Managing certificates in Exchange - Part 2

Managing certificates in Exchange - Part 2 Picture 1 Managing certificates in Exchange - Part 1

Network Administration - In this section we will introduce the requirements that need to be considered when working with certificates.

Introduce

Certificates can be used to encrypt communication data streams between two end points, which can be clients and servers. They are also used by endpoints to authenticate themselves. There are several components in Exchange 2007 that rely on certificates for encryption and authentication. In the first part of this article series, I talked about an overview of Exchange components that use their certificates and their uses. In addition, the first part also introduces some features of the default self-signed certificate. In Part 2 of this series, we will introduce the requirements of a certificate you need to know when working with them. To conclude, in part three of this article series, I will give you a closer look at the Exchange Management Shell commands used to create, manage, and delete Exchange certificates.

How to trust the self-signed certificate?

As introduced in part 1 of this series, it is possible to configure Exchange to use a self-signed certificate for internal scenarios. To ensure that your clients do not encounter any security warning messages when connecting to the Exchange 2007 Client Access server, you need to make the user trust the self-signed certificate. Remember, it is not an absolute perfect idea to educate users to remove security warnings! Figure 1 shows that the Self-Signed certificate is not trusted when using Outlook Web Access.

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Figure 1: Self-signed certificate is not trusted

There are several methods to ensure that a user who recognizes a self-signed certificate is a trusted certificate. However, we will only introduce one method, which is the method that does not require any action from the user itself and this method publishes a self-signed certificate using Group Policies. Note, however, that you still need to repeat this action every time you renew the self-signed certificate!

Export self-signed certificate

To export a self-signed certificate, you can use the Export-ExchangeCertificate command. Since this command will group the private key automatically, you need to define the password, you can see the example we did in Figure 2. Note that you can only export the self-signed certificate if marked a certificate to obtain a private key with export capability (see introduction in section 1).

You can publish an exported certificate in the user's personal repository using Group Policy. In the example below, we used the Group Policy Management interface to create a new policy and apply it to the domain (Figure 3).

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Figure 3: Creating and linking a new GPO to the domain

We call the new GPO Trust Self Signed Certificate and do not use any Source Starter GPO (Figure 4).

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Figure 4: Name of the new GPO

Because we want to import an exported self-signed certificate, go to User Configuration, Policies, Windows Settings, Public Key Policies, and right-click Trusted People to launch the Certificate Import Wizard (see Figure 5).

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Figure 5: Launch the Certificate Import Wizard

Specify the previously created file by running Export-ExchangeCertificate, and click Next (Figure 6).

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Figure 6: Select File to Import

Next, enter the password that was used to export the private key, then click Next to continue (Figure 7).

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Figure 7: Typing the password used to protect the private key

The certificate store will be set to Personal Store, click Next to continue (Figure 8).

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Figure 8: Select where to store the certificate

To finish, click Finish after reviewing the settings (Figure 9).

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Figure 9: Complete the Certificate Import Wizard

The Certificate Import Wizard will tell you that the import process has been successfully performed. When you click OK and import is done, Group Policy is now ready for you to use (Figure 10).

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Figure 10: The import process is successful

The next time the user logs in to the domain, or refreshes the group policy, then the self-signed certificate will be trusted. You can see when increasing access to Outlook Web Access (Figure 11).

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Figure 11: Self-signed certificate has been trusted

Get a certificate from a public assessor

Although Exchange 2007 has the ability to create a self-signed certificate during the installation process, you can enable clients to trust it, but keep in mind what was introduced in part one:

1. Self-signed certificates are only valid for one year
2. The self-signed certificate is only trusted by its issuer
3. Self-signed certificates are not supported for Outlook Anywhere without Exchange ActiveSync

So you need to get a certificate from the appraiser. You can deploy your own certification authority or get a certificate from a public assessor. The second way is advised by Microsoft in the following situations:

1. Access external clients to Exchange (POP, IMAP, Outlook Web Access, Outlook Anywhere, Exchange ActiveSync, Autodiscover)
2. If you want to install Domain security with partner organizations

If you get a certificate from a public certificate authority, you will take a lot of hassle in letting the certificate authority recognize a certificate trusted by clients that have not yet entered the domain, and the The partner organization wants to configure domain security for the Exchange environment.

Microsoft has published an article titled Unified Communications Certificate Partners for Exchange 2007 and for Communications Server 2007, which provides a list of Unified Communications Certificates issued certificates for Microsoft Exchange and for Communications Server 2007. , can be used to deploy Domain Security features.

What is a public certification examiner?

A public certificate authority is a certificate issuer trusted by all mainstream browsers and applications. When deciding to get a certificate from an appraiser, you need to consider whether the public certification authority is trusted by all the applications you will use and see if it can allow you to get a certificate. only you need (mention name, valid date and, .)

Name in a certificate

Observe a certificate and why a certificate is not acceptable to be used for encryption and authentication by Exchange, it is encapsulated into one of the following reasons:

1. The security certificate must be issued by a trusted certificate authority;
2. The security certificate must not be revoked by the reviewer who issued it;
3. The security certificate must not expire;
4. The security certificate comes with a name that does not match the expected name.

Although some applications such as Outlook Web Access allow you to use a certificate that is not even issued by a trusted appraiser or a security certificate that has been issued to a different website address, the user remains Don't ignore these warnings because it's almost like someone or some process wants to attack you or block your data (Figure 12).

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Figure 12: Security certificate warning

Outlook Anywhere and Exchange ActiveSync will not work if there is a problem with the certificate (Figure 13).

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Figure 13: Outlook Anywhere fails when connecting because the name of the security certificate does not correspond to the name of the target site.

We have to consider the names you need for a security certificate for your Client Access server:

1. NetBIOS name of Client Access server;
2. Full Qualified Domain Name of Client Access server
3. Autodiscover domain of Exchange organization
4. The name is used to publish Outlook Web Access, Outlook Anywhere, Exchange ActiveSync, Pop, or IMAP to other external computers.

The names you need for a security certificate for the Hub / Edge Transport server:

1. Fully Qualified Domain Name
2. All domains are accepted in the Exchange organization.

And with the Unified Messaging server, you only need Fully Qualified Domain Name of the Unified Messaging server role.

Example situation

Imagine you have an environment as shown in Figure 14 below.

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Figure 14: An example Exchange organization

In this Exchange environment, you will publish both Outlook Web Access and Outlook Anywhere using the ISA server located at the DMZ. Mails sent to and from the organization will go through the Exchange Edge server role, also placed in the DMZ. Your Exchange organization has two domains that are responsible for it: ProExchange.Global and BelgianBeers.Rock. You have agreed to configure Domain Security between your Exchange organization and one of your partner organizations Sunshine.Edu. EdgeSync is configured to create a copy of your configuration and recipient information into the Edge server. You will obtain two certificates from a public CA, one to publish Outlook Web Access and Outlook Anywhere and one to establish domain security between the Exchange organization and Sunhine.Edu.

Table 1 lists the Exchange servers that exist in this Exchange environment and their roles.

The role has been installed

Edge.ProExchange.dmz

Edge Server role

Ex2007EE.ProExchange.Global

Mailbox + Client Access + Hub Transport server role

Ex2007SE.ProExchange.Global

Unified Messaging role server

Table 1

Look closely at your Exchange organization showing the URLs listed in Table 2 that have been used externally and internally by users who connect to their mailbox.

Connect using HTTP (s)

Connect with RPC

Outlook Web Access

https://webmail.proexchange.global
https://webmail.belgianbeers.rock

https://Ex2007EE.proexchange.global

Outlook Anywhere

https://webmail.proexchange.global

https://Ex2007EE.proexchange.global

Free and Busy information

https://webmail.proexchange.global/EWS/Exchange.asmx

https://Ex2007EE.proexchange.global/EWS/Exchange.asmx

Download OAB

http://webmail.proexchange.global/OAB

http://Ex2007EE.proexchange.global/OAB

Change Unified Messaging settings

https://webmail.proexchange.global/UnifiedMessaging/Service.asmx

https://Ex2007EE.proexchange.global UnifiedMessaging / Service.asmx

Autodiscover

https://autodiscover.proexchange.global/autodiscover/autodiscover.xml
https: //autodiscover.belgianbeers.rock/autodiscover/autodiscover.xml

https://Ex2007EE.proexchange.global/Autodiscover/autodiscover.xml

Table 2: URLs

These URLs are also retrieved and changed using the Exchange Management Shell. Figure 15 shows the command to retrieve the URLs provided by Exchange Web service Autodiscover for Microsoft Office Outlook 2007 clients.

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Figure 15: Configuration settings for InteralUrl and ExternalUrl

Table 3 lists the records that are registered in DNS

Type

Data

Autodiscover.ProExchange.Global

Alias ​​(CNAME)

Webmail.ProExchange.Global

Autodiscover.BelgianBeers.Rock

Alias ​​(CNAME)

Webmail.BelgianBeers.Rock

Webmail.ProExchange.Global

Host (A)

External IP ISA Server

Webmail.BelgianBeers.Rock

Host (A)

External IP ISA Server

ProExchange.Global

Mail Exchanger (MX)

[10] Edge.ProExchange.Dmz

BelgianBeers.Rock

Mail Exchanger (MX)

[10] Edge.ProExchange.Dmz

Edge.ProExchange.Dmz

Host (A)

External IP Edge Server

Ex2007SE.ProExchange.Global

Host (A)

10.10.10.102

Ex2007EE.ProExchange.Global

Host (A)

10.10.10.101

Table 3: Logs registered in DNS

To enable secure access to Outlook Web Access and publish Outlook Anywhere, the following names must be present on the certificate that you will enable for the IIS service on the Client Access Server inside and export to the ISA 2006 server. Sp1:

To enable EdgeSync, provide TLS and configure domain security with partner organization Sunshine.Edu, you need a certificate for the Microsoft Exchange Edge server role with the following names:

Conclude

This is all introduced in part two. In Part 3 of this series, we will give you detailed steps on how to create a certificate request with Subject Alternative Names and how to import and activate the certificate obtained for translations. Exchange service.