SSHAuth Class

Properties   Methods   Events   Config Settings   Errors  

The SSHAuth class provides a simple way to authenticate a user against an SSH server.

Syntax

ipworksauth.sshauth()

Remarks

The SSHAuth class offers a simply way to authenticate a user against an SSH server.

To begin specify the SSHHost, User, and Password. Next call Authenticate to authenticate the user.

The class supports multiple authentication methods including public key authentication, keyboard interactive authentication, password authentication, and more. Set AuthMode to the desired authentication mechanism before calling Authenticate.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

SSHAuth.AuthMode Property

The authentication method to be used the class when calling Authenticate .

Syntax

getAuthMode(): SshauthAuthModes;
setAuthMode(authMode: SshauthAuthModes): void;

enum SshauthAuthModes {
  amNone,
  amMultiFactor,
  amPassword,
  amPublicKey,
  amKeyboardInteractive,
  amGSSAPIWithMic,
  amCustom
}

Default Value

2

Remarks

The SSH Authentication specification (RFC 4252) specifies multiple methods by which a user can be authenticated by an SSH server. When a call is made to Authenticate, the class will connect to the SSH server and establish the security layer. After the connection has been secured, the client will send an authentication request to the SSHHost containing the User. The server will respond containing a list of methods by which that user may be authenticated.

The class will attempt to authenticate the user by one of those methods based on the value of AuthMode and other property values supplied by the user. Currently, the class supports the following authentication methods:

Example (User/Password Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

SSHAuth.Firewall Property

A set of properties related to firewall access.

Syntax

getFirewall(): Firewall;
setFirewall(firewall: Firewall): void;

Default Value

Remarks

This is a Firewall-type property, which contains fields describing the firewall through which the class will attempt to connect.

SSHAuth.LocalHost Property

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

getLocalHost(): string;
setLocalHost(localHost: string): void;

Default Value

""

Remarks

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

SSHAuth.LocalPort Property

The TCP port in the local host where the class binds.

Syntax

getLocalPort(): number;
setLocalPort(localPort: number): void;

Default Value

0

Remarks

This property must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this property to 0 (default) enables the system to choose an open port at random. The chosen port will be returned by the LocalPort property after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this property when a connection is active will generate an error.

This property is useful when trying to connect to services that require a trusted port in the client side.

SSHAuth.Password Property

The password for SSH password-based authentication.

Syntax

getPassword(): string;
setPassword(password: string): void;

Default Value

""

Remarks

Password specifies the password which is used to authenticate the client to the SSH server.

SSHAuth.SSHAcceptServerHostKey Property

Instructs the class to accept the server host key that matches the supplied key.

Syntax

getSSHAcceptServerHostKey(): Certificate;
setSSHAcceptServerHostKey(SSHAcceptServerHostKey: Certificate): void;

Default Value

Remarks

If the host key that will be used by the server is known in advance, this property may be set to accept the expected key. Otherwise the SSHServerAuthentication event should be trapped, and the key should be accepted or refused in the event.

If this property is not set and the SSHServerAuthentication event is not trapped, the server will not be authenticated and the connection will be terminated by the client.

SSHAuth.SSHCert Property

A certificate to be used for authenticating the SSHUser .

Syntax

getSSHCert(): Certificate;
setSSHCert(SSHCert: Certificate): void;

Default Value

Remarks

In order to use public key authentication, SSHCert must contain a Certificate with a valid private key. The certificate's public key value is sent to the server along with a signature produced using the private key. The server will first check to see if the public key values match what is known for the user, and then will attempt to use those values to verify the signature.

Example (User/Password Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

SSHAuth.SSHEncryptionAlgorithms Property

A comma-separated list containing all allowable encryption algorithms.

Syntax

getSSHEncryptionAlgorithms(): string;
setSSHEncryptionAlgorithms(SSHEncryptionAlgorithms: string): void;

Default Value

"aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,arcfour256,arcfour128,arcfour,cast128-cbc,aes256-gcm@openssh.com,aes128-gcm@openssh.com,chacha20-poly1305@openssh.com"

Remarks

During the SSH handshake, this list will be used to negotiate the encryption algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, the class will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following encryption algorithms are supported by the class:

SSHAuth.SSHHost Property

The address of the SSH host.

Syntax

getSSHHost(): string;
setSSHHost(SSHHost: string): void;

Default Value

""

Remarks

The SSHHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If the SSHHost property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, the SSHHost property is set to the corresponding address. If the search is not successful, an error is returned.

The SSHHost must be the same host that will be assumed for SSH as for the remote service being connected to.

SSHAuth.SSHPort Property

The port on the SSH server where the SSH service is running; by default, 22.

Syntax

getSSHPort(): number;
setSSHPort(SSHPort: number): void;

Default Value

22

Remarks

The SSHPort specifies a service port on the SSH host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

SSHAuth.Timeout Property

A timeout for the class.

Syntax

getTimeout(): number;
setTimeout(timeout: number): void;

Default Value

60

Remarks

If the Timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If Timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of Timeout seconds.

The class will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the class .

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

SSHAuth.User Property

The username for SSH authentication.

Syntax

getUser(): string;
setUser(user: string): void;

Default Value

""

Remarks

User specifies the username which is used to authenticate the client to the SSH server. This property is required.

Example (User/Password Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): Control.SSHAuthMode = SshauthSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

SSHAuth.authenticate Method

Authenticates the user.

Syntax

async sshauth.authenticate(): Promise<void>

Remarks

This method authenticates the user against the SSHHost. If authentication succeeds this method returns without error. If authentication fails, or an error is encountered, the class .

The following common properties are applicable when calling this method:

• User (required)
• Password (required for password authentication)
• SSHCert (required for public key authentication)
• SSHHost (required)
• SSHPort
• AuthMode
• SSHEncryptionAlgorithms

Keyboard interactive authentication is handled through the SSHKeyboardInteractive event.

SSHAuth.config Method

Sets or retrieves a configuration setting.

Syntax

async sshauth.config(configurationString : string): Promise<string>

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

SSHAuth.doEvents Method

Processes events from the internal message queue.

Syntax

async sshauth.doEvents(): Promise<void>

Remarks

When DoEvents is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

SSHAuth.interrupt Method

Interrupt the current method.

Syntax

async sshauth.interrupt(): Promise<void>

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

SSHAuth.reset Method

Resets the class.

Syntax

async sshauth.reset(): Promise<void>

Remarks

When called, the class will reset all of its properties to their default values.

SSHAuth.Connected Event

This event is fired immediately after a connection completes (or fails).

Syntax

sshauth.on('Connected', listener: (e: {readonly statusCode: number, readonly description: string}) => void )

Remarks

If the connection is made normally, StatusCode is 0 and Description is "OK".

If the connection fails, StatusCode has the error code returned by the Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Please refer to the Error Codes section for more information.

SSHAuth.ConnectionStatus Event

This event is fired to indicate changes in the connection state.

Syntax

sshauth.on('ConnectionStatus', listener: (e: {readonly connectionEvent: string, readonly statusCode: number, readonly description: string}) => void )

Remarks

The ConnectionStatus event is fired when the connection state changes: for example, completion of a firewall or proxy connection or completion of a security handshake.

The ConnectionEvent parameter indicates the type of connection event. Values may include the following:

SSHAuth.Disconnected Event

This event is fired when a connection is closed.

Syntax

sshauth.on('Disconnected', listener: (e: {readonly statusCode: number, readonly description: string}) => void )

Remarks

If the connection is broken normally, StatusCode is 0 and Description is "OK".

If the connection is broken for any other reason, StatusCode has the error code returned by the Transmission Control Protocol (TCP/IP) subsystem. Description contains a description of this code. The value of StatusCode is equal to the value of the TCP/IP error.

Please refer to the Error Codes section for more information.

SSHAuth.Error Event

Information about errors during data delivery.

Syntax

sshauth.on('Error', listener: (e: {readonly errorCode: number, readonly description: string}) => void )

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class .

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

SSHAuth.Log Event

Fires once for each log message.

Syntax

sshauth.on('Log', listener: (e: {readonly logLevel: number, readonly message: string, readonly logType: string}) => void )

Remarks

This event fires once for each log messages generated by the class. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the detail level of the message. Possible values are:

Message is the log message.

LogType is reserved for future use.

SSHAuth.SSHCustomAuth Event

Fired when the class is doing custom authentication.

Syntax

sshauth.on('SSHCustomAuth', listener: (e: {packet: string}) => void )

Remarks

SSHCustomAuth is fired during the user authentication stage of the SSH logon process if SSHAuthMode is set to amCustom. Packet contains the raw last SSH packet sent by the server, in HEX-encoded format.

The client should create a new raw SSH packet to send to the server and set Packet to the HEX-encoded representation of the packet to send.

In all cases, Packet will start with the message type field.

To read the incoming packet call DecodePacket and then use the GetSSHParam and GetSSHParamBytes methods. To create a packet use the SetSSHParam method and then call EncodePacket to obtain a HEX-encoded value and assign this to the Packet parameter.

SSHAuth.SSHKeyboardInteractive Event

Fired when the class receives a request for user input from the server.

Syntax

sshauth.on('SSHKeyboardInteractive', listener: (e: {readonly name: string, readonly instructions: string, readonly prompt: string, response: string, readonly echoResponse: boolean}) => void )

Remarks

SSHKeyboardInteractive is fired during the user authentication stage of the SSH logon process. During authentication, the class will request a list of available authentication methods for the SSHUser. For example, if the SSHHost responds with "keyboard-interactive", the class will fire this event to allow the client application to set the password.

During authentication, the SSH server may respond with a request for the user's authentication information. Name is a server-provided value associated with the authentication method such as "CRYPTOCard Authentication". Instructions will contain specific instructions, also supplied by the server, for how the user should respond.

Along with these values, the server will also send at least one input Prompt to be displayed to and filled out by the user. Response should be set to the user's input, and will be sent back in the user authentication information response. EchoResponse is a server recommendation for whether or not the user's response should be echoed back during input.

Note: the server may send several prompts in a single packet. The class will fire the SSHKeyboardInteractive event once for each prompt.

SSHAuth.SSHServerAuthentication Event

Fired after the server presents its public key to the client.

Syntax

sshauth.on('SSHServerAuthentication', listener: (e: {readonly hostKey: string, readonly hostKeyB: Uint8Array, readonly fingerprint: string, readonly keyAlgorithm: string, readonly certSubject: string, readonly certIssuer: string, readonly status: string, accept: boolean}) => void )

Remarks

This event is where the client can decide whether to continue with the connection process or not. If the public key is known to be a valid key for the SSH server, Accept should be set to True within the event. Otherwise, the server will not be authenticated and the connection will be broken.

Accept will be True only if either HostKey or Fingerprint is identical to the value of SSHAcceptServerHostKey.

Accept may be set to True manually to accept the server host key.

Note that SSH's security inherently relies on client verification of the host key. Ignoring the host key and always setting Accept to true is strongly discouraged, and could cause potentially serious security vulnerabilities in your application. It is recommended that clients maintain a list of known keys for each server and check HostKey against this list each time a connection is attempted.

Host Key contains the full binary text of the key, in the same format used internally by SSH.

Fingerprint holds the SHA-256 hash of HostKey in the hex-encoded form: 0a:1b:2c:3d. To configure the hash algorithm used to calculate this value see SSHFingerprintHashAlgorithm.

KeyAlgorithm identifies the host key algorithm. Supported values are:

• ssh-rsa
• ssh-dss
• rsa-sha2-256
• rsa-sha2-512
• x509v3-sign-rsa
• x509v3-sign-dss
• ecdsa-sha2-nistp256
• ecdsa-sha2-nistp384
• ecdsa-sha2-nistp521

CertSubject is the subject of the certificate. This is only applicable when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

CertIssuer is the issuer of the certificate. This is only applicable when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

Status is reserved for future use.

SSHAuth.SSHStatus Event

Shows the progress of the secure connection.

Syntax

sshauth.on('SSHStatus', listener: (e: {readonly message: string}) => void )

Remarks

The event is fired for informational and logging purposes only. Used to track the progress of the connection.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

public Certificate();

Creates a Certificate instance whose properties can be set. This is useful for use with CERTMGR when generating new certificates.

public Certificate(String certificateFile);

Opens CertificateFile and reads out the contents as an X509 public key.

public Certificate(byte[] certificateData);

Parses CertificateData as an X509 public key.

public Certificate(int certStoreType, String store, String storePassword, String subject);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate(int certStoreType, String store, String storePassword, String subject, String configurationString);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. ConfigurationString is a newline separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CyrptoAPI option. The default value is True (the key is persisted). "Thumbprint" - a MD5, SHA1, or SHA256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to cstUser, cstMachine, cstPublicKeyFile, and cstPFXFile store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate(int certStoreType, String store, String storePassword, byte[] encoded);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

public Certificate(int certStoreType, byte[] storeBlob, String storePassword, String subject);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate(int certStoreType, byte[] storeBlob, String storePassword, String subject, String configurationString);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate(int certStoreType, byte[] storeBlob, String storePassword, byte[] encoded);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a string (binary- or base64-encoded) containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

Firewall Type

This is the firewall the class will connect through.

Remarks

When connecting through a firewall, this type is used to specify different properties of the firewall, such as the firewall and the .

Fields

Constructors

public Firewall();

Config Settings (class ipworksauth.sshauth)

SSHAuth Config Settings

SSHClient Config Settings

*SSH-1.99-*,*SSH-2.0-*,*SSH-2.99-*

TCPClient Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (class ipworksauth.sshauth)

TCPClient Errors

TCP/IP Errors