# ``twisted`.`conch`.`ssh`.`userauth`.`SSHUserAuthServer``

class documentation

`class SSHUserAuthServer(service.SSHService): (source)`

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A service implementing the server side of the 'ssh-userauth' service. It is used to authenticate the user on the other side as being able to access this server.

Method | `auth_password` | Password authentication. Payload:: string password
Method | `auth_publickey` | No summary
Method | `serviceStarted` | No summary
Method | `serviceStopped` | Called when the userauth service is stopped. Cancel the login timeout if it's still going.
Method | `ssh_USERAUTH_REQUEST` | No summary
Method | `timeoutAuthentication` | Called when the user has timed out on authentication. Disconnect with a DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE message.
Method | `tryAuth` | Try to authenticate the user with the given method. Dispatches to a auth_* method.
Instance Variable | `attemptsBeforeDisconnect` | the number of failed login attempts we allow before disconnecting.
Instance Variable | `authenticatedWith` | a list of authentication methods that have already been used.
Instance Variable | `clock` | an object with a callLater method. Stubbed out for testing.
Instance Variable | `interfaceToMethod` | a `dict` mapping credential interfaces to authentication methods. The server checks to see which of the cred interfaces have checkers and tells the client that those methods are valid for authentication.
Instance Variable | `loginAttempts` | the number of login attempts that have been made
Instance Variable | `loginTimeout` | the number of seconds we wait before disconnecting the user for taking too long to authenticate
Instance Variable | `method` | the current authentication method
Instance Variable | `name` | the name of this service: 'ssh-userauth'
Instance Variable | `nextService` | the service the user wants started after authentication has been completed.
Instance Variable | `passwordDelay` | the number of seconds to delay when the user gives an incorrect password
Instance Variable | `portal` | the `twisted.cred.portal.Portal` we are using for authentication
Instance Variable | `supportedAuthentications` | A list of the supported authentication methods.
Instance Variable | `user` | the last username the client tried to authenticate with
Method | `_cbFinishedAuth` | The callback when user has successfully been authenticated. For a description of the arguments, see `twisted.cred.portal.Portal.login`. We start the service requested by the user.
Method | `_ebBadAuth` | No summary
Method | `_ebCheckKey` | Called back if the user did not sent a signature. If reason is error.ValidPublicKey then this key is valid for the user to authenticate with. Send MSG_USERAUTH_PK_OK.
Method | `_ebMaybeBadAuth` | An intermediate errback. If the reason is error.NotEnoughAuthentication, we send a MSG_USERAUTH_FAILURE, but with the partial success indicator set.
Method | `_ebPassword` | If the password is invalid, wait before sending the failure in order to delay brute-force password guessing.
Class Variable | `_log` | Undocumented
Instance Variable | `_cancelLoginTimeout` | Undocumented

Inherited from `SSHService`:

Method | `logPrefix` | Undocumented
Method | `packetReceived` | called when we receive a packet on the transport
Class Variable | `protocolMessages` | Undocumented
Class Variable | `transport` | Undocumented

def auth_password(self, packet): (source)

Password authentication. Payload:

        string password

Make a UsernamePassword credential and verify it with our portal.

def auth_publickey(self, packet): (source)

Public key authentication. Payload:

        byte has signature
        string algorithm name
        string key blob
        [string signature] (if has signature is True)

Create a SSHPublicKey credential and verify it using our portal.

def serviceStarted(self): (source)
overrides `twisted.conch.ssh.service.SSHService.serviceStarted`
Called when the userauth service is started. Set up instance variables, check if we should allow password authentication (only allow if the outgoing connection is encrypted) and set up a login timeout.
def serviceStopped(self): (source)
overrides `twisted.conch.ssh.service.SSHService.serviceStopped`
Called when the userauth service is stopped. Cancel the login timeout if it's still going.
def ssh_USERAUTH_REQUEST(self, packet): (source)

The client has requested authentication. Payload:

        string user
        string next service
        string method
        <authentication specific data>

Parameters
packet:`bytes` | Undocumented

def timeoutAuthentication(self): (source)
Called when the user has timed out on authentication. Disconnect with a DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE message.
def tryAuth(self, kind, user, data): (source)
Try to authenticate the user with the given method. Dispatches to a auth_* method.

Parameters
kind:`bytes` | the authentication method to try.
user:`bytes` | the username the client is authenticating with.
data:`bytes` | authentication specific data sent by the client.
Returns
`defer.Deferred` | A Deferred called back if the method succeeded, or erred back if it failed.

attemptsBeforeDisconnect: `int` = (source)
the number of failed login attempts we allow before disconnecting.
authenticatedWith: `list` = (source)
a list of authentication methods that have already been used.
clock = (source)
an object with a callLater method. Stubbed out for testing.
interfaceToMethod: `dict` = (source)
a `dict` mapping credential interfaces to authentication methods. The server checks to see which of the cred interfaces have checkers and tells the client that those methods are valid for authentication.
loginAttempts: `int` = (source)
the number of login attempts that have been made
loginTimeout: `int` = (source)
the number of seconds we wait before disconnecting the user for taking too long to authenticate
method: `bytes` = (source)
the current authentication method
name: `bytes` = (source)
overrides `twisted.conch.ssh.service.SSHService.name`
the name of this service: 'ssh-userauth'
nextService: `bytes` = (source)
the service the user wants started after authentication has been completed.
passwordDelay: `int` = (source)
the number of seconds to delay when the user gives an incorrect password
portal: `twisted.cred.portal.Portal` = (source)
the `twisted.cred.portal.Portal` we are using for authentication
supportedAuthentications: `list` of `bytes` = (source)
A list of the supported authentication methods.
user: `bytes` = (source)
the last username the client tried to authenticate with
def _cbFinishedAuth(self, result): (source)
The callback when user has successfully been authenticated. For a description of the arguments, see `twisted.cred.portal.Portal.login`. We start the service requested by the user.
def _ebBadAuth(self, reason): (source)
The final errback in the authentication chain. If the reason is error.IgnoreAuthentication, we simply return; the authentication method has sent its own response. Otherwise, send a failure message and (if the method is not 'none') increment the number of login attempts.

Parameters
reason:`twisted.python.failure.Failure` | Undocumented

def _ebCheckKey(self, reason, packet): (source)
Called back if the user did not sent a signature. If reason is error.ValidPublicKey then this key is valid for the user to authenticate with. Send MSG_USERAUTH_PK_OK.
def _ebMaybeBadAuth(self, reason): (source)
An intermediate errback. If the reason is error.NotEnoughAuthentication, we send a MSG_USERAUTH_FAILURE, but with the partial success indicator set.

Parameters
reason:`twisted.python.failure.Failure` | Undocumented

def _ebPassword(self, f): (source)
If the password is invalid, wait before sending the failure in order to delay brute-force password guessing.
_log = (source)
overrides `twisted.conch.ssh.service.SSHService._log`

Undocumented

_cancelLoginTimeout = (source)

Undocumented