關(guān)于顯式TLS和隱式TLS
為了提高FTP的安全性，我們使用了FTPS。FTPS是建立在SSL協(xié)議上一種增強型FTP協(xié)議。但是SSL安全拓展至少有兩種不同的初始化方法：顯式完全和隱式安全

• 顯式安全：當(dāng)啟用顯式模式時，用戶連接和FTP連接方式和默認端口一樣，然后需要以命令A(yù)UTH SSL/TLS類型的命令進行激活安全連接；
• 隱式安全：當(dāng)啟用隱式模式時，F(xiàn)TP的默認端口將修改為TCP/990,服務(wù)器自動建立安全連接，同時客戶端也要支持才安全連接模式的建立才行；

python自帶的ftplib中有FTP_TLS類
FTP_TLS類默認是不支持隱式的鏈接，為了支持隱式的鏈接就必須改寫connect方法

from ftplib import FTP_TLS
import ssl
import socket
class tyFTP(FTP_TLS):
    def connect(self, host='', port=0, timeout=-999):
        '''Connect to host.  Arguments are:
        - host: hostname to connect to (string, default previous host)
        - port: port to connect to (integer, default previous port)
        '''
        if host != '':
            self.host = host
        if port > 0:
            self.port = port
        if timeout != -999:
            self.timeout = timeout
        try:
            self.sock = socket.create_connection((self.host, self.port), self.timeout)
            self.af = self.sock.family
            #add this line!!!
            self.sock = ssl.wrap_socket(self.sock, self.keyfile, self.certfile,ssl_version=ssl.PROTOCOL_TLSv1)
            #add end
            self.file = self.sock.makefile('rb')
            self.welcome = self.getresp()
        except Exception as e:
            print e
        return self.welcome

客戶端實現(xiàn)

import os
class FTPSClient(object):

    def __init__(self, username, password, hostname, port=990):
        self.username = username
        self.password = password
        self.hostname = hostname
        self.port = port

    def get_conn(self, ftp_class=tyFTP):
        conn = ftp_class()
        conn.connect(self.hostname, self.port)
        conn.login(self.username, self.password)
        conn.prot_p()
        return conn

    def upload(self, content, filename_server):
        ftps = self.get_conn()
        # filename_server = filename_server.ltrip("/")
        dirname = os.path.dirname(filename_server)
        try:
            ftps.mkd(dirname)
        except Exception as e:
            if str(e) == "550 Directory already exists":
                pass
            else:
                raise Exception(repr(e))

        ftps.cwd(dirname)

        bufsize = 1024  
        fp = open(content,'rb')  
        fp.seek(0)
        try:
            ftps.storbinary('STOR '+ os.path.basename(filename_server) ,fp,bufsize)
        except Exception as e:
            if str(e) == "[Errno 0] Error":
                pass
            else:
                raise Exception("Upload error")

        fp.close()
        # ftps.set_debuglevel(0)  
        ftps.close()