/*
* Copyright 2011-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://aws.amazon.com/apache2.0
*
* This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
* OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and
* limitations under the License.
*/
package com.amazonaws.auth;
import com.amazonaws.ClientConfiguration;
import com.amazonaws.services.securitytoken.AWSSecurityTokenService;
import com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient;
import com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest;
import com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityResult;
import com.amazonaws.services.securitytoken.model.Credentials;
import java.util.Date;
/**
* AWSCredentialsProvider implementation that uses the AWS Security Token
* Service to create temporary, short-lived sessions to use for authentication.
*/
public class WebIdentityFederationSessionCredentialsProvider implements AWSCredentialsProvider {
/** Default duration for started sessions */
public static final int DEFAULT_DURATION_SECONDS = 3600;
/** Default threshold for refreshing session credentials */
public static final int DEFAULT_THRESHOLD_SECONDS = 500;
/** The client for starting STS sessions */
private final AWSSecurityTokenService securityTokenService;
/** The current session credentials */
private AWSSessionCredentials sessionCredentials;
/** The expiration time for the current session credentials */
private Date sessionCredentialsExpiration;
private final String wifToken;
private final String wifProvider;
private final String roleArn;
private int sessionDuration;
private int refreshThreshold;
private String subjectFromWIF;
/**
* Constructs a new WebIdentityFederationSessionCredentialsProvider, which
* will use the specified 3rd-party web identity provider to make a request
* to the AWS Security Token Service (STS) to request short lived session
* credentials, which will then be returned by this class's
* {@link #getCredentials()} method.
*
* @param wifToken The OAuth/OpenID token from the the Identity Provider
* @param wifProvider The name of the Identity Provider (null for OpenID
* providers)
* @param roleArn The ARN of the IAM Role that will be assumed
*/
public WebIdentityFederationSessionCredentialsProvider(String wifToken, String wifProvider,
String roleArn) {
this(wifToken, wifProvider, roleArn, new ClientConfiguration());
}
/**
* Constructs a new WebIdentityFederationSessionCredentialsProvider, which
* will use the specified 3rd-party web identity provider to make a request
* to the AWS Security Token Service (STS) to request short lived session
* credentials, which will then be returned by this class's
* {@link #getCredentials()} method.
*
* @param wifToken The OAuth/OpenID token from the the Identity Provider
* @param wifProvider The name of the Identity Provider (null for OpenID
* providers)
* @param roleArn The ARN of the IAM Role that will be assumed
* @param clientConfiguation Configuration to apply to STS client created
*/
public WebIdentityFederationSessionCredentialsProvider(String wifToken, String wifProvider,
String roleArn, ClientConfiguration clientConfiguration) {
this(wifToken, wifProvider, roleArn, new AWSSecurityTokenServiceClient(
new AnonymousAWSCredentials(), clientConfiguration));
}
/**
* Constructs a new WebIdentityFederationSessionCredentialsProvider, which
* will use the specified 3rd-party web identity provider to make a request
* to the AWS Security Token Service (STS) using the provided client to
* request short lived session credentials, which will then be returned by
* this class's {@link #getCredentials()} method.
*
* @param wifToken The OAuth/OpenID token from the the Identity Provider
* @param wifProvider The name of the Identity Provider (null for OpenID
* providers)
* @param roleArn The ARN of the IAM Role that will be assumed
* @param stsClient Preconfigured STS client to make requests with
*/
public WebIdentityFederationSessionCredentialsProvider(String wifToken, String wifProvider,
String roleArn, AWSSecurityTokenService stsClient) {
this.securityTokenService = stsClient;
this.wifProvider = wifProvider;
this.wifToken = wifToken;
this.roleArn = roleArn;
this.sessionDuration = DEFAULT_DURATION_SECONDS;
this.refreshThreshold = DEFAULT_THRESHOLD_SECONDS;
}
@Override
public AWSCredentials getCredentials() {
if (needsNewSession())
startSession();
return sessionCredentials;
}
@Override
public void refresh() {
startSession();
}
/**
* Set the duration of the session credentials created by this client in
* seconds. Values must be supported by AssumeRoleWithWebIdentityRequest.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @param sessionDuration The new duration for session credentials created by
* this provider
*/
public void setSessionDuration(int sessionDuration) {
this.sessionDuration = sessionDuration;
}
/**
* Set the duration of the session credentials created by this client in
* seconds. Values must be supported by AssumeRoleWithWebIdentityRequest.
* Returns refreence to object so methods can be chained together.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @param sessionDuration The new duration for session credentials created by
* this provider
* @return A reference to this updated object so that method calls can be
* chained together.
*/
public WebIdentityFederationSessionCredentialsProvider withSessionDuration(int sessionDuration) {
this.setSessionDuration(sessionDuration);
return this;
}
/**
* Get the duration of the session credentials created by this client in
* seconds. Values must be supported by AssumeRoleWithWebIdentityRequest.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @return The duration for session credentials created by this provider
*/
public int getSessionDuration() {
return this.sessionDuration;
}
/**
* Set the refresh threshold for the session credentials created by this
* client in seconds. This value will be used internally to determine if new
* credentials should be fetched from STS.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @param refreshThreshold The new refresh threshold for session credentials
* created by this provider
*/
public void setRefreshThreshold(int refreshThreshold) {
this.refreshThreshold = refreshThreshold;
}
/**
* Set the refresh threshold for the session credentials created by this
* client in seconds. This value will be used internally to determine if new
* credentials should be fetched from STS. Returns a refrence to the object
* so methods can be chained.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @param refreshThreshold The new refresh threshold for session credentials
* created by this provider
* @return A reference to this updated object so that method calls can be
* chained together.
*/
public WebIdentityFederationSessionCredentialsProvider withRefreshThreshold(int refreshThreshold) {
this.setRefreshThreshold(refreshThreshold);
return this;
}
/**
* Get the refresh threshold for the session credentials created by this
* client in seconds. This value will be used internally to determine if new
* credentials should be fetched from STS.
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityRequest
* @return The refresh threshold for session credentials created by this
* provider
*/
public int getRefreshThreshold() {
return this.refreshThreshold;
}
/**
* Get the identifier returned from the Identity Provider for the
* authenticated user. This value is returned as part of the
* AssumeRoleWithIdentityResult
*
* @see com.amazonaws.services.securitytoken.model.AssumeRoleWithWebIdentityResult
* @return The identifier returned from Identity Provider
*/
public String getSubjectFromWIF() {
return this.subjectFromWIF;
}
/**
* Starts a new session by sending a request to the AWS Security Token
* Service (STS) with the long lived AWS credentials. This class then vends
* the short lived session credentials sent back from STS.
*/
private void startSession() {
AssumeRoleWithWebIdentityResult sessionTokenResult = securityTokenService
.assumeRoleWithWebIdentity(new AssumeRoleWithWebIdentityRequest()
.withWebIdentityToken(wifToken)
.withProviderId(wifProvider)
.withRoleArn(roleArn)
.withRoleSessionName("ProviderSession")
.withDurationSeconds(this.sessionDuration));
Credentials stsCredentials = sessionTokenResult.getCredentials();
subjectFromWIF = sessionTokenResult.getSubjectFromWebIdentityToken();
sessionCredentials = new BasicSessionCredentials(
stsCredentials.getAccessKeyId(),
stsCredentials.getSecretAccessKey(),
stsCredentials.getSessionToken());
sessionCredentialsExpiration = stsCredentials.getExpiration();
}
/**
* Returns true if a new STS session needs to be started. A new STS session
* is needed when no session has been started yet, or if the last session is
* within the configured refresh threshold.
*
* @return True if a new STS session needs to be started.
*/
private boolean needsNewSession() {
if (sessionCredentials == null)
return true;
long timeRemaining = sessionCredentialsExpiration.getTime() - System.currentTimeMillis();
return timeRemaining < (this.refreshThreshold * 1000);
}
}