IdentityHandler.m

/*
 * Copyright 2016-2018 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Except as set forth below, this software is licensed under the Amazon Software License (the "License").  You may not use this software except in compliance with the License.
 * A copy of the License is located at
 *  http://aws.amazon.com/asl/
 * and is also copied below.
 *
 * This software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied. See the License for the specific language governing permissions and limitations under the License.
 *
 * NOTICE REGARDING LOGIN WITH AMAZON
 *
 * This software includes certain Login with Amazon software (the "LWA Software") and requires the LWA Software to function.  The LWA Software is licensed as "Program Materials" under the Program Materials License Agreement of the Amazon Mobile App Distribution program, which is available at https://developer.amazon.com/sdk/pml.html.  See the Program Materials License Agreement for the specific language governing permissions and limitations applicable to the LWA Software.
 * The LWA Software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * FULL TEXT OF AMAZON SOFTWARE LICENSE
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 * Effective Date – April 18, 2008 © 2008 Amazon.com, Inc. or its affiliates. All rights reserved.
 */


#import "IdentityHandler.h"
#import <LoginWithAmazon/LoginWithAmazon.h>
#import "CodeChallengeGenerator.h"
#import "Constants.h"
#import "TokenGenerator.h"


/**
 * Logout success message.
 */
NSString *const LOGOUT_SUCCESS_MESSAGE = @"Logout successful";

/**
 * Logout failure message.
 */
NSString *const LOGOUT_FAILURE_MESSAGE = @"Logout failed: %@";

/**
 * The user canceled login message.
 */
NSString *const CANCEL_MESSAGE = @"Canceled by the user.";

@interface IdentityHandler ()

@property(nonatomic) id <DrsDeviceProtocol> drsHandler;

@end

#pragma mark -

@implementation IdentityHandler {
    CodeChallengeGenerator *codeChallengeGenerator;
}

#pragma mark - Initialization

- (instancetype)initWithDrsHandler:(id <DrsDeviceProtocol>)drsHandler andCodeChallengeGenerator:(CodeChallengeGenerator *) generator {
    self = [super init];
    if (self) {
        _drsHandler = drsHandler;
        codeChallengeGenerator = generator;
    }
    return self;
}

#pragma mark - Public methods

- (void)login {
    AMZNAuthorizationManager *manager = [AMZNAuthorizationManager sharedManager];
    AMZNAuthorizeRequest *request = [self getLoginRequest];
    [manager authorize:request withHandler:[self requestLoginHandler]];
}

- (void)logout {
    AMZNAuthorizationManager *manager = [AMZNAuthorizationManager sharedManager];
    [manager signOut:[self requestLogoutHandler]];
}

- (void)getNewAccessTokenWithRefreshToken:(NSString *)refreshToken {
    TokenGenerator *tokenGenerator = [self getTokenGeneratorWithRefreshToken:refreshToken];
    [tokenGenerator getNewAccessToken];
}

#pragma mark - Private methods

/**
 * Build the login request.
 * @return The AMZNAuthorizeRequest object.
 */
- (AMZNAuthorizeRequest *)getLoginRequest {
    AMZNAuthorizeRequest *request = [[AMZNAuthorizeRequest alloc] init];
    request.interactiveStrategy = AMZNInteractiveStrategyAuto;
    
    NSMutableArray *scopeObjectArray = NSMutableArray.new;
    NSString *requestScopes = LOGIN_SCOPE_CONST;
    NSDictionary *options = [self getOptions];
    
    id<AMZNScope> drsScope = [AMZNScopeFactory scopeWithName:requestScopes data:options];
    [scopeObjectArray addObject:drsScope];
    
    request.scopes = scopeObjectArray;
    request.grantType = AMZNAuthorizationGrantTypeCode;
    codeChallengeGenerator.codeVerifier = [codeChallengeGenerator generateCodeVerifier];
    request.codeChallenge = [codeChallengeGenerator generateCodeChallengeWithMethod:SHA_256];
    request.codeChallengeMethod = SHA_256;
    
    return request;
}

/**
 * Generate the TokenGenerator object.
 * @param clientID NSString client ID.
 * @param authorizationCode NSString authorization code.
 * @param redirectURL NSString redirect URL.
 * @return The TokenGenerator.
 */
- (TokenGenerator *)getTokenGeneratorWithClientID:(NSString *)clientID
                                    lwaAccessCode:(NSString *)authorizationCode
                                   andRedirectURL:(NSString *)redirectURL {
    return [[TokenGenerator alloc] initWithDrsHandler:self.drsHandler
                                             clientID:clientID
                                        lwaAccessCode:authorizationCode
                                          redirectURL:redirectURL];
}

/**
 * @return The NSDictionary containing parameters for login.
 */
- (NSDictionary *)getOptions {
    NSMutableDictionary *options = NSMutableDictionary.new;
    options[DEVICE_SERIAL_CONST] = [self.drsHandler loadDeviceSerialNumber];
    options[DEVICE_MODEL_CONST] = [self.drsHandler loadDeviceModel];
    
    // NOTE: This should not be included in your final application. This is to be used for test purposes only
    // and should be removed when releasing your application to the general public.
    options[IS_TEST_DEVICE_CONST] = [self.drsHandler isTestDevice] ? TRUE_STRING : FALSE_STRING;
    
    // NOTE: This should not be included in your final application. This is to be used for test purposes only
    // and should be removed when releasing your application to the general public.
    options[INCLUDE_NON_LIVE_DEVICES] = [self.drsHandler includeNonLiveDevices] ? TRUE_STRING : FALSE_STRING;
    
    return options;
}

/**
 * @return The TokenGenerator object.
 */
- (TokenGenerator *)getTokenGeneratorWithRefreshToken:(NSString *)refreshToken {
    NSString *clientID = [AIMobileLib getClientId];
    return [[TokenGenerator alloc] initWithDrsHandler:self.drsHandler
                                             clientID:clientID
                                         refreshToken:refreshToken];
}

#pragma mark - Handlers

/**
 * Login request handler.
 */
- (AMZNAuthorizationRequestHandler)requestLoginHandler {
    AMZNAuthorizationRequestHandler requestHandler = ^(AMZNAuthorizeResult * result, BOOL userDidCancel, NSError * error) {
        if (error) {
            NSString *errorMessage = error.userInfo[@"AMZNLWAErrorNonLocalizedDescription"];
            [self.drsHandler handleOutputMessage:errorMessage];
        } else if (userDidCancel) {
            [self.drsHandler handleOutputMessage:CANCEL_MESSAGE];
        } else {
            // Authentication was successful. Obtain the data.
            NSString *authCode = result.authorizationCode;
            NSString *clientId = result.clientId;
            NSString *redirectUri = result.redirectUri;
            TokenGenerator *tokenGenerator = [self getTokenGeneratorWithClientID:clientId
                                                                   lwaAccessCode:authCode
                                                                  andRedirectURL:redirectUri];
            [tokenGenerator requestAccessAndRefreshTokens];
        }
    };
    
    return [requestHandler copy];
}

/**
 * Logout request handler.
 */
- (AMZNSignOutRequestHandler)requestLogoutHandler {
    AMZNSignOutRequestHandler requestHandler = ^(NSError * _Nullable error) {
        if(error) {
            NSString *errorMessage = error.userInfo[@"AMZNLWAErrorNonLocalizedDescription"];
            [self.drsHandler handleOutputMessage:[NSString stringWithFormat:LOGOUT_FAILURE_MESSAGE, errorMessage]];
        } else {
            [self.drsHandler saveAccessToken:nil];
            [self.drsHandler saveRefreshToken:nil];
            [self.drsHandler handleOutputMessage:LOGOUT_SUCCESS_MESSAGE];
        }
    };
    return [requestHandler copy];
}

@end