/*
 *	um.c -- User Management
 *
 *	Copyright (c) GoAhead Software Inc., 1995-2000. All Rights Reserved.
 *
 *	See the file "license.txt" for usage and redistribution license requirements
 *
 *	$Id: um.c,v 1.5 2002/10/24 14:44:50 bporter Exp $
 */

/******************************** Description *********************************/
/*
 *	User Management routines for adding/deleting/changing users and groups
 *  Also, routines for determining user access
 */

/********************************* Includes ***********************************/

#include	"um.h"
#include	"emfdb.h"
#include	"webs.h"

/********************************** Defines ***********************************/

#define UM_DB_FILENAME	T("um.xml")
#define UM_TXT_FILENAME	T("umconfig.txt")

/*
 *	Table names
 */
#define UM_USER_TABLENAME	T("users")
#define UM_GROUP_TABLENAME	T("groups")
#define UM_ACCESS_TABLENAME	T("access")

/*
 *	Column names
 */
#define UM_NAME			T("name")
#define UM_PASS			T("password")
#define UM_GROUP		T("group")
#define UM_PROT			T("prot")
#define UM_DISABLE		T("disable")
#define UM_METHOD		T("method")
#define UM_PRIVILEGE	T("priv")
#define UM_SECURE		T("secure")

/*
 *	XOR encryption mask
 *		Note:	This string should be modified for individual sites
 *				in order to enhance user password security.
 */
#define UM_XOR_ENCRYPT	T("*j7a(L#yZ98sSd5HfSgGjMj8;Ss;d)(*&^#@$a2s0i3g")

/******************************** Local Data **********************************/

#ifdef qHierarchicalAccess
/*
 * user-provided function to allow hierarchical access protection. See below.
 * for details.
 */
extern bool_t dmfCanAccess(const char_t* usergroup, const char_t* group);
#endif
#ifdef UEMF
/*
 *	User table definition
 */
#define NUMBER_OF_USER_COLUMNS	5

char_t	*userColumnNames[NUMBER_OF_USER_COLUMNS] = {
			UM_NAME, UM_PASS, UM_GROUP, UM_PROT, UM_DISABLE
};

int		userColumnTypes[NUMBER_OF_USER_COLUMNS] = {
			T_STRING, T_STRING, T_STRING, T_INT, T_INT
};

dbTable_t userTable = {
	UM_USER_TABLENAME,
	NUMBER_OF_USER_COLUMNS,
	userColumnNames,
	userColumnTypes,
	0,
	NULL
};

/*
 *	Group table definition
 */
#define NUMBER_OF_GROUP_COLUMNS	5

char_t	*groupColumnNames[NUMBER_OF_GROUP_COLUMNS] = {
			UM_NAME, UM_PRIVILEGE, UM_METHOD, UM_PROT, UM_DISABLE
};

int		groupColumnTypes[NUMBER_OF_GROUP_COLUMNS] = {
			T_STRING, T_INT, T_INT, T_INT, T_INT
};

dbTable_t groupTable = {
	UM_GROUP_TABLENAME,
	NUMBER_OF_GROUP_COLUMNS,
	groupColumnNames,
	groupColumnTypes,
	0,
	NULL
};

/*
 *	Access Limit table definition
 */
#define NUMBER_OF_ACCESS_COLUMNS	4

char_t	*accessColumnNames[NUMBER_OF_ACCESS_COLUMNS] = {
			UM_NAME, UM_METHOD, UM_SECURE, UM_GROUP
};

int		accessColumnTypes[NUMBER_OF_ACCESS_COLUMNS] = {
			T_STRING, T_INT, T_INT, T_STRING
};

dbTable_t accessTable = {
	UM_ACCESS_TABLENAME,
	NUMBER_OF_ACCESS_COLUMNS,
	accessColumnNames,
	accessColumnTypes,
	0,
	NULL
};
#endif	/* #ifdef UEMF */

/* 
 *	Database Identifier returned from dbOpen()
 */
static int		didUM = -1;	

/* 
 *	Configuration database persist filename
 */
static char_t	*saveFilename = NULL;

static int		umOpenCount = 0;		/* count of apps using this module */

/*************************** Forward Declarations *****************************/

static bool_t umCheckName(char_t *name);

/*********************************** Code *************************************/
/*
 *	umOpen() registers the UM tables in the fake emf-database 
 */

int umOpen()
{
	if (++umOpenCount != 1) {
		return didUM;
	}
/*
 *	Do not initialize if intialization has already taken place
 */
	if (didUM == -1) {
		didUM = dbOpen(UM_USER_TABLENAME, UM_DB_FILENAME, NULL, 0);
#ifdef UEMF
		dbRegisterDBSchema(&userTable);
		dbRegisterDBSchema(&groupTable);
		dbRegisterDBSchema(&accessTable);
#endif
	}

	if (saveFilename == NULL) {
		saveFilename = bstrdup(B_L, UM_TXT_FILENAME);
	}

	return didUM;
}

/******************************************************************************/
/*
 *	umClose() frees up the UM tables in the fake emf-database 
 */

void umClose()
{
	if (--umOpenCount > 0) {
		return;
	}
/*
 *	Do not close if intialization has not taken place
 */
	if (didUM != -1) {
		dbClose(didUM);
		didUM = -1;
	}

	if (saveFilename != NULL) {
		bfree(B_L, saveFilename);
		saveFilename = NULL;
	}
}

/******************************************************************************/
/*
 *	umCommit() persists all of the UM tables
 */

int	umCommit(char_t *filename)
{
	if (filename && *filename) {
		if (saveFilename != NULL) {
			bfree(B_L, saveFilename);
		}

		saveFilename = bstrdup(B_L, filename);
	}

	a_assert (saveFilename && *saveFilename);
	trace(3, T("UM: Writing User Configuration to file <%s>\n"), 
		saveFilename);

	return dbSave(didUM, saveFilename, 0);
}

/******************************************************************************/
/*
 *	umRestore() loads up the UM tables with persisted data
 */

int umRestore(char_t *filename)
{
	if (filename && *filename) {
		if (saveFilename != NULL) {
			bfree(B_L, saveFilename);
		}

		saveFilename = bstrdup(B_L, filename);
	}

	a_assert(saveFilename && *saveFilename);

	trace(3, T("UM: Loading User Configuration from file <%s>\n"), 
		saveFilename);

/*
 *	First empty the database, otherwise we wind up with duplicates!
 */
	dbZero(didUM);
	return dbLoad(didUM, saveFilename, 0);
}

/******************************************************************************/
/*
 *	Encrypt/Decrypt a text string.  
 *		Returns the number of characters encrypted.
 */

static int umEncryptString(char_t *textString)
{
	char_t	*enMask;
	char_t	enChar;
	int		numChars;

	a_assert(textString);

	enMask = UM_XOR_ENCRYPT;
	numChars = 0;

	while (*textString) {
		enChar = *textString ^ *enMask;
/*
 *		Do not produce encrypted text with embedded linefeeds or tabs.
 *			Simply use existing character.
 */
		if (enChar && !gisspace(enChar)) 
			*textString = enChar;
/*
 *		Increment all pointers.
 */
		enMask++;
		textString++;
		numChars++;
/*
 *		Wrap encryption mask pointer if at end of length.
 */
		if (*enMask == '\0') {
			enMask = UM_XOR_ENCRYPT;
		}
	}

	return numChars;
}

/******************************************************************************/
/*
 *	umGetFirstRowData() -	return a pointer to the first non-blank key value
 *							in the given column for the given table.
 */

static char_t *umGetFirstRowData(char_t *tableName, char_t *columnName)
{
	char_t	*columnData;
	int		row;
	int		check;

	a_assert(tableName && *tableName);
	a_assert(columnName && *columnName);

	row = 0;
/*
 *	Move through table until we retrieve the first row with non-null 
 *	column data.
 */
	columnData = NULL;
	while ((check = dbReadStr(didUM, tableName, columnName, row++, 
		&columnData)) == 0 || (check == DB_ERR_ROW_DELETED)) {
		if (columnData && *columnData) {
			return columnData;
		}
	}

	return NULL;
}

/******************************************************************************/
/*
 *	umGetNextRowData() -	return a pointer to the first non-blank 
 *						key value following the given one.
 */

static char_t *umGetNextRowData(char_t *tableName, char_t *columnName, 
								char_t *keyLast)
{
	char_t	*key;
	int		row;
	int		check;

	a_assert(tableName && *tableName);
	a_assert(columnName && *columnName);
	a_assert(keyLast && *keyLast);
/*
 *	Position row counter to row where the given key value was found
 */
	row = 0;
	key = NULL;

	while ((((check = dbReadStr(didUM, tableName, columnName, row++, 
		&key)) == 0) || (check == DB_ERR_ROW_DELETED)) &&
		((key == NULL) || (gstrcmp(key, keyLast) != 0))) {
	}
/*
 *	If the last key value was not found, return NULL
 */
	if (!key || gstrcmp(key, keyLast) != 0) {
		return NULL;
	}
/*
 *	Move through table until we retrieve the next row with a non-null key
 */
	while (((check = dbReadStr(didUM, tableName, columnName, row++, &key)) 
		== 0) || (check == DB_ERR_ROW_DELETED)) {
		if (key && *key && (gstrcmp(key, keyLast) != 0)) {
			return key;
		}
	}

	return NULL;
}

/******************************************************************************/
/*
 *	umAddUser() - Adds a user to the "users" table.
 */

int	umAddUser(char_t *user, char_t *pass, char_t *group, 
			  bool_t prot, bool_t disabled)
{
	int		row;
	char_t	*password;

	a_assert(user && *user);
	a_assert(pass && *pass);
	a_assert(group && *group);

	trace(3, T("UM: Adding User <%s>\n"), user);

/*
 *	Do not allow duplicates
 */
	if (umUserExists(user)) {
		return UM_ERR_DUPLICATE;
	}

/*
 *	Make sure user name and password contain valid characters
 */
	if (!umCheckName(user)) {
		return UM_ERR_BAD_NAME;
	}

	if (!umCheckName(pass)) {
		return UM_ERR_BAD_PASSWORD;
	}

/*
 *	Make sure group exists
 */
	if (!umGroupExists(group)) {
		return UM_ERR_NOT_FOUND;
	}

/*
 *	Now create the user record
 */
	row = dbAddRow(didUM, UM_USER_TABLENAME);

	if (row < 0) {
		return UM_ERR_GENERAL;
	}

	if (dbWriteStr(didUM, UM_USER_TABLENAME, UM_NAME, row, user) != 0) {
		return UM_ERR_GENERAL;
	}

	password = bstrdup(B_L, pass);
	umEncryptString(password);
	dbWriteStr(didUM, UM_USER_TABLENAME, UM_PASS, row, password);
	bfree(B_L, password);
	dbWriteStr(didUM, UM_USER_TABLENAME, UM_GROUP, row, group);
	dbWriteInt(didUM, UM_USER_TABLENAME, UM_PROT, row, prot); 
	dbWriteInt(didUM, UM_USER_TABLENAME, UM_DISABLE, row, disabled);

	return 0;
}

/******************************************************************************/
/*
 *	umDeleteUser() - remove a user from the "users" table
 */

int	umDeleteUser(char_t *user)
{
	int row;

	a_assert(user && *user);
	trace(3, T("UM: Deleting User <%s>\n"), user);
/*
 *	Check to see if user is delete-protected
 */
	if (umGetUserProtected(user)) {
		return UM_ERR_PROTECTED;
	} 

/*
 *	If found, delete the user from the database
 */
	if ((row = dbSearchStr(didUM, UM_USER_TABLENAME, UM_NAME, user, 0)) >= 0) {
		return dbDeleteRow(didUM, UM_USER_TABLENAME, row);
	} 

	return UM_ERR_NOT_FOUND;
}

/******************************************************************************/
/*
 *	umGetFirstUser() -	Returns the user ID of the first user found in the
 *						"users" table.
 */

char_t *umGetFirstUser()
{
	return umGetFirstRowData(UM_USER_TABLENAME, UM_NAME);
}

/******************************************************************************/
/*
 *	umGetNextUser()	Returns the next user found in the "users" table after
 *					the given user. 	
 */

char_t *umGetNextUser(char_t *userLast)
{