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sslcertmode

This option determines whether a client certificate may be sent to the server, and whether the server is required to request one. There are three modes:

Reading PostgreSQL 18.6.

Description

This option determines whether a client certificate may be sent to the server, and whether the server is required to request one. There are three modes:

Client library: libpq 18.6
Manual definition: Documented
Source environment fallback: PGSSLCERTMODE
Compiled fallback expression: NULL

Usage

sslcertmode

Default resolution and service-file precedence

The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb , PQsetdbLogin and PQsetdb if no value is directly specified by the calling code. These are useful to avoid hard-coding database connection information into simple client applications, for example.

Service names can be defined in either a per-user service file or a system-wide file. If the same service name exists in both the user and the system file, the user file takes precedence. By default, the per-user service file is named ~/.pg_service.conf . On Microsoft Windows, it is named %APPDATA%\postgresql\.pg_service.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile). A different file name can be specified by setting the environment variable PGSERVICEFILE . The system-wide file is named pg_service.conf . By default it is sought in the etc directory of the PostgreSQL installation (use pg_config --sysconfdir to identify this directory precisely). Another directory, but not a different file name, can be specified by setting the environment variable PGSYSCONFDIR .

Connection parameters obtained from a service file are combined with parameters obtained from other sources. A service file setting overrides the corresponding environment variable, and in turn can be overridden by a value given directly in the connection string. For example, using the above service file, a connection string service=mydb port=5434 will use host somehost , port 5434 , user admin , and other parameters as set by environment variables or built-in defaults.

Environment variable evidence

PGSSLCERTMODE behaves the same as the sslcertmode connection parameter.

Environment fallback

Variable	Documented behavior
PGSSLCERTMODE	PGSSLCERTMODE behaves the same as the sslcertmode connection parameter.

Manual definition

sslcertmode

This option determines whether a client certificate may be sent to the server, and whether the server is required to request one. There are three modes:

disable: A client certificate is never sent, even if one is available (default location or provided via sslcert).
allow (default): A certificate may be sent, if the server requests one and the client has one to send.
require: The server must request a certificate. The connection will fail if the client does not send a certificate and the server successfully authenticates the client anyway.

Note

sslcertmode=require doesn't add any additional security, since there is no guarantee that the server is validating the certificate correctly; PostgreSQL servers generally request TLS certificates from clients whether they validate them or not. The option may be useful when troubleshooting more complicated TLS setups.

Related entries

Documentation and source

Source build

Version: 18.6
Build: https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2
Source fingerprint: ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8

Compare versions

PostgreSQL 15 → 16: added.

--- PostgreSQL 15
+++ PostgreSQL 16
@@ -1 +1,10 @@
-Not recorded in this version
+{
+  "compiled_default_expression": "NULL",
+  "default_evidence": [
+    "A client certificate is never sent, even if one is available (default location or provided via sslcert )."
+  ],
+  "definition": "This option determines whether a client certificate may be sent to the server, and whether the server is required to request one. There are three modes: disable A client certificate is never sent, even if one is available (default location or provided via sslcert ). allow (default) A certificate may be sent, if the server requests one and the client has one to send. require The server must request a certificate. The connection will fail if the client does not send a certificate and the server successfully authenticates the client anyway. Note sslcertmode=require doesn't add any additional security, since there is no guarantee that the server is validating the certificate correctly; PostgreSQL servers generally request TLS certificates from clients whether they validate them or not. The option may be useful when troubleshooting more complicated TLS setups.",
+  "documented": true,
+  "environment": "PGSSLCERTMODE",
+  "keyword": "sslcertmode"
+}

Compares recorded interfaces and attributes. Source fingerprints and build metadata are excluded; an absent sample is not proof of the introduction or removal release.

Related entries

Export JSON · Back to Connection Parameters · Recorded in PostgreSQL 16 through 20; the first sample is not necessarily its introduction.