Port various other bugfixes in smtplib.py from upstream

src/calibre/utils/smtplib.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python2
 from __future__ import print_function
 
 '''SMTP/ESMTP client class.
@@ -47,8 +48,8 @@ import re
 import email.utils
 import base64
 import hmac
-import sys
 from email.base64mime import encode as encode_base64
+from sys import stderr
 from functools import partial
 
 __all__ = ["SMTPException", "SMTPServerDisconnected", "SMTPResponseException",
@@ -59,9 +60,11 @@ __all__ = ["SMTPException","SMTPServerDisconnected","SMTPResponseException",
 SMTP_PORT = 25
 SMTP_SSL_PORT = 465
 CRLF = "\r\n"
+_MAXLINE = 8192  # more than 8 times larger than RFC 821, 4.5.3
 
 OLDSTYLE_AUTH = re.compile(r"auth=(.*)", re.I)
 
+
 # Exception classes used by this module.
 class SMTPException(Exception):
     """Base class for all exceptions raised by this module."""
@@ -130,6 +133,7 @@ class SMTPAuthenticationError(SMTPResponseException):
     combination provided.
     """
 
+
 def quoteaddr(addr):
     """Quote a subset of the email addresses defined by RFC 821.
 
@@ -149,6 +153,13 @@ def quoteaddr(addr):
     else:
         return "<%s>" % m
 
+def _addr_only(addrstring):
+    displayname, addr = email.utils.parseaddr(addrstring)
+    if (displayname, addr) == ('', ''):
+        # parseaddr couldn't parse it, so use it as is.
+        return addrstring
+    return addr
+
 def quotedata(data):
     """Quote data for email.
 
@@ -172,10 +183,14 @@ else:
         def __init__(self, sslobj):
             self.sslobj = sslobj
 
-        def readline(self):
+        def readline(self, size=-1):
+            if size < 0:
+                size = None
             str = ""
             chr = None
             while chr != "\n":
+                if size is not None and len(str) >= size:
+                    break
                 chr = self.sslobj.read(1)
                 if not chr:
                     break
@@ -222,10 +237,11 @@ class SMTP:
     ehlo_msg = "ehlo"
     ehlo_resp = None
     does_esmtp = 0
+    default_port = SMTP_PORT
 
     def __init__(self, host='', port=0, local_hostname=None,
                  timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
-                 debug_to=partial(print, file=sys.stderr)):
+                 debug_to=partial(print, file=stderr)):
         """Initialize a new instance.
 
         If specified, `host' is the name of the remote host to which to
@@ -241,7 +257,6 @@ class SMTP:
         self.timeout = timeout
         self.debug = debug_to
         self.esmtp_features = {}
-        self.default_port = SMTP_PORT
         if host:
             (code, msg) = self.connect(host, port)
             if code != 220:
@@ -356,14 +371,18 @@ class SMTP:
             self.file = self.sock.makefile('rb')
         while True:
             try:
-                line = self.file.readline()
-            except socket.error:
-                line = ''
+                line = self.file.readline(_MAXLINE + 1)
+            except socket.error as e:
+                self.close()
+                raise SMTPServerDisconnected("Connection unexpectedly closed: " +
+                                             str(e))
             if line == '':
                 self.close()
                 raise SMTPServerDisconnected("Connection unexpectedly closed")
             if self.debuglevel > 0:
                 self.debug('reply:', repr(line))
+            if len(line) > _MAXLINE:
+                raise SMTPResponseException(500, "Line too long.")
             resp.append(line[4:].strip())
             code = line[:3]
             # Check that the error code is syntactically correct.
@@ -509,14 +528,14 @@ class SMTP:
 
     def verify(self, address):
         """SMTP 'verify' command -- checks for address validity."""
-        self.putcmd("vrfy", quoteaddr(address))
+        self.putcmd("vrfy", _addr_only(address))
         return self.getreply()
     # a.k.a.
     vrfy = verify
 
     def expn(self, address):
         """SMTP 'expn' command -- expands a mailing list."""
-        self.putcmd("expn", quoteaddr(address))
+        self.putcmd("expn", _addr_only(address))
         return self.getreply()
 
     # some useful methods
@@ -749,16 +768,24 @@ class SMTP:
 
     def close(self):
         """Close the connection to the SMTP server."""
-        if self.file:
-            self.file.close()
+        try:
+            file = self.file
             self.file = None
-        if self.sock:
-            self.sock.close()
+            if file:
+                file.close()
+        finally:
+            sock = self.sock
             self.sock = None
+            if sock:
+                sock.close()
 
     def quit(self):
         """Terminate the SMTP session."""
         res = self.docmd("quit")
+        # A new EHLO is required after reconnecting with connect()
+        self.ehlo_resp = self.helo_resp = None
+        self.esmtp_features = {}
+        self.does_esmtp = False
         self.close()
         return res
 
@@ -772,15 +799,17 @@ if _have_ssl:
         are also optional - they can contain a PEM formatted private key and
         certificate chain file for the SSL connection.
         """
+
+        default_port = SMTP_SSL_PORT
+
         def __init__(self, host='', port=0, local_hostname=None,
                      keyfile=None, certfile=None,
                      timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
-                     debug_to=partial(print, file=sys.stderr)):
+                     debug_to=partial(print, file=stderr)):
             self.keyfile = keyfile
             self.certfile = certfile
             SMTP.__init__(self, host, port, local_hostname, timeout,
                     debug_to=debug_to)
-            self.default_port = SMTP_SSL_PORT
 
         def _get_socket(self, host, port, timeout):
             if self.debuglevel > 0:
@@ -825,18 +854,40 @@ class LMTP(SMTP):
         try:
             self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
             self.sock.connect(host)
-        except socket.error as msg:
+        except socket.error:
             if self.debuglevel > 0:
                 self.debug('connect fail:', host)
             if self.sock:
                 self.sock.close()
             self.sock = None
-            raise socket.error(msg)
+            raise
         (code, msg) = self.getreply()
         if self.debuglevel > 0:
             self.debug("connect:", msg)
         return (code, msg)
 
 
+# Test the sendmail method, which tests most of the others.
+# Note: This always sends to localhost.
+if __name__ == '__main__':
+    import sys
 
+    def prompt(prompt):
+        sys.stdout.write(prompt + ": ")
+        return sys.stdin.readline().strip()
 
+    fromaddr = prompt("From")
+    toaddrs = prompt("To").split(',')
+    print ("Enter message, end with ^D:")
+    msg = ''
+    while 1:
+        line = sys.stdin.readline()
+        if not line:
+            break
+        msg = msg + line
+    print ("Message length is %d" % len(msg))
+
+    server = SMTP('localhost')
+    server.set_debuglevel(1)
+    server.sendmail(fromaddr, toaddrs, msg)
+    server.quit()