Add PostgreSQL & Redis TLS/mTLS support

doc/admin/config.rst

@@ -152,6 +152,10 @@ Example::
     password=abcd
     host=localhost
     port=3306
+    sslmode=require
+    sslrootcert=/etc/pretix/postgresql-ca.crt
+    sslcert=/etc/pretix/postgresql-client-crt.crt
+    sslkey=/etc/pretix/postgresql-client-key.key
 
 ``backend``
     One of ``sqlite3`` and ``postgresql``.
@@ -163,6 +167,11 @@ Example::
 ``user``, ``password``, ``host``, ``port``
     Connection details for the database connection. Empty by default.
 
+``sslmode``, ``sslrootcert``
+    Connection TLS details for the PostgreSQL database connection. Possible values of ``sslmode`` are ``disable``, ``allow``, ``prefer``, ``require``, ``verify-ca``, and ``verify-full``. ``sslrootcert`` should be the accessible path of the ca certificate. Both values are empty by default.
+
+``sslcert``, ``sslkey``
+    Connection mTLS details for the PostgreSQL database connection. It's also necessary to specify ``sslmode`` and ``sslrootcert`` parameters, please check the correct values from the TLS part. ``sslcert`` should be the accessible path of the client certificate.  ``sslkey`` should be the accessible path of the client key. All values are empty by default.
 .. _`config-replica`:
 
 Database replica settings
@@ -324,6 +333,10 @@ to speed up various operations::
             ["sentinel_host_3", 26379]
         ]
     password=password
+    ssl_cert_reqs=required
+    ssl_ca_certs=/etc/pretix/redis-ca.pem
+    ssl_keyfile=/etc/pretix/redis-client-crt.pem
+    ssl_certfile=/etc/pretix/redis-client-key.key
 
 ``location``
     The location of redis, as a URL of the form ``redis://[:password]@localhost:6379/0``
@@ -347,6 +360,22 @@ to speed up various operations::
     If your redis setup doesn't require a password or you already specified it in the location you can omit this option.
     If this is set it will be passed to redis as the connection option PASSWORD.
 
+``ssl_cert_reqs``
+    If this is set it will be passed to redis as the connection option ``SSL_CERT_REQS``.
+    Possible values are ``none``, ``optional``, and ``required``.
+
+``ssl_ca_certs``
+    If your redis setup doesn't require TLS you can omit this option.
+    If this is set it will be passed to redis as the connection option ``SSL_CA_CERTS``. Possible value is the ca path.
+
+``ssl_keyfile``
+    If your redis setup doesn't require mTLS you can omit this option.
+    If this is set it will be passed to redis as the connection option ``SSL_KEYFILE``. Possible value is the keyfile path.
+
+``ssl_certfile``
+    If your redis setup doesn't require mTLS you can omit this option.
+    If this is set it will be passed to redis as the connection option ``SSL_CERTFILE``. Possible value is the certfile path.
+
 If redis is not configured, pretix will store sessions and locks in the database. If memcached
 is configured, memcached will be used for caching instead of redis.
 
@@ -396,6 +425,8 @@ The two ``transport_options`` entries can be omitted in most cases.
 If they are present they need to be a valid JSON dictionary.
 For possible entries in that dictionary see the `Celery documentation`_.
 
+It is possible the use Redis with TLS/mTLS for the broker or the backend. To do so, it is necessary to specify the TLS identifier ``rediss``, the ssl mode ``ssl_cert_reqs`` and optionally specify the CA (TLS) ``ssl_ca_certs``, cert ``ssl_certfile`` and key ``ssl_keyfile`` (mTLS) path as encoded string. the following uri describes the format and possible parameters ``rediss://0.0.0.0:6379/1?ssl_cert_reqs=required&ssl_ca_certs=%2Fetc%2Fpretix%2Fredis-ca.pem&ssl_certfile=%2Fetc%2Fpretix%2Fredis-client-crt.pem&ssl_keyfile=%2Fetc%2Fpretix%2Fredis-client-key.key``
+
 To use redis with sentinels set the broker or backend to ``sentinel://sentinel_host_1:26379;sentinel_host_2:26379/0``
 and the respective transport_options to ``{"master_name":"mymaster"}``.
 If your redis instances behind the sentinel have a password use ``sentinel://:my_password@sentinel_host_1:26379;sentinel_host_2:26379/0``.

src/pretix/settings.py

@@ -116,6 +116,29 @@
 
 db_options = {}
 
+postgresql_sslmode = config.get('database', 'sslmode', fallback='disable')
+USE_DATABASE_TLS = postgresql_sslmode != 'disable'
+USE_DATABASE_MTLS = USE_DATABASE_TLS and config.has_option('database', 'sslcert')
+
+if USE_DATABASE_TLS or USE_DATABASE_MTLS:
+    tls_config = {}
+    if not USE_DATABASE_MTLS:
+        if 'postgresql' in db_backend:
+            tls_config = {
+                'sslmode': config.get('database', 'sslmode'),
+                'sslrootcert': config.get('database', 'sslrootcert'),
+            }
+    else:
+        if 'postgresql' in db_backend:
+            tls_config = {
+                'sslmode': config.get('database', 'sslmode'),
+                'sslrootcert': config.get('database', 'sslrootcert'),
+                'sslcert': config.get('database', 'sslcert'),
+                'sslkey': config.get('database', 'sslkey'),
+            }
+
+    db_options.update(tls_config)
+
 DATABASES = {
     'default': {
         'ENGINE': 'django.db.backends.' + db_backend,
@@ -227,6 +250,9 @@
 
 HAS_REDIS = config.has_option('redis', 'location')
 USE_REDIS_SENTINEL = config.has_option('redis', 'sentinels')
+redis_ssl_cert_reqs = config.get('redis', 'ssl_cert_reqs', fallback='none')
+USE_REDIS_TLS = redis_ssl_cert_reqs != 'none'
+USE_REDIS_MTLS = USE_REDIS_TLS and config.has_option('redis', 'ssl_certfile')
 HAS_REDIS_PASSWORD = config.has_option('redis', 'password')
 if HAS_REDIS:
     OPTIONS = {
@@ -242,6 +268,29 @@
         OPTIONS["SENTINEL_KWARGS"] = {"socket_timeout": 1}
         OPTIONS["SENTINELS"] = [tuple(sentinel) for sentinel in loads(config.get('redis', 'sentinels'))]
 
+    if USE_REDIS_TLS or USE_REDIS_MTLS:
+        tls_config = {}
+        if not USE_REDIS_MTLS:
+            tls_config = {
+                'ssl_cert_reqs': config.get('redis', 'ssl_cert_reqs'),
+                'ssl_ca_certs': config.get('redis', 'ssl_ca_certs'),
+            }
+        else:
+            tls_config = {
+                'ssl_cert_reqs': config.get('redis', 'ssl_cert_reqs'),
+                'ssl_ca_certs': config.get('redis', 'ssl_ca_certs'),
+                'ssl_keyfile': config.get('redis', 'ssl_keyfile'),
+                'ssl_certfile': config.get('redis', 'ssl_certfile'),
+            }
+
+        if USE_REDIS_SENTINEL is False:
+            # The CONNECTION_POOL_KWARGS option is necessary for self-signed certs. For further details, please check
+            # https://github.com/jazzband/django-redis/issues/554#issuecomment-949498321
+            OPTIONS["CONNECTION_POOL_KWARGS"] = tls_config
+            OPTIONS["REDIS_CLIENT_KWARGS"].update(tls_config)
+        else:
+            OPTIONS["SENTINEL_KWARGS"].update(tls_config)
+
     if HAS_REDIS_PASSWORD:
         OPTIONS["PASSWORD"] = config.get('redis', 'password')