ssh: Learn to type passwords and supply pubkeys.

Now ssh requires a tty allocation. This presents a scalability problem,
a future version could selectively allocate a tty only if typing
passwords is desired.

Sudo's tty handling is now moved into mitogen.master.

mitogen/master.py

@@ -12,11 +12,13 @@ import itertools
 import logging
 import os
 import pkgutil
+import pty
 import re
 import select
 import signal
 import socket
 import sys
+import termios
 import textwrap
 import time
 import types
@@ -73,6 +75,78 @@ def create_child(*args):
     return pid, os.dup(parentfp.fileno())
 
 
+def flags(names):
+    """Return the result of ORing a set of (space separated) :py:mod:`termios`
+    module constants together."""
+    return sum(getattr(termios, name) for name in names.split())
+
+
+def cfmakeraw((iflag, oflag, cflag, lflag, ispeed, ospeed, cc)):
+    """Given a list returned by :py:func:`termios.tcgetattr`, return a list
+    that has been modified in the same manner as the `cfmakeraw()` C library
+    function."""
+    iflag &= ~flags('IGNBRK BRKINT PARMRK ISTRIP INLCR IGNCR ICRNL IXON')
+    oflag &= ~flags('OPOST IXOFF')
+    lflag &= ~flags('ECHO ECHOE ECHONL ICANON ISIG IEXTEN')
+    cflag &= ~flags('CSIZE PARENB')
+    cflag |= flags('CS8')
+
+    iflag = 0
+    oflag = 0
+    lflag = 0
+    return [iflag, oflag, cflag, lflag, ispeed, ospeed, cc]
+
+
+def disable_echo(fd):
+    old = termios.tcgetattr(fd)
+    new = cfmakeraw(old)
+    flags = (
+        termios.TCSAFLUSH |
+        getattr(termios, 'TCSASOFT', 0)
+    )
+    termios.tcsetattr(fd, flags, new)
+
+
+def close_nonstandard_fds():
+    for fd in xrange(3, 1024):
+        try:
+            os.close(fd)
+        except OSError:
+            pass
+
+
+def tty_create_child(*args):
+    """
+    Return a file descriptor connected to the master end of a pseudo-terminal,
+    whose slave end is connected to stdin/stdout/stderr of a new child process.
+    The child is created such that the pseudo-terminal becomes its controlling
+    TTY, ensuring access to /dev/tty returns a new file descriptor open on the
+    slave end.
+
+    :param args:
+        execl() arguments.
+    """
+    master_fd, slave_fd = os.openpty()
+    disable_echo(master_fd)
+    disable_echo(slave_fd)
+
+    pid = os.fork()
+    if not pid:
+        os.dup2(slave_fd, 0)
+        os.dup2(slave_fd, 1)
+        os.dup2(slave_fd, 2)
+        close_nonstandard_fds()
+        os.setsid()
+        os.close(os.open(os.ttyname(1), os.O_RDWR))
+        os.execvp(args[0], args)
+        raise SystemExit
+
+    os.close(slave_fd)
+    LOG.debug('tty_create_child() child %d fd %d, parent %d, args %r',
+              pid, master_fd, os.getpid(), args)
+    return pid, master_fd
+
+
 def write_all(fd, s):
     written = 0
     while written < len(s):
@@ -105,8 +179,8 @@ def iter_read(fd, deadline):
 
         if not s:
             raise mitogen.core.StreamError(
-                'EOF on stream; last 100 bytes received: %r' %
-                (''.join(bits)[-100:],)
+                'EOF on stream; last 300 bytes received: %r' %
+                (''.join(bits)[-300:],)
             )
 
         bits.append(s)

mitogen/ssh.py

@@ -3,36 +3,58 @@ Functionality to allow establishing new slave contexts over an SSH connection.
 """
 
 import commands
+import logging
+import time
 
 import mitogen.master
 
 
+LOG = logging.getLogger('mitogen')
+
+PASSWORD_PROMPT = 'password'
+PERMDENIED_PROMPT = 'permission denied'
+
+
+class PasswordError(mitogen.core.Error):
+    pass
+
+
 class Stream(mitogen.master.Stream):
-    python_path = 'python'
+    create_child = staticmethod(mitogen.master.tty_create_child)
+    python_path = 'python2.7'
 
     #: The path to the SSH binary.
     ssh_path = 'ssh'
 
+    identity_file = None
+    password = None
     port = None
 
     def construct(self, hostname, username=None, ssh_path=None, port=None,
-                  check_host_keys=True, **kwargs):
+                  check_host_keys=True, password=None, identity_file=None,
+                  **kwargs):
         super(Stream, self).construct(**kwargs)
         self.hostname = hostname
         self.username = username
         self.port = port
         self.check_host_keys = check_host_keys
+        self.password = password
+        self.identity_file = identity_file
         if ssh_path:
             self.ssh_path = ssh_path
 
     def get_boot_command(self):
         bits = [self.ssh_path]
-        bits += ['-o', 'BatchMode yes']
+        #bits += ['-o', 'BatchMode yes']
 
         if self.username:
             bits += ['-l', self.username]
         if self.port is not None:
             bits += ['-p', str(self.port)]
+        if self.identity_file or self.password:
+            bits += ['-o', 'IdentitiesOnly yes']
+        if self.identity_file:
+            bits += ['-i', self.identity_file]
         if not self.check_host_keys:
             bits += [
                 '-o', 'StrictHostKeyChecking no',
@@ -47,3 +69,27 @@ class Stream(mitogen.master.Stream):
         self.name = 'ssh.' + self.hostname
         if self.port:
             self.name += ':%s' % (self.port,)
+
+    password_incorrect_msg = 'SSH password is incorrect'
+    password_required_msg = 'SSH password was requested, but none specified'
+
+    def _connect_bootstrap(self):
+        password_sent = False
+        for buf in mitogen.master.iter_read(self.receive_side.fd,
+                                             time.time() + 10.0):
+            LOG.debug('%r: received %r', self, buf)
+            if buf.endswith('EC0\n'):
+                return self._ec0_received()
+            elif PERMDENIED_PROMPT in buf.lower():
+                if self.password is not None and password_sent:
+                    raise PasswordError(self.password_incorrect_msg)
+                else:
+                    raise PasswordError(self.auth_incorrect_msg)
+            elif PASSWORD_PROMPT in buf.lower():
+                if self.password is None:
+                    raise PasswordError(self.password_required_msg)
+                LOG.debug('sending password')
+                self.transmit_side.write(self.password + '\n')
+                password_sent = True
+        else:
+            raise mitogen.core.StreamError('bootstrap failed')

mitogen/sudo.py

 
 import logging
 import os
-import pty
-import termios
 import time
 
 import mitogen.core
@@ -17,80 +15,8 @@ class PasswordError(mitogen.core.Error):
     pass
 
 
-def flags(names):
-    """Return the result of ORing a set of (space separated) :py:mod:`termios`
-    module constants together."""
-    return sum(getattr(termios, name) for name in names.split())
-
-
-def cfmakeraw((iflag, oflag, cflag, lflag, ispeed, ospeed, cc)):
-    """Given a list returned by :py:func:`termios.tcgetattr`, return a list
-    that has been modified in the same manner as the `cfmakeraw()` C library
-    function."""
-    iflag &= ~flags('IGNBRK BRKINT PARMRK ISTRIP INLCR IGNCR ICRNL IXON')
-    oflag &= ~flags('OPOST IXOFF')
-    lflag &= ~flags('ECHO ECHOE ECHONL ICANON ISIG IEXTEN')
-    cflag &= ~flags('CSIZE PARENB')
-    cflag |= flags('CS8')
-
-    iflag = 0
-    oflag = 0
-    lflag = 0
-    return [iflag, oflag, cflag, lflag, ispeed, ospeed, cc]
-
-
-def disable_echo(fd):
-    old = termios.tcgetattr(fd)
-    new = cfmakeraw(old)
-    flags = (
-        termios.TCSAFLUSH |
-        getattr(termios, 'TCSASOFT', 0)
-    )
-    termios.tcsetattr(fd, flags, new)
-
-
-def close_nonstandard_fds():
-    for fd in xrange(3, 1024):
-        try:
-            os.close(fd)
-        except OSError:
-            pass
-
-
-def tty_create_child(*args):
-    """
-    Return a file descriptor connected to the master end of a pseudo-terminal,
-    whose slave end is connected to stdin/stdout/stderr of a new child process.
-    The child is created such that the pseudo-terminal becomes its controlling
-    TTY, ensuring access to /dev/tty returns a new file descriptor open on the
-    slave end.
-
-    :param args:
-        execl() arguments.
-    """
-    master_fd, slave_fd = os.openpty()
-    disable_echo(master_fd)
-    disable_echo(slave_fd)
-
-    pid = os.fork()
-    if not pid:
-        os.dup2(slave_fd, 0)
-        os.dup2(slave_fd, 1)
-        os.dup2(slave_fd, 2)
-        close_nonstandard_fds()
-        os.setsid()
-        os.close(os.open(os.ttyname(1), os.O_RDWR))
-        os.execvp(args[0], args)
-        raise SystemExit
-
-    os.close(slave_fd)
-    LOG.debug('tty_create_child() child %d fd %d, parent %d, args %r',
-              pid, master_fd, os.getpid(), args)
-    return pid, master_fd
-
-
 class Stream(mitogen.master.Stream):
-    create_child = staticmethod(tty_create_child)
+    create_child = staticmethod(mitogen.master.tty_create_child)
     sudo_path = 'sudo'
     password = None