PasswdController.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
    MIT License

    Copyright (c) 2013-2016 Frantisek Uhrecky

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
"""
import logging
import sqlite3
import CryptoBasics
import time
import struct
from PasswdModel import PasswdModel
from TransController import tr

class PasswdController:
    """
        Provides manipulating passwords in database. Encrypts and decrypts data.
    """
    def __init__(self, db_controller, master):
        self._db_ctrl = db_controller
        self._connection = db_controller._connection
        self._cursor = db_controller._cursor
        self._master = master
        
        # timestamp encoding little endian and double precision
        self._TIME_PRECISION = "<d"
    
    def selectAll(self):
        """
            Select all password from table Passwords and decrypt.
            @return: rows touple of dictionaries, decrypted data
        """
        try:
            self._cursor.execute("SELECT * FROM Passwords;")
            rows = self._cursor.fetchall()
            
            # decrypt selected data
            for i in range(0, len(rows)):
                rows[i] = self.decryptRowDic(rows[i])                      
            
            logging.info("passwords selected: %d", len(rows))
        except sqlite3.Error as e:
            logging.exception(e)
            
            raise e
        finally:
            passwords = []
            
            for row in rows:
                passwords.append(self.createPasswdObj(row))
            return passwords
        
    def selectById(self, p_id):
        """
            Search password by id.
            @paramp_id: password id
            @return: row
        """
        try:
            # select from table
            self._cursor.execute("SELECT * FROM Passwords WHERE id = :id;", {"id" : p_id})
            row = self._cursor.fetchone()
            
            # if exists ID
            if (row):
                count = 1
                
                # now decrypt data
                row = self.decryptRowDic(row)
            else:
                count = 0
            
            logging.info("passwords selected: %d", count)
        except sqlite3.Error as e:
            logging.exception(e)
            
            raise e
        finally:
            return [self.createPasswdObj(row)]
        
    def selectByGroupId(self, g_id):
        """
            Search password by group id.
            @param g_id: group id
            @return: rows
        """
        try:
            # select from table
            self._cursor.execute("SELECT * FROM Passwords WHERE grp_id = :id;", {"id" : g_id})
            rows = self._cursor.fetchall()
            
            # decrypt selected data
            for i in range(0, len(rows)):
                rows[i] = self.decryptRowDic(rows[i])                      
            
            logging.info("passwords selected: %d", len(rows))
        except sqlite3.Error as e:
            logging.exception(e)
            
            raise e
        finally:
            passwords = []
            
            for row in rows:
                passwords.append(self.createPasswdObj(row))
            return passwords
        
    def selectByUserId(self, u_id):
        """
            Search password by user id.
            @param u_id: group id
            @return: rows
        """
        try:
            # select from table
            self._cursor.execute("SELECT * FROM Passwords WHERE user_id = :id;", {"id" : u_id})
            rows = self._cursor.fetchall()
            
            # decrypt selected data
            for i in range(0, len(rows)):
                rows[i] = self.decryptRowDic(rows[i])                      
            
            logging.info("passwords selected: %d", len(rows))
        except sqlite3.Error as e:
            logging.exception(e)
            
            raise e
        finally:
            passwords = []
            
            for row in rows:
                passwords.append(self.createPasswdObj(row))
            return passwords
        
    def selectByUserGrpId(self, u_id, g_id):
        """
            Search password by user and group id.
            
            @param u_id: user id
            @param g_id: group id
            @return: rows
        """
        try:
            # select from table
            self._cursor.execute("SELECT * FROM Passwords WHERE user_id = :id AND grp_id = :g_id;", {"id" : u_id, "g_id" : g_id})
            rows = self._cursor.fetchall()
            
            # decrypt selected data
            for i in range(0, len(rows)):
                rows[i] = self.decryptRowDic(rows[i])                      
            
            logging.info("passwords selected: %d", len(rows))
        except sqlite3.Error as e:
            logging.exception(e)
            
            raise e
        finally:
            passwords = []
            
            for row in rows:
                passwords.append(self.createPasswdObj(row))
            return passwords

    def insertPassword(self, title, username, passwd, url, comment, c_date, e_date, grp_id, user_id, attachment, att_name, expire):
        """
            Inserts password in table Passwords. Encrypts inserted data. Only grp_id, user_id salt and iv are not encrypted.
            @param title: password title
            @param username: account username
            @param passwd: account password
            @param url: account url
            @param comment: password comment
            @param c_date: date of creation
            @param e_date: date of expiration
            @param grp_id: password group ID, from Groups table
            @param user_id: user ID, from Users table
            @param attachment: attachment of password
            @param att_name: attachment name
            @param expire: if password expires, should be set to 'true' string
        """
        salt = CryptoBasics.genKeySalt().decode("utf8")
        iv = CryptoBasics.genIV()
        
        # encrypt data       
        encrypted_row = self.encryptAndPrepRow(title, username, passwd, url, 
                                               comment, c_date, e_date, 
                                               grp_id, user_id, attachment,
                                               att_name, 
                                               salt, iv, expire)
        
        try:
            self._cursor.execute("""INSERT INTO 
                Passwords(title, username, passwd, url, comment, c_date, m_date, e_date, grp_id, user_id, attachment, att_name, salt, iv, expire)
                VALUES(:title, :username, :passwd, :url, :comment, :c_date, :m_date, :e_date, :grp_id, :user_id, :attachment, :att_name, 
                :salt, :iv, :expire)""",
                                  encrypted_row)
            self._connection.commit()
            
            logging.info("passwords with ID: %d, inserted: %d", self._cursor.lastrowid, self._cursor.rowcount)
        except sqlite3.IntegrityError as e:
            logging.warning(e)
            
            self._connection.rollback()
        except sqlite3.Error as e:
            logging.exception(e)
            
            self._connection.rollback()
            raise e
            
    def updatePasswd(self, p_id, title, username, passwd, url, comment, e_date, grp_id, user_id, attachment, att_name, expire):
        """
            Updates password in table Passwords. Encrypts inserted data. Only grp_id, user_id salt and iv are not encrypted.
            @param title: password title
            @param username: account username
            @param passwd: account password
            @param url: account url
            @param comment: password comment
            @param e_date: date of expiration
            @param grp_id: password group ID, from Groups table
            @param user_id: user ID, from Users table
            @param attachment: attachment of password
            @param att_name: attachment name
            @param expire: if password expires, should be set to 'true' string
        """
        try:
            # first select old row to get salt and iv
            old = self.selectById(p_id)[0]
            
            # if old row exists
            if old:
                # encrypt data and prepare for sqlite
                # creation date doesnt matter, cant be changed
                row = self.encryptAndPrepRow(title, username, passwd, url, comment, old._c_date, 
                                             e_date, grp_id, user_id, attachment, att_name, old._salt, old._iv, expire)
                
                # add password ID to row
                row["id"] = p_id
                
                self._cursor.execute("""UPDATE Passwords SET title = :title, username = :username, passwd = :passwd, url = :url, 
                                    comment = :comment, m_date = :m_date, e_date = :e_date, grp_id = :grp_id,
                                    attachment = :attachment, att_name = :att_name, expire = :expire WHERE id = :id;""", row)
                self._connection.commit()
                
                logging.debug("passwd with ID: %d updated.", p_id)
            else:
                logging.warning("password with id: %d doesn't exists. Can't be updated.", p_id)
        except sqlite3.IntegrityError as e:
            logging.exception(e)
            
            self._connection.rollback()
            raise e
        except sqlite3.Error as e:
            logging.exception(e)
            
            self._connection.rollback()
            raise e
          
    def updatePasswdDic(self, row):
        """
            Updates password record, implements updatePasswd().
            
            @param row: new data
        """
        self.updatePasswd(row["p_id"], row["title"], row["username"], row["passwd"], row["url"], row["comment"], 
                        row["e_date"], row["grp_id"], row["user_id"], row["attachment"], row["att_name"], row["expire"])
        
    def deletePassword(self, p_id):
        """
            Delete password with ID.
            @param p_id: password ID
        """
        try:
            self._cursor.execute("DELETE FROM Passwords WHERE id = :id", {"id" : p_id})
            self._connection.commit()
            
            count = self._cursor.rowcount
            
            if (count > 0):
                logging.info("%d password with id: %d deleted", count, p_id)
            else:
                logging.info("%d password with id: %d found", count, p_id)
        except sqlite3.Error as e:
            logging.exception(e)
            
            self._connection.rollback()
            raise e
            
    def encryptAndPrepRow(self, title, username, passwd, url, comment, c_date, e_date, grp_id, user_id, attachment, att_name, salt, iv, expire):
        """
            Encrypts password in table Passwords. Encrypts inserted data. Only grp_id, user_id salt and iv are not encrypted.
            Also change m_date column, modification date, to current timestamp. Encrypted data are inserted as BLOB type.
            
            And prepares them for sqlite binary data.
            @param title: password title
            @param username: account username
            @param passwd: account password
            @param url: account url
            @param comment: password comment
            @param c_date: date of creation
            @param e_date: date of expiration
            @param grp_id: password group ID, from Groups table
            @param user_id: user ID, from Users table
            @param attachment: attachment of password
            @param att_name: attachment name
            @param salt: secret key salt
            @param iv: cipher input vector
            @param expire: if password expires, should be set to 'true' string
            
            @return: encrypted dictionary data
        """
        secret_key = CryptoBasics.genCipherKey(self._master, salt)
        
        # pack time (float) to bytes, need to encrypt it, add padding
        m_date = time.time()
        logging.debug("modification timestamp: %f", m_date)
        
        # use little endian and float type to convert timestamp
        c_date = struct.pack(self._TIME_PRECISION, c_date)
        e_date = struct.pack(self._TIME_PRECISION, e_date)
        m_date = struct.pack(self._TIME_PRECISION, m_date)

        # encrypt data
        title = CryptoBasics.encryptDataAutoPad(title, secret_key, iv)
        username = CryptoBasics.encryptDataAutoPad(username, secret_key, iv)
        passwd = CryptoBasics.encryptDataAutoPad(passwd, secret_key, iv)
        url = CryptoBasics.encryptDataAutoPad(url, secret_key, iv)
        comment = CryptoBasics.encryptDataAutoPad(comment, secret_key, iv)
        c_date = CryptoBasics.encryptDataAutoPad(c_date, secret_key, iv)
        m_date = CryptoBasics.encryptDataAutoPad(m_date, secret_key, iv)
        e_date = CryptoBasics.encryptDataAutoPad(e_date, secret_key, iv)
        attachment = CryptoBasics.encryptDataAutoPad(attachment, secret_key, iv)
        att_name = CryptoBasics.encryptDataAutoPad(att_name, secret_key, iv)
        expire = CryptoBasics.encryptDataAutoPad(expire, secret_key, iv)
        
        # prepare binary data
        title = sqlite3.Binary(title)
        username = sqlite3.Binary(username)
        passwd = sqlite3.Binary(passwd)
        url = sqlite3.Binary(url)
        comment = sqlite3.Binary(comment)
        c_date = sqlite3.Binary(c_date)
        m_date = sqlite3.Binary(m_date)
        e_date = sqlite3.Binary(e_date)
#         grp_id = sqlite3.Binary(grp_id)
#         user_id = sqlite3.Binary(user_id)
        attachment = sqlite3.Binary(attachment)
        att_name = sqlite3.Binary(att_name)
        iv = sqlite3.Binary(iv)
        expire = sqlite3.Binary(expire)
        
        return {'title' : title, 'username' : username, 'passwd' : passwd, 'url' : url, 'comment' : comment, 
            'c_date' : c_date, 'm_date' : m_date, 'e_date' : e_date, 'grp_id' : grp_id, 'user_id' : user_id,
            'attachment' : attachment, 'att_name' : att_name, 'salt' : salt, 'iv' : iv, 'expire' : expire}
    
    def decryptRow(self, p_id, title, username, passwd, url, comment, c_date, m_date, e_date, grp_id, user_id, attachment, att_name, salt, iv, expire):
        """
            Decrypts password in table Passwords. Decrypts slected data. Only grp_id, user_id salt and iv are not encrypted.
            
            @param p_id: password id
            @param title: password title
            @param username: account username
            @param passwd: account password
            @param url: account url
            @param comment: password comment
            @param c_date: date of creation
            @param m_date: date of modification
            @param e_date: date of expiration
            @param grp_id: password group ID, from Groups table
            @param user_id: user ID, from Users table
            @param attachment: attachment of password
            @param att_name: attachment name
            @param salt: secret key salt
            @param iv: cipher input vector
            @param expire: if password expires, should be set to 'true' string
            
            @return: enrypted dictionary data
        """
        secret_key = CryptoBasics.genCipherKey(self._master, salt)
        
        # decrypt data
        title = CryptoBasics.decryptDataAutoPad(title, secret_key, iv)
        username = CryptoBasics.decryptDataAutoPad(username, secret_key, iv)
        passwd = CryptoBasics.decryptDataAutoPad(passwd, secret_key, iv)
        url = CryptoBasics.decryptDataAutoPad(url, secret_key, iv)
        comment = CryptoBasics.decryptDataAutoPad(comment, secret_key, iv)
        c_date = CryptoBasics.decryptDataAutoPad(c_date, secret_key, iv)
        e_date = CryptoBasics.decryptDataAutoPad(e_date, secret_key, iv)
        m_date = CryptoBasics.decryptDataAutoPad(m_date, secret_key, iv)
        
        
        # unpack returns a touple, but I need just one value
        m_date = struct.unpack(self._TIME_PRECISION, m_date)[0]
        c_date = struct.unpack(self._TIME_PRECISION, c_date)[0]
        e_date = struct.unpack(self._TIME_PRECISION, e_date)[0]
      
        attachment = CryptoBasics.decryptDataAutoPad(attachment, secret_key, iv)
        att_name = CryptoBasics.decryptDataAutoPad(att_name, secret_key, iv)
        expire = CryptoBasics.decryptDataAutoPad(expire, secret_key, iv)
        
        return {"id" :p_id, "title" : title, "username" : username, "passwd" : passwd, "url" : url, "comment" : comment, 
            "c_date" : c_date, "m_date" : m_date, "e_date" : e_date, "grp_id" : grp_id, "user_id" : user_id,
            "attachment" : attachment, "att_name" : att_name, "salt" : salt, "iv" : iv, "expire" : expire}
        
    def decryptRowDic(self, row):
        """
            Decrypts password in table Passwords. Decrypts slected data. Only grp_id, user_id salt and iv are not encrypted.
            
            @param row: selected row, encrypted, as dictionary
            
            @return: enrypted dictionary data
        """
        return self.decryptRow(row["id"], row["title"], row["username"], row["passwd"], row["url"], row["comment"],
                            row["c_date"], row["m_date"], row["e_date"], row["grp_id"], row["user_id"], 
                            row["attachment"], row["att_name"], row["salt"], row["iv"], row["expire"])
    
    def createPasswdObj(self, dic):
        """
            Creates group from dictionary returned from db.
            
            @param dic: group returned from db
            
            @return: GroupModel object
        """
        if (dic):
            return PasswdModel(dic["id"], dic["title"], dic["username"], dic["passwd"], dic["url"], dic["comment"],
                            dic["c_date"], dic["m_date"], dic["e_date"], dic["grp_id"], dic["user_id"], 
                            dic["attachment"], dic["att_name"], dic["salt"], dic["iv"], dic["expire"], self._db_ctrl)
        return None
        
    @staticmethod
    def getVisibleColumns():
        """
            Return visible table columns.
            
            @return: list of column names
        """
        return [tr("Title"), tr("Username"), tr("Password"), tr("Url"), tr("Comment"), 
                tr("C. Date"), tr("M. Date"), tr("E. Date"), tr("Group"), tr("Att. Name"), tr("Expire")]
        
    @staticmethod
    def getTableColumns():
        """
            Return minimum table columns.
            
            @return: list of column names
        """
        return [tr("Title"), tr("Username"), tr("Password"), tr("Url")]