certificate > Trusted Certificates > Edit 

Label
Description
Name
This field displays the identifying name of this certificate. You can change the name. You can use up to 31 alphanumeric and ;`~!@#$%^&()_+[]{}',.=- characters.
Certification Path
Click the Refresh button to have this read-only text box display the end entity's certificate and a list of certification authority certificates that shows the hierarchy of certification authorities that validate the end entity's certificate. If the issuing certification authority is one that you have imported as a trusted certificate, it may be the only certification authority in the list (along with the end entity's own certificate). The ZyWALL does not trust the end entity's certificate and displays "Not trusted" in this field if any certificate on the path has expired or been revoked.
Refresh
Click Refresh to display the certification path.
Enable X.509v3 CRL Distribution Points and OCSP checking
Select this check box to have the ZyWALL check incoming certificates that are signed by this certificate against a Certificate Revocation List (CRL) or an OCSP server. You also need to configure the OSCP or LDAP server details.
OCSP Server
Select this check box if the directory server uses OCSP (Online Certificate Status Protocol).
URL
Type the protocol, IP address and pathname of the OCSP server.
ID
The ZyWALL may need to authenticate itself in order to assess the OCSP server. Type the login name (up to 31 ASCII characters) from the entity maintaining the server (usually a certification authority).
Password
Type the password (up to 31 ASCII characters) from the entity maintaining the OCSP server (usually a certification authority).
LDAP Server
Select this check box if the directory server uses LDAP (Lightweight Directory Access Protocol). LDAP is a protocol over TCP that specifies how clients access directories of certificates and lists of revoked certificates.
Address
Type the IP address (in dotted decimal notation) of the directory server.
Port
Use this field to specify the LDAP server port number.
You must use the same server port number that the directory server uses.
389 is the default server port number for LDAP.
ID
The ZyWALL may need to authenticate itself in order to assess the CRL directory server. Type the login name (up to 31 ASCII characters) from the entity maintaining the server (usually a certification authority).
Password
Type the password (up to 31 ASCII characters) from the entity maintaining the CRL directory server (usually a certification authority).
Certificate Information
These read-only fields display detailed information about the certificate.
Type
This field displays general information about the certificate. CA-signed means that a Certification Authority signed the certificate. Self-signed means that the certificate's owner signed the certificate (not a certification authority). X.509 means that this certificate was created and signed according to the ITU-T X.509 recommendation that defines the formats for public-key certificates.
Version
This field displays the X.509 version number.
Serial Number
This field displays the certificate's identification number given by the certification authority.
Subject
This field displays information that identifies the owner of the certificate, such as Common Name (CN), Organizational Unit (OU), Organization (O) and Country (C).
Issuer
This field displays identifying information about the certificate's issuing certification authority, such as Common Name, Organizational Unit, Organization and Country.
With self-signed certificates, this is the same information as in the Subject Name field.
Signature Algorithm
This field displays the type of algorithm that was used to sign the certificate. Some certification authorities use rsa-pkcs1-sha1 (RSA public-private key encryption algorithm and the SHA1 hash algorithm). Other certification authorities may use rsa-pkcs1-md5 (RSA public-private key encryption algorithm and the MD5 hash algorithm).
Valid From
This field displays the date that the certificate becomes applicable. The text displays in red and includes a Not Yet Valid! message if the certificate has not yet become applicable.
Valid To
This field displays the date that the certificate expires. The text displays in red and includes an Expiring! or Expired! message if the certificate is about to expire or has already expired.
Key Algorithm
This field displays the type of algorithm that was used to generate the certificate's key pair (the ZyWALL uses RSA encryption) and the length of the key set in bits (1024 bits for example).
Subject Alternative Name
This field displays the certificate's owner`s IP address (IP), domain name (DNS) or e-mail address (EMAIL).
Key Usage
This field displays for what functions the certificate's key can be used. For example, "DigitalSignature" means that the key can be used to sign certificates and "KeyEncipherment" means that the key can be used to encrypt text.
Basic Constraint
This field displays general information about the certificate. For example, Subject Type=CA means that this is a certification authority's certificate and "Path Length Constraint=1" means that there can only be one certification authority in the certificate's path.
MD5 Fingerprint
This is the certificate's message digest that the ZyWALL calculated using the MD5 algorithm. You can use this value to verify with the certification authority (over the phone for example) that this is actually their certificate.
SHA1 Fingerprint
This is the certificate's message digest that the ZyWALL calculated using the SHA1 algorithm. You can use this value to verify with the certification authority (over the phone for example) that this is actually their certificate.
Certificate in PEM (Base-64) Encoded Format
This read-only text box displays the certificate or certification request in Privacy Enhanced Mail (PEM) format. PEM uses 64 ASCII characters to convert the binary certificate into a printable form.
You can copy and paste the certificate into an e-mail to send to friends or colleagues or you can copy and paste the certificate into a text editor and save the file on a management computer for later distribution (via floppy disk for example).
Export Certificate
Click this button and then Save in the File Download screen. The Save As screen opens, browse to the location that you want to use and click Save.
OK
Click OK to save your changes back to the ZyWALL. You can only change the name.
Cancel
Click Cancel to quit and return to the Trusted Certificates screen.

Trusted Certificates Import Screen

Follow the instructions in this screen to save a trusted certificate to the ZyWALL.

Note: You must remove any spaces from the certificate's filename before you can import the certificate.

Object > Certificate > Trusted Certificates > Import 

Label
Description
File Path
Type in the location of the file you want to upload in this field or click Browse to find it.
You cannot import a certificate with the same name as a certificate that is already in the ZyWALL.
Browse
Click Browse to find the certificate file you want to upload.