First stab at cracklib support (password quality checking) in Samba 3.0

This adds a configure test, that tries to find out if we have a working
cracklib installation, and tries to pick up the debian hints on where
the dictionary might be found.  Default is per my Fedora Core 1 system -
I'm not sure how much it changes.

Andrew Bartlett
(This used to be commit bc770edb788f0b6f719011cda683f045b76b7ba5)

1 files changed, 56 insertions, 23 deletions

diff --git a/source3/smbd/chgpasswd.c b/source3/smbd/chgpasswd.c
index e6117245e7..07def7549e 100644
--- a/source3/smbd/chgpasswd.c
+++ b/source3/smbd/chgpasswd.c
@@ -49,6 +49,14 @@
 
 #include "includes.h"
 
+#include <crack.h>
+
+#ifndef HAVE_CRACKLIB_DICTPATH
+#ifndef CRACKLIB_DICTPATH
+#define CRACKLIB_DICTPATH SAMBA_CRACKLIB_DICTPATH
+#endif
+#endif
+
 extern struct passdb_ops pdb_ops;
 
 static NTSTATUS check_oem_password(const char *user,
@@ -441,25 +449,14 @@ while we were waiting\n", WTERMSIG(wstat)));
 	return (chstat);
 }
 
-BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
+BOOL chgpasswd(const char *name, const struct passwd *pass, 
+	       const char *oldpass, const char *newpass, BOOL as_root)
 {
 	pstring passwordprogram;
 	pstring chatsequence;
 	size_t i;
 	size_t len;
 
-	struct passwd *pass;
-
-	if (!name) {
-		DEBUG(1, ("chgpasswd: NULL username specfied !\n"));
-	}
-	
-	pass = Get_Pwnam(name);
-	if (!pass) {
-		DEBUG(1, ("chgpasswd: Username does not exist in system !\n"));
-		return False;
-	}
-
 	if (!oldpass) {
 		oldpass = "";
 	}
@@ -471,13 +468,6 @@ BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL
 #endif
 
 	/* Take the passed information and test it for minimum criteria */
-	/* Minimum password length */
-	if (strlen(newpass) < lp_min_passwd_length()) {
-		/* too short, must be at least MINPASSWDLENGTH */
-		DEBUG(0, ("chgpasswd: Password Change: user %s, New password is shorter than minimum password length = %d\n",
-		       name, lp_min_passwd_length()));
-		return (False);	/* inform the user */
-	}
 
 	/* Password is same as old password */
 	if (strcmp(oldpass, newpass) == 0) {
@@ -570,7 +560,8 @@ the string %%u, and the given string %s does not.\n", passwordprogram ));
 
 #else /* ALLOW_CHANGE_PASSWORD */
 
-BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
+BOOL chgpasswd(const char *name, const struct passwd *pass, 
+	       const char *oldpass, const char *newpass, BOOL as_root)
 {
 	DEBUG(0, ("chgpasswd: Password changing not compiled in (user=%s)\n", name));
 	return (False);
@@ -909,6 +900,8 @@ static NTSTATUS check_oem_password(const char *user,
 
 NTSTATUS change_oem_password(SAM_ACCOUNT *hnd, char *old_passwd, char *new_passwd, BOOL as_root)
 {
+	struct passwd *pass;
+
 	BOOL ret;
 	uint32 min_len;
 
@@ -936,7 +929,47 @@ NTSTATUS change_oem_password(SAM_ACCOUNT *hnd, char *old_passwd, char *new_passw
 /* 		return NT_STATUS_PWD_TOO_SHORT; */
 	}
 
-	/* TODO:  Add cracklib support here */
+	pass = Get_Pwnam(pdb_get_username(hnd));
+	if (!pass) {
+		DEBUG(1, ("check_oem_password: Username does not exist in system !?!\n"));
+	}
+
+#ifdef HAVE_WORKING_CRACKLIB
+	if (pass) {
+		/* if we can, become the user to overcome internal cracklib sillyness */
+		if (!push_sec_ctx())
+			return NT_STATUS_UNSUCCESSFUL;
+		
+		set_sec_ctx(pass->pw_uid, pass->pw_gid, 0, NULL, NULL);
+		set_re_uid();
+	}
+
+	if (lp_use_cracklib()) {
+		const char *crack_check_reason;
+		DEBUG(4, ("change_oem_password: Checking password for user [%s]"
+			  " against cracklib. \n", pdb_get_username(hnd)));
+		DEBUGADD(4, ("If this is your last message, then something is "
+			     "wrong with cracklib, it might be missing it's "
+			     "dictionaries at %s\n", 
+			     CRACKLIB_DICTPATH));
+		dbgflush();
+
+		crack_check_reason = FascistCheck(new_passwd, (char *)CRACKLIB_DICTPATH);
+		if (crack_check_reason) {
+			DEBUG(1, ("Password Change: user [%s], "
+				  "New password failed cracklib test - %s\n",
+			  pdb_get_username(hnd), crack_check_reason));
+			
+			/* get back to where we should be */
+			if (pass)
+				pop_sec_ctx();
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+	}
+
+	if (pass)
+		pop_sec_ctx();
+#endif
 
 	/*
 	 * If unix password sync was requested, attempt to change
@@ -951,7 +984,7 @@ NTSTATUS change_oem_password(SAM_ACCOUNT *hnd, char *old_passwd, char *new_passw
 	 */
 	
 	if(lp_unix_password_sync() &&
-		!chgpasswd(pdb_get_username(hnd), old_passwd, new_passwd, as_root)) {
+		!chgpasswd(pdb_get_username(hnd), pass, old_passwd, new_passwd, as_root)) {
 		return NT_STATUS_ACCESS_DENIED;
 	}