Perform user authentication by username and password, and provide back a session token.
The session token must be used for authenticate the requests to the other web services.
To auhtenticate the requests to the other web services, clients must use WS-Security protocol using the Username Token Security. The UsernameToken must be composed by the username and the session token provided by this service.
Access to this service is not restricted.

The following operations are supported. For a formal definition, please review the Service Description.

• Authenticate
  Performs an username/password authentication.
  

  Input message

  Domain	The domain unique code.
  Username	The user name.
  Password	The user password.

  Output message

  AuthenticationToken	The session token identifier.
  TokenLifeTime	The token lifetime, in seconds.

• CHAPAuthenticate
  Performs a CHAP authentication.
  To be authenticated, the client must provide the correct response. The challengeResponse value must be calculated in this way:

  challengeResponse = MD5(<username> + <password> + <CHAPChallengeString>)

  Where <CHAPChallengeString> is the one-time use key provide by the method GetChallengeString().

  Input message

  Domain	The domain unique code.
  Username	The user name.
  ChallengeString	The challenge string used.
  ChallengeResponse	The client calculated challenge response.

  Output message

  AuthenticationToken	The session token identifier.
  TokenLifeTime	The token lifetime, in seconds.

• GetChallengeString
  Generates the one-time use random key for the CHAP authentication.
  

  Output message

  ChallengeString	The randomly generate challenge string.

• GetTokenInfo
  Returns the information related to the specified token.
  

  Input message

  Token	The session token identifier.

  Output message

  Username	The username related to the token.
  Domain	The domain related to the token.

• Impersonate
  Performs an username/password authentication and impersonate another user in the specified domain.
  The authentication token provided is of the impersonated user.
  Only users with the permission canImpersonateUsers can perform impersonation.

  Input message

  Domain	The domain unique code.
  Username	The user name.
  Password	The user password.
  UsernameToImpersonate	The username of the user to impersonate.

  Output message

  AuthenticationToken	The session token identifier.
  TokenLifeTime	The token lifetime, in seconds.

• KeepSessionAlive
  Refreshes session keeping it alive postponing expire date time.
  

  Input message

  Token	The session token identifier.

• Logoff
  Closes a session and invalidates the session token.
  

  Input message

  Token	The session token identifier.

• ValidateToken
  Verifies if a session token is valid.
  

  Input message

  Token	The session token identifier.

  Output message

  IsValid	True if the token is valid, False otherwise.