org.apache.hc.client5.http.auth

Interface AuthScheme

All Known Implementing Classes:

BasicScheme, DigestScheme, GGSSchemeBase, KerberosScheme, NTLMScheme, SPNegoScheme

public interface AuthScheme

This interface represents an abstract challenge-response oriented authentication scheme.

Authentication schemes can be either request or connection based. The former are expected to provide an authorization response with each request message while the latter is executed only once and applies to the underlying connection for its entire life span. Care must be taken when re-using connections authorized through a connection based authentication scheme and they may carry a particular security context and be authorized for a particular user identity. It is important that such schemes always provide the user identity they represent through the getPrincipal() method.

Authentication scheme are expected to transition through a series of standard phases or states.

Authentication scheme starts off its life cycle with no context and no specific state.

The processChallenge(AuthChallenge, HttpContext) method is called to process an authentication challenge received either from the target server or a proxy. The authentication scheme transitions to CHALLENGED state and is expected to validate the token passed to it as a parameter and initialize its internal state based on challenge details. Standard authentication schemes are expected to provide a realm attribute in the challenge. getRealm() can be called to obtain an identifier of the realm that requires authorization.

Once the challenge has been fully processed the isResponseReady(HttpHost, CredentialsProvider, HttpContext) method to determine whether the scheme is capable of generating a authorization response based on its current state and it holds user credentials required to do so. If this method returns false the authentication is considered to be in FAILED state and no authorization response. Otherwise the scheme is considered to be in RESPONSE_READY state.

Once the scheme is ready to respond to the challenge the generateAuthResponse( HttpHost, HttpRequest, HttpContext) method to generate a response token, which will be sent to the opposite endpoint in the subsequent request message.

Certain non-standard schemes may involve multiple challenge / response exchanges to fully establish a shared context and complete the authentication process. Authentication schemes are required to return true isChallengeComplete() once the handshake is considered complete.

The authentication scheme is considered successfully completed and in SUCCESS state if the opposite endpoint accepts the request message containing the authorization response and responds with a message indicating no authentication failure . If the opposite endpoint sends status code 401 or 407 in response to a request message containing the terminal authorization response, the scheme is considered unsuccessful and in FAILED state.

Since:

4.0

Method Summary

Modifier and Type	Method and Description
java.lang.String	generateAuthResponse(HttpHost host, HttpRequest request, HttpContext context) Generates an authorization response based on the current state.
java.lang.String	getName() Returns textual designation of the given authentication scheme.
java.security.Principal	getPrincipal() Returns Principal whose credentials are used to generate an authentication response.
java.lang.String	getRealm() Returns authentication realm.
boolean	isChallengeComplete() Authentication process may involve a series of challenge-response exchanges.
boolean	isConnectionBased() Determines if the authentication scheme is expected to provide an authorization response on a per connection basis instead of the standard per request basis
boolean	isResponseReady(HttpHost host, CredentialsProvider credentialsProvider, HttpContext context) Determines whether or not an authorization response can be generated based on the actual authentication state.
void	processChallenge(AuthChallenge authChallenge, HttpContext context) Processes the given auth challenge.

Method Detail

getName

java.lang.String getName()

Returns textual designation of the given authentication scheme.

Returns:

the name of the given authentication scheme

isConnectionBased

boolean isConnectionBased()

Determines if the authentication scheme is expected to provide an authorization response on a per connection basis instead of the standard per request basis

Returns:

true if the scheme is connection based, false if the scheme is request based.

processChallenge

void processChallenge(AuthChallenge authChallenge,
                      HttpContext context)
               throws MalformedChallengeException

Processes the given auth challenge. Some authentication schemes may involve multiple challenge-response exchanges. Such schemes must be able to maintain internal state when dealing with sequential challenges

Parameters:

authChallenge - the auth challenge

context - HTTP context

Throws:

MalformedChallengeException - in case the auth challenge is incomplete, malformed or otherwise invalid.

Since:

5.0

isChallengeComplete

boolean isChallengeComplete()

Authentication process may involve a series of challenge-response exchanges. This method tests if the authorization process has been fully completed (either successfully or unsuccessfully), that is, all the required authorization challenges have been processed in their entirety.

Returns:

true if the authentication process has been completed, false otherwise.

Since:

5.0

getRealm

java.lang.String getRealm()

Returns authentication realm. If the concept of an authentication realm is not applicable to the given authentication scheme, returns null.

Returns:

the authentication realm

isResponseReady

boolean isResponseReady(HttpHost host,
                        CredentialsProvider credentialsProvider,
                        HttpContext context)
                 throws AuthenticationException

Determines whether or not an authorization response can be generated based on the actual authentication state. Generally the outcome of this method will depend upon availability of user credentials necessary to produce an authorization response.

Parameters:

credentialsProvider - The credentials to be used for authentication

context - HTTP context

Returns:

true if an authorization response can be generated and the authentication handshake can proceed, false otherwise.

Throws:

AuthenticationException - if authorization string cannot be generated due to an authentication failure

Since:

5.0

getPrincipal

java.security.Principal getPrincipal()

Returns Principal whose credentials are used to generate an authentication response. Connection based schemes are required to return a user Principal if authorization applies to for the entire life span of connection.

Returns:

user principal

Since:

5.0

See Also:

isConnectionBased()

generateAuthResponse

java.lang.String generateAuthResponse(HttpHost host,
                                      HttpRequest request,
                                      HttpContext context)
                               throws AuthenticationException

Generates an authorization response based on the current state. Some authentication schemes may need to load user credentials required to generate an authorization response from a CredentialsProvider prior to this method call.

Parameters:

request - The request being authenticated

context - HTTP context

Returns:

authorization header

Throws:

AuthenticationException - if authorization string cannot be generated due to an authentication failure

Since:

5.0

See Also:

isResponseReady(HttpHost, CredentialsProvider, HttpContext)