cracklib patch for qmailadmin-1.2.16 by Roberto Puzzanghera v. 2023.04.26
Add a call to cracklib to enforce strong passwords
Based on http://sourceforge.net/p/qmailadmin/patches/28/ by Inter7
More info here: https://notes.sagredo.eu/en/qmail-notes-185/qmailadmin-23.html

Install as follows:

cd qmailadmin.1.2.16
patch -p1 < qmailadmin-cracklib.patch

autoreconf -f -i
./configure --enable-cracklib=/path/to/cracklib/pw_dict
make
make install-strip

==================================================================================

diff -ruN ../qmailadmin-1.2.16-original/configure.in qmailadmin-1.2.16/configure.in
--- ../qmailadmin-1.2.16-original/configure.in	2011-02-22 15:45:47.000000000 +0100
+++ qmailadmin-1.2.16/configure.in	2023-04-25 21:31:17.205987784 +0200
@@ -26,6 +26,7 @@
 dnl Checks for libraries.
 AC_CHECK_LIB(crypt,crypt)
 AC_CHECK_LIB(shadow,crypt)
+AC_CHECK_LIB(crack,FascistCheck)
 #AC_CHECK_LIB(m,floor)
 #AC_CHECK_LIB(nsl, gethostbyaddr)
 #AC_CHECK_LIB(socket, getsockname)
@@ -421,6 +422,31 @@
 AC_DEFINE_UNQUOTED(SPAM_COMMAND, "$spam_command","")
 AC_SUBST(SPAM_COMMAND)
 
+cracklib=no
+AC_ARG_ENABLE(cracklib, [  --enable-cracklib=PATH     Path to cracklib dictionary.],
+    cracklib="$enableval",
+    [
+        if test "$cracklib" = ""
+        then
+            AC_MSG_ERROR([Unable to find your cracklib directory, specify --enable-cracklib.])
+        fi
+    ] )
+
+if test "$cracklib" = "yes"
+then
+       cracklib="/usr/lib/cracklib_dict"
+fi
+
+case $cracklib in
+0*|n*|N*)
+       echo "checking whether to use password checking... no"
+       ;;
+*)
+       AC_DEFINE_UNQUOTED(CRACKLIB,"$cracklib","")
+       echo "checking whether to use password checking... yes"
+       ;;
+esac
+
 HELP=no
 AC_ARG_ENABLE(help, [  --enable-help  Display help links on login page.],
     HELP="$enableval",)
@@ -485,4 +511,7 @@
 then
         echo "      spam command = "$spam_command""
 fi
-
+if test "$cracklib" != "no"
+then
+       echo "cracklib dictionary= "$cracklib""
+fi
diff -ruN ../qmailadmin-1.2.16-original/qmailadmin.c qmailadmin-1.2.16/qmailadmin.c
--- ../qmailadmin-1.2.16-original/qmailadmin.c	2011-02-22 15:45:48.000000000 +0100
+++ qmailadmin-1.2.16/qmailadmin.c	2023-04-25 21:31:52.051893616 +0200
@@ -50,6 +50,11 @@
 #include "template.h"
 #include "user.h"
 #include "util.h"
+/* cracklib patch */
+#ifdef CRACKLIB
+#      include <crack.h>
+#endif
+/* end cracklib */
 
 char Username[MAX_BUFF];
 char Domain[MAX_BUFF];
@@ -131,6 +136,7 @@
  int argc;
  char *argv[];
 {
+ char *tmpstr;
  const char *ip_addr=getenv("REMOTE_ADDR");
  const char *x_forward=getenv("HTTP_X_FORWARDED_FOR");
  char *pi;
@@ -221,12 +227,18 @@
           snprintf (StatusMessage, sizeof(StatusMessage), "%s", html_text[200]);
         } else if (*Password1 == '\0') {
           snprintf (StatusMessage, sizeof(StatusMessage), "%s", html_text[234]);
-        } else if (vpasswd (User, Domain, Password1, USE_POP) != VA_SUCCESS) {
-          snprintf (StatusMessage, sizeof(StatusMessage), "%s", html_text[140]);
 #ifndef TRIVIAL_PASSWORD_ENABLED
          } else if ( strstr(User,Password1)!=NULL) {
           snprintf (StatusMessage, sizeof(StatusMessage), "%s\n", html_text[320]);
 #endif
+/* cracklib patch */
+#ifdef CRACKLIB
+	} else if ((tmpstr = FascistCheck(Password1, CRACKLIB)) != NULL ) {
+	  sprintf (StatusMessage, "Bad password - %s\n", tmpstr);
+#endif
+/* end cracklib */
+        } else if (vpasswd (User, Domain, Password1, USE_POP) != VA_SUCCESS) {
+          snprintf (StatusMessage, sizeof(StatusMessage), "%s", html_text[140]);
         } else {
           /* success */
           snprintf (StatusMessage, sizeof(StatusMessage), "%s", html_text[139]);
diff -ruN ../qmailadmin-1.2.16-original/user.c qmailadmin-1.2.16/user.c
--- ../qmailadmin-1.2.16-original/user.c	2011-02-22 15:45:48.000000000 +0100
+++ qmailadmin-1.2.16/user.c	2023-04-25 21:31:17.206987781 +0200
@@ -47,7 +47,11 @@
 #include "user.h"
 #include "util.h"
 #include "vauth.h"
-
+/* cracklib patch */
+#ifdef CRACKLIB
+#	include <crack.h>
+#endif
+/* end cracklib patch */
 
 #define HOOKS 1
 
@@ -318,6 +322,7 @@
 
 void addusernow()
 {
+ char *tmpstr;
  int cnt=0, num;
  char *c_num;
  char **mailingListNames;
@@ -394,6 +399,16 @@
     exit(0);
   }
 #endif
+/* cracklib patch */
+#ifdef CRACKLIB
+    if ((tmpstr = FascistCheck(Password1, CRACKLIB)) != NULL ) {
+       sprintf(StatusMessage, "Bad password - %s\n", tmpstr);
+       adduser();
+       vclose();
+       exit(0);
+    }
+#endif
+/* end cracklib */
 
 #ifndef ENABLE_LEARN_PASSWORDS
   if ( strlen(Password1) <= 0 ) {
@@ -796,6 +811,16 @@
        exit(0);
      }
 #endif
+/* cracklib patch */
+#ifdef CRACKLIB
+    if ((tmpstr = FascistCheck(Password1, CRACKLIB)) != NULL ) {
+       sprintf(StatusMessage, "Bad password - %s\n", tmpstr);
+       moduser();
+       vclose();
+       exit(0);
+    }
+#endif
+/* end cracklib */
     ret_code = vpasswd( ActionUser, Domain, Password1, USE_POP);
     if ( ret_code != VA_SUCCESS ) {
       snprintf (StatusMessage, sizeof(StatusMessage), "%s (%s)", html_text[140],