def prompt(self):
# Obtain cached password, if any
password = get_password(*normalize(env.host_string))
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
del self.capture[-1 * len(env.sudo_prompt):]
# If the password we just tried was bad, prompt the user again.
if (not password) or self.reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not self.printing:
self._flush(self.prefix)
if self.reprompt:
self._flush(env.again_prompt + '\n' + self.prefix)
self._flush(env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
self.chan.input_enabled = False
password = fabric.network.prompt_for_password(
prompt=" ", no_colon=True, stream=self.stream
)
self.chan.input_enabled = True
# Update env.password, env.passwords if necessary
user, host, port = normalize(env.host_string)
set_password(user, host, port, password)
# Reset reprompt flag
self.reprompt = False
# Send current password down the pipe
self.chan.sendall(password + '\n')
def prompt(self):
# Obtain cached password, if any
password = get_password(*normalize(env.host_string))
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
# NOTE: Yes, the original RingBuffer from Fabric can do this more elegantly.
# This removes the last N elements from the list.
_pop_count = min(len(self.capture), len(env.sudo_prompt))
for i in range(0, _pop_count):
self.capture.pop()
# If the password we just tried was bad, prompt the user again.
if (not password) or self.reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not self.printing:
self._flush(self.prefix)
if self.reprompt:
self._flush(env.again_prompt + '\n' + self.prefix)
self._flush(env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
self.chan.input_enabled = False
password = fabric.network.prompt_for_password(
prompt=" ", no_colon=True, stream=self.stream
)
self.chan.input_enabled = True
# Update env.password, env.passwords if necessary
user, host, port = normalize(env.host_string)
# TODO: in 2.x, make sure to only update sudo-specific password
# config values, not login ones.
set_password(user, host, port, password)
# Reset reprompt flag
self.reprompt = False
# Send current password down the pipe
self.chan.sendall(password + '\n')
def connect(user, host, port, cache, seek_gateway=True):
"""
Create and return a new SSHClient instance connected to given host.
:param user: Username to connect as.
:param host: Network hostname.
:param port: SSH daemon port.
:param cache:
A ``HostConnectionCache`` instance used to cache/store gateway hosts
when gatewaying is enabled.
:param seek_gateway:
Whether to try setting up a gateway socket for this connection. Used so
the actual gateway connection can prevent recursion.
"""
from state import env, output
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load system hosts file (e.g. /etc/ssh/ssh_known_hosts)
known_hosts = env.get('system_known_hosts')
if known_hosts:
client.load_system_host_keys(known_hosts)
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password(user, host, port)
tries = 0
sock = None
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
tries += 1
# (Re)connect gateway socket, if needed.
# Nuke cached client object if not on initial try.
if seek_gateway:
sock = get_gateway(host, port, cache, replace=tries > 0)
# Ready to connect
client.connect(
hostname=host,
port=int(port),
username=user,
password=password,
pkey=key_from_env(password),
key_filename=key_filenames(),
timeout=env.timeout,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys,
sock=sock
)
connected = True
# set a keepalive if desired
if env.keepalive:
client.get_transport().set_keepalive(env.keepalive)
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException, e:
raise NetworkError("Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack." % host, e)
# Prompt for new password to try on auth failure
except (
ssh.AuthenticationException,
ssh.PasswordRequiredException,
ssh.SSHException
), e:
msg = str(e)
# If we get SSHExceptionError and the exception message indicates
# SSH protocol banner read failures, assume it's caused by the
# server load and try again.
if e.__class__ is ssh.SSHException \
and msg == 'Error reading SSH protocol banner':
if _tried_enough(tries):
raise NetworkError(msg, e)
continue
# For whatever reason, empty password + no ssh key or agent
# results in an SSHException instead of an
# AuthenticationException. Since it's difficult to do
# otherwise, we must assume empty password + SSHException ==
# auth exception.
#
# Conversely: if we get SSHException and there
# *was* a password -- it is probably something non auth
# related, and should be sent upwards. (This is not true if the
# exception message does indicate key parse problems.)
#
# This also holds true for rejected/unknown host keys: we have to
# guess based on other heuristics.
if e.__class__ is ssh.SSHException \
and (password or msg.startswith('Unknown server')) \
and not is_key_load_error(e):
raise NetworkError(msg, e)
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# Paramiko doesn't handle prompting for locked private
# keys (i.e. keys with a passphrase and not loaded into an agent)
# so we have to detect this and tweak our prompt slightly.
# (Otherwise, however, the logic flow is the same, because
# ssh's connect() method overrides the password argument to be
# either the login password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because ssh.connect:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# ssh raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException \
or is_key_load_error(e):
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because ssh doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(user, host, port, password)
def output_loop(chan, which, capture):
# Obtain stdout or stderr related values
func = getattr(chan, which)
if which == 'recv':
prefix = "out"
pipe = sys.stdout
else:
prefix = "err"
pipe = sys.stderr
printing = getattr(output, 'stdout' if (which == 'recv') else 'stderr')
# Initialize loop variables
reprompt = False
initial_prefix_printed = False
while True:
# Handle actual read/write
byte = func(1)
if byte == '':
break
# A None capture variable implies that we're in open_shell()
if capture is None:
# Just print directly -- no prefixes, no capturing, nada
# And since we know we're using a pty in this mode, just go
# straight to stdout.
_flush(sys.stdout, byte)
# Otherwise, we're in run/sudo and need to handle capturing and
# prompts.
else:
_prefix = "[%s] %s: " % (env.host_string, prefix)
# Print to user
if printing:
# Initial prefix
if not initial_prefix_printed:
_flush(pipe, _prefix)
initial_prefix_printed = True
# Byte itself
_flush(pipe, byte)
# Trailing prefix to start off next line
if byte in ("\n", "\r"):
_flush(pipe, _prefix)
# Store in capture buffer
capture += byte
# Handle prompts
prompt = _endswith(capture, env.sudo_prompt)
try_again = (_endswith(capture, env.again_prompt + '\n')
or _endswith(capture, env.again_prompt + '\r\n'))
if prompt:
# Obtain cached password, if any
password = get_password()
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
del capture[-1*len(env.sudo_prompt):]
# If the password we just tried was bad, prompt the user again.
if (not password) or reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not printing:
_flush(pipe, _prefix)
if reprompt:
_flush(pipe, env.again_prompt + '\n' + _prefix)
_flush(pipe, env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
password = fabric.network.prompt_for_password(
prompt=" ", no_colon=True, stream=pipe
)
# Update env.password, env.passwords if necessary
set_password(password)
# Reset reprompt flag
reprompt = False
# Send current password down the pipe
chan.sendall(password + '\n')
elif try_again:
# Remove text from capture buffer
capture = capture[:len(env.again_prompt)]
# Set state so we re-prompt the user at the next prompt.
reprompt = True
def connect(user, host, port):
"""
Create and return a new SSHClient instance connected to given host.
"""
from state import env
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password()
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
client.connect(
hostname=host,
port=int(port),
username=user,
password=password,
key_filename=env.key_filename,
timeout=10,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys
)
connected = True
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException:
abort("Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack." % env.host)
# Prompt for new password to try on auth failure
except (
ssh.AuthenticationException,
ssh.PasswordRequiredException,
ssh.SSHException
), e:
# For whatever reason, empty password + no ssh key or agent results
# in an SSHException instead of an AuthenticationException. Since
# it's difficult to do otherwise, we must assume empty password +
# SSHException == auth exception. Conversely: if we get
# SSHException and there *was* a password -- it is probably
# something non auth related, and should be sent upwards.
if e.__class__ is ssh.SSHException and password:
abort(str(e))
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# Paramiko doesn't handle prompting for locked private keys (i.e.
# keys with a passphrase and not loaded into an agent) so we have
# to detect this and tweak our prompt slightly. (Otherwise,
# however, the logic flow is the same, because Paramiko's connect()
# method overrides the password argument to be either the login
# password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because Paramiko:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# Paramiko raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException:
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because Paramiko doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(password)
# Ctrl-D / Ctrl-C for exit
except (EOFError, TypeError):
# Print a newline (in case user was sitting at prompt)
print('')
sys.exit(0)
def connect(user, host, port, cache, seek_gateway=True):
"""
Create and return a new SSHClient instance connected to given host.
:param user: Username to connect as.
:param host: Network hostname.
:param port: SSH daemon port.
:param cache:
A ``HostConnectionCache`` instance used to cache/store gateway hosts
when gatewaying is enabled.
:param seek_gateway:
Whether to try setting up a gateway socket for this connection. Used so
the actual gateway connection can prevent recursion.
"""
from state import env, output
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load system hosts file (e.g. /etc/ssh/ssh_known_hosts)
known_hosts = env.get('system_known_hosts')
if known_hosts:
client.load_system_host_keys(known_hosts)
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password(user, host, port)
tries = 0
sock = None
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
tries += 1
# (Re)connect gateway socket, if needed.
# Nuke cached client object if not on initial try.
if seek_gateway:
sock = get_gateway(host, port, cache, replace=tries > 0)
# Ready to connect
client.connect(
hostname=host,
port=int(port),
username=user,
password=password,
pkey=key_from_env(password),
key_filename=key_filenames(),
timeout=env.timeout,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys,
sock=sock
)
connected = True
# set a keepalive if desired
if env.keepalive:
client.get_transport().set_keepalive(env.keepalive)
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException as e:
raise NetworkError("Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack." % host, e)
# Prompt for new password to try on auth failure
except (ssh.AuthenticationException,
ssh.PasswordRequiredException,
ssh.SSHException
) as e:
msg = str(e)
# If we get SSHExceptionError and the exception message indicates
# SSH protocol banner read failures, assume it's caused by the
# server load and try again.
if e.__class__ is ssh.SSHException \
and msg == 'Error reading SSH protocol banner':
if _tried_enough(tries):
raise NetworkError(msg, e)
continue
# For whatever reason, empty password + no ssh key or agent
# results in an SSHException instead of an
# AuthenticationException. Since it's difficult to do
# otherwise, we must assume empty password + SSHException ==
# auth exception.
#
# Conversely: if we get SSHException and there
# *was* a password -- it is probably something non auth
# related, and should be sent upwards. (This is not true if the
# exception message does indicate key parse problems.)
#
# This also holds true for rejected/unknown host keys: we have to
# guess based on other heuristics.
if e.__class__ is ssh.SSHException \
and (password or msg.startswith('Unknown server')) \
and not is_key_load_error(e):
raise NetworkError(msg, e)
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# Paramiko doesn't handle prompting for locked private
# keys (i.e. keys with a passphrase and not loaded into an agent)
# so we have to detect this and tweak our prompt slightly.
# (Otherwise, however, the logic flow is the same, because
# ssh's connect() method overrides the password argument to be
# either the login password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because ssh.connect:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# ssh raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException \
or is_key_load_error(e):
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because ssh doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(user, host, port, password)
# Ctrl-D / Ctrl-C for exit
# TODO: this may no longer actually serve its original purpose and may
# also hide TypeErrors from paramiko. Double check in v2.
except (EOFError, TypeError):
# Print a newline (in case user was sitting at prompt)
print('')
sys.exit(0)
# Handle DNS error / name lookup failure
except socket.gaierror as e:
raise NetworkError('Name lookup failed for %s' % host, e)
# Handle timeouts and retries, including generic errors
# NOTE: In 2.6, socket.error subclasses IOError
except socket.error as e:
not_timeout = type(e) is not socket.timeout
giving_up = _tried_enough(tries)
# Baseline error msg for when debug is off
msg = "Timed out trying to connect to %s" % host
# Expanded for debug on
err = msg + " (attempt %s of %s)" % (tries, env.connection_attempts)
if giving_up:
err += ", giving up"
err += ")"
# Debuggin'
if output.debug:
sys.stderr.write(err + '\n')
# Having said our piece, try again
if not giving_up:
# Sleep if it wasn't a timeout, so we still get timeout-like
# behavior
if not_timeout:
time.sleep(env.timeout)
continue
# Override eror msg if we were retrying other errors
if not_timeout:
msg = "Low level socket error connecting to host %s on port %s: %s" % (
host, port, e[1]
)
# Here, all attempts failed. Tweak error msg to show # tries.
# TODO: find good humanization module, jeez
s = "s" if env.connection_attempts > 1 else ""
msg += " (tried %s time%s)" % (env.connection_attempts, s)
raise NetworkError(msg, e)
# Ensure that if we terminated without connecting and we were given an
# explicit socket, close it out.
finally:
if not connected and sock is not None:
sock.close()
def connect(user, host, port):
"""
Create and return a new SSHClient instance connected to given host.
"""
from state import env, output
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password()
tries = 0
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
tries += 1
client.connect(hostname=host,
port=int(port),
username=user,
password=password,
key_filename=key_filenames(),
timeout=env.timeout,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys)
connected = True
# set a keepalive if desired
if env.keepalive:
client.get_transport().set_keepalive(env.keepalive)
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException, e:
raise NetworkError(
"Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack."
% host, e)
# Prompt for new password to try on auth failure
except (ssh.AuthenticationException, ssh.PasswordRequiredException,
ssh.SSHException), e:
# For whatever reason, empty password + no ssh key or agent results
# in an SSHException instead of an AuthenticationException. Since
# it's difficult to do otherwise, we must assume empty password +
# SSHException == auth exception. Conversely: if we get
# SSHException and there *was* a password -- it is probably
# something non auth related, and should be sent upwards.
if e.__class__ is ssh.SSHException and password:
raise NetworkError(str(e), e)
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# The 'ssh' library doesn't handle prompting for locked private
# keys (i.e. keys with a passphrase and not loaded into an agent)
# so we have to detect this and tweak our prompt slightly.
# (Otherwise, however, the logic flow is the same, because
# ssh's connect() method overrides the password argument to be
# either the login password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because ssh.connect:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# ssh raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException:
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because ssh doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(password)
def connect(user, host, port, cache, seek_gateway=True):
"""
Create and return a new SSHClient instance connected to given host.
:param user: Username to connect as.
:param host: Network hostname.
:param port: SSH daemon port.
:param cache:
A ``HostConnectionCache`` instance used to cache/store gateway hosts
when gatewaying is enabled.
:param seek_gateway:
Whether to try setting up a gateway socket for this connection. Used so
the actual gateway connection can prevent recursion.
"""
from fabric.state import env, output
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load system hosts file (e.g. /etc/ssh/ssh_known_hosts)
known_hosts = env.get('system_known_hosts')
if known_hosts:
client.load_system_host_keys(known_hosts)
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password(user, host, port)
tries = 0
sock = None
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
tries += 1
# (Re)connect gateway socket, if needed.
# Nuke cached client object if not on initial try.
if seek_gateway:
sock = get_gateway(host, port, cache, replace=tries > 0)
# Ready to connect
client.connect(
hostname=host,
port=int(port),
username=user,
password=password,
pkey=key_from_env(password),
key_filename=key_filenames(),
timeout=env.timeout,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys,
sock=sock
)
connected = True
# set a keepalive if desired
if env.keepalive:
client.get_transport().set_keepalive(env.keepalive)
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException as e:
raise NetworkError("Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack." % host, e)
# Prompt for new password to try on auth failure
except (
ssh.AuthenticationException,
ssh.PasswordRequiredException,
ssh.SSHException
) as e:
msg = str(e)
# If we get SSHExceptionError and the exception message indicates
# SSH protocol banner read failures, assume it's caused by the
# server load and try again.
if e.__class__ is ssh.SSHException \
and msg == 'Error reading SSH protocol banner':
if _tried_enough(tries):
raise NetworkError(msg, e)
continue
# For whatever reason, empty password + no ssh key or agent
# results in an SSHException instead of an
# AuthenticationException. Since it's difficult to do
# otherwise, we must assume empty password + SSHException ==
# auth exception.
#
# Conversely: if we get SSHException and there
# *was* a password -- it is probably something non auth
# related, and should be sent upwards. (This is not true if the
# exception message does indicate key parse problems.)
#
# This also holds true for rejected/unknown host keys: we have to
# guess based on other heuristics.
if e.__class__ is ssh.SSHException \
and (password or msg.startswith('Unknown server')) \
and not is_key_load_error(e):
raise NetworkError(msg, e)
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# Paramiko doesn't handle prompting for locked private
# keys (i.e. keys with a passphrase and not loaded into an agent)
# so we have to detect this and tweak our prompt slightly.
# (Otherwise, however, the logic flow is the same, because
# ssh's connect() method overrides the password argument to be
# either the login password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because ssh.connect:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# ssh raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException \
or is_key_load_error(e):
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because ssh doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(user, host, port, password)
# Ctrl-D / Ctrl-C for exit
# TODO: this may no longer actually serve its original purpose and may
# also hide TypeErrors from paramiko. Double check in v2.
except (EOFError, TypeError):
# Print a newline (in case user was sitting at prompt)
print('')
sys.exit(0)
# Handle DNS error / name lookup failure
except socket.gaierror as e:
raise NetworkError('Name lookup failed for %s' % host, e)
# Handle timeouts and retries, including generic errors
# NOTE: In 2.6, socket.error subclasses IOError
except socket.error as e:
not_timeout = type(e) is not socket.timeout
giving_up = _tried_enough(tries)
# Baseline error msg for when debug is off
msg = "Timed out trying to connect to %s" % host
# Expanded for debug on
err = msg + " (attempt %s of %s)" % (tries, env.connection_attempts)
if giving_up:
err += ", giving up"
err += ")"
# Debuggin'
if output.debug:
sys.stderr.write(err + '\n')
# Having said our piece, try again
if not giving_up:
# Sleep if it wasn't a timeout, so we still get timeout-like
# behavior
if not_timeout:
time.sleep(env.timeout)
continue
# Override eror msg if we were retrying other errors
if not_timeout:
msg = "Low level socket error connecting to host %s on port %s: %s" % (
host, port, e.args[1]
)
# Here, all attempts failed. Tweak error msg to show # tries.
# TODO: find good humanization module, jeez
s = "s" if env.connection_attempts > 1 else ""
msg += " (tried %s time%s)" % (env.connection_attempts, s)
raise NetworkError(msg, e)
# Ensure that if we terminated without connecting and we were given an
# explicit socket, close it out.
finally:
if not connected and sock is not None:
sock.close()
def output_loop(chan, which, capture):
# Internal capture-buffer-like buffer, used solely for state keeping.
# Unlike 'capture', nothing is ever purged from this.
_buffer = []
# Obtain stdout or stderr related values
func = getattr(chan, which)
if which == 'recv':
prefix = "out"
pipe = sys.stdout
else:
prefix = "err"
pipe = sys.stderr
_prefix = "[%s] %s: " % (env.host_string, prefix)
printing = getattr(output, 'stdout' if (which == 'recv') else 'stderr')
# Initialize loop variables
reprompt = False
initial_prefix_printed = False
line = []
linewise = (env.linewise or env.parallel)
while True:
# Handle actual read/write
byte = func(1)
# Empty byte == EOS
if byte == '':
# If linewise, ensure we flush any leftovers in the buffer.
if linewise and line:
_flush(pipe, _prefix)
_flush(pipe, "".join(line))
break
# A None capture variable implies that we're in open_shell()
if capture is None:
# Just print directly -- no prefixes, no capturing, nada
# And since we know we're using a pty in this mode, just go
# straight to stdout.
_flush(sys.stdout, byte)
# Otherwise, we're in run/sudo and need to handle capturing and
# prompts.
else:
# Allow prefix to be turned off.
if not env.output_prefix:
_prefix = ""
# Print to user
if printing:
if linewise:
# Print prefix + line after newline is seen
if _was_newline(_buffer, byte):
_flush(pipe, _prefix)
_flush(pipe, "".join(line))
line = []
# Add to line buffer
line += byte
else:
# Prefix, if necessary
if (not initial_prefix_printed
or _was_newline(_buffer, byte)):
_flush(pipe, _prefix)
initial_prefix_printed = True
# Byte itself
_flush(pipe, byte)
# Store in capture buffer
capture += byte
# Store in internal buffer
_buffer += byte
# Handle prompts
prompt = _endswith(capture, env.sudo_prompt)
try_again = (_endswith(capture, env.again_prompt + '\n')
or _endswith(capture, env.again_prompt + '\r\n'))
if prompt:
# Obtain cached password, if any
password = get_password()
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
del capture[-1 * len(env.sudo_prompt):]
# If the password we just tried was bad, prompt the user again.
if (not password) or reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not printing:
_flush(pipe, _prefix)
if reprompt:
_flush(pipe, env.again_prompt + '\n' + _prefix)
_flush(pipe, env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
chan.input_enabled = False
password = fabric.network.prompt_for_password(
prompt=" ", no_colon=True, stream=pipe)
chan.input_enabled = True
# Update env.password, env.passwords if necessary
set_password(password)
# Reset reprompt flag
reprompt = False
# Send current password down the pipe
chan.sendall(password + '\n')
elif try_again:
# Remove text from capture buffer
capture = capture[:len(env.again_prompt)]
# Set state so we re-prompt the user at the next prompt.
reprompt = True
def output_loop(chan, attr, stream, capture):
"""
Loop, reading from <chan>.<attr>(), writing to <stream> and buffering to <capture>.
"""
# Internal capture-buffer-like buffer, used solely for state keeping.
# Unlike 'capture', nothing is ever purged from this.
_buffer = []
# Obtain stdout or stderr related values
func = getattr(chan, attr)
_prefix = "[%s] %s: " % (
env.host_string,
"out" if attr == 'recv' else "err"
)
printing = getattr(output, 'stdout' if (attr == 'recv') else 'stderr')
# Initialize loop variables
reprompt = False
initial_prefix_printed = False
line = []
linewise = (env.linewise or env.parallel)
while True:
# Handle actual read/write
byte = func(1)
# Empty byte == EOS
if byte == '':
# If linewise, ensure we flush any leftovers in the buffer.
if linewise and line:
_flush(stream, _prefix)
_flush(stream, "".join(line))
break
# A None capture variable implies that we're in open_shell()
if capture is None:
# Just print directly -- no prefixes, no capturing, nada
# And since we know we're using a pty in this mode, just go
# straight to stdout.
_flush(sys.stdout, byte)
# Otherwise, we're in run/sudo and need to handle capturing and
# prompts.
else:
# Allow prefix to be turned off.
if not env.output_prefix:
_prefix = ""
# Print to user
if printing:
if linewise:
# Print prefix + line after newline is seen
if _was_newline(_buffer, byte):
_flush(stream, _prefix)
_flush(stream, "".join(line))
line = []
# Add to line buffer
line += byte
else:
# Prefix, if necessary
if (
not initial_prefix_printed
or _was_newline(_buffer, byte)
):
_flush(stream, _prefix)
initial_prefix_printed = True
# Byte itself
_flush(stream, byte)
# Store in capture buffer
capture += byte
# Store in internal buffer
_buffer += byte
# Handle prompts
prompt = _endswith(capture, env.sudo_prompt)
try_again = (_endswith(capture, env.again_prompt + '\n')
or _endswith(capture, env.again_prompt + '\r\n'))
if prompt:
# Obtain cached password, if any
password = get_password()
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
del capture[-1 * len(env.sudo_prompt):]
# If the password we just tried was bad, prompt the user again.
if (not password) or reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not printing:
_flush(stream, _prefix)
if reprompt:
_flush(stream, env.again_prompt + '\n' + _prefix)
_flush(stream, env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
chan.input_enabled = False
password = fabric.network.prompt_for_password(
prompt=" ", no_colon=True, stream=stream
)
chan.input_enabled = True
# Update env.password, env.passwords if necessary
set_password(password)
# Reset reprompt flag
reprompt = False
# Send current password down the pipe
chan.sendall(password + '\n')
elif try_again:
# Remove text from capture buffer
capture = capture[:len(env.again_prompt)]
# Set state so we re-prompt the user at the next prompt.
reprompt = True
def connect(user, host, port):
"""
Create and return a new SSHClient instance connected to given host.
"""
from state import env, output
#
# Initialization
#
# Init client
client = ssh.SSHClient()
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not env.disable_known_hosts:
client.load_system_host_keys()
# Unless user specified not to, accept/add new, unknown host keys
if not env.reject_unknown_hosts:
client.set_missing_host_key_policy(ssh.AutoAddPolicy())
#
# Connection attempt loop
#
# Initialize loop variables
connected = False
password = get_password()
tries = 0
proxy_command = None
if env.use_ssh_config:
host = env._ssh_config.lookup(env.host_string)
proxy_command = host.get('proxycommand')
user = host.get('user')
# Loop until successful connect (keep prompting for new password)
while not connected:
# Attempt connection
try:
tries += 1
client.connect(
hostname=host,
port=int(port),
username=user,
password=password,
key_filename=key_filenames(),
timeout=env.timeout,
allow_agent=not env.no_agent,
look_for_keys=not env.no_keys,
proxy_command=proxy_command,
)
connected = True
# set a keepalive if desired
if env.keepalive:
client.get_transport().set_keepalive(env.keepalive)
return client
# BadHostKeyException corresponds to key mismatch, i.e. what on the
# command line results in the big banner error about man-in-the-middle
# attacks.
except ssh.BadHostKeyException, e:
raise NetworkError("Host key for %s did not match pre-existing key! Server's key was changed recently, or possible man-in-the-middle attack." % host, e)
# Prompt for new password to try on auth failure
except (
ssh.AuthenticationException,
ssh.PasswordRequiredException,
ssh.SSHException
), e:
msg = str(e)
# For whatever reason, empty password + no ssh key or agent
# results in an SSHException instead of an
# AuthenticationException. Since it's difficult to do
# otherwise, we must assume empty password + SSHException ==
# auth exception. Conversely: if we get SSHException and there
# *was* a password -- it is probably something non auth
# related, and should be sent upwards.
#
# This also holds true for rejected/unknown host keys: we have to
# guess based on other heuristics.
if e.__class__ is ssh.SSHException \
and (password or msg.startswith('Unknown server')):
raise NetworkError(msg, e)
# Otherwise, assume an auth exception, and prompt for new/better
# password.
# The 'ssh' library doesn't handle prompting for locked private
# keys (i.e. keys with a passphrase and not loaded into an agent)
# so we have to detect this and tweak our prompt slightly.
# (Otherwise, however, the logic flow is the same, because
# ssh's connect() method overrides the password argument to be
# either the login password OR the private key passphrase. Meh.)
#
# NOTE: This will come up if you normally use a
# passphrase-protected private key with ssh-agent, and enter an
# incorrect remote username, because ssh.connect:
# * Tries the agent first, which will fail as you gave the wrong
# username, so obviously any loaded keys aren't gonna work for a
# nonexistent remote account;
# * Then tries the on-disk key file, which is passphrased;
# * Realizes there's no password to try unlocking that key with,
# because you didn't enter a password, because you're using
# ssh-agent;
# * In this condition (trying a key file, password is None)
# ssh raises PasswordRequiredException.
text = None
if e.__class__ is ssh.PasswordRequiredException:
# NOTE: we can't easily say WHICH key's passphrase is needed,
# because ssh doesn't provide us with that info, and
# env.key_filename may be a list of keys, so we can't know
# which one raised the exception. Best not to try.
prompt = "[%s] Passphrase for private key"
text = prompt % env.host_string
password = prompt_for_password(text)
# Update env.password, env.passwords if empty
set_password(password)
def output_loop(chan, which, capture):
# Obtain stdout or stderr related values
func = getattr(chan, which)
if which == 'recv':
prefix = "out"
pipe = sys.stdout
else:
prefix = "err"
pipe = sys.stderr
host_prefix = "[%s]" % env.host_string
if env.colors:
host_prefix = env.color_settings['host_prefix'](host_prefix)
printing = getattr(output, 'stdout' if (which == 'recv') else 'stderr')
# Initialize loop variables
reprompt = False
initial_prefix_printed = False
while True:
# Handle actual read/write
byte = func(1)
if byte == '':
break
# A None capture variable implies that we're in open_shell()
if capture is None:
# Just print directly -- no prefixes, no capturing, nada
# And since we know we're using a pty in this mode, just go
# straight to stdout.
_flush(sys.stdout, byte)
# Otherwise, we're in run/sudo and need to handle capturing and
# prompts.
else:
_prefix = "%s %s: " % (host_prefix, prefix)
# Print to user
if printing:
# Initial prefix
if not initial_prefix_printed:
_flush(pipe, _prefix)
initial_prefix_printed = True
# Byte itself
_flush(pipe, byte)
# Trailing prefix to start off next line
if byte in ("\n", "\r"):
_flush(pipe, _prefix)
# Store in capture buffer
capture += byte
# Handle prompts
prompt = _endswith(capture, env.sudo_prompt)
try_again = (_endswith(capture, env.again_prompt + '\n')
or _endswith(capture, env.again_prompt + '\r\n'))
if prompt:
# Obtain cached password, if any
password = get_password()
# Remove the prompt itself from the capture buffer. This is
# backwards compatible with Fabric 0.9.x behavior; the user
# will still see the prompt on their screen (no way to avoid
# this) but at least it won't clutter up the captured text.
del capture[-1 * len(env.sudo_prompt):]
# If the password we just tried was bad, prompt the user again.
if (not password) or reprompt:
# Print the prompt and/or the "try again" notice if
# output is being hidden. In other words, since we need
# the user's input, they need to see why we're
# prompting them.
if not printing:
_flush(pipe, _prefix)
if reprompt:
_flush(pipe, env.again_prompt + '\n' + _prefix)
_flush(pipe, env.sudo_prompt)
# Prompt for, and store, password. Give empty prompt so the
# initial display "hides" just after the actually-displayed
# prompt from the remote end.
password = prompt_for_password(prompt=" ",
no_colon=True,
stream=pipe)
# Update env.password, env.passwords if necessary
set_password(password)
# Reset reprompt flag
reprompt = False
# Send current password down the pipe
chan.sendall(password + '\n')
elif try_again:
# Remove text from capture buffer
capture = capture[:len(env.again_prompt)]
# Set state so we re-prompt the user at the next prompt.
reprompt = True