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TLS and authentication

YSQL

TLS can be configured in conjunction with authentication using the following configuration flags related to TLS and authentication:

ysql_enable_auth to enable password (md5) authentication
use_client_to_server_encryption to enable client-server TLS encryption
ysql_hba_conf_csv to manually set a host-based authentication (HBA) configuration

The default (auto-generated) configuration in the ysql_hba.conf file depends on whether auth (ysql_enable_auth) and/or TLS (use_client_to_server_encryption) are enabled.

The four default cases are shown in the following table.

	Auth disabled	Auth enabled
TLS disabled	`host all all all trust` (no ssl, no password)	`host all all all md5` (no ssl, password required)
TLS enabled	`hostssl all all all trust` (require ssl, no password)	`hostssl all all all md5` (require ssl and password)

Note

Before version 2.5.2, when TLS was enabled the default was to use the more strict cert option when auth was disabled, and md5 clientcert=1 (effectively md5 + cert) when auth was enabled.

Additionally, ysql_hba_conf_csv can be used to manually configure a custom HBA configuration.

For instance, to use TLS with both md5 and cert authentication, you can set the ysql_hba_conf_csv flag as follows:

hostssl all all all md5 clientcert=1

The ysql_hba_conf_csv rules are added above the auto-generated rules in the ysql_hba.conf file, so if they do not match the connection type, database, user, or host, then the auto-generated rules (that is, from the table above) may still be used.

If the custom user-defined rules only apply to some connection types (for example, host vs hostssl), databases, users, or hosts, the auto-generated rules are applied to the non-matching hosts, users, or databases. To fully disable the auto-generated rules, use the reject auth option.

For instance, to enable TLS with cert authentication, but only for some particular database, user, and host, use the following ysql_hba_conf_csv setting:

hostssl mydb myuser myhost cert,hostssl all all all reject

Examples

To begin, download and configure sample certificates:

$ wget https://raw.githubusercontent.com/yugabyte/yugabyte-db/master/ent/test_certs/ca.crt
$ wget -O node.127.0.0.1.key https://raw.githubusercontent.com/yugabyte/yugabyte-db/master/ent/test_certs/ysql.key
$ wget -O node.127.0.0.1.crt https://raw.githubusercontent.com/yugabyte/yugabyte-db/master/ent/test_certs/ysql.crt
$ chmod 600 ca.crt node.127.0.0.1.key node.127.0.0.1.crt
$ CERTS=`pwd`
$ ENABLE_TLS="use_client_to_server_encryption=true,certs_for_client_dir=$CERTS"

node.127.0.0.1.crt and node.127.0.0.1.key are the default values for the ssl_cert_file and ssl_key_file server-side configuration for a YSQL node. If your local IP is not 127.0.0.1, then use the appropriate local IP to name the two files. Alternatively use ysql_pg_conf to set ssl_cert_file and ssl_key_file to the appropriate values.

TLS without authentication

This configuration requires the client to use client-to-server encryption to connect.

Create the database:

$ ./bin/yb-ctl destroy && ./bin/yb-ctl create --tserver_flags="$ENABLE_TLS"

Without SSL enabled in the client, the connection fails.

$ ./bin/ysqlsh "sslmode=disable"

ysqlsh: FATAL:  no pg_hba.conf entry for host "127.0.0.1", user "yugabyte", database "yugabyte", SSL off

To connect, SSL must be enabled in the client.

$ ./bin/ysqlsh "sslmode=require"

ysqlsh (11.2-YB-2.7.0.0-b0)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

The default ysqlsh SSL mode is prefer (see https://www.postgresql.org/docs/11/libpq-ssl.html), which tries SSL first, but falls back to no-ssl if the server does not support it.

In this case, a plain ysqlsh with no options will work and use encryption:

$ ./bin/ysqlsh

ysqlsh (11.2-YB-2.7.0.0-b0)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

The following examples omit setting sslmode for brevity.

TLS with authentication

This configuration requires the client to use client-to-server encryption and authenticate with a password to connect.

To create the database, execute the following command:

$ ./bin/yb-ctl destroy && ./bin/yb-ctl create --tserver_flags="$ENABLE_TLS,ysql_enable_auth=true"

To connect to the database, the password is required (see second line below):

$ ./bin/ysqlsh

Password for user yugabyte:
ysqlsh (11.2-YB-2.7.0.0-b0)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

The other modes (that is, sslmode=require or disable) behave analogously.

TLS with authentication via certificate

This configuration requires the client to use client-to-server encryption and authenticate with the appropriate certificate to connect.

Note

Before version 2.5.2, this was the default for TLS without authentication. This example shows the ysql_hba_conf_csv configuration to use to replicate the previous behavior.

To create the database, execute the following command:

$ ./bin/yb-ctl destroy && ./bin/yb-ctl create \
    --tserver_flags="$ENABLE_TLS" \
    --ysql_hba_conf_csv="hostssl all all all cert"

Without a certificate, the connection fails.

$ ./bin/ysqlsh

ysqlsh: FATAL:  connection requires a valid client certificate
FATAL:  no pg_hba.conf entry for host "127.0.0.1", user "yugabyte", database "yugabyte", SSL off

Use the following command to connect with a certificate:

$ ./bin/ysqlsh "sslcert=$CERTS/node.127.0.0.1.crt sslkey=$CERTS/node.127.0.0.1.key sslrootcert=$CERTS/ca.crt"

ysqlsh (11.2-YB-2.7.0.0-b0)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

TLS with password and certificate authentication

This configuration requires the client to use client-to-server encryption and authenticate with both the appropriate certificate and the password to connect.

Note

Before version 2.5.2, this was the default for TLS with authentication. This example shows the ysql_hba_conf_csv configuration to use to replicate the previous behavior.

To create the database, execute the following command:

$ ./bin/yb-ctl destroy && ./bin/yb-ctl create \
    --tserver_flags="$ENABLE_TLS,ysql_enable_auth=true" \
    --ysql_hba_conf_csv="hostssl all all all md5 clientcert=1"

The ysql_enable_auth=true flag is redundant in this case, but included to demonstrate the ability to override the auto-generated configuration using ysql_hba_conf_csv.

Without a certificate and password, the connection fails.

$ ./bin/ysqlsh

ysqlsh: FATAL:  connection requires a valid client certificate
FATAL:  no pg_hba.conf entry for host "127.0.0.1", user "yugabyte", database "yugabyte", SSL off

Use the following command to connect with a certificate and password:

$ ./bin/ysqlsh "sslcert=$CERTS/node.127.0.0.1.crt sslkey=$CERTS/node.127.0.0.1.key sslrootcert=$CERTS/ca.crt"

Password for user yugabyte:
ysqlsh (11.2-YB-2.7.0.0-b0)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.