Help Center/ GaussDB(DWS)/ Developer Guide/ Standard data warehouse (8.1.3.x)/ GUC Parameters of the GaussDB(DWS) Database/ Connection and Authentication/ Security and Authentication (postgresql.conf)
Updated on 2024-05-13 GMT+08:00
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Security and Authentication (postgresql.conf)

This section describes parameters about how to securely authenticate the client and server.

authentication_timeout

Parameter description: Specifies the longest duration to wait before the client authentication times out. If a client is not authenticated by the server within the timeout period, the server automatically breaks the connection from the client so that the faulty client does not occupy connection resources.

Type: SIGHUP

Value range: an integer ranging from 1 to 600. The minimum unit is second (s).

Default value: 1min

session_timeout

Parameter description: Specifies the longest duration with no operations after the connection to the server.

Type: USERSET

Value range: an integer ranging from 0 to 86400. The minimum unit is second (s). 0 means to disable the timeout.

Default value: 10 min

  • The gsql client of GaussDB(DWS) has an automatic reconnection mechanism. If the initialized local connection of a user to the server times out, gsql disconnects from and reconnects to the server.
  • Connections from the pooler connection pool to other CNs and DNs are not controlled by the session_timeout parameter.

ssl_ciphers

Parameter description: Specifies the encryption algorithm list supported by the SSL.

Type: POSTMASTER

Value range: a string. Separate multiple encryption algorithms with semicolons (;).

Default value: ALL

  • The default value of ssl_ciphers is ALL, indicating that all the following encryption algorithms are supported. Users are advised to retain the default value, unless there are other special requirements on the encryption algorithm.
    • TLS1_3_RFC_AES_128_GCM_SHA256
    • TLS1_3_RFC_AES_256_GCM_SHA384
    • TLS1_3_RFC_CHACHA20_POLY1305_SHA256
    • TLS1_3_RFC_AES_128_CCM_SHA256
    • TLS1_3_RFC_AES_128_CCM_8_SHA256
  • Currently, SSL connection authentication supports only the TLS1.3 encryption algorithm, which has better performance and security. It is also compatible with SSL connection authentication between clients that comply with TLS1.2.

ssl_renegotiation_limit

Parameter description: Specifies the traffic volume over the SSL-encrypted channel before the session key is renegotiated. The renegotiation traffic limitation mechanism reduces the probability that attackers use the password analysis method to crack the key based on a huge amount of data but causes big performance losses. The traffic indicates the sum of sent and received traffic.

Type: USERSET

You are advised to retain the default value, that is, disable the renegotiation mechanism. You are not advised to use the gs_guc tool or other methods to set the ssl_renegotiation_limit parameter in the postgresql.conf file. The setting does not take effect.

Value range: an integer ranging from 0 to INT_MAX. The unit is KB. 0 indicates that the renegotiation mechanism is disabled.

Default value: 0

password_policy

Parameter description: Specifies whether to check the password complexity when you run the CREATE ROLE/USER or ALTER ROLE/USER command to create or modify a GaussDB(DWS) account.

Type: SIGHUP

For security purposes, do not disable the password complexity policy.

Value range: an integer, 0 or 1

  • 0 indicates that no password complexity policy is enabled.
  • 1 indicates that the default password complexity policy is disabled.

Default value: 1

password_reuse_time

Parameter description: Specifies whether to check the reuse days of the new password when you run the ALTER USER or ALTER ROLE command to change a user password.

Type: SIGHUP

When you change the password, the system checks the values of password_reuse_time and password_reuse_max.

  • If the values of password_reuse_time and password_reuse_max are both positive numbers, the password can be reused if either of the following conditions is met:
  • If the value of password_reuse_time is 0, the days of password reuse are not limited and only the times of password reuse are limited.
  • If the value of password_reuse_max is 0, the times of password reuse are not limited and only the days of password reuse are limited.
  • If the values of password_reuse_time and password_reuse_max are both 0, password reuse is not limited.

Value range: a floating number ranging from 0 to 3650. The unit is day.

  • 0 indicates that the password reuse days are not checked.
  • A positive number indicates that the new password cannot be the one that is used within the specified days.

Default value: 60

password_reuse_max

Parameter description: Specifies whether to check the reuse times of the new password when you run the ALTER USER or ALTER ROLE command to change a user password.

Type: SIGHUP

When you change the password, the system checks the values of password_reuse_time and password_reuse_max.

  • If the values of password_reuse_time and password_reuse_max are both positive numbers, the password can be reused if either of the following conditions is met:
  • If the value of password_reuse_time is 0, the days of password reuse are not limited and only the times of password reuse are limited.
  • If the value of password_reuse_max is 0, the times of password reuse are not limited and only the days of password reuse are limited.
  • If the values of password_reuse_time and password_reuse_max are both 0, password reuse is not limited.

Value range: an integer ranging from 0 to 1000

  • 0 indicates that the password reuse times are not checked.
  • A positive number indicates that the new password cannot be the one whose reuse times exceed the specified number.

Default value: 0

password_lock_time

Parameter description: Specifies the duration before an account is automatically unlocked.

Type: SIGHUP

  • The locking and unlocking functions take effect only when the values of password_lock_time and failed_login_attempts are positive numbers.
  • The integral part of the value of the password_lock_time parameter indicates the number of days and its decimal part can be converted into hours, minutes, and seconds.

Value range: a floating number ranging from 0 to 365. The unit is day.

  • 0 indicates that the automatic locking function does not take effect if the password verification fails.
  • A positive number indicates the duration after which an account is automatically unlocked.

Default value: 1

failed_login_attempts

Parameter description: Specifies the maximum number of incorrect password attempts before an account is locked. The account will be automatically unlocked after the time specified in password_lock_time. For example, incorrect password attempts during login and password input failures when using the ALTER USER command

Type: SIGHUP

Value range: an integer ranging from 0 to 1000

  • 0 indicates that the automatic locking function does not take effect.
  • A positive number indicates that an account is locked when the number of incorrect password attempts reaches the value of failed_login_attempts.

Default value: 10

  • The locking and unlocking functions take effect only when the values of failed_login_attempts and password_lock_time are positive numbers.
  • failed_login_attempts works with the SSL connection mode of the client to identify the number of incorrect password attempts. If PGSSLMODE is set to allow or prefer, two connection requests are generated for a password connection request. One request attempts an SSL connection, and the other request attempts a non-SSL connection. In this case, the number of incorrect password attempts perceived by the user is the value of failed_login_attempts divided by 2.

password_encryption_type

Parameter description: Specifies the encryption type of user passwords.

Type: SIGHUP

Value range: an integer, 0, 1, or 2
Table 1 Value description:

Value

Password Storage Format

Driver

0

Passwords are encrypted in by MD5 and stored in ciphertext.

GaussDB and open-source drivers are supported.

1

Passwords are encrypted by SHA256 and are compatible with the MD5 user authentication of the postgres client.

Passwords are encrypted by MD5+SHA256.

GaussDB and open-source drivers are supported.

2

Passwords are encrypted by SHA256 and stored in ciphertext.

GaussDB drivers are supported.
  • MD5 is not recommended because it is not a secure encryption algorithm.
  • For a user created when password_encryption_type is set to 2, the password has been saved using the SHA256 algorithm. In this case, changing the parameter value does not change the password storage mode in the database. Therefore, open-source clients using MD5 may still fail to connect to the database.
  • When password_encryption_type is set to 1, no matter the pg_hba authentication mode is set to MD5 or SHA256, both the two encryption modes are checked to ensure function compatibility.

Default value: 1

password_min_length

Parameter description: Specifies the minimum account password length.

Type: SIGHUP

Value range: an integer. A password can contain 6 to 999 characters.

Default value: 8

password_max_length

Parameter description: Specifies the maximum account password length.

Type: SIGHUP

Value range: an integer. A password can contain 6 to 999 characters.

Default value: 32

password_min_uppercase

Parameter description: Specifies the minimum number of uppercase letters that an account password must contain.

Type: SIGHUP

Value range: an integer ranging from 0 to 999.

  • 0 means no limit.
  • A positive integer indicates the minimum number of uppercase letters in the password specified for creating an account.

Default value: 0

password_min_lowercase

Parameter description: Specifies the minimum number of lowercase letters that an account password must contain.

Type: SIGHUP

Value range: an integer ranging from 0 to 999.

  • 0 means no limit.
  • A positive integer indicates the minimum number of lowercase letters in the password specified for creating an account.

Default value: 0

password_min_digital

Parameter description: Specifies the minimum number of digits that an account password must contain.

Type: SIGHUP

Value range: an integer ranging from 0 to 999.

  • 0 means no limit.
  • A positive integer indicates the minimum number of digits in the password specified for creating an account.

Default value: 0

password_min_special

Parameter description: Specifies the minimum number of special characters that an account password must contain.

Type: SIGHUP

Value range: an integer ranging from 0 to 999.

  • 0 means no limit.
  • A positive integer indicates the minimum number of special characters in the password specified for creating an account.

Default value: 0

Table 2 Special characters

ID

Character

ID

Character

ID

Character

ID

Character

1

~

9

*

17

|

25

<

2

!

10

(

18

[

26

.

3

@

11

)

19

{

27

>

4

#

12

-

20

}

28

/

5

$

13

_

21

]

29

?

6

%

14

=

22

;

-

-

7

^

15

+

23

:

-

-

8

&

16

\

24

,

-

-

password_effect_time

Parameter description: Specifies the validity period of an account password.

Type: SIGHUP

Value range: a floating number ranging from 0 to 999. The unit is day.

  • 0 indicates the function of validity period restriction is disabled.
  • A floating point number from 1 to 999 indicates the validity period of the password specified for creating an account. When the password is about to expire or has expired, the system prompts the user to change the password.

Default value: 90

password_notify_time

Parameter description: Specifies how many days in advance users are notified before the account password expires.

Type: SIGHUP

Value range: an integer ranging from 0 to 999. The unit is day.

  • 0 indicates the reminder is disabled.
  • A positive integer indicates how long before expiry the reminder will appear.

Default value: 7