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/*! @file GTMOAuth2Compatibility.m
@brief GTMAppAuth SDK
@copyright
Copyright 2016 Google Inc.
@copydetails
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://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License 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.
*/
#import "GTMOAuth2KeychainCompatibility.h"
#ifndef GTMAPPAUTH_USER_IMPORTS
#import <AppAuth/AppAuthCore.h>
#else // GTMAPPAUTH_USER_IMPORTS
#import "AppAuthCore.h"
#endif // GTMAPPAUTH_USER_IMPORTS
#import "GTMKeychain.h"
// standard OAuth keys
static NSString *const kOAuth2AccessTokenKey = @"access_token";
static NSString *const kOAuth2RefreshTokenKey = @"refresh_token";
static NSString *const kOAuth2ScopeKey = @"scope";
static NSString *const kOAuth2ErrorKey = @"error";
static NSString *const kOAuth2TokenTypeKey = @"token_type";
static NSString *const kOAuth2ExpiresInKey = @"expires_in";
static NSString *const kOAuth2CodeKey = @"code";
static NSString *const kOAuth2AssertionKey = @"assertion";
static NSString *const kOAuth2RefreshScopeKey = @"refreshScope";
// additional persistent keys
static NSString *const kServiceProviderKey = @"serviceProvider";
static NSString *const kUserIDKey = @"userID";
static NSString *const kUserEmailKey = @"email";
static NSString *const kUserEmailIsVerifiedKey = @"isVerified";
// URI indicating an installed app is signing in. This is described at
//
// https://developers.google.com/identity/protocols/OAuth2InstalledApp#formingtheurl
//
static NSString *const kOOBString = @"urn:ietf:wg:oauth:2.0:oob";
@implementation GTMOAuth2KeychainCompatibility
// This returns a "response string" that can be passed later to
// setKeysForResponseString: to reuse an old access token in a new auth object
+ (NSString *)persistenceResponseStringForAuthorization:
(GTMAppAuthFetcherAuthorization *)authorization {
NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
NSString *refreshToken = authorization.authState.refreshToken;
NSString *accessToken = authorization.authState.lastTokenResponse.accessToken;
// Any nil values will not set a dictionary entry
[dict setValue:refreshToken forKey:kOAuth2RefreshTokenKey];
[dict setValue:accessToken forKey:kOAuth2AccessTokenKey];
[dict setValue:authorization.serviceProvider forKey:kServiceProviderKey];
[dict setValue:authorization.userID forKey:kUserIDKey];
[dict setValue:authorization.userEmail forKey:kUserEmailKey];
[dict setValue:authorization.userEmailIsVerified forKey:kUserEmailIsVerifiedKey];
[dict setValue:authorization.authState.scope forKey:kOAuth2ScopeKey];
NSString *result = [self encodedQueryParametersForDictionary:dict];
return result;
}
+ (GTMAppAuthFetcherAuthorization *)authorizeFromKeychainForName:(NSString *)keychainItemName
tokenURL:(NSURL *)tokenURL
redirectURI:(NSString *)redirectURI
clientID:(NSString *)clientID
clientSecret:(nullable NSString *)clientSecret {
// Loads password string from keychain.
NSString *password = [GTMKeychain passwordFromKeychainForName:keychainItemName];
if (!password) {
return nil;
}
GTMAppAuthFetcherAuthorization *authorization =
[self authorizeFromPersistenceString:password
tokenURL:tokenURL
redirectURI:redirectURI
clientID:clientID
clientSecret:clientSecret];
return authorization;
}
+ (GTMAppAuthFetcherAuthorization *)authorizeFromPersistenceString:(NSString *)persistenceString
tokenURL:(NSURL *)tokenURL
redirectURI:(NSString *)redirectURIString
clientID:(NSString *)clientID
clientSecret:(NSString *)clientSecret {
// Parses persistence data into NSDictionary.
NSDictionary *dict = [self dictionaryWithResponseString:persistenceString];
NSURL *redirectURI = (NSURL *)[NSURL URLWithString:redirectURIString];
// OIDAuthState is based on the request/response history.
// Creates history based on the data from the keychain, and client details passed in.
OIDServiceConfiguration *authConfig =
[[OIDServiceConfiguration alloc] initWithAuthorizationEndpoint:tokenURL tokenEndpoint:tokenURL];
OIDAuthorizationRequest *authRequest =
[[OIDAuthorizationRequest alloc] initWithConfiguration:authConfig
clientId:clientID
clientSecret:clientSecret
scope:dict[kOAuth2ScopeKey]
redirectURL:redirectURI
responseType:OIDResponseTypeCode
state:nil
nonce:nil
codeVerifier:nil
codeChallenge:nil
codeChallengeMethod:nil
additionalParameters:nil];
OIDAuthorizationResponse *authResponse =
[[OIDAuthorizationResponse alloc] initWithRequest:authRequest parameters:dict];
// Exclude scope and refresh token parameters from additionalParameters.
NSMutableDictionary *additionalParameters = [dict mutableCopy];
[additionalParameters removeObjectForKey:kOAuth2ScopeKey];
[additionalParameters removeObjectForKey:kOAuth2RefreshTokenKey];
OIDTokenRequest *tokenRequest =
[[OIDTokenRequest alloc] initWithConfiguration:authConfig
grantType:@"token"
authorizationCode:nil
redirectURL:redirectURI
clientID:clientID
clientSecret:clientSecret
scope:dict[kOAuth2ScopeKey]
refreshToken:dict[kOAuth2RefreshTokenKey]
codeVerifier:nil
additionalParameters:additionalParameters];
OIDTokenResponse *tokenResponse =
[[OIDTokenResponse alloc] initWithRequest:tokenRequest parameters:dict];
OIDAuthState *authState = [[OIDAuthState alloc] initWithAuthorizationResponse:authResponse
tokenResponse:tokenResponse];
// We're not serializing the token expiry date, so the first refresh needs to be forced.
[authState setNeedsTokenRefresh];
GTMAppAuthFetcherAuthorization *authorizer =
[[GTMAppAuthFetcherAuthorization alloc] initWithAuthState:authState
serviceProvider:dict[kServiceProviderKey]
userID:dict[kUserIDKey]
userEmail:dict[kUserEmailKey]
userEmailIsVerified:dict[kUserEmailIsVerifiedKey]];
return authorizer;
}
#if !GTM_OAUTH2_SKIP_GOOGLE_SUPPORT
+ (GTMAppAuthFetcherAuthorization *)authForGoogleFromKeychainForName:(NSString *)keychainItemName
clientID:(NSString *)clientID
clientSecret:(NSString *)clientSecret {
Class signInClass = self;
NSURL *tokenURL = [signInClass googleTokenURL];
NSString *redirectURI = [signInClass nativeClientRedirectURI];
GTMAppAuthFetcherAuthorization *auth;
auth = [self authorizeFromKeychainForName:keychainItemName
tokenURL:tokenURL
redirectURI:redirectURI
clientID:clientID
clientSecret:clientSecret];
return auth;
}
#endif // !GTM_OAUTH2_SKIP_GOOGLE_SUPPORT
/*! @brief Removes stored tokens, such as when the user signs out.
@return YES the tokens were removed successfully (or didn't exist).
*/
+ (BOOL)removeAuthFromKeychainForName:(NSString *)keychainItemName {
return [GTMKeychain removePasswordFromKeychainForName:keychainItemName];
}
/*! @brief Saves the authorization state to the keychain, in a GTMOAuth2 compatible manner.
@return YES when the state was saved successfully.
*/
+ (BOOL)saveAuthToKeychainForName:(NSString *)keychainItemName
authentication:(GTMAppAuthFetcherAuthorization *)auth {
[self removeAuthFromKeychainForName:keychainItemName];
NSString *password = [self persistenceResponseStringForAuthorization:auth];
return [GTMKeychain savePasswordToKeychainForName:keychainItemName password:password];
}
#pragma mark Utility Routines
+ (NSString *)encodedQueryParametersForDictionary:(NSDictionary *)dict {
// Make a string like "cat=fluffy&dog=spot"
NSMutableString *result = [NSMutableString string];
NSArray *sortedKeys =
[[dict allKeys] sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
NSString *joiner = @"";
for (NSString *key in sortedKeys) {
NSString *value = [dict objectForKey:key];
NSString *encodedValue = [self encodedOAuthValueForString:value];
NSString *encodedKey = [self encodedOAuthValueForString:key];
[result appendFormat:@"%@%@=%@", joiner, encodedKey, encodedValue];
joiner = @"&";
}
return result;
}
+ (NSString *)encodedOAuthValueForString:(NSString *)originalString {
// For parameters, we'll explicitly leave spaces unescaped now, and replace
// them with +'s
NSString *const kForceEscape = @"!*'();:@&=+$,/?%#[]";
#if (!TARGET_OS_IPHONE && defined(MAC_OS_X_VERSION_10_9) && MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_9) \
|| (TARGET_OS_IPHONE && defined(__IPHONE_7_0) && __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_7_0)
// Builds targeting iOS 7/OS X 10.9 and higher only.
NSMutableCharacterSet *cs = [[NSCharacterSet URLQueryAllowedCharacterSet] mutableCopy];
[cs removeCharactersInString:kForceEscape];
return [originalString stringByAddingPercentEncodingWithAllowedCharacters:cs];
#else
// Builds targeting iOS 6/OS X 10.8.
CFStringRef escapedStr = NULL;
if (originalString) {
escapedStr = CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)originalString,
NULL,
(CFStringRef)kForceEscape,
kCFStringEncodingUTF8);
}
return (__bridge NSString *)escapedStr;
#endif
}
+ (NSDictionary *)dictionaryWithResponseString:(NSString *)responseStr {
// Build a dictionary from a response string of the form
// "cat=fluffy&dog=spot". Missing or empty values are considered
// empty strings; keys and values are percent-decoded.
if (responseStr == nil) return nil;
NSArray *items = [responseStr componentsSeparatedByString:@"&"];
NSMutableDictionary *responseDict = [NSMutableDictionary dictionaryWithCapacity:items.count];
for (NSString *item in items) {
NSString *key;
NSString *value = @"";
NSRange equalsRange = [item rangeOfString:@"="];
if (equalsRange.location != NSNotFound) {
// The parameter has at least one '='
key = [item substringToIndex:equalsRange.location];
// There are characters after the '='
if (equalsRange.location + 1 < item.length) {
value = [item substringFromIndex:(equalsRange.location + 1)];
}
} else {
// The parameter has no '='
key = item;
}
NSString *plainKey = [self unencodedOAuthParameterForString:key];
NSString *plainValue = [self unencodedOAuthParameterForString:value];
[responseDict setObject:plainValue forKey:plainKey];
}
return responseDict;
}
+ (NSString *)unencodedOAuthParameterForString:(NSString *)str {
#if (!TARGET_OS_IPHONE \
&& defined(MAC_OS_X_VERSION_10_9) \
&& MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_9) \
|| (TARGET_OS_IPHONE \
&& defined(__IPHONE_7_0) \
&& __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_7_0)
// On iOS 7, -stringByRemovingPercentEncoding incorrectly returns nil for an empty string.
if (str != nil && [str length] == 0) return @"";
NSString *plainStr = [str stringByRemovingPercentEncoding];
return plainStr;
#else
NSString *plainStr = [str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
return plainStr;
#endif
}
#if !GTM_OAUTH2_SKIP_GOOGLE_SUPPORT
// Endpoint URLs are available at https://accounts.google.com/.well-known/openid-configuration
+ (NSURL *)googleAuthorizationURL {
NSString *str = @"https://accounts.google.com/o/oauth2/v2/auth";
return (NSURL *)[NSURL URLWithString:str];
}
+ (NSURL *)googleTokenURL {
NSString *str = @"https://www.googleapis.com/oauth2/v4/token";
return (NSURL *)[NSURL URLWithString:str];
}
+ (NSURL *)googleRevocationURL {
NSString *urlStr = @"https://accounts.google.com/o/oauth2/revoke";
return (NSURL *)[NSURL URLWithString:urlStr];
}
+ (NSURL *)googleUserInfoURL {
NSString *urlStr = @"https://www.googleapis.com/oauth2/v3/userinfo";
return (NSURL *)[NSURL URLWithString:urlStr];
}
+ (NSString *)nativeClientRedirectURI {
return kOOBString;
}
#endif // !GTM_OAUTH2_SKIP_GOOGLE_SUPPORT
@end
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