r1388: Adding password history code for ldap backend, based on a patch from

"Jianliang Lu" <j.lu@tiesse.com>. Multi-string attribute changed to
linearised pstring due to ordering issues. A few other changes to
fix race conditions. I will add the tdb backend code next. This code
compiles but has not yet been tested with password history policy
set to greater than zero. Targeted for 3.0.6.
Jeremy.
(This used to be commit dd54b2a3c45e202e504ad69d170eb798da4e6fc9)

7 files changed, 245 insertions, 40 deletions

diff --git a/source3/include/passdb.h b/source3/include/passdb.h
index d08fd13a72..7d3e0014b6 100644
--- a/source3/include/passdb.h
+++ b/source3/include/passdb.h
@@ -99,6 +99,7 @@ enum pdb_elements {
 	PDB_UNKNOWN6,
 	PDB_LMPASSWD,
 	PDB_NTPASSWD,
+	PDB_PWHISTORY,
 	PDB_BACKEND_PRIVATE_DATA,
 
 	/* this must be the last element */
@@ -165,16 +166,17 @@ typedef struct sam_passwd
 		const char * dir_drive;    /* home directory drive string */
 		const char * logon_script; /* logon script string */
 		const char * profile_path; /* profile path string */
-		const char * acct_desc  ;  /* user description string */
+		const char * acct_desc;    /* user description string */
 		const char * workstations; /* login from workstations string */
-		const char * unknown_str ; /* don't know what this is, yet. */
-		const char * munged_dial ; /* munged path name and dial-back tel number */
+		const char * unknown_str;  /* don't know what this is, yet. */
+		const char * munged_dial;  /* munged path name and dial-back tel number */
 		
 		DOM_SID user_sid;    /* Primary User SID */
 		DOM_SID group_sid;   /* Primary Group SID */
 		
 		DATA_BLOB lm_pw; /* .data is Null if no password */
 		DATA_BLOB nt_pw; /* .data is Null if no password */
+		DATA_BLOB nt_pw_his; /* nt hashed password history .data is Null if not available */
 		char* plaintext_pw; /* is Null if not available */
 		
 		uint16 acct_ctrl; /* account info (ACB_xxxx bit-mask) */
diff --git a/source3/include/smbldap.h b/source3/include/smbldap.h
index c7de7d84b3..b94577178b 100644
--- a/source3/include/smbldap.h
+++ b/source3/include/smbldap.h
@@ -93,8 +93,9 @@
 #define LDAP_ATTR_LOGON_COUNT		36
 #define LDAP_ATTR_MUNGED_DIAL		37
 #define LDAP_ATTR_BAD_PASSWORD_TIME	38
-
-#define LDAP_ATTR_SID_LIST              40
+#define LDAP_ATTR_PWD_HISTORY		39
+#define LDAP_ATTR_SID_LIST		40
+#define LDAP_ATTR_MOD_TIMESTAMP		41
 
 typedef struct _attrib_map_entry {
 	int		attrib;
diff --git a/source3/lib/smbldap.c b/source3/lib/smbldap.c
index d058613f00..9b6d597606 100644
--- a/source3/lib/smbldap.c
+++ b/source3/lib/smbldap.c
@@ -100,6 +100,8 @@ ATTRIB_MAP_ENTRY attrib_map_v30[] = {
 	{ LDAP_ATTR_MUNGED_DIAL,	"sambaMungedDial"	},
 	{ LDAP_ATTR_BAD_PASSWORD_COUNT,	"sambaBadPasswordCount" },
 	{ LDAP_ATTR_BAD_PASSWORD_TIME,	"sambaBadPasswordTime" 	},
+	{ LDAP_ATTR_PWD_HISTORY,	"sambaPasswordHistory"  },
+	{ LDAP_ATTR_MOD_TIMESTAMP,	"modifyTimestamp"	},
 	{ LDAP_ATTR_LIST_END,		NULL 			}
 };
 
@@ -345,19 +347,19 @@ static BOOL fetch_ldap_pw(char **dn, char** pw)
 
 	/* sanity checks on the mod values */
 
-	if (attribute == NULL || *attribute == '\0')
+	if (attribute == NULL || *attribute == '\0') {
 		return;	
+	}
+
 #if 0	/* commented out after discussion with abartlet.  Do not reenable.
 	   left here so other so re-add similar code   --jerry */
        	if (value == NULL || *value == '\0')
 		return;
 #endif
 
-	if (mods == NULL) 
-	{
+	if (mods == NULL) {
 		mods = (LDAPMod **) malloc(sizeof(LDAPMod *));
-		if (mods == NULL)
-		{
+		if (mods == NULL) {
 			DEBUG(0, ("make_a_mod: out of memory!\n"));
 			return;
 		}
@@ -369,17 +371,14 @@ static BOOL fetch_ldap_pw(char **dn, char** pw)
 			break;
 	}
 
-	if (mods[i] == NULL)
-	{
+	if (mods[i] == NULL) {
 		mods = (LDAPMod **) Realloc (mods, (i + 2) * sizeof (LDAPMod *));
-		if (mods == NULL)
-		{
+		if (mods == NULL) {
 			DEBUG(0, ("make_a_mod: out of memory!\n"));
 			return;
 		}
 		mods[i] = (LDAPMod *) malloc(sizeof(LDAPMod));
-		if (mods[i] == NULL)
-		{
+		if (mods[i] == NULL) {
 			DEBUG(0, ("make_a_mod: out of memory!\n"));
 			return;
 		}
@@ -389,8 +388,7 @@ static BOOL fetch_ldap_pw(char **dn, char** pw)
 		mods[i + 1] = NULL;
 	}
 
-	if (value != NULL)
-	{
+	if (value != NULL) {
 		char *utf8_value = NULL;
 
 		j = 0;
diff --git a/source3/passdb/pdb_get_set.c b/source3/passdb/pdb_get_set.c
index e69dac524f..4abb951d7b 100644
--- a/source3/passdb/pdb_get_set.c
+++ b/source3/passdb/pdb_get_set.c
@@ -150,6 +150,19 @@ const uint8* pdb_get_lanman_passwd (const SAM_ACCOUNT *sampass)
 		return (NULL);
 }
 
+const uint8* pdb_get_pw_history (const SAM_ACCOUNT *sampass, uint32 *current_hist_len)
+{
+	if (sampass) {
+		SMB_ASSERT((!sampass->private.nt_pw_his.data) 
+			   || ((sampass->private.nt_pw_his.length % NT_HASH_LEN) == 0));
+		*current_hist_len = sampass->private.nt_pw_his.length / NT_HASH_LEN;
+		return ((uint8*)sampass->private.nt_pw_his.data);
+	} else {
+		*current_hist_len = 0;
+		return (NULL);
+	}
+}
+
 /* Return the plaintext password if known.  Most of the time
    it isn't, so don't assume anything magic about this function.
    
@@ -982,6 +995,30 @@ BOOL pdb_set_lanman_passwd (SAM_ACCOUNT *sampass, const uint8 pwd[LM_HASH_LEN],
 }
 
 /*********************************************************************
+ Set the user's password history hash. historyLen is the number of NT_HASH_LEN
+ entries to store in the history - this must match the size of the uint8 array
+ in pwd.
+********************************************************************/
+
+BOOL pdb_set_pw_history (SAM_ACCOUNT *sampass, const uint8 *pwd, uint32 historyLen, enum pdb_value_state flag)
+{
+	if (!sampass)
+		return False;
+
+	if (historyLen && pwd){
+		sampass->private.nt_pw_his = data_blob_talloc(sampass->mem_ctx, pwd, historyLen*NT_HASH_LEN);
+		if (!sampass->private.nt_pw_his.length) {
+			DEBUG(0, ("pdb_set_pw_history: data_blob_talloc() failed!\n"));
+			return False;
+		}
+	} else {
+		sampass->private.nt_pw_his = data_blob_talloc(sampass->mem_ctx, NULL, 0);
+	}
+
+	return pdb_set_init_flags(sampass, PDB_PWHISTORY, flag);
+}
+
+/*********************************************************************
  Set the user's plaintext password only (base procedure, see helper
  below)
  ********************************************************************/
@@ -1133,12 +1170,20 @@ BOOL pdb_set_pass_changed_now (SAM_ACCOUNT *sampass)
 
 BOOL pdb_set_plaintext_passwd (SAM_ACCOUNT *sampass, const char *plaintext)
 {
-	uchar new_lanman_p16[16];
-	uchar new_nt_p16[16];
+	uchar new_lanman_p16[LM_HASH_LEN];
+	uchar new_nt_p16[NT_HASH_LEN];
+	uchar current_ntpw_copy[NT_HASH_LEN];
+	uchar *current_ntpw = NULL;
 
 	if (!sampass || !plaintext)
 		return False;
-	
+
+	/* Store the current password for history purposes. */
+	current_ntpw = (uint8 *)pdb_get_nt_passwd(sampass);
+	if (current_ntpw) {
+		memcpy (current_ntpw_copy, current_ntpw, NT_HASH_LEN);
+	}
+
 	/* Calculate the MD4 hash (NT compatible) of the password */
 	E_md4hash(plaintext, new_nt_p16);
 
@@ -1164,6 +1209,45 @@ BOOL pdb_set_plaintext_passwd (SAM_ACCOUNT *sampass, const char *plaintext)
 	if (!pdb_set_pass_changed_now (sampass))
 		return False;
 
+	/* Store the password history. */
+	if (pdb_get_acct_ctrl(sampass) & ACB_NORMAL) {
+		uchar *pwhistory;
+		uint32 pwHistLen;
+		account_policy_get(AP_PASSWORD_HISTORY, &pwHistLen);
+		if (pwHistLen != 0){
+			uint32 current_history_len;
+			/* We need to make sure we don't have a race condition here - the
+			   account policy history length can change between when the pw_history
+			   was first loaded into the SAM_ACCOUNT struct and now.... JRA. */
+			pwhistory = (uchar *)pdb_get_pw_history(sampass, &current_history_len);
+
+			if (current_history_len != pwHistLen) {
+				/* After closing and reopening SAM_ACCOUNT the history
+					values will sync up. We can't do this here. */
+
+				/* current_history_len > pwHistLen is not a problem - we
+					have more history than we need. */
+
+				if (current_history_len < pwHistLen) {
+					/* We only have room for current_history_len entries. */
+					pwHistLen = current_history_len;
+				}
+			}
+			if (pwhistory && current_ntpw && pwHistLen){
+				if (pwHistLen > 1) {
+					memmove(&pwhistory[NT_HASH_LEN], pwhistory, (pwHistLen -1)*NT_HASH_LEN );
+				}
+				memcpy(pwhistory, current_ntpw_copy, NT_HASH_LEN);
+				pdb_set_pw_history(sampass, pwhistory, pwHistLen, PDB_CHANGED);
+			} else {
+				DEBUG (10,("pdb_get_set.c: pdb_set_plaintext_passwd: pwhistory was NULL!\n"));
+			}
+		} else {
+			/* Set the history length to zero. */
+			pdb_set_pw_history(sampass, NULL, 0, PDB_CHANGED);
+		}
+	}
+
 	return True;
 }
 
diff --git a/source3/passdb/pdb_ldap.c b/source3/passdb/pdb_ldap.c
index d2ee9a2d9d..fed92cea56 100644
--- a/source3/passdb/pdb_ldap.c
+++ b/source3/passdb/pdb_ldap.c
@@ -81,8 +81,6 @@
 #define SAM_ACCOUNT struct sam_passwd
 #endif
 
-#define MODIFY_TIMESTAMP_STRING "modifyTimestamp"
-
 #include "smbldap.h"
 
 struct ldapsam_privates {
@@ -301,7 +299,9 @@ static NTSTATUS ldapsam_delete_entry(struct ldapsam_privates *ldap_state,
 		   really exist. */
 
 		for (attrib = attrs; *attrib != NULL; attrib++) {
-			if (StrCaseCmp(*attrib, name) == 0) {
+			if ((StrCaseCmp(*attrib, name) == 0) &&
+					!(StrCaseCmp(*attrib,
+						get_userattr_key2string(ldap_state->schema_ver, LDAP_ATTR_MOD_TIMESTAMP)))) {
 				DEBUG(10, ("ldapsam_delete_entry: deleting attribute %s\n", name));
 				smbldap_set_mod(&mods, LDAP_MOD_DELETE, name, NULL);
 			}
@@ -400,8 +400,9 @@ static time_t ldapsam_get_entry_timestamp(
 	pstring temp;	
 	struct tm tm;
 
-	if (!smbldap_get_single_pstring(ldap_state->smbldap_state->ldap_struct,
-					entry, MODIFY_TIMESTAMP_STRING, temp)) 
+	if (!smbldap_get_single_pstring(ldap_state->smbldap_state->ldap_struct, entry,
+			get_userattr_key2string(ldap_state->schema_ver,LDAP_ATTR_MOD_TIMESTAMP),
+			temp))
 		return (time_t) 0;
 
 	strptime(temp, "%Y%m%d%H%M%SZ", &tm);
@@ -448,6 +449,7 @@ static BOOL init_sam_from_ldap (struct ldapsam_privates *ldap_state,
 	uint8 		hours[MAX_HOURS_LEN];
 	pstring temp;
 	LOGIN_CACHE	*cache_entry = NULL;
+	int pwHistLen;
 
 	/*
 	 * do a little initialization
@@ -694,6 +696,37 @@ static BOOL init_sam_from_ldap (struct ldapsam_privates *ldap_state,
 		ZERO_STRUCT(smbntpwd);
 	}
 
+	account_policy_get(AP_PASSWORD_HISTORY, &pwHistLen);
+	if (pwHistLen > 0){
+		uint8 *pwhist = NULL;
+		int i;
+
+		if ((pwhist = malloc(NT_HASH_LEN * pwHistLen)) == NULL){
+			DEBUG(0, ("init_sam_from_ldap: malloc failed!\n"));
+			return False;
+		}
+		memset(pwhist, '\0', NT_HASH_LEN * pwHistLen);
+
+		if (!smbldap_get_single_pstring (ldap_state->smbldap_state->ldap_struct, entry, 
+			get_userattr_key2string(ldap_state->schema_ver, LDAP_ATTR_PWD_HISTORY), temp)) {
+			/* leave as default - zeros */
+		} else {
+			for (i = 0; i < pwHistLen; i++){
+				if (!pdb_gethexpwd(&temp[i*32], smbntpwd)) {
+					break;
+				}
+				memset(&temp[i*32], '\0', 32);
+				memcpy(&pwhist[i*NT_HASH_LEN], smbntpwd, NT_HASH_LEN);
+				ZERO_STRUCT(smbntpwd);
+			}
+		}
+		if (!pdb_set_pw_history(sampass, pwhist, pwHistLen, PDB_SET)){
+			SAFE_FREE(pwhist);
+			return False;
+		}
+		SAFE_FREE(pwhist);
+	}
+
 	if (!smbldap_get_single_pstring (ldap_state->smbldap_state->ldap_struct, entry,
 			get_userattr_key2string(ldap_state->schema_ver, LDAP_ATTR_ACB_INFO), temp)) {
 		acct_ctrl |= ACB_NORMAL;
@@ -781,7 +814,7 @@ static BOOL init_sam_from_ldap (struct ldapsam_privates *ldap_state,
 }
 
 /**********************************************************************
- Initialize SAM_ACCOUNT from an LDAP query.
+ Initialize the ldap db from a SAM_ACCOUNT. Called on update.
  (Based on init_buffer_from_sam in pdb_tdb.c)
 *********************************************************************/
 
@@ -985,6 +1018,29 @@ static BOOL init_ldap_from_sam (struct ldapsam_privates *ldap_state,
 			}
 		}
 
+		if (need_update(sampass, PDB_PWHISTORY)) {
+			int pwHistLen = 0;
+			account_policy_get(AP_PASSWORD_HISTORY, &pwHistLen);
+			if (pwHistLen == 0) {
+				/* Remove any password history from the LDAP store. */
+				pstrcpy(temp, "00000000000000000000000000000000");
+			} else {
+				int i, currHistLen = 0;
+				const uint8 *pwhist = pdb_get_pw_history(sampass, &currHistLen);
+				if (pwhist != NULL) {
+					/* We can only store (sizeof(pstring)-1)/32 password history entries. */
+					pwHistLen = MIN(pwHistLen, ((sizeof(temp)-1)/32));
+					for (i=0; i< pwHistLen && i < currHistLen; i++) {
+						pdb_sethexpwd (&temp[i*32], &pwhist[i*NT_HASH_LEN], 0);
+						DEBUG(100, ("temp=%s\n", temp));
+					}
+				} 
+			}
+			smbldap_make_mod(ldap_state->smbldap_state->ldap_struct, existing, mods,
+					 get_userattr_key2string(ldap_state->schema_ver, LDAP_ATTR_PWD_HISTORY), 
+					 temp);
+		}
+
 		if (need_update(sampass, PDB_PASSLASTSET)) {
 			slprintf (temp, sizeof (temp) - 1, "%li", pdb_get_pass_last_set_time(sampass));
 			smbldap_make_mod(ldap_state->smbldap_state->ldap_struct, existing, mods,
@@ -1162,7 +1218,7 @@ static NTSTATUS ldapsam_getsampwnam(struct pdb_methods *my_methods, SAM_ACCOUNT
 	int rc;
 	
 	attr_list = get_userattr_list( ldap_state->schema_ver );
-	append_attr(&attr_list, MODIFY_TIMESTAMP_STRING);
+	append_attr(&attr_list, get_userattr_key2string(ldap_state->schema_ver,LDAP_ATTR_MOD_TIMESTAMP));
 	rc = ldapsam_search_suffix_by_name(ldap_state, sname, &result, attr_list);
 	free_attr_list( attr_list );
 
@@ -1208,7 +1264,7 @@ static int ldapsam_get_ldap_user_by_sid(struct ldapsam_privates *ldap_state,
 	switch ( ldap_state->schema_ver ) {
 		case SCHEMAVER_SAMBASAMACCOUNT:
 			attr_list = get_userattr_list(ldap_state->schema_ver);
-			append_attr(&attr_list, MODIFY_TIMESTAMP_STRING);
+			append_attr(&attr_list, get_userattr_key2string(ldap_state->schema_ver,LDAP_ATTR_MOD_TIMESTAMP));
 			rc = ldapsam_search_suffix_by_sid(ldap_state, sid, result, attr_list);
 			free_attr_list( attr_list );
 
diff --git a/source3/passdb/pdb_tdb.c b/source3/passdb/pdb_tdb.c
index 9bfb10c400..2cf7c55049 100644
--- a/source3/passdb/pdb_tdb.c
+++ b/source3/passdb/pdb_tdb.c
@@ -746,4 +746,3 @@ NTSTATUS pdb_tdbsam_init(void)
 {
 	return smb_register_passdb(PASSDB_INTERFACE_VERSION, "tdbsam", pdb_init_tdbsam);
 }
-
diff --git a/source3/smbd/chgpasswd.c b/source3/smbd/chgpasswd.c
index ca13a167fb..a1b90c8fed 100644
--- a/source3/smbd/chgpasswd.c
+++ b/source3/smbd/chgpasswd.c
@@ -933,6 +933,65 @@ static NTSTATUS check_oem_password(const char *user,
 }
 
 /***********************************************************
+ This routine takes the given password and checks it against
+ the password history. Returns True if this password has been
+ found in the history list.
+************************************************************/
+
+static BOOL check_passwd_history(SAM_ACCOUNT *sampass, const char *plaintext)
+{
+	uchar new_nt_p16[NT_HASH_LEN];
+	uchar zero_nt_pw[NT_HASH_LEN];
+	const uint8 *nt_pw;
+	const uint8 *pwhistory;
+	BOOL found = False;
+	int i, pwHisLen, curr_pwHisLen;
+
+	account_policy_get(AP_PASSWORD_HISTORY, &pwHisLen);
+	if (pwHisLen == 0) {
+		return False;
+	}
+
+	pwhistory = pdb_get_pw_history(sampass, &curr_pwHisLen);
+	if (!pwhistory || curr_pwHisLen == 0) {
+		return False;
+	}
+
+	/* Only examine the minimum of the current history len and
+	   the stored history len. Avoids race conditions. */
+	pwHisLen = MIN(pwHisLen,curr_pwHisLen);
+
+	nt_pw = pdb_get_nt_passwd(sampass);
+
+	E_md4hash(plaintext, new_nt_p16);
+
+	if (!memcmp(nt_pw, new_nt_p16, NT_HASH_LEN)) {
+		DEBUG(10,("check_passwd_history: proposed new password for user %s is the same as the current password !\n",
+			pdb_get_username(sampass) ));
+		return True;
+	}
+
+	dump_data(100, new_nt_p16, NT_HASH_LEN);
+	dump_data(100, pwhistory, NT_HASH_LEN*pwHisLen);
+
+	memset(zero_nt_pw, '\0', NT_HASH_LEN);
+	for (i=0; i<pwHisLen; i++) {
+		if (!memcmp(&pwhistory[i*NT_HASH_LEN], zero_nt_pw, NT_HASH_LEN)) {
+			/* Ignore zero entries. */
+			continue;
+		}
+		if (!memcmp(&pwhistory[i*NT_HASH_LEN], new_nt_p16, NT_HASH_LEN)) {
+			DEBUG(1,("check_passwd_history: proposed new password for user %s found in history list !\n",
+				pdb_get_username(sampass) ));
+			found = True;
+			break;
+		}
+	}
+
+	return found;
+}
+
+/***********************************************************
  Code to change the oem password. Changes both the lanman
  and NT hashes.  Old_passwd is almost always NULL.
  NOTE this function is designed to be called as root. Check the old password
@@ -941,20 +1000,21 @@ 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;
+	struct passwd *pass = NULL;
+	const char *username = pdb_get_username(hnd);
+	time_t can_change_time = pdb_get_pass_can_change_time(hnd);
 
-	if (time(NULL) < pdb_get_pass_can_change_time(hnd)) {
+	if ((can_change_time != 0) && (time(NULL) < can_change_time)) {
 		DEBUG(1, ("user %s cannot change password now, must wait until %s\n", 
-			  pdb_get_username(hnd), http_timestring(pdb_get_pass_can_change_time(hnd))));
-		return NT_STATUS_PASSWORD_RESTRICTION;
+			  username, http_timestring(can_change_time)));
+		return NT_STATUS_ACCOUNT_RESTRICTION;
 	}
 
 	if (account_policy_get(AP_MIN_PASSWORD_LEN, &min_len) && (strlen(new_passwd) < min_len)) {
 		DEBUG(1, ("user %s cannot change password - password too short\n", 
-			  pdb_get_username(hnd)));
+			  username));
 		DEBUGADD(1, (" account policy min password len = %d\n", min_len));
 		return NT_STATUS_PASSWORD_RESTRICTION;
 /* 		return NT_STATUS_PWD_TOO_SHORT; */
@@ -965,14 +1025,19 @@ NTSTATUS change_oem_password(SAM_ACCOUNT *hnd, char *old_passwd, char *new_passw
 	if (strlen(new_passwd) < lp_min_passwd_length()) {
 		/* too short, must be at least MINPASSWDLENGTH */
 		DEBUG(1, ("Password Change: user %s, New password is shorter than minimum password length = %d\n",
-		       pdb_get_username(hnd), lp_min_passwd_length()));
+		       username, lp_min_passwd_length()));
 		return NT_STATUS_PASSWORD_RESTRICTION;
 /* 		return NT_STATUS_PWD_TOO_SHORT; */
 	}
 
-	pass = Get_Pwnam(pdb_get_username(hnd));
+	if (check_passwd_history(hnd,new_passwd)) {
+		return NT_STATUS_PASSWORD_RESTRICTION;
+	}
+
+	pass = Get_Pwnam(username);
 	if (!pass) {
-		DEBUG(1, ("check_oem_password: Username does not exist in system !?!\n"));
+		DEBUG(1, ("check_oem_password: Username %s does not exist in system !?!\n", username));
+		return NT_STATUS_ACCESS_DENIED;
 	}
 
 	/*
@@ -988,7 +1053,7 @@ NTSTATUS change_oem_password(SAM_ACCOUNT *hnd, char *old_passwd, char *new_passw
 	 */
 	
 	if(lp_unix_password_sync() &&
-		!chgpasswd(pdb_get_username(hnd), pass, old_passwd, new_passwd, as_root)) {
+		!chgpasswd(username, pass, old_passwd, new_passwd, as_root)) {
 		return NT_STATUS_ACCESS_DENIED;
 	}