Managing SSL certificates ========================= PEM uses SSL certificates: - To secure requests to the :ref:`Web server certificates ` , which provides the user interface and REST API. - To secure and authenticate the :ref:`PEM backend database server and agent connection certificates ` . Web server certificates ----------------------- PEM generates an SSL certificate and key file for the web server during initial configuration. Because the certificate is self-signed, a warning states that the site is insecure when users open the PEM web application URL in a browser. To increase security and remove this warning, you can replace the self-signed SSL certificate with a certificate signed by a trusted certificate authority. Replace the web server certificates (NGINX) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ To use your own SSL certificate with NGINX, update the configuration file: - On RHEL-like systems: ``/etc/nginx/conf.d/edb-pem.conf`` - On Debian-like systems: ``/etc/nginx/sites-available/edb-pem.conf`` Change the server name and file paths in the configuration file to match your certificate files: .. code:: text server { # lines omitted here server_name ; # lines omitted here } server { # lines omitted here server_name ; ssl_certificate /path/to/your_domain_name.crt ssl_certificate_key /path/to/your_private.key # lines omitted here } Replace the web server certificates (Apache HTTPD) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ To use your own SSL certificate with Apache HTTPD, update the configuration file ``edb-ssl-pem.conf`` . Change the server name and file paths in the configuration file to match your certificate files. .. code:: shell ServerName yourdomain.com # lines omitted here SSLCertificateFile /path/to/your_domain_name.crt SSLCertificateKeyFile /path/to/your_private.key .. Note "Example":: For a worked example, see `Replacing httpd self-signed SSL certificates `_ . PEM backend database server and agent connection certificates ------------------------------------------------------------- PEM implements secured SSL/TLS connections between PEM agents and the backend database. Each agent has an SSL certificate that’s used both to encrypt its communication with the server and to authenticate with the server in place of a password. PEM uses the sslutils extension to allow the PEM server to generate and sign SSL certificates and keys. When a new agent is registered, the PEM server issues it a certificate. Certificates issued by the PEM server are signed by the PEM server, meaning the PEM server is acting as a certificate authority (CA). If this approach isn’t suitable, you can use SSL certificates and keys generated outside of PEM and signed by a trusted CA. For more information, see :ref:`Use certificates and keys signed by trusted CA ` . Certificates and key files on the PEM server ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ During initial configuration of the PEM server, the following files are generated in the Postgres data directory of the PEM server: - ``ca_certificate.crt`` - ``ca_key.key`` - ``root.crt`` - ``root.crl`` - ``server.crt`` - ``server.key`` The ``ca_certificate.crt`` and ``ca_key.key`` files are used by the PEM server to sign certificates generated for agents during agent registration. They’re also used to sign ``server.crt`` . Unless replaced manually, the ‘ca_certificate.crt’ file is a self-signed certificate because it’s acting as the root CA. The ``root.crt`` file is a copy of the ``ca_certificate.crt`` file. The ``ssl_ca_file`` parameter in the ``postgresql.conf`` file points to this file. The ``root.crl`` is the certificate revocation list (CRL) of certificates revoked by the issuing CA before their actual or assigned expiration date. The ``ssl_crl_file`` parameter in the ``postgresql.conf`` file points to this file. The ``server.crt`` file is the signed certificate for the PEM server, and the ``server.key`` file is the private key to the certificate. The ``ssl_cert_file`` parameter in the ``postgresql.conf`` file points to this file. These files are automatically renewed when they near their expiry date. See :ref:`PEM certificate renewal ` . Certificates and key files for PEM agents ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Each agent’s SSL certificate and keys are generated during :ref:`Registering a PEM agent ` . The PEM agent connects to the PEM backend database server using the libpq interface, acting as a client of the backend database server. The PEM agent connects to the server using the ``cert`` auth method and with ssl enabled. This means that the connection is encrypted using the agent’s key and authenticated using the agent’s certificate instead of, for example, a password. Each agent has a unique identifier, and the agent certificates and keys have the corresponding identifier. If required, you can use the same certificate for all agents rather than one certificate per agent. For more information, see :ref:`Generate a common agent certificate and key pair ` . For more information on using the SSL certificates to connect in Postgres, see `Securing TCP/IP connections with SSL `_ in the Postgres documentation. PEM certificate renewal ^^^^^^^^^^^^^^^^^^^^^^^ SSL certificates have an expiry date. If you’re using certificates and keys generated by PEM, PEM replaces them before they expire. The PEM agent installed with the PEM server monitors the expiration date of the ``ca_certificate.crt`` file. When the certificate is about to expire, PEM: - Makes a backup of the existing certificate files. - Creates new certificate files and appends the new CA certificate file to the ``root.crt`` file on the PEM server. - Creates a job to renew the certificate file for any active agents. - Restarts the PEM server. .. Important:: If you choose to provide your own certificates or use a single certificate for all agents, disable the automatic renewal job. On the PEM server, execute the following SQL: .. code:: sql UPDATE pem.job SET jobenabled=false WHERE jobname = Check CA certificate expiry; .. :: If you need to regenerate the server or agent certificates manually, see: - :ref:`Regenerating the server SSL certificates ` - :ref:`Regenerating the agent SSL certificates ` Generate a common agent certificate and key pair ------------------------------------------------ By creating and using a single Postgres user for all PEM agents rather than one user per agent (the default), you can use the same certificate for all agents. Create a user, generate an agent certificate and key pair, and use them for all PEM agents. 1. Create one common agent user in the PEM backend database. Grant the pem_agent role to the user. .. code:: shell # Running as enterprisedb psql -p 5444 -U enterprisedb -d pem CREATE USER pem_agent_common_user; GRANT pem_agent TO pem_agent_common_user; 1. Generate an agent key: .. code:: shell # Running as root openssl genrsa -out agent.key 4096 1. Generate a CSR for the agent: .. code:: shell openssl req -new -key agent.key -out agent.csr -subj /C=IN/ST=MH/L=Pune/O=PEM/CN= Where ``-subj`` is provided as per your requirements. 1. Use the ``openssl x509`` command to sign the CSR and generate an agent certificate: .. code:: shell openssl x509 -req -days 365 -in agent.csr -CA ca_certificate.crt -CAkey ca_key.key -CAcreateserial -out agent.crt 1. Change the permissions on the ``agent.crt`` and ``agent.key`` files: .. code:: shell chmod 600 agent.crt agent.key 1. Use this agent certificate and key pair: - For registering the new PEM agent from the remote host to the PEM server. a. Copy the agent certificate and key pair to the remote agent host and register the agent: .. code:: shell export PEM_SERVER_PASSWORD=edb /usr/edb/pem/agent/bin/pemworker --register-agent \ --pem-server 192.168.99.130 \ --pem-user enterprisedb \ --pem-port 5444 \ --pem-agent-user pem_agent_common_user \ -o agent_ssl_crt= agent.crt \ -o agent_ssl_key= agent.key b. Enable and start the pemagent services: .. code:: shell systemctl enable pemagent systemctl start pemagent - To replace the agent certificate and key pair with the registered agent. a. Edit the ``agent_user`` , ``agent_ssl_key`` , and ``agent_ssl_crt`` parameters in the ``agent.cfg`` file of the agent host: .. code:: shell vi /usr/edb/pem/agent/etc/agent.cfg # Edit the agent username agent_user=pem_agent_common_user # Edit the ssl parameters with new certificate and key file location agent_ssl_key=/agent.key agent_ssl_crt=/agent.crt b. Restart the pemagent service: .. code:: shell systemctl restart pemagent Use certificates and keys signed by trusted CA ---------------------------------------------- You can replace the PEM SSL certificates and keys with certificates and keys signed by a trusted CA. After obtaining the trusted CA certificates and keys, replace the :ref:`Replace the server SSL certificates with certificates signed by a trusted CA ` and :ref:`Replace the agent SSL certificates with certificates signed by a trusted CA ` certificates and keys. Replace the server SSL certificates with certificates signed by a trusted CA ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1. Back up the old server certificate and key files: .. code:: shell # Running as root mkdir /var/lib/edb/as/data/certs cd /var/lib/edb/as/data/ mv server.* root.* ca_* /var/lib/edb/as/data/certs 1. Generate a private key for the server: .. code:: shell openssl genrsa -out server.key 4096 1. Generate a CSR for the server: .. code:: shell openssl req -new -key server.key -out server.csr -subj /C=IN/ST=MH/L=Pune/O=EDB/CN=PEM Where ``-subj`` is provided as per your requirements. We recommend using the hostname or domain qualified full name of the PEM server host for ``CN`` . 1. Obtain the CA certificate (``trusted_ca.crt`` ) from a trusted CA. 2. Ask your CA to sign the CSR and generate the server certificate for you. 3. Verify that the details of the new server certificate aren’t tampered with and match your provided details: .. code:: shell openssl x509 -noout -text -in server.crt 1. Use the new certificate obtained from the CA as the ``root.crt`` file: .. code:: shell cp trusted_ca.crt root.crt 1. If the trusted CA doesn’t provide CRL, disable CRL usage by the server. To disable the CRL usage, comment the ``ssl_crl_file`` parameter in the ``postgresql.conf`` file. .. Note:: If you leave a CRL from a previous CA in place and don't comment out `ssl_crl_file` , the server will start. However, authentication will fail with an SSL error message: `tlsv1 alert unknown ca` . The error doesn't specify that the CRL is the cause, so this issue can be difficult to debug if encountered out of context. 1. Copy the new ``root.crt`` , ``server.key`` , and ``server.crt`` files to the data directory of the backend database server: .. code:: shell cp root.crt server.key server.crt /var/lib/edb/as/data 1. Change the owner and permissions of the new certificates and key files to the same name as the data directory: .. code:: shell cd /var/lib/edb/as/data/ chown enterprisedb server.* root.crt ca_certificate.crt chmod 600 server.* root.crt ca_certificate.crt .. Note:: Don't restart the PEM server now. If you restart the PEM server, all the registered agents will stop working. 1. Replace each PEM agent SSL certificates with the trusted CA certificates. For more information, see these :ref:`Replace the agent SSL certificates with certificates signed by a trusted CA ` . 2. Restart the PEM backend database server. Replace the agent SSL certificates with certificates signed by a trusted CA ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Replace the agent SSL certificates only after replacing the server certificates ``server.crt`` and ``server.key`` and CA certificate ``root.crt`` . 1. Use psql to find all the agent identifiers (IDs) needed to replace the SSL certificates: .. code:: shell psql -U enterprisedb -d pem --no-psqlrc -t -A -c "SELECT id FROM pem.agent WHERE active=true" 1. After identifying the agents that need key files, generate an ``agent.key`` for each agent: .. code:: shell openssl genrsa -out agent.key 4096 Where ```` is the agent identifier. 1. Generate a CSR for each agent: .. code:: shell openssl req -new -key agent.key -out agent.csr -subj /C=IN/ST=MH/L=Pune/O=PEM/CN=agent Where ``-subj`` is provided as per your requirements. Replace ```` in ``CN`` with an appropriate agent identifier. .. Note:: If you prefer to use a single certificate for all PEM agents rather than one per agent, create a common Postgres user and supply this username in place of `ID` . See :ref:`Generate a common agent certificate and key pair ` . 1. Ask your CA to sign the CSR and generate the agent certificate for you. 2. Copy the certificate and key files on the respective hosts, where ```` matches the ``agent_id`` in the ``/usr/edb/pem/agent/etc/agent.cfg`` file. 3. Change the ownership and permission on the new ``agent.crt`` and ``agent.key`` file: .. code:: shell chown root agent.crt agent.key chmod 600 agent.crt agent.key 1. Back up the old agent certificate and key file: .. code:: shell # Running as root mkdir root/.pem/certs mv root/.pem/agent.* root/.pem/certs 1. Replace each agent’s certificate and key file with the newly generated files: .. code:: shell cp agent.key agent.crt root/.pem 7. Restart the PEM agent service. - On Linux: .. code:: shell # Running as root systemctl restart pemagent - On Windows: Use the Services applet to restart the PEM agent. The PEM agent service is named Postgres Enterprise Manager Agent. Select the service name in the Services dialog box, and select **Restart the service**. .. Note:: For agents registered after following the preceding process, you can provide a certificate to the agent at the time of registration as shown in the `Providing an existing SSL certificate and key `_ . !!!note If the new agent certificate requires a passphrase, then specify the path to a script that returns the passphrase using the ``agent_ssl_passphrase_script`` parameter. For more information on the parameter, see :ref:`Modifying agent configuration ` . Testing certificates -------------------- If you experience authentication problems, you can use these tests to validate certificates. Validate a certificate against the root certificate ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ To check whether a PEM agent certificate is trusted according to the server’s ``root.crt`` , copy both certificates to the same machine. Then execute the following command: .. code:: shell openssl verify -verbose -CAfile root.crt agent1.crt This command returns ``agent1.crt: OK`` on success or an explanatory message on failure. Make a test connection to the PEM backend database ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ To verify whether the agent user can connect using a certificate, as root on the server where the agent is located, execute: .. code:: shell PGHOST= PGPORT= PGUSER=agent PGSSLCERT=/root/.pem/agent.crt PGSSLKEY=/root/.pem/agent.key PGSSLMODE=require export PGHOST PGPORT PGUSER PGSSLCERT PGSSLKEY PGSSLMODE -A -t -c "SELECT version()" Where: - ```` is the full path to the psql executable, for example ``/usr/edb/as15/bin/psql`` . - ```` is the hostname or IP address of PEM server. - ```` is the PEM backend database server port. - ```` is the ID of the agent you’re testing, as defined in the file ``/usr/edb/pem/agent/etc/agent.cfg`` . .. Note:: If you used the instructions in :ref:`Generate a common agent certificate and key pair ` , you must set `PGUSER` to the common agent username. If the connection succeeds, it returns the Postgres version of the database server. Success means that your certificate is valid and the Postgres user is correctly configured. .. toctree:: :maxdepth: 3 Administering--certificates--replacing_ssl_certificates Administering--certificates--regenerating_agent_certificates