diff --git a/src/class_smtpServer.py b/src/class_smtpServer.py index 2f1b3097..c9d52daa 100644 --- a/src/class_smtpServer.py +++ b/src/class_smtpServer.py @@ -31,6 +31,7 @@ class bitmessageSMTPChannel(asynchat.async_chat): self.__data = '' self.__fqdn = socket.getfqdn() self.__version = 'Python SMTP proxy version 0.2a' + self.__invalid_command_count = 0 self.logged_in = False try: self.__peer = conn.getpeername() @@ -53,6 +54,15 @@ class bitmessageSMTPChannel(asynchat.async_chat): def collect_incoming_data(self, data): self.__line.append(data) + # Close the connection after enough errors + def invalid_command(self, msg): + self.__invalid_command_count += 1 + if self.__invalid_command_count >= 10: + self.push(msg + " (closing connection)") + self.close_when_done() + else: + self.push(msg) + # Implementation of base class abstract method def found_terminator(self): line = ''.join(self.__line) @@ -60,7 +70,7 @@ class bitmessageSMTPChannel(asynchat.async_chat): self.__line = [] if self.__state == self.COMMAND: if not line: - self.push('500 Error: bad syntax') + self.invalid_command('500 Error: bad syntax') return method = None i = line.find(' ') @@ -72,13 +82,13 @@ class bitmessageSMTPChannel(asynchat.async_chat): arg = line[i+1:].strip() method = getattr(self, 'smtp_' + command, None) if not method: - self.push('502 Error: command "%s" not implemented' % command) + self.invalid_command('502 Error: command "%s" not implemented' % command) return method(arg) return else: if self.__state != self.DATA: - self.push('451 Internal confusion') + self.invalid_command('451 Internal confusion') return # Remove extraneous carriage returns and de-transparency according # to RFC 821, Section 4.5.2. @@ -110,10 +120,11 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_EHLO(self, arg): if not arg: - self.push('501 Syntax: EHLO hostname') + self.invalid_command('501 Syntax: EHLO hostname') return if self.__greeting: - self.push('503 Duplicate HELO/EHLO') + self.invalid_command('503 Duplicate HELO/EHLO') + return else: self.__greeting = arg self.push('250-%s offers:' % self.__fqdn) @@ -121,10 +132,10 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_HELO(self, arg): if not arg: - self.push('501 Syntax: HELO hostname') + self.invalid_command('501 Syntax: HELO hostname') return if self.__greeting: - self.push('503 Duplicate HELO/EHLO') + self.invalid_command('503 Duplicate HELO/EHLO') else: self.__greeting = arg self.push('250 %s' % self.__fqdn) @@ -132,7 +143,7 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_AUTH(self, arg): encoding, pw = arg.split(' ') if encoding != 'PLAIN': - self.push('501 method not understood') + self.invalid_command('501 method not understood') return try: @@ -141,11 +152,11 @@ class bitmessageSMTPChannel(asynchat.async_chat): z = 'error' if z != '': - self.push('501 method not understood') + self.invalid_command('501 method not understood') return if '@' not in username: - self.push('530 Access denied.') + self.invalid_command('530 Access denied.') return capitalization, address = username.split('@', 1) @@ -168,7 +179,7 @@ class bitmessageSMTPChannel(asynchat.async_chat): # Must match full email address with capitalization if username != self.fullUsername: - self.push('530 Access denied.') + self.invalid_command('530 Access denied.') return # Each identity must be enabled independly by setting the smtppop3password for the identity @@ -183,11 +194,11 @@ class bitmessageSMTPChannel(asynchat.async_chat): except: pass - self.push('530 Access denied.') + self.invalid_command('530 Access denied.') def smtp_NOOP(self, arg): if arg: - self.push('501 Syntax: NOOP') + self.invalid_command('501 Syntax: NOOP') else: self.push('250 Ok') @@ -215,19 +226,19 @@ class bitmessageSMTPChannel(asynchat.async_chat): address = self.__getaddr('FROM:', arg) if arg else None if not address: - self.push('501 Syntax: MAIL FROM:
') + self.invalid_command('501 Syntax: MAIL FROM:
') return if self.__mailfrom: - self.push('503 Error: nested MAIL command') + self.invalid_command('503 Error: nested MAIL command') return if not self.logged_in: - self.push('503 Not authenticated.') + self.invalid_command('503 Not authenticated.') return if address != self.fullUsername: - self.push('530 Access denied: address domain must match Bitmessage identity') + self.invalid_command('530 Access denied: address domain must match Bitmessage identity') return self.__mailfrom = address @@ -237,15 +248,15 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_RCPT(self, arg): print >> smtpd.DEBUGSTREAM, '===> RCPT', arg if not self.__mailfrom: - self.push('503 Error: need MAIL command') + self.invalid_command('503 Error: need MAIL command') return if not self.logged_in: # This will never happen. :) - self.push('503 Not authenticated.') + self.invalid_command('503 Not authenticated.') return address = self.__getaddr('TO:', arg) if arg else None if not address: - self.push('501 Syntax: RCPT TO:
') + self.invalid_command('501 Syntax: RCPT TO:
') return capitalization, address = address.split('@', 1) realAddress = applyBase58Capitalization(address, int(capitalization)) @@ -255,7 +266,7 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_RSET(self, arg): if arg: - self.push('501 Syntax: RSET') + self.invalid_command('501 Syntax: RSET') return # Resets the sender, recipients, and data, but not the greeting self.__mailfrom = None @@ -266,13 +277,13 @@ class bitmessageSMTPChannel(asynchat.async_chat): def smtp_DATA(self, arg): if not self.logged_in: - self.push('503 Not authenticated.') + self.invalid_command('503 Not authenticated.') return if not self.__rcpttos: - self.push('503 Error: need RCPT command') + self.invalid_command('503 Error: need RCPT command') return if arg: - self.push('501 Syntax: DATA') + self.invalid_command('501 Syntax: DATA') return self.__state = self.DATA self.set_terminator('\r\n.\r\n')