min_password_length_v6.patch

diff --git a/contrib/passwordcheck/expected/passwordcheck.out b/contrib/passwordcheck/expected/passwordcheck.out
index 2027681daf..a49b913e46 100644
--- a/contrib/passwordcheck/expected/passwordcheck.out
+++ b/contrib/passwordcheck/expected/passwordcheck.out
@@ -1,9 +1,13 @@
 LOAD 'passwordcheck';
+SET passwordcheck.min_password_length = 12;
 CREATE USER regress_passwordcheck_user1;
 -- ok
 ALTER USER regress_passwordcheck_user1 PASSWORD 'a_nice_long_password';
 -- error: too short
-ALTER USER regress_passwordcheck_user1 PASSWORD 'tooshrt';
+ALTER USER regress_passwordcheck_user1 PASSWORD 'tooshort';
+ERROR:  password is too short
+-- error: too short
+ALTER USER regress_passwordcheck_user1 PASSWORD 'äbcdefghijk';
 ERROR:  password is too short
 -- error: contains user name
 ALTER USER regress_passwordcheck_user1 PASSWORD 'xyzregress_passwordcheck_user1';
diff --git a/contrib/passwordcheck/passwordcheck.c b/contrib/passwordcheck/passwordcheck.c
index 0785618f2a..f4f90274b7 100644
--- a/contrib/passwordcheck/passwordcheck.c
+++ b/contrib/passwordcheck/passwordcheck.c
@@ -6,6 +6,8 @@
  * Copyright (c) 2009-2024, PostgreSQL Global Development Group
  *
  * Author: Laurenz Albe <laurenz.albe@wien.gv.at>
+ * Author: Maurizio Boriani <maurizio@boriani.cloud>
+ * Author: Emanuele Musella <emamuse86@gmail.com>
  *
  * IDENTIFICATION
  *	  contrib/passwordcheck/passwordcheck.c
@@ -20,17 +22,19 @@
 #include <crack.h>
 #endif
 
+#include "commands/explain.h"
 #include "commands/user.h"
 #include "fmgr.h"
 #include "libpq/crypt.h"
+#include "utils/guc.h"
 
 PG_MODULE_MAGIC;
 
 /* Saved hook value in case of unload */
 static check_password_hook_type prev_check_password_hook = NULL;
 
-/* passwords shorter than this will be rejected */
-#define MIN_PWD_LENGTH 8
+/* GUC variables */
+static int min_pwd_len;
 
 /*
  * check_password
@@ -84,7 +88,7 @@ check_password(const char *username,
 		 * For unencrypted passwords we can perform better checks
 		 */
 		const char *password = shadow_pass;
-		int			pwdlen = strlen(password);
+		int			pwdlen = pg_mbstrlen(password);
 		int			i;
 		bool		pwd_has_letter,
 					pwd_has_nonletter;
@@ -93,7 +97,7 @@ check_password(const char *username,
 #endif
 
 		/* enforce minimum length */
-		if (pwdlen < MIN_PWD_LENGTH)
+		if (pwdlen < min_pwd_len)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("password is too short")));
@@ -142,6 +146,21 @@ check_password(const char *username,
 void
 _PG_init(void)
 {
+	/* Define custom GUC variables. */
+	DefineCustomIntVariable("passwordcheck.min_password_length",
+				"Sets the minimum allowed password length.",
+				NULL,
+				&min_pwd_len,
+				8,
+				0, INT_MAX,
+				PGC_SUSET,
+				GUC_UNIT_BYTE,
+				NULL,
+				NULL,
+				NULL);
+
+	MarkGUCPrefixReserved("passwordcheck");
+
 	/* activate password checks when the module is loaded */
 	prev_check_password_hook = check_password_hook;
 	check_password_hook = check_password;
diff --git a/contrib/passwordcheck/sql/passwordcheck.sql b/contrib/passwordcheck/sql/passwordcheck.sql
index 1fbd6b0e96..4b0cea82d4 100644
--- a/contrib/passwordcheck/sql/passwordcheck.sql
+++ b/contrib/passwordcheck/sql/passwordcheck.sql
@@ -1,12 +1,15 @@
 LOAD 'passwordcheck';
-
+SET passwordcheck.min_password_length = 12;
 CREATE USER regress_passwordcheck_user1;
 
 -- ok
 ALTER USER regress_passwordcheck_user1 PASSWORD 'a_nice_long_password';
 
 -- error: too short
-ALTER USER regress_passwordcheck_user1 PASSWORD 'tooshrt';
+ALTER USER regress_passwordcheck_user1 PASSWORD 'tooshort';
+
+-- error: too short
+ALTER USER regress_passwordcheck_user1 PASSWORD 'äbcdefghijk';
 
 -- error: contains user name
 ALTER USER regress_passwordcheck_user1 PASSWORD 'xyzregress_passwordcheck_user1';
diff --git a/doc/src/sgml/passwordcheck.sgml b/doc/src/sgml/passwordcheck.sgml
index 601f489227..f847ff1860 100644
--- a/doc/src/sgml/passwordcheck.sgml
+++ b/doc/src/sgml/passwordcheck.sgml
@@ -59,4 +59,39 @@
   </para>
  </caution>
 
+ <sect2 id="passwordcheck-configuration-parameters">
+  <title>Configuration Parameters</title>
+
+ <para>
+  There is a configuration parameter that control the behavior 
+  <filename>passwordcheck</filename>. This is the minumum password length.
+ </para>
+
+  <variablelist>
+   <varlistentry id="passwordcheck-configuration-parameters-min-password-length">
+    <term>
+     <varname>passwordcheck.min_password_length</varname> (<type>integer</type>)
+     <indexterm>
+      <primary><varname>passwordcheck.min_password_length</varname> configuration parameter</primary>
+     </indexterm>
+    </term>
+    <listitem>
+     <para>
+      <varname>passwordcheck.min_password_length</varname> is the minimum length
+      of accepted password on database users.
+      If not setted the default is 8 bytes.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+<programlisting>
+# postgresql.conf
+session_preload_libraries = 'passwordcheck'
+passwordcheck.min_password_length = 12
+
+</programlisting>
+
+ </sect2>
+
 </sect1>