Friday, April 28, 2017

Procedure to Build an Off-line (Standalone) Root CA with a Issuing (Enterprise) Subordinate CA having the functionality of OCSP Responder also.

To go further in this topic, let's see What is CA?

So the answer is:
"A certification authority (CA) is responsible for attesting to the identity of users, computers, and    
organizations.
The CA authenticates an entity and vouches for that identity by issuing a digitally signed certificate.

The CA can also manage, revoke, and renew certificates.

A certification authority can refer to following:
First, An organization that vouches for the identity of an end user.
Second, A server that is used by the organization to issue and manage certificates.”

Now, to achieve this, we have configured 3 Servers.
The Details of three machines are as follows:
Server-1: It is a Domain Controller or AD Machine.
               a) Computer Name: ProjectK-AD.
               b) OS: Microsoft Windows Server 2012 R2 Standard Edition
               c) Domain: prok.nkn.res.in
               d) FQDN: ProjectK-AD.prok.nkn.res.in
               e) IP: 10.40.128.179

Server-2: It is a Standalone Root CA Server.
               a) Computer Name: RootCA.
               b) OS: Microsoft Windows Server 2012 R2 Standard Edition
               c) Domain: prok.nkn.res.in
               d) FQDN: RootCA.prok.nkn.res.in
               e) IP: 10.40.128.154

Server-3: It is a Enterprise Subordinate CA.
               a) Computer Name: SubCA.
               b) OS: Microsoft Windows Server 2012 R2 Standard Edition
               c) Domain: prok.nkn.res.in
               d) FQDN: SubCA.prok.nkn.res.in
               e) IP: 10.40.128.184

Now, we use this Strategy to achieve the above mentioned goal.

Stag-1: Configure Server-1 with Microsoft ADDS Services & make it a Simple Domain Controller with having one or two Domain Admins user accounts.

Stag-2: Configure Server-2 as Standalone Root CA with only configuring Certification Authority role on it.

Stag-3: Configure Server-3 as Enterprise Subordinate CA which is having following roles on it.
             i) Certification Authority.
             ii) Certification Authority Web Enrollment.
             iii) Online Responder.

Now, from here, we start to configure this:

For this tutorial, we assume that we already completed the Stag-1 means we already have Server-1 which is having Domain Controller or AD ready with user "Administrator" who are having Domain Admin & Enterprise Admin Privileges.

Now, Quickly move to Stag-2 which is "Configure Server-2 as Standalone Root CA".

We have the Windows 2012 R2 Standard Edition Server which is used for setting up the Server-2 as the Standalone Root CA Server.
The Computer Name is: RootCA.
The Computer is the part of AD i.e. of prok.nkn.res.in domain.

1. On Main Desktop, Open the Server Manager.
2. Go to Manage & Add Roles & Features. (Once click, a wizard starts)
3. In Installation Type, Select Role Base or Feature Based Installation & click Next.
4. On Server Selection by default the machine i.e. ROOTCA is selected so not do anything, just click next.
5. On Select Server Roles, Select Active Directory Certificate Services, then click on Add Features then click Next.


6. On Features section, do not change anything, just click Next.
7. Then on AD CS Section, just click Next & move forward.
8. Then on Role Services, Select Only Certification Authority & Click Next.
9. Then on Confirmation Section, Just Click on Install & the Installation will going on.

10. Once the installation completes, click on “ Configure Active Directory Certificate Services on Destination Server. Then Another window opens for AD CS Configuration to configure Active Directory Certificate Services & close this current window.
11. In AD CS Configuration first Page, Just click Next to Move on to the next Step.
      (The Credentials mentioned are of AD User account credentials.)
12. Now, on Role Services, the Certification Authority is already selected so just click Next.
13. Now, in Setup Type the Enterprise CA  & Subordinate CA both are Enabled because this Root CA computer is the part of the AD. Otherwise if this machine is not the part of the AD then the Enterprise CA option will by default disabled or Gray Out.
As we want to setup this as Standalone CA So, Choose Standalone CA & click Next.
14. Now, in CA Type Section, Select Root CA because we want to Setup this machine as ROOT CA & click Next.
 15. Now in Private Key Section, Choose “ Create a New Private Key” & Click Next.
16. Now, In Cryptography Section,
      a) Select the Cryptographic Provider as: RSA# Microsoft Software Key Storage Provider.
      b) Select Key Length as: 2048
      c) Select hash algorithm  for signing certificates issued by this CA as: SHA256
      & Click Next.

17. In CA Name Section: Give the Common Name for this CA as: “ ProjectK” & Click Next.
                                  
18. Specify the Validity Period as 10 Years & Click Next.
                                   
19. On Certificate Database Section, do not change the location, make it as default & click Next.
                                    
20. Now on Confirmation Page, Summary of the Selected option given so Just Click “Configure”.
                                    
21. Once the configuration completes, Please close the Window.

22. Now, Start the Server Manager, Go to Tools & then Certificate Authority.

23. Certsrv - [Certification Authority (Local)] Snap-In Starts.
      See the Root CA named: ProjectK is showing Right Green Mark on it.
                                     
24. Now, In the certsrv – [Certification Authority (Local)] console, right-click ProjectK, and then click Properties.
25. In the ProjectK dialog box, click the Extensions tab then on select extension drop-down list, click CRL Distribution Point (CDP) and then
Select ldap:// line & click remove.
Select http:// line & click remove.
Select file:/// line & click remove.
Only C:\\Winows\ line remaining in CDP Extensions Section.
Now, Click Add button.

26. In the Location text box, type http://pki.nkn.res.in/certdata/, in the Variable drop-down list box, click <CaName>, and then click Insert.
Then again, in the Variable drop-down list box, click <CRLNameSuffix>, and then click Insert.
Then again, in the Variable drop-down list box, click <DeltaCRLAllowed>, and then click Insert,
Then, at the end of URL, type .crl, and then click OK.

27. Next, tick the following options, and then click Apply:
– Include in CRLs. Clients use this to find Delta CRL locations.
– Include in the CDP extensions of issued certificates.
28. In the Certification Authority pop-up box, click No to restart the service.
29. In the Select extension drop-down list box, click Authority Information Access (AIA), and then
Select ldap:// line & click remove.
Select http:// line & click remove.
Select file:/// line & click remove.
Only C:\\Winows\ line remaining in AIA Extensions Section.
Now, Click Add button.
30. In the Location text box, type http://pki.nkn.res.in/certdata/, in Variable drop-down box click <ServerDNSName>, and then click Insert.
Then, in the Location text box, type an underscore (_),
Then again, in the Variable drop-down list box, click <CaName> & click Insert.
and then click Insert. Put your cursor at the end of URL.
Then, in the Variable drop-down list box, click <CertificateName>, and then click Insert.
Then, in the Location text box, put your cursor at the end of URL, type .crt, and click OK.
31. Select the Include in the AIA extension of issued certificates box, and then click OK.
32. Click Yes to restart Certification Authority Service.
33. In the Certification Authority console, expand ProjectK, right-click Revoked Certificates, point to All Tasks, and then click Publish.
34. In the Publish CRL box, click OK.
35. Right-click ProjectK, and then click Properties.
36. In the ProjectK Properties box, click View Certificate.
37. In the Certificate box, click the Details tab and then click Copy to File.
38. In the Certificate Export Wizard, on the Welcome box, click Next.
39. On the Export File Format box, select DER encoded binary X.509 (.CER), and then click Next.
40. On the File to Export box, click Browse and then in the File name text box, type\\ProjectK-AD\c$, and then press Save Button.

41. In the File name text box, type RootCA, click Save, and then click Next.
42. Click Finish, and then click OK.
43. Next, browse to C:\Windows\System32\CertSrv\CertEnroll, copy both files…
44. and then paste to \\Project-AD\c$
So, we have successfully deploy a Root Standalone CA i.e. ProjectK in RootCA Server.
Now , we move on to the third Stag i.e. " Server-3 as Enterprise Subordinate CA".
We have the another Windows 2012 R2 Standard Edition Server which is used for setting up as Server-3 as the Enterprise Subordinate CA Server.
The Computer Name is: SubCA.
The Computer is the part of AD i.e. of prok.nkn.res.in domain.
1. On Main Desktop, Open the Server Manager.
2. Then go to Manage & Add Roles & Features. (Once click, a wizard starts).
3. Then on Installation Type, Select Role Base or Feature Based Installation & click Next.


4. Then on Server Selection by default the machine i.e. SubCA is selected so not do anything, just click next.
5. On Select Server Roles, Select Active Directory Certificate Services, then click on Add Features  then click Next.

























6. Now, on Features section, do not change anything, just click Next.
                                
7. Then on AD CS Section, just click Next & move forward.
8. Then on Role Services, Select Three Things: a) Certification Authority & b) Certification Authority WebEnrollment & c) Online Responder then Click Next.
9. Then on Confirmation Section, Just Click on Install & the Installation will going on.


10. Once the installation completes, click on “ Configure Active Directory Certificate Services on Destination Server. Then Another window opens for AD CS Configuration to configure Active Directory Certificate Services & close this current window.

11. In AD CS Configuration first Page, Just click Next to Move on to the next Step.
     (The Credentials mentioned are of AD User account credentials.)
12. Now, on Role Services, Select all three i.e. Certification Authority, Certification Authority Web Enrollment, Online Responder & click Next.
13. Now, in Setup Type, we have selected the Enterprise CA because we have a need to configure this machine as Enterprise Subordinate CA & click Next.
14. Now, in CA Type Section, Select Subordinate CA because we want to Setup this machine as Subordinate CA  & click Next.
15. Now in Private Key Section, Choose “ Create a New Private Key” & Click Next.
16. Now, In Cryptography Section,
      a) Select the Cryptographic Provider as: RSA# Microsoft Software Key Storage Provider.
      b) Select Key Length as: 2048
      c) Select hash algorithm  for signing certificates issued by this CA as: SHA256
      & Click Next.


17. In CA Name Section: Give the Common Name for this CA as: “ IssuningCA” & Click Next.

Important Note: When we configure the Subordinate CA, the wizard is not asking for Sub CA Validity Period. By Default it has set the Validity Period of Two Years for Enterprise Subordinate CA & One Year for Standalone Subordinate CA.

We will change the Validity Period of Enterprise Subordinate CA by Standalone Root CA manually from 2 year to 3 Year. We will See it in this tutorial later. For time being, we will go as wizard configures it i.e. for Two Year validity.

18. Now, in Certificate Request Section, we have two option to send the Certificate Signing Request of Sub CA to Root CA Server.

a) First is to “Save a Certificate Request to a File on the target machine” & the Path of Saved File is as follows: C:\SUBCA_SUBCA-CA.req

b) Second, we will search the ROOTCA on our Network & send it Directly to ROOTCA Server i.e. ProjectK in our case.

For this, Select First option “ Send a certificate request to a Parent CA” then select “Computer Name” then Click on Select.

Once click on Select, “Select computer” window opened then Click on Advanced & Click on Find Now.

It lists the Machines of your AD where we find the Machine Named ROOTCA on which our Parent CA (ProjectK) is setup. Choose the Machine ROOTCA & Click OK & then Click NEXT.







19. On Certificate Database Section, do not change the location, make it as default & click Next.

20. Now on Confirmation Page, Summary of the Selected option given so Just Click “Configure”.

21. Once the configuration completes, Please close the Window.
22. Next, access to the Domain Server from this machine. to do this, open Run and type \\ProjectK-AD\c$
23. Once we successfully access the AD Server, copy the RootCA file.
24. Then paste the RootCA file in SubCA Server C: Drive.
25. Right-click RootCA, and then click Install Certificate.
26. In the Certificate Import Wizard, click Local Machine, and then click Next.
27. On the Certificate Store box, click Place all certificates in the following store, and then click Browse, then you need to click Trusted Root Certification Authorities, and then click OK.
28. Click Next, and then click Finish.


29. When the Certificate Import Wizard window pops up, click OK.
30. Next, from the SubCA Server, access to ProjectK-AD Domain Server and copy both Certification Revocation List and Security Certificate.
31.Next, on the SubCA Server, browse to your C drive and open inetpub folder and then open wwwroot folder, then create a new folder, and name it CertData.
32. Paste the two copied files into that folder…
33. Now, go to RootCA Server to do two things:
a) Increase the Default Validity Period from Two Years to Three Years for Sub CA.
b) Issue the Sub CA Certificate  from Root CA Server & Export it & Install it on Sub CA Server.
34.  Now, First we extend the validity of Sub CA from Default Two Years to three Years.
For this, Start the Certification Authority Snap-in on RootCA Server.
Once Certification Authority Snap-In Starts, Expand the RootCA Tree (ProjectK), See in the pending request, we have to see the SubCA Request Comes with ID 2.
Now run the below command on command prompt (as Administrator) to change the Default Validity Period from two years to three years.

certutil -setreg ca\ValidityPeriod "Years"

then

certutil -setreg ca\ValidityPeriodUnits "3"

The Snapshots for running the above command are as follows:


Now, restart the Certification Authority Service on Root CA Server.
By Right Click on ProjectK, Select All Tasks then choose Stop Service.
Again Right Click on ProjectK, Select All Tasks then choose Start Service.

35. Issue the Sub CA Certificate  from Root CA Server & Export it & Install it on Sub CA Server.

For this, go to the RootCA Server, open the Certificate Authority Snap-in & Expand the ProjectK CA.
Go to Pending Requests Section then on right pane, just right-click the request (with ID 2), point to All Tasks, and then click Issue.
36. Now, on Root CA Server in Certificate Authority Snap-in, click the Issued Certificates container then double-click the certificate, and then click the Details tab and click Copy to File.
The Certificate Export Wizard opens with the Welcome page, click Next.

37. On the Export File Format box, click Cryptographic Message Syntax Standard – PKCS #7 Certificates (.P7B), click Include all certificates in the certification path if possible, and then click Next.
38. On the File to Export box, click Browse (SubCA Server), then in the File name text box, type SubCA, and then press Enter.
39. Then click Next, then click Finish and then OK.
40. Next, On SubCA Server, in the Certification Authority console,right-click IssuningCA, point to All Tasks, and then click Install CA Certificate.
41. Navigate to (C:), click the SubCA.p7b file, and then click Open.
42. Wait for few second, then right click IssuningCA, click All Tasks and click Start Service.
43. Verify that the CA starts successfully which confirm by Right Green Sign on IssuningCA.
44. Next, you can start publish the root CA certificate to your infrastructure using Group Policy.
On AD Server (ProjectK-AD) server, open Group Policy Management, then right-click Default Domain Policy, and then click Edit.

45. In the Computer Configuration node, expand Policies, expand Windows Settings, expand Security Settings, expand Public Key Policies, right-click Trusted Root Certification Authorities, and then click Import.                   
46. In the Certificate Import Wizard, click Next…
47. On the File to Import page, click Browse, in the file name text field, type \\SubCA\c$, and then press Enter, then choose RootCA.cer, and then click Open.
48. Click Next two times, and then click Finish. When the Certificate Import Wizard window pops up, click OK.





1. Now, One more thing to do is put the .crl & .crt files of RootCA Server & SubCA Server at one place.
To do this, we copy the .crl & .crt files of SubCA Server from c C:\Windows\System32\certsrv\CertEnroll & paste it in C:\inetpub\wwwroot\certdata folder.
We already copy the .crl & .crt files of RootCA Server from RootCA Server & paste it in C:\inetpub\wwwroot\certdata so no need to copy it again.
This C:\inetpub\wwwroot\certdata folder is publish thru IIS which gives the information of the respective server .crl & .crt files.
2. Now, Final thing to configure is OCSP Response for this CA using Online responder.
First Understand, What is Online Responder so the answer is :
The Microsoft Online Responder service makes it possible to configure and manage Online Certificate Status Protocol (OCSP) validation and revocation checking in Windows-based networks. The Online Responder snap-in allows you to configure and manage revocation configurations and Online Responder Arrays to support public key infrastructure (PKI) clients in diverse environments.

Setting up Online Responder services involves several interrelated steps.
Several of these steps must be performed on the certification authority (CA) that will be used to issue the Online Certificate Status Protocol (OCSP) signing certificates necessary for an Online Responder to function.
These steps include configuring the appropriate certificate template, enabling the certificate template, and configuring and completing certificate auto enrollment so that the computer hosting the Online Responder has the certificates needed for the Online Responder to function.

The following Steps are involved to complete the online responder installation and configuration.
a. Configure a CA to Support OCSP Responders 
b. Set Up an Online Responder
c. Creating a Revocation Configuration 
d. Verify an Online Responder Installation 

3. First we will see Point a i.e. Configure a CA to Support OCSP Responders.
To function properly, an Online Responder must have a valid Online Certificate Status Protocol (OCSP) Response Signing certificate. This OCSP Response Signing certificate is also needed if you are using a non-Microsoft OCSP responder.

The certificate template used to issue an OCSP Response Signing certificate must contain an extension titled "OCSP No Revocation Checking" and the OCSP Signing application policy. Permissions must also be configured to allow the computer that will host the Online Responder to enroll for this certificate.
The following procedure is for a CA that is installed on a computer running Windows Server 2012 R2.
Membership in Domain Admins or Enterprise Admins, or equivalent, is the minimum required to complete this procedure.

To configure the certificate template for an OCSP Response Signing certificate, follow these steps:
a. Open the Certificate Templates snap-in.
b. Right-click the OCSP Response Signing template, and then click Properties.
c. Click the Security tab. Under Group or user name, click Add.
d. Click Object Types, select the Computers check box, and then click OK.
e. Type the name of or browse to select the computer hosting the Online Responder or OCSP responder services, and click OK.
f. In the Group or user names dialog box, click the computer name, and in the Permissions dialog box, select the Read and Enroll check boxes. Then click OK.

4. Now, move to Second step i.e. Set Up an Online Responder.
For this important thing is that Internet Information Services (IIS) must also be installed on this computer before the Online Responder can be installed.
The Role of Online Responder, we already installed on the SubCA Machine so quickly move to third step.

5. Now, see " How to creating the revocation configuration"

An Online Responder can make revocation information available from multiple certification authorities (CAs) and multiple CA certificates. However, each CA and CA certificate served by an Online Responder requires a separate revocation configuration.

A revocation configuration includes all of the settings that are needed to respond to status requests regarding certificates that have been issued by using a specific CA key. These configuration settings include the following:
CA certificate. This certificate can be located in Active Directory Domain Services (AD DS), in the local certificate store, or imported from a file. 
Signing certificate for the Online Responder. This signing certificate can be selected automatically for you, selected manually (which involves a separate import step after you add the revocation configuration), or you can use the selected CA certificate to also serve as the signing certificate.
Revocation provider. The revocation provider will provide the revocation data used by this configuration. For a Windows Server 2008 R2 or Windows Server 2008 provider, this information is entered as one or more URLs where valid base CRLs and delta CRLs can be obtained. 
Before we begin to add a new revocation configuration, make sure you have the information in the preceding list available.
We must have Manage Online Responder permissions on all of the Online Responders in the Array to complete this procedure.

To add a revocation configuration to an Online Responder:
a. Open the Online Responder snap-in.

b. In the console tree, click Revocation Configuration.

c. A list of existing revocation configurations appears in the details pane.

d. In the Actions pane, click Add Revocation Configuration to start the Add Revocation Configuration Wizard.

e. Provide the information requested in the wizard.

f. Select CA Certificate Location: Three ways to select CA Certificate Location.

i) If the certification authority (CA) certificate has been published to Active Directory Domain Services (AD DS) and the computer you are configuring has access to this information in AD DS, click Select a certificate for an existing enterprise CA.

ii) If AD DS cannot be accessed and you know the name of the CA certificate and that it exists in the local root certificate store, click Select a certificate from the local certificate store.

iii) If AD DS cannot be accessed and the CA certificate (with a .cer extension) is available on removable media, click Import certificate from a file. 

g.  Select Signing Certificate: Three ways to select Signing Certificate.

i) The default option, Automatically select a signing certificate, will generally meet most organization's needs. This option allows the revocation configuration setup process to identify a suitable signing certificate in the local certificate store. However, if you also enable an option to automatically enroll for a signing certificate, the Online Responder service will enroll for and use that signing certificate.

ii) When selecting Manually select a signing certificate, the Online Responder will not assign any signing certificate and the user will have to manually select a signing certificates for each of the Online Responder Array members.

iii) Use the CA certificate for the revocation configuration can be selected if the Online Responder is installed on the same computer as the certification authority (CA).

When all the information has been entered, click Finish, and then click Yes to complete the setup process.

We can modify the properties of an existing revocation configuration, view its CA certificate, or delete the revocation configuration, by selecting the revocation configuration and clicking Edit Properties in the Actions pane.

The following properties of a revocation configuration can be modified:
Local CRL, Revocation provider, Signing.
Thanks & Regards,
Saurabh Srivastava,
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