Difference between revisions of "Using Your Own SSL Certificate"

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__NOTOC__
 
 
 
== Background ==
 
== Background ==
 
During the installation of MailStore Server, an SSL certificate is generated which all MailStore Server components use when an encrypted connection is to be established. Since the certificate is issued to the server name ''MailStoreServer'' and does not come from a reliable certification authority (CA), it is not trusted by the client side.  
 
During the installation of MailStore Server, an SSL certificate is generated which all MailStore Server components use when an encrypted connection is to be established. Since the certificate is issued to the server name ''MailStoreServer'' and does not come from a reliable certification authority (CA), it is not trusted by the client side.  
  
[[File:MScert.png|300px|center]]
+
[[File:MScert.png|360px|center]]
 
   
 
   
 
Because of this, the following or a similar warning message is displayed when calling up MailStore Web Access via HTTPS (SSL):
 
Because of this, the following or a similar warning message is displayed when calling up MailStore Web Access via HTTPS (SSL):
  
[[File:MSnotrust.png|300px|center]]
+
[[File:MSnotrust.png|360px|center]]
 +
 +
To eliminate warning and increase security as well as enhance usability, MailStore needs to be reconfigured to use your own certificate.
  
Besides the option to use a certificate from a trusted CA, one could create a self signed certificate and deploy it to the clients by using group policies. This procedure is described in the article [[Deploying a Self-signed SSL Certificate]].
+
If the ''Personal'' certificate store of the ''Computer account'' does already contain the desired certificate, follow the instructions in the [[#Using_the_Certificate_with_MailStore|Using the Certificate with MailStore]] section.
  
To configure MailStore Server for the use of your own certificate, please proceed as follows:
+
== Prerequisites ==
  
== Creating a Certificate Signing Request (CSR) ==
+
* A trusted [[wikipedia:Certificate_authority|Certificate Authority (CA)]]
Multiple tools like OpenSSL, certreq and the MMC snap-in ''Certificates '' are available to create a certificate signing request (CSR). The following steps describe how to generate such a certificate signing request with ''certreq'' and how to import the resulting certificate into the windows certificate store. ''certreq'' is shipped with most windows versions.
+
* ''certreq'' tool (available on most Windows installations by default)
 +
 
 +
== Creating a New Certificate ==
 +
Unless a certificate for the host name that is to be used for accessing  MailStore Server already exists, follow the below instructions to create a new certificate and import it into Windows' certificate store.
 +
 
 +
=== Creating a Certificate Signing Request (CSR) ===
 +
The following describes how to generate a certificate signing request by using the ''certreq'' tool.  
  
 
* Log on to the MailStore Server computer.
 
* Log on to the MailStore Server computer.
Line 43: Line 49:
 
[EnhancedKeyUsageExtension]
 
[EnhancedKeyUsageExtension]
 
OID = 1.3.6.1.5.5.7.3.1 ; this is for Server Authentication
 
OID = 1.3.6.1.5.5.7.3.1 ; this is for Server Authentication
 +
 +
[Extensions]
 +
2.5.29.17 = "{text}"
 +
_continue_ = "DNS=*.example.com&"
 +
_continue_ = "DNS=mailstoreserver.example.com&"
 
</pre>
 
</pre>
 
* Adjust the ''Subject'' and ''FriendlyName'' values according to your needs.  
 
* Adjust the ''Subject'' and ''FriendlyName'' values according to your needs.  
 +
* Adjust the ''Subject Alternative Names (SAN)'' in the ''[Extensions]'' section as well. Please note that the ''Common Name (CN)'' in the ''Subject'' is irrelevant for the verification by clients and that all host names must be included as SANs. Additional host names may be added with appending additional ''_continue_'' lines.
 
* Save the file.
 
* Save the file.
 
* Open an elevated command prompt and navigate to the directory where the ''request.inf'' is stored.  
 
* Open an elevated command prompt and navigate to the directory where the ''request.inf'' is stored.  
Line 50: Line 62:
 
  certreq -new request.inf request.csr
 
  certreq -new request.inf request.csr
  
=== ''Optional:'' Subject Alternative Names (SAN) ===
+
=== Validating the Certificate Signing Request ===
If the certificate should be valid for multiple host names, so called Subject Alternative Named (SAN) must be included in the CSR. Add the ''Extensions'' section as shown below to the the end of the <tt>request.inf</tt> file and adjust the host names to your needs or add additional ones by appending additional ''_continue_'' lines. Then save the file and create the request as explained previously.
 
 
 
<pre>
 
[Extensions]
 
2.5.29.17 = "{text}"
 
_continue_ = "DNS=mailstoreserver.example.com&"
 
_continue_ = "DNS=mailstoreserver&"
 
</pre>
 
 
 
<p class="msnote">'''Important notice:''' When SANs are defined, the CN in the ''Subject'' field will be ignored by clients. Therefore all valid host names have to be added to the SAN extension.</p>
 
 
 
== Validating the Certificate Signing Request ==
 
 
To verify that the CSR is correct, execute the following command to display it in a human readable format:
 
To verify that the CSR is correct, execute the following command to display it in a human readable format:
  
 
  certutil -dump request.csr
 
  certutil -dump request.csr
  
== Submitting the Certificate Signing Request ==
+
=== Submitting the Certificate Signing Request ===
Submit the CSR to your preferred CA. Usually you upload the CSR file to a website of the CA. The CA might ask for the server platform during the submission process. Selecting ''IIS 7'' or ''None of the listed'' should be sufficient. After successful approval of the CSR, you will get the signed certificate in return.
+
Submit the CSR to your preferred CA. Typically you upload the CSR file to a website of the CA. The CA might ask for the server platform during the submission process. Selecting ''IIS 7'' or ''None of the listed'' should be sufficient. After successful approval of the CSR, you will get the signed certificate in return.
  
 
<p class="msnote">'''Please note:''' Nowadays the certificate mostly is signed by intermediate CAs. It is required that the certificate of the intermediate CA is imported into the certificate store. Detailed information about the installation process of intermediate CA certificates is typically included in the electronic delivery of your certificate.</p>
 
<p class="msnote">'''Please note:''' Nowadays the certificate mostly is signed by intermediate CAs. It is required that the certificate of the intermediate CA is imported into the certificate store. Detailed information about the installation process of intermediate CA certificates is typically included in the electronic delivery of your certificate.</p>
  
== ''Alternative 1:'' Importing the Certificate using MMC ==
+
=== Importing the Certificate ===
* Log on to the server as administrator.
+
* Open an elevated command prompt and navigate to the directory where the certificate file is stored.
* Click on ''Start | Execute''.
+
* Execute the following command to import the certificate into the computer's personal certificate store:
* Execute the command ''mmc''.
+
 
* Select ''File | Add/Remove Snap-In | Add | Certificate''.
+
certreq -accept certificate.cer
* Select ''Local Computer Account'' and then ''Local Computer''.
+
 
* Click on ''Finish'' and close any open dialog windows.
+
=== Verifying the Import ===
* In the management console, select ''My Certificates | Certificates''.
+
* Log on to the MailStore Server computer as administrator.
* Right-click on the folder ''Certificates'' and select ''All Tasks | Import''.
+
* Open the ''Microsoft Management Console (MMC)''
* Follow the instructions in the wizard and select the file containing the certificate and the private key, if applicable.
+
* Add the Certificate Snap-In by following these steps:
* On the page ''Certificate Store'' select the container ''My Certificates'' and finish the wizard.
+
** Click on ''File'' > ''Add/Remove Snap-In'' > ''Certificate'' > ''Add >''
* The certificate is now shown in the container ''My Certificates''.
+
** Select ''Computer Account'' and click on ''Next >''
* To verify this and to make sure that the private key for the certificate is available, open the certificate with a double-click.
+
** Select ''Local Computer'' and click on ''Finish''  
 +
** Close any open dialog windows
 +
* Click on ''Certificates (Local Computer)'' > ''Personal'' > ''Certificates''
 +
* Double-click on the previously imported certificate
 +
* Make sure that the private key for the certificate is available:
  
 
[[File:Private_key.png|center]]
 
[[File:Private_key.png|center]]
  
* Sometimes the matching private key cannot be found and the certificate store has to be repaired.
+
==== Repairing the Certificate Store ====
 +
Sometimes the matching private key cannot be found although the certificate was imported successfully into the correct certificate store. Try to repair the certificate store as follows:
  
* First you have to get the subjects, serialnumbers and fingerprints of the installed certificates, to identify, which certificate is used by MailStore.
+
* Open an elevated PowerShell and execute the following command:
* Open an elevated PowerShell and enter the following command:
 
  
 
  Get-ChildItem Cert:\LocalMachine\My | select Subject, Serialnumber, Thumbprint, HasPrivateKey
 
  Get-ChildItem Cert:\LocalMachine\My | select Subject, Serialnumber, Thumbprint, HasPrivateKey
  
* Then you can try to repair the certificate store with the following command, where ''SerialNumber'' is the serial number of the certificate that should be used.
+
* Check the subjects, serialnumbers and fingerprints of the installed certificates, to identify the certificate to be used by MailStore.
 +
* Repair the corresponding certificate store by executing the following command, where ''SerialNumber'' is the serial number of the certificate that should be used.
  
 
  certutil -repairstore my SerialNumber
 
  certutil -repairstore my SerialNumber
  
== ''Alternative 2:'' Importing the Certificate using certreq ==
+
=== Using the Certificate with MailStore ===
* Open an elevated command prompt and navigate to the directory where the certificate file is stored.
 
* Execute the following command to import the certificate into the computer's personal certificate store:
 
 
 
certreq -accept certificate.cer
 
 
 
* Use MMC's certificate snap-in or ''certlm.msc'' (Windows Server 2012 or newer only) to verify that the certificate has been imported properly in the computer's ''Personal'' certificate store and that a matching private key can be found.
 
 
 
[[File:Private_key.png|center]]
 
 
 
== Using the Certificate with MailStore Server ==
 
 
* Open the MailStore Server Service Configuration.  
 
* Open the MailStore Server Service Configuration.  
 
* Select ''IP Addresses and Ports''.
 
* Select ''IP Addresses and Ports''.
 
* In the section you want to change to certificate for, click on the button next to the ''Server Certificate'' field and select ''Select from Certificate Store...''
 
* In the section you want to change to certificate for, click on the button next to the ''Server Certificate'' field and select ''Select from Certificate Store...''
 
* Choose the new certificate from the certificate store.
 
* Choose the new certificate from the certificate store.
* Confirm your entries and restart the MailStore Server service.
+
* Confirm your selection and restart the MailStore Server service.
  
== Appendix: Creating a PFX Container with OpenSSL ==
+
== Importing an Existing Certificate ==
When the CSR was created with OpenSSL, the private key is never stored in the Windows certificate store. To use certificates that have been created with OpenSSL in MailStore, it is therefore required to merge the private key,  certificate and optionally the CA's certificate chain into a PFX container. This container can then be imported into Window's certificate store.
+
Typically certificates are exchanged between computers by means of Personal Information Exchange (PFX/P12) containers. These can, for example, be created using the export functions of the MMC Snap-In ''Certificates''.
  
* Copy certificate, private key and the certificates of the certificate chain into the OpenSSL directory.
+
=== Optional: Creating a PFX Container with OpenSSL/LibreSSL ===
* Open an elevated command prompt and navigate to the OpenSSL directory.
+
When the original CSR was not created with Windows' own tools or not even created on a Windows computer, it is unlikely that the private key or the vertificate is available in Windows' certificate store of the MailStore Server computer, but on stored on the file system instead.
 +
 
 +
In this case, a Personal Information Exchange (PFX) container need to be created first. This needs to contain the certificate, private key, and all certificates of the certificate chain. After that, the PFX container can by imported into Windows' certificate store.
 +
 
 +
The following steps need to be executes to convert the certificate files into a PFX container with OpenSSL or LibreSSL:
 +
 
 +
* Copy the certificate, private key and the certificates of the certificate chain into the OpenSSL or LibreSSL directory.
 +
* Open an elevated command prompt and navigate to this directory.
 
* Create the PFX container by executing the following command, adjust the file names of necessary:
 
* Create the PFX container by executing the following command, adjust the file names of necessary:
 
  openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
 
  openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
* Import the content of the PFX container into the computer's personal certificate store by executing the following command:
+
 
certutil -importpfx certificate.pfx
+
=== Importing a PFX container ===
 +
* Open the MailStore Server Service Configuration.
 +
* Select ''IP Addresses and Ports''.
 +
* In the section you want to change to certificate for, click on the button next to the ''Server Certificate'' field and select ''Import from file...''
 +
* Choose the PFX file.
 +
* If the PFX file has been password protected, you are being ask to provide the password now.
 +
* Confirm your selection and restart the MailStore Server service.
  
 
== Weblinks ==
 
== Weblinks ==
Line 130: Line 138:
 
* [https://technet.microsoft.com/en-us/library/cc732443.aspx Microsoft Technet: Certutil]
 
* [https://technet.microsoft.com/en-us/library/cc732443.aspx Microsoft Technet: Certutil]
 
* [https://technet.microsoft.com/de-de/library/ff625722.aspx Microsoft Technet: How to Request a Certificate With a Custom Subject Alternative Name]
 
* [https://technet.microsoft.com/de-de/library/ff625722.aspx Microsoft Technet: How to Request a Certificate With a Custom Subject Alternative Name]
* [https://www.openssl.org/docs/apps/openssl.html OpenSSL documentation]
+
* [https://www.libressl.org/ LibreSSL]
 +
* [https://www.openssl.org/docs/apps/openssl.html OpenSSL Documentation]
 +
 
 
[[de:Verwendung_eigener_SSL_Zertifikate]]
 
[[de:Verwendung_eigener_SSL_Zertifikate]]
 
[[en:Using Your Own SSL Certificate]]
 
[[en:Using Your Own SSL Certificate]]

Revision as of 12:08, 16 July 2018

Background

During the installation of MailStore Server, an SSL certificate is generated which all MailStore Server components use when an encrypted connection is to be established. Since the certificate is issued to the server name MailStoreServer and does not come from a reliable certification authority (CA), it is not trusted by the client side.

MScert.png

Because of this, the following or a similar warning message is displayed when calling up MailStore Web Access via HTTPS (SSL):

MSnotrust.png

To eliminate warning and increase security as well as enhance usability, MailStore needs to be reconfigured to use your own certificate.

If the Personal certificate store of the Computer account does already contain the desired certificate, follow the instructions in the Using the Certificate with MailStore section.

Prerequisites

Creating a New Certificate

Unless a certificate for the host name that is to be used for accessing MailStore Server already exists, follow the below instructions to create a new certificate and import it into Windows' certificate store.

Creating a Certificate Signing Request (CSR)

The following describes how to generate a certificate signing request by using the certreq tool.

  • Log on to the MailStore Server computer.
  • Prepare a text file request.inf with the following content:
;----------------- request.inf -----------------
[Version]
Signature="$Windows NT$"

[NewRequest]
; replace Subject attributes in the line below with real values
Subject = "CN=mailstoreserver.example.com, OU=Department, O=Organisation, L=Locality, S=State, C=Country"
KeySpec = 1
KeyLength = 2048
Exportable = TRUE
FriendlyName = mailstoreserver.example.com
MachineKeySet = TRUE
SMIME = False
PrivateKeyArchive = FALSE
UserProtected = FALSE
UseExistingKeySet = FALSE
ProviderName = "Microsoft RSA SChannel Cryptographic Provider"
ProviderType = 12
RequestType = PKCS10
KeyUsage = 0xa0
 
[EnhancedKeyUsageExtension]
OID = 1.3.6.1.5.5.7.3.1 ; this is for Server Authentication

[Extensions]
2.5.29.17 = "{text}"
_continue_ = "DNS=*.example.com&"
_continue_ = "DNS=mailstoreserver.example.com&"
  • Adjust the Subject and FriendlyName values according to your needs.
  • Adjust the Subject Alternative Names (SAN) in the [Extensions] section as well. Please note that the Common Name (CN) in the Subject is irrelevant for the verification by clients and that all host names must be included as SANs. Additional host names may be added with appending additional _continue_ lines.
  • Save the file.
  • Open an elevated command prompt and navigate to the directory where the request.inf is stored.
  • Create the CSR by executing the following command:
certreq -new request.inf request.csr

Validating the Certificate Signing Request

To verify that the CSR is correct, execute the following command to display it in a human readable format:

certutil -dump request.csr

Submitting the Certificate Signing Request

Submit the CSR to your preferred CA. Typically you upload the CSR file to a website of the CA. The CA might ask for the server platform during the submission process. Selecting IIS 7 or None of the listed should be sufficient. After successful approval of the CSR, you will get the signed certificate in return.

Please note: Nowadays the certificate mostly is signed by intermediate CAs. It is required that the certificate of the intermediate CA is imported into the certificate store. Detailed information about the installation process of intermediate CA certificates is typically included in the electronic delivery of your certificate.

Importing the Certificate

  • Open an elevated command prompt and navigate to the directory where the certificate file is stored.
  • Execute the following command to import the certificate into the computer's personal certificate store:
certreq -accept certificate.cer

Verifying the Import

  • Log on to the MailStore Server computer as administrator.
  • Open the Microsoft Management Console (MMC)
  • Add the Certificate Snap-In by following these steps:
    • Click on File > Add/Remove Snap-In > Certificate > Add >
    • Select Computer Account and click on Next >
    • Select Local Computer and click on Finish
    • Close any open dialog windows
  • Click on Certificates (Local Computer) > Personal > Certificates
  • Double-click on the previously imported certificate
  • Make sure that the private key for the certificate is available:
Private key.png

Repairing the Certificate Store

Sometimes the matching private key cannot be found although the certificate was imported successfully into the correct certificate store. Try to repair the certificate store as follows:

  • Open an elevated PowerShell and execute the following command:
Get-ChildItem Cert:\LocalMachine\My | select Subject, Serialnumber, Thumbprint, HasPrivateKey
  • Check the subjects, serialnumbers and fingerprints of the installed certificates, to identify the certificate to be used by MailStore.
  • Repair the corresponding certificate store by executing the following command, where SerialNumber is the serial number of the certificate that should be used.
certutil -repairstore my SerialNumber

Using the Certificate with MailStore

  • Open the MailStore Server Service Configuration.
  • Select IP Addresses and Ports.
  • In the section you want to change to certificate for, click on the button next to the Server Certificate field and select Select from Certificate Store...
  • Choose the new certificate from the certificate store.
  • Confirm your selection and restart the MailStore Server service.

Importing an Existing Certificate

Typically certificates are exchanged between computers by means of Personal Information Exchange (PFX/P12) containers. These can, for example, be created using the export functions of the MMC Snap-In Certificates.

Optional: Creating a PFX Container with OpenSSL/LibreSSL

When the original CSR was not created with Windows' own tools or not even created on a Windows computer, it is unlikely that the private key or the vertificate is available in Windows' certificate store of the MailStore Server computer, but on stored on the file system instead.

In this case, a Personal Information Exchange (PFX) container need to be created first. This needs to contain the certificate, private key, and all certificates of the certificate chain. After that, the PFX container can by imported into Windows' certificate store.

The following steps need to be executes to convert the certificate files into a PFX container with OpenSSL or LibreSSL:

  • Copy the certificate, private key and the certificates of the certificate chain into the OpenSSL or LibreSSL directory.
  • Open an elevated command prompt and navigate to this directory.
  • Create the PFX container by executing the following command, adjust the file names of necessary:
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

Importing a PFX container

  • Open the MailStore Server Service Configuration.
  • Select IP Addresses and Ports.
  • In the section you want to change to certificate for, click on the button next to the Server Certificate field and select Import from file...
  • Choose the PFX file.
  • If the PFX file has been password protected, you are being ask to provide the password now.
  • Confirm your selection and restart the MailStore Server service.

Weblinks

Navigation
Tools
Print/export
About MailStore

  • MailStore Server is one of the leading email archiving solutions for SMB.
  • For private use there is a free tool for email archiving furthermore: MailStore Home.