diff options
Diffstat (limited to 'Lib/smtpd.py')
| -rwxr-xr-x | Lib/smtpd.py | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/Lib/smtpd.py b/Lib/smtpd.py index 23787fd..599e79b 100755 --- a/Lib/smtpd.py +++ b/Lib/smtpd.py @@ -109,6 +109,9 @@ class SMTPChannel(asynchat.async_chat): COMMAND = 0 DATA = 1 + data_size_limit = 33554432 + command_size_limit = 512 + def __init__(self, server, conn, addr): asynchat.async_chat.__init__(self, conn) self.smtp_server = server @@ -121,6 +124,7 @@ class SMTPChannel(asynchat.async_chat): self.rcpttos = [] self.received_data = '' self.fqdn = socket.getfqdn() + self.num_bytes = 0 try: self.peer = conn.getpeername() except socket.error as err: @@ -262,6 +266,15 @@ class SMTPChannel(asynchat.async_chat): # Implementation of base class abstract method def collect_incoming_data(self, data): + limit = None + if self.smtp_state == self.COMMAND: + limit = self.command_size_limit + elif self.smtp_state == self.DATA: + limit = self.data_size_limit + if limit and self.num_bytes > limit: + return + elif limit: + self.num_bytes += len(data) self.received_lines.append(str(data, "utf8")) # Implementation of base class abstract method @@ -270,6 +283,11 @@ class SMTPChannel(asynchat.async_chat): print('Data:', repr(line), file=DEBUGSTREAM) self.received_lines = [] if self.smtp_state == self.COMMAND: + if self.num_bytes > self.command_size_limit: + self.push('500 Error: line too long') + self.num_bytes = 0 + return + self.num_bytes = 0 if not line: self.push('500 Error: bad syntax') return @@ -290,6 +308,11 @@ class SMTPChannel(asynchat.async_chat): else: if self.smtp_state != self.DATA: self.push('451 Internal confusion') + self.num_bytes = 0 + return + if self.num_bytes > self.data_size_limit: + self.push('552 Error: Too much mail data') + self.num_bytes = 0 return # Remove extraneous carriage returns and de-transparency according # to RFC 821, Section 4.5.2. @@ -307,6 +330,7 @@ class SMTPChannel(asynchat.async_chat): self.rcpttos = [] self.mailfrom = None self.smtp_state = self.COMMAND + self.num_bytes = 0 self.set_terminator(b'\r\n') if not status: self.push('250 Ok') |