add migration logic

Author: camden-king

GoogleSignIn/Sources/GIDAuthStateMigration.h

@@ -27,8 +27,7 @@ NS_ASSUME_NONNULL_BEGIN
 /// Creates an instance of this migration type with the keychain storage wrapper it will use.
 - (instancetype)initWithKeychainStore:(GTMKeychainStore *)keychainStore NS_DESIGNATED_INITIALIZER;
 
-/// Perform a one-time migration for auth state saved by GPPSignIn 1.x or GIDSignIn 1.0 - 4.x to the
-/// GTMAppAuth storage introduced in GIDSignIn 5.0.
+/// Perform necessary migrations from legacy auth state storage to most recent GTMAppAuth version.
 - (void)migrateIfNeededWithTokenURL:(NSURL *)tokenURL
                        callbackPath:(NSString *)callbackPath
                        keychainName:(NSString *)keychainName

GoogleSignIn/Sources/GIDAuthStateMigration.m

@@ -72,10 +72,20 @@ - (void)migrateIfNeededWithTokenURL:(NSURL *)tokenURL
   // If this is not a fresh install, attempt to migrate state.  If this is a fresh install, take no
   // action and go on to mark the migration check as having been performed.
   if (!isFreshInstall) {
-    // Attempt migration
-    GTMAuthSession *authSession =
-        [self extractAuthSessionWithTokenURL:tokenURL callbackPath:callbackPath];
-
+    GTMAuthSession *authSession = nil;
+#if TARGET_OS_MAC || TARGET_OS_MACCATALYST
+    // Migrate from the fileBasedKeychain to dataProtectedKeychain with GTMAppAuth 5.0.
+    GTMKeychainAttribute *fileBasedKeychain = [GTMKeychainAttribute useFileBasedKeychain];
+    NSSet *attributes = [NSSet setWithArray:@[fileBasedKeychain]];
+    GTMKeychainStore *keychainStoreLegacy =
+        [[GTMKeychainStore alloc] initWithItemName:self.keychainStore.itemName
+        keychainAttributes:attributes];
+    authSession = [keychainStoreLegacy retrieveAuthSessionWithError:nil];
+#else // TARGET_OS_IOS && !TARGET_OS_MACCATALYST
+    // Migrate from GPPSignIn 1.x or GIDSignIn 1.0 - 4.x to the GTMAppAuth storage introduced in
+    // GIDSignIn 5.0.
+    authSession = [self extractAuthSessionWithTokenURL:tokenURL callbackPath:callbackPath];
+#endif
     // If migration was successful, save our migrated state to the keychain.
     if (authSession) {
       NSError *err;
@@ -84,6 +94,9 @@ - (void)migrateIfNeededWithTokenURL:(NSURL *)tokenURL
       if (err) {
         return;
       };
+#if TARGET_OS_MAC || TARGET_OS_MACCATALYST
+      [keychainStoreLegacy removeAuthSessionWithError:nil];
+#endif
     }
   }
 

GoogleSignIn/Sources/GIDSignIn.m

@@ -27,11 +27,11 @@
 #import "GoogleSignIn/Sources/GIDCallbackQueue.h"
 #import "GoogleSignIn/Sources/GIDScopes.h"
 #import "GoogleSignIn/Sources/GIDSignInCallbackSchemes.h"
+#import "GoogleSignIn/Sources/GIDAuthStateMigration.h"
 #if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
 #import <AppCheckCore/GACAppCheckToken.h>
 #import "GoogleSignIn/Sources/GIDAppCheck/Implementations/GIDAppCheck.h"
 #import "GoogleSignIn/Sources/GIDAppCheck/UI/GIDActivityIndicatorViewController.h"
-#import "GoogleSignIn/Sources/GIDAuthStateMigration.h"
 #import "GoogleSignIn/Sources/GIDEMMErrorHandler.h"
 #import "GoogleSignIn/Sources/GIDTimedLoader/GIDTimedLoader.h"
 #endif // TARGET_OS_IOS && !TARGET_OS_MACCATALYST
@@ -560,15 +560,13 @@ - (instancetype)initWithKeychainStore:(GTMKeychainStore *)keychainStore {
                              initWithAuthorizationEndpoint:[NSURL URLWithString:authorizationEnpointURL]
                              tokenEndpoint:[NSURL URLWithString:tokenEndpointURL]];
     _keychainStore = keychainStore;
-#if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
     // Perform migration of auth state from old (before 5.0) versions of the SDK if needed.
     GIDAuthStateMigration *migration =
         [[GIDAuthStateMigration alloc] initWithKeychainStore:_keychainStore];
     [migration migrateIfNeededWithTokenURL:_appAuthConfiguration.tokenEndpoint
                               callbackPath:kBrowserCallbackPath
                               keychainName:kGTMAppAuthKeychainName
                             isFreshInstall:isFreshInstall];
-#endif // TARGET_OS_IOS && !TARGET_OS_MACCATALYST
   }
   return self;
 }