sslsni
If set to 1 (default), libpq sets the TLS extension “ Server Name Indication ” ( SNI ) on SSL-enabled connections. By setting this parameter to 0, this is turned off.
Reading PG 18·Select a recorded version
- Client library
- libpq 18.6
- Manual definition
- Documented
- Source environment fallback
- PGSSLSNI
- Compiled fallback expression
- "1"
- default evidence
- If set to 1 (default), libpq sets the TLS extension “ Server Name Indication ” ( SNI ) on SSL-enabled connections. By setting this parameter to 0, this is turned off.
- documented
- true
- environment
- map[description:PGSSLSNI behaves the same as the sslsni connection parameter. name:PGSSLSNI source_url:/docs/18/libpq-envars.html]
- keyword
- sslsni
- manual path
- libpq-connect.html#LIBPQ-CONNECT-SSLSNI
- signature
- sslsni
Definition PG 18
sslsni-
If set to 1 (default), libpq sets the TLS extension “Server Name Indication” (SNI) on SSL-enabled connections. By setting this parameter to 0, this is turned off.
The Server Name Indication can be used by SSL-aware proxies to route connections without having to decrypt the SSL stream. (Note that unless the proxy is aware of the PostgreSQL protocol handshake this would require setting
sslnegotiationtodirect.) However, SNI makes the destination host name appear in cleartext in the network traffic, so it might be undesirable in some cases.
Environment fallback
| Variable | Documented behavior |
|---|---|
| PGSSLSNI | PGSSLSNI behaves the same as the sslsni connection parameter. |
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Complete source facts
precedence evidence
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.
source option
{"compiled_default_expression":"\"1\"","declaration":"\"sslsni\", \"PGSSLSNI\", \"1\", NULL, \"SSL-SNI\", \"\", 1, offsetof(struct pg_conn, sslsni)","environment":"PGSSLSNI","keyword":"sslsni","source_notes":[]}Source references
- 18.6 English manual · libpq-connect.html
- 18.6 libpq connection option declarations
- 18.6 English manual · libpq-envars.html
- 18.6 English manual · libpq-pgservice.html
- Pinned PostgreSQL source archive
Full definition and evidence JSON
Definition sources
center · PostgreSQL 18 · ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8
Text language: en · ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8