在 iOS 中将电子邮件/密码保存到钥匙串

Saving Email/Password to Keychain in iOS

提问by Jason

I'm very new to iOS development so forgive me if this is a newbie question. I have a simple authentication mechanism for my app that takes a user's email address and password. I also have a switch that says 'Remember me'. If the user toggles that switch on, I'd like to preserve their email/password so those fields can be auto-populated in the future.

我对 iOS 开发很陌生，所以如果这是一个新手问题，请原谅我。我的应用程序有一个简单的身份验证机制，它采用用户的电子邮件地址和密码。我还有一个开关，上面写着“记住我”。如果用户打开该开关，我想保留他们的电子邮件/密码，以便将来可以自动填充这些字段。

I've gotten this to work with saving to a plist file but I know that's not the best idea since the password is unencrypted. I found some sample code for saving to the keychain, but to be honest, I'm a little lost. For the function below, I'm not sure how to call it and how to modify it to save the email address as well.

我已经将其保存到 plist 文件中，但我知道这不是最好的主意，因为密码未加密。我找到了一些保存到钥匙串的示例代码，但说实话，我有点迷茫。对于下面的函数，我不确定如何调用它以及如何修改它以保存电子邮件地址。

I'm guessing to call it would be: saveString(@"passwordgoeshere");

我猜想称之为： saveString(@"passwordgoeshere");

Thank you for any help!!!

感谢您的任何帮助！！！

+ (void)saveString:(NSString *)inputString forKey:(NSString *)account {

    NSAssert(account != nil, @"Invalid account");
    NSAssert(inputString != nil, @"Invalid string");

    NSMutableDictionary *query = [NSMutableDictionary dictionary];

    [query setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass];
    [query setObject:account forKey:(id)kSecAttrAccount];
    [query setObject:(id)kSecAttrAccessibleWhenUnlocked forKey:(id)kSecAttrAccessible];

    OSStatus error = SecItemCopyMatching((CFDictionaryRef)query, NULL);
    if (error == errSecSuccess) {
        // do update
        NSDictionary *attributesToUpdate = [NSDictionary dictionaryWithObject:[inputString dataUsingEncoding:NSUTF8StringEncoding] 
                                                                      forKey:(id)kSecValueData];

        error = SecItemUpdate((CFDictionaryRef)query, (CFDictionaryRef)attributesToUpdate);
        NSAssert1(error == errSecSuccess, @"SecItemUpdate failed: %d", error);
    } else if (error == errSecItemNotFound) {
        // do add
        [query setObject:[inputString dataUsingEncoding:NSUTF8StringEncoding] forKey:(id)kSecValueData];

        error = SecItemAdd((CFDictionaryRef)query, NULL);
        NSAssert1(error == errSecSuccess, @"SecItemAdd failed: %d", error);
    } else {
        NSAssert1(NO, @"SecItemCopyMatching failed: %d", error);
    }
}

回答by Anomie

I've written a simple wrapper that allows saving of any NSCoding-compliant object to the keychain. You could, for example, store your email and password in an NSDictionary and store the NSDictionary to the keychain using this class.

我编写了一个简单的包装器，允许将任何符合 NSCoding 的对象保存到钥匙串。例如，您可以将您的电子邮件和密码存储在 NSDictionary 中，并使用此类将 NSDictionary 存储到钥匙串中。

SimpleKeychain.h

简单钥匙串.h

#import <Foundation/Foundation.h>

@class SimpleKeychainUserPass;

@interface SimpleKeychain : NSObject

+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)delete:(NSString *)service;

@end

SimpleKeychain.m

SimpleKeychain.m

#import "SimpleKeychain.h"

@implementation SimpleKeychain

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (id)kSecClassGenericPassword, (id)kSecClass,
            service, (id)kSecAttrService,
            service, (id)kSecAttrAccount,
            (id)kSecAttrAccessibleAfterFirstUnlock, (id)kSecAttrAccessible,
            nil];
}

+ (void)save:(NSString *)service data:(id)data {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((CFDictionaryRef)keychainQuery);
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(id)kSecValueData];
    SecItemAdd((CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
    [keychainQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(NSData *)keyData];
        }
        @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        }
        @finally {}
    }
    if (keyData) CFRelease(keyData);
    return ret;
}

+ (void)delete:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((CFDictionaryRef)keychainQuery);
}

@end

回答by Vlad Spreys

ARC ready code:

ARC 就绪代码：

KeychainUserPass.h

钥匙串用户密码.h

#import <Foundation/Foundation.h>

@interface KeychainUserPass : NSObject

+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)delete:(NSString *)service;

@end

KeychainUserPass.m

KeychainUserPass.m

#import "KeychainUserPass.h"

@implementation KeychainUserPass

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (__bridge id)kSecClassGenericPassword, (__bridge id)kSecClass,
            service, (__bridge id)kSecAttrService,
            service, (__bridge id)kSecAttrAccount,
            (__bridge id)kSecAttrAccessibleAfterFirstUnlock, (__bridge id)kSecAttrAccessible,
            nil];
}

+ (void)save:(NSString *)service data:(id)data {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge id)kSecValueData];
    SecItemAdd((__bridge CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge id)kSecReturnData];
    [keychainQuery setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((__bridge CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
        }
        @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        }
        @finally {}
    }
    if (keyData) CFRelease(keyData);
    return ret;
}

+ (void)delete:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
}

@end