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• Upgrade a Cluster to Use TLS/SSL

Upgrade a Cluster to Use TLS/SSL

The MongoDB server supports listening for both TLS/SSL encrypted and unencrypted connections on the same TCP port. This allows upgrades of MongoDB clusters to use TLS/SSL encrypted connections.

Note

Starting in version 4.0, MongoDB disables support for TLS 1.0 encryption on systems where TLS 1.1+ is available. For more details, see Disable TLS 1.0.

Procedure (Using tls Settings)

Important

A full description of TLS/SSL, PKI (Public Key Infrastructure) certificates, and Certificate Authority is beyond the scope of this document. This page assumes prior knowledge of TLS/SSL as well as access to valid certificates.

To upgrade from a MongoDB cluster using no TLS/SSL encryption to one using only TLS/SSL encryption, use the following rolling upgrade process.

Note

The procedures in this section use the tls settings/option (Available in MongoDB 4.2). For procedures using their ssl aliases, see Procedure (Using ssl Settings).

The tls settings/options provide identical functionality as the ssl options since MongoDB has always supported TLS 1.0 and later.

1. For each node of a cluster, start the node with the command-line option --tlsMode or the configuration file option net.tls.mode set to allowTLS. The allowTLS setting allows the node to accept both TLS/SSL and non-TLS/non-SSL incoming connections. Its connections to other servers do not use TLS/SSL. Include other TLS/SSL options [2] as well as any other options that are required for your specific configuration.

   Note

   Starting in MongoDB 3.6, mongod and mongos bind to localhost by default. If the members of your deployment are run on different hosts or if you wish remote clients to connect to your deployment, you must specify --bind_ip or net.bindIp. For more information, see Localhost Binding Compatibility Changes.

   For example:

   • Command-Line Options
   • Configuration File Options

   copy

   mongod --replSet <name> --tlsMode allowTLS --tlsCertificateKeyFile <TLS/SSL certificate and key file> --sslCAFile <path to root CA PEM file> <additional options>
   

   To specify these options in the configuration file, include the following settings in the file:

   copy

   net:
      tls:
         mode: allowTLS
         PEMKeyFile: <path to TLS/SSL certificate and key PEM file>
         CAFile: <path to root CA PEM file>
   

   Upgrade all nodes of the cluster to these settings.

2. Switch all clients to use TLS/SSL. See TLS/SSL Configuration for Clients.

3. For each node of a cluster, use the setParameter command to update the tlsMode to preferTLS. [1] With preferTLS as its net.tls.mode, the node accepts both TLS/SSL and non-TLS/non-SSL incoming connections, and its connections to other servers use TLS/SSL. For example:

   copy

   db.adminCommand( { setParameter: 1, tlsMode: "preferTLS" } )
   

   Upgrade all nodes of the cluster to these settings.

   At this point, all connections should be using TLS/SSL.

4. For each node of the cluster, use the setParameter command to update the tlsMode to requireTLS. [1] With requireTLS as its net.tls.mode, the node will reject any non-TLS/non-SSL connections. For example:

   copy

   db.adminCommand( { setParameter: 1, tlsMode: "requireTLS" } )
   

5. After the upgrade of all nodes, edit the configuration file with the appropriate TLS/SSL settings to ensure that upon subsequent restarts, the cluster uses TLS/SSL.

Procedure (Using ssl Settings)

Important

A full description of TLS/SSL, PKI (Public Key Infrastructure) certificates, and Certificate Authority is beyond the scope of this document. This page assumes prior knowledge of TLS/SSL as well as access to valid certificates.

To upgrade from a MongoDB cluster using no TLS/SSL encryption to one using only TLS/SSL encryption, use the following rolling upgrade process.

Note

The procedures in this section use the ssl settings/option. For procedures using their tls aliases (Available in MongoDB 4.2), see Procedure (Using tls Settings).

The tls settings/options provide identical functionality as the ssl options since MongoDB has always supported TLS 1.0 and later.

1. For each node of a cluster, start the node with the command-line option --sslMode or the configuration file option net.ssl.mode set to allowSSL. The allowSSL setting allows the node to accept both TLS/SSL and non-TLS/non-SSL incoming connections. Its connections to other servers do not use TLS/SSL. Include other TLS/SSL options [2] as well as any other options that are required for your specific configuration.

   Note

   Starting in MongoDB 3.6, mongod and mongos bind to localhost by default. If the members of your deployment are run on different hosts or if you wish remote clients to connect to your deployment, you must specify --bind_ip or net.bindIp. For more information, see Localhost Binding Compatibility Changes.

   For example:

   • Command-Line Options
   • Configuration File Options

   copy

   mongod --replSet <name> --sslMode allowSSL --sslPEMKeyFile <path to TLS/SSL Certificate and key PEM file> --sslCAFile <path to root CA PEM file> <additional options>
   

   To specify these options in the configuration file, include the following settings in the file:

   copy

   net:
      ssl:
         mode: <allowSSL>
         PEMKeyFile: <path to TLS/SSL certificate and key PEM file>
         CAFile: <path to root CA PEM file>
   

   Upgrade all nodes of the cluster to these settings.

2. Switch all clients to use TLS/SSL. See TLS/SSL Configuration for Clients.

3. For each node of a cluster, use the setParameter command to update the sslMode to preferSSL. [1] With preferSSL as its net.ssl.mode, the node accepts both TLS/SSL and non-TLS/non-SSL incoming connections, and its connections to other servers use TLS/SSL. For example:

   copy

   db.adminCommand( { setParameter: 1, sslMode: "preferSSL" } )
   

   Upgrade all nodes of the cluster to these settings.

   At this point, all connections should be using TLS/SSL.

4. For each node of the cluster, use the setParameter command to update the sslMode to requireSSL. [1] With requireSSL as its net.ssl.mode, the node will reject any non-TLS/non-SSL connections. For example:

   copy

   db.adminCommand( { setParameter: 1, sslMode: "requireSSL" } )
   

5. After the upgrade of all nodes, edit the configuration file with the appropriate TLS/SSL settings to ensure that upon subsequent restarts, the cluster uses TLS/SSL.

[1]	(1, 2, 3, 4) As an alternative to using the setParameter command, you can also restart the nodes with the appropriate TLS/SSL options and values.

[2]

(1, 2) Starting in MongoDB 4.0, you can use system SSL certificate stores for Windows and macOS. To use the system SSL certificate store, use: net.tls.certificateSelector (or the command-line option --tlsCertificateSelector) instead of net.tls.certificateKeyFile (or the command-line option``–certificateKeyFile``). net.ssl.certificateSelector (or the command-line option --sslCertificateSelector) instead of net.ssl.PEMKeyFile (or the command-line option``–sslPEMKeyFile``). When using the system SSL certificate store, OCSP (Online Certificate Status Protocol) is used to validate the revocation status of certificates.

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