iOS - Sign up/in 注册/登录

1、Sign up/in

1.1 用户登录安全原则

• 不能在网络上传输用户隐私数据的明文。
• 不能在本地和服务器上存储用户隐私数据的明文。

1.2 用户登录流程

• 登录成功之后，应该跳转视图控制器到主页。

• 如果用户上次登录成功，启动应用程序时，直接进入主页。

• 当用户主动注销的时候，返回登录页面。

• 在实际开发中，关于网络方面的代码执行，通常会有一个单例统一管理。涉及到网络就涉及到多线程的异步，需要控制最大并发数。

1.3 iOS 中加解密

• 详情见 iOS - Safe iOS 加密安全

2、明文登录

• Objective-C

  • GET 登录

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 用户密码明文
    	NSString *pwd = self.pwdText.text;
    
    	NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:
    	                     @"http://192.168.88.200/login/login.php?username=%@&password=%@", username, pwd]];
    	NSURLRequest *request = [NSURLRequest requestWithURL:url];
    
    	[[[NSURLSession sharedSession] dataTaskWithRequest:request
    	                                 completionHandler:^(NSData * _Nullable data,
    	                                              NSURLResponse * _Nullable response,
    	                                                    NSError * _Nullable error) {
    
        	if (error == nil || data != nil) {
            	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
            	if ([dict[@"userId"] intValue] > 0) {
    				[self saveUserLoginInfo];
            	}
        	}
    	}] resume];
    

  • POST 登录

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 用户密码明文
    	NSString *pwd = self.pwdText.text;
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/login.php"];
    	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    	request.HTTPMethod = @"POST";
    	request.HTTPBody = [[NSString stringWithFormat:@"username=%@&password=%@", username, pwd]
    	                                                  dataUsingEncoding:NSUTF8StringEncoding];
    
    	[[[NSURLSession sharedSession] dataTaskWithRequest:request
    	                                 completionHandler:^(NSData * _Nullable data,
    	                                              NSURLResponse * _Nullable response,
    	                                                    NSError * _Nullable error) {
    
        	if (error == nil || data != nil) {
            	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
            	if ([dict[@"userId"] intValue] > 0) {
    				[self saveUserLoginInfo];
            	}
        	}
    	}] resume];
    

3、Base64 编码登录

• Base64 编码具体实现代码见 GitHub 源码 QExtension

• Objective-C

  • NSString+Base64.m

    	// 对 ASCII 编码的字符串进行 base64 编码
    	- (NSString *)base64Encode {
    
        	NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];
        	return [data base64EncodedStringWithOptions:0];
    	}
    
    	// 对 base64 编码的字符串进行解码
    	- (NSString *)base64Decode {
    
        	NSData *data = [[NSData alloc] initWithBase64EncodedString:self options:0];
        	return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    	}
    

  • POST 登录

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 经 base64 编码的用户密码
    	NSString *pwd = [self.pwdText.text base64Encode];
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/login.php"];
    	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    	request.HTTPMethod = @"POST";
    	request.HTTPBody = [[NSString stringWithFormat:@"username=%@&password=%@", username, pwd]
    	                                                  dataUsingEncoding:NSUTF8StringEncoding];
    
    	[[[NSURLSession sharedSession] dataTaskWithRequest:request
    	                                 completionHandler:^(NSData * _Nullable data,
    	                                              NSURLResponse * _Nullable response,
    	                                                    NSError * _Nullable error) {
    
        	if (error == nil || data != nil) {
            	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
            	if ([dict[@"userId"] intValue] > 0) {
    				[self saveUserLoginInfo];
            	}
        	}
    	}] resume];
    

4、MD5 加密登录

• MD5 加密具体实现代码见 GitHub 源码 QExtension

• Objective-C

  • NSString+Hash.m

    	#import <CommonCrypto/CommonCrypto.h>
    
    	// MD5 散列函数
    	- (NSString *)md5String {
    
        	const char *str = self.UTF8String;
        	uint8_t buffer[CC_MD5_DIGEST_LENGTH];
    
        	CC_MD5(str, (CC_LONG)strlen(str), buffer);
    
        	return [self stringFromBytes:buffer length:CC_MD5_DIGEST_LENGTH];
    	}
    
    	// HMAC 散列函数
    	- (NSString *)hmacMD5StringWithKey:(NSString *)key {
    
        	const char *keyData = key.UTF8String;
        	const char *strData = self.UTF8String;
        	uint8_t buffer[CC_MD5_DIGEST_LENGTH];
    
        	CCHmac(kCCHmacAlgMD5, keyData, strlen(keyData), strData, strlen(strData), buffer);
    
        	return [self stringFromBytes:buffer length:CC_MD5_DIGEST_LENGTH];
    	}
    
    	// 时间戳散列函数
    	- (NSString *)timeMD5StringWithKey:(NSString *)key {
    
        	NSString *hmacKey = key.md5String;
        	NSString *hmacStr = [self hmacMD5StringWithKey:hmacKey];
    
        	NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
        	fmt.dateFormat = @"yyyy-MM-ddHH:mm";
        	NSString *dateStr = [fmt stringFromDate:[NSDate date]];
    
        	hmacStr = [hmacStr stringByAppendingString:dateStr];
    
        	return [hmacStr hmacMD5StringWithKey:hmacKey];
    	}
    
    	// 助手方法
    	- (NSString *)stringFromBytes:(uint8_t *)bytes length:(int)length {
    
        	NSMutableString *strM = [NSMutableString string];
    
        	for (int i = 0; i < length; i++) {
            	[strM appendFormat:@"%02x", bytes[i]];
        	}
    
        	return [strM copy];
    	}
    

  • 直接 md5 加密

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 经 md5 加密的用户密码
    	NSString *pwd = [self.pwdText.text md5String];
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/login.php"];
    

  • md5 + 盐 加密

    	// “盐”，随机添加的字符串，要够长，够复杂
    	static NSString *salt = @"FUYGIUHIJKJHVBNOIUYUGVHJK@#$%^&))(&*^%W%$^%ukjsbcjcgvbk,jmhnrhjbjknklHDYCHGNKJB";
    
    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 经 md5 加 盐 加密的用户密码
    	NSString *pwd = [[self.pwdText.text stringByAppendingString:salt] md5String];
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/login.php"];
    

  • md5 + HMAC 加密

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 经 md5 加 HMAC 加密的用户密码
    	NSString *pwd = [[self.pwdText.text hmacMD5StringWithKey:@"qianqian"] md5String];
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/login.php"];
    

  • md5 + HMAC ＋ 时间戳 加密

    	// 用户名
    	NSString *username = self.usernameText.text;
    
    	// 经 md5 加 HMAC 加 时间戳 加密的用户密码
    	NSString *pwd = [self.pwdText.text timeMD5StringWithKey:@"qianqian"];
    
    	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/loginhmac.php"];
    

  • 登录代码段

    	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    	request.HTTPMethod = @"POST";
    	request.HTTPBody = [[NSString stringWithFormat:@"username=%@&password=%@", username, pwd]
    	                                                  dataUsingEncoding:NSUTF8StringEncoding];
    
    	[[[NSURLSession sharedSession] dataTaskWithRequest:request
    	                                 completionHandler:^(NSData * _Nullable data,
    	                                              NSURLResponse * _Nullable response,
    	                                                    NSError * _Nullable error) {
    
        	if (error == nil || data != nil) {
            	NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
            	if ([dict[@"userId"] intValue] > 0) {
    				[self saveUserLoginInfo];
            	}
        	}
    	}] resume];
    

5、完整登录

• Objective-C

  • AppDelegate.m

    	- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
        	// 注册通知
        	/*
        		AppDelegate 中可以不移除
    		*/
    
        	[[NSNotificationCenter defaultCenter] addObserver:self
        	                                         selector:@selector(loginSuccess)
        	                                             name:HQUserLoginSuccessedNotification
        	                                           object:nil];
        	[[NSNotificationCenter defaultCenter] addObserver:self
        	                                         selector:@selector(logout)
        	                                             name:HQUserLogoutNotification
        	                                           object:nil];
        	[[NSNotificationCenter defaultCenter] addObserver:self
        	                                         selector:@selector(touchIDAuthentication)
        	                                             name:HQTouchIDAuthenticationNotification
        	                                           object:nil];
    
        	// 直接用户登录
    
    		// 如果成功，进入主页
        	[[NetworkTools sharedNetworkTools] userLoginWithTouchID:(BOOL)YES Failed:^{
    
        		// 如果失败，进入登录页面
            	[self logout];
        	}];
    
        	return YES;
    	}
    
    	/// 登录成功
    	- (void)loginSuccess {
    
    		// 显示主页面
        	[self switchStroyboard:@"Home"];
    	}
    
    	/// 用户注销
    	- (void)logout {
    
    		// 显示登录页面
        	[self switchStroyboard:@"Login"];
    	}
    
    	/// 指纹验证
    	- (void)touchIDAuthentication {
        	[self switchStroyboard:@"TouchID"];
    	}
    
    	/// 切换显示页面
    	- (void)switchStroyboard:(NSString *)sbName {
    
        	UIStoryboard *sb = [UIStoryboard storyboardWithName:sbName bundle:nil];
        	self.window.rootViewController = sb.instantiateInitialViewController;
    	}
    

  • HomeViewController.m

    	#import "NetworkTools.h"
    
    	/// 用户注销
    	- (IBAction)logout:(UIButton *)sender {
    
        	[[NetworkTools sharedNetworkTools] userLogout];
    	}
    

  • LoginViewController.m

    	#import "NetworkTools.h"
    
    	@property (weak, nonatomic) IBOutlet UITextField *usernameText;
    	@property (weak, nonatomic) IBOutlet UITextField *pwdText;
    	@property (weak, nonatomic) IBOutlet UISwitch *savePwdSwitch;
    
    	- (void)viewDidLoad {
        	[super viewDidLoad];
    
        	[self loadUserInfo];
    	}
    
    	/// 用户登录
    
    	- (IBAction)postLogin {
    
        	NetworkTools *tools = [NetworkTools sharedNetworkTools];
    
        	tools.username = self.usernameText.text;
        	tools.pwd = self.pwdText.text;
        	tools.isSavePwd = self.savePwdSwitch.isOn;
    
        	[tools userLoginWithTouchID:(BOOL)NO Failed:^{
            	UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示"
            	                                                                         message:@"用户名或密码错误"
            	                                                                  preferredStyle:UIAlertControllerStyleAlert];
            	[alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:nil]];
            	[self presentViewController:alertController animated:YES completion:nil];
        	}];
    	}
    
    	/// 加载用户信息
    
    	- (void)loadUserInfo {
    
        	self.usernameText.text = [NetworkTools sharedNetworkTools].username;
        	self.pwdText.text = [NetworkTools sharedNetworkTools].pwd;
    	}
    
    	/// 键盘回收
    
    	- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
        	[self.view endEditing:YES];
    	}
    

  • TouchIDViewController.m

    	#import "NetworkTools.h"
    
    	- (void)viewDidLoad {
        	[super viewDidLoad];
    
        	[self touchIDAuthentication];
    	}
    
    	- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    
        	[self touchIDAuthentication];
    	}
    
    	/// 指纹验证
    
    	- (void)touchIDAuthentication {
    
        	NetworkTools *tools = [NetworkTools sharedNetworkTools];
    
        	[tools touchIDAuthenticationFailed:^{
            	UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示"
            	                                                                         message:@"指纹验证失败，请重试"
            	                                                                  preferredStyle:UIAlertControllerStyleAlert];
            	[alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:nil]];
            	[self presentViewController:alertController animated:YES completion:nil];
        	}];
    	}
    

  • NetworkTools.h

    	extern NSString * const HQUserLoginSuccessedNotification;
    	extern NSString * const HQUserLogoutNotification;
    	extern NSString * const HQTouchIDAuthenticationNotification;
    
    	@interface NetworkTools : NSObject
    
    	/// 用户名
    	@property (nonatomic, copy) NSString *username;
    
    	/// 用户口令
    	@property (nonatomic, copy) NSString *pwd;
    
    	/// 是否记住密码
    	@property (nonatomic, assign) BOOL isSavePwd;
    
    	/// 单例方法
    	+ (instancetype)sharedNetworkTools;
    
    	/// 用户登录
    	- (void)userLoginWithTouchID:(BOOL)touch Failed:(void (^)())failed;
    
    	/// 用户注销
    	- (void)userLogout;
    
    	/// 用户指纹验证
    	- (void)touchIDAuthenticationFailed:(void (^)())failed;
    
    	@end
    

  • NetworkTools.m

    	#import "NSString+TimePwd.h"
    	#import "SSKeychain.h"
    	#import <LocalAuthentication/LocalAuthentication.h>
    
    	// 定义通知字符串常量
    	NSString * const HQUserLoginSuccessedNotification = @"HMUserLoginSuccessedNotification";
    	NSString * const HQUserLogoutNotification = @"HMUserLogoutNotification";
    	NSString * const HQTouchIDAuthenticationNotification = @"HQTouchIDAuthenticationNotification";
    
    	@implementation NetworkTools
    
    	/**
     			单例创建中，使用 allocWithZone, copyWithZone ... 等等方法，会把所有创建第二个实例可能性全部堵死。
     		在真正开发中，有的时候，会需要额外创建一个副本。
     	*/
    	+ (instancetype)sharedNetworkTools {
    
        	static id instance;
    
        	static dispatch_once_t onceToken;
        	dispatch_once(&onceToken, ^{
            	instance = [[self alloc] init];
        	});
        	return instance;
    	}
    
    	- (instancetype)init {
        	self = [super init];
        	if (self) {
    
        		// 第一次被实例化的时候，加载用户信息
        		[self loadUserLoginInfo];
        	}
        	return self;
    	}
    
    	/// 用户登录
    
    	/**
     		程序启动直接执行，如果登录成功，进入主界面。如果登录失败，进入登录页面。
     	*/
    	- (void)userLoginWithTouchID:(BOOL)touch Failed:(void (^)())failed {
    
        	NSString *username = self.username;
    
        	// md5 + HMAC ＋ 时间戳 加密
        	NSString *pwd = [self.pwd timeMD5StringWithKey:@"qianqian"];
    
        	NSURL *url = [NSURL URLWithString:@"http://192.168.88.200/login/loginhmac.php"];
        	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
        	request.HTTPMethod = @"POST";
        	request.HTTPBody = [[NSString stringWithFormat:@"username=%@&password=%@", username, pwd]
        	                                                  dataUsingEncoding:NSUTF8StringEncoding];
    
    		[[[NSURLSession sharedSession] dataTaskWithRequest:request
        	                                 completionHandler:^(NSData * _Nullable data,
        	                                              NSURLResponse * _Nullable response,
        	                                                    NSError * _Nullable error) {
    
    			if (error == nil || data != nil) {
    
    				NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
    
    				dispatch_async(dispatch_get_main_queue(), ^{
    
    					if ([dict[@"userId"] intValue] > 0) {
    
    						[self saveUserLoginInfo];
    
    						if (touch == NO || [UIDevice currentDevice].systemVersion.floatValue < 8.0) {
    
    							// 发送登录成功通知
    							[[NSNotificationCenter defaultCenter] postNotificationName:HQUserLoginSuccessedNotification object:nil];
    						} else {
    
    							// 发送指纹验证通知
    							[[NSNotificationCenter defaultCenter] postNotificationName:HQTouchIDAuthenticationNotification object:nil];
    						}
    					} else {
    						if (failed != nil) {
    
    							// 执行失败回调
    							failed();
    						}
    					}
    				});
    			}
    		}] resume];
    	}
    
    	/// 用户注销
    
    	- (void)userLogout {
    
        	[SSKeychain deletePasswordForService:[NSBundle mainBundle].bundleIdentifier account:self.username];
    
        	// 发送注销通知
        	[[NSNotificationCenter defaultCenter] postNotificationName:HQUserLogoutNotification object:nil];
    	}
    
    	/// 指纹验证
    
    	- (void)touchIDAuthenticationFailed:(void (^)())failed {
    
    		// 实例化本地身份验证上下文
        	LAContext *context= [[LAContext alloc] init];
    
        	// 判断是否支持指纹识别
        	if (![context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:NULL]) {
    
        		// 发送登录成功通知
            	[[NSNotificationCenter defaultCenter] postNotificationName:HQUserLoginSuccessedNotification object:nil];
    
            	return;
        	}
    
    		[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
        	        localizedReason:@"请验证已有指纹"
        	                  reply:^(BOOL success, NSError * _Nullable error) {
    
    			dispatch_async(dispatch_get_main_queue(), ^{
    
              	// 输入指纹开始验证，异步执行
               	if (success) {
    
               		// 发送登录成功通知
                  	[[NSNotificationCenter defaultCenter] postNotificationName:HQUserLoginSuccessedNotification object:nil];
    				} else {
    					switch (error.code) {
    						case -1:
    							if (failed != nil) {
    
    								// 执行失败回调
    								failed();
    							}
    							break;
    
    						case -2:
    						case -3:
    						case -4:
    						case -5:
    						case -6:
    						case -7:
    							// 发送注销通知
    							[[NSNotificationCenter defaultCenter] postNotificationName:HQUserLogoutNotification object:nil];
    							break;
    
    						default:
    							break;
    					}
    				}
    			});
    		}];
    	}
    
    	/// 用户登录信息存储
    
    	- (void)saveUserLoginInfo {
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    
        	[userDefaults setObject:self.username forKey:@"userNameKey"];
        	[userDefaults setBool:self.isSavePwd forKey:@"isSavePwdKey"];
        	[userDefaults synchronize];
    
        	if (self.isSavePwd) {
    
        		// 将密码保存到钥匙串中
            	[SSKeychain setPassword:self.pwd forService:[NSBundle mainBundle].bundleIdentifier account:self.username];
        	} else {
            	self.pwd = nil;
            	[SSKeychain deletePasswordForService:[NSBundle mainBundle].bundleIdentifier account:self.username];
        	}
    	}
    
    	- (void)loadUserLoginInfo {
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
        	self.username = [userDefaults objectForKey:@"userNameKey"];
        	self.isSavePwd = [userDefaults boolForKey:@"isSavePwdKey"];
    
        	// 将密码从钥匙串中取出
        	self.pwd = [SSKeychain passwordForService:[NSBundle mainBundle].bundleIdentifier account:self.username];
    	}
    
    	@end
    

  • NSString+Hash.m

    	#import <CommonCrypto/CommonCrypto.h>
    
    	/// 时间戳散列函数
    
    	- (NSString *)timeMD5StringWithKey:(NSString *)key {
        	NSString *hmacKey = key.md5String;
        	NSString *hmacStr = [self hmacMD5StringWithKey:hmacKey];
    
        	NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
        	fmt.dateFormat = @"yyyy-MM-ddHH:mm";
        	NSString *dateStr = [fmt stringFromDate:[NSDate date]];
    
        	hmacStr = [hmacStr stringByAppendingString:dateStr];
    
        	return [hmacStr hmacMD5StringWithKey:hmacKey];
    	}
    
    	/// HMAC 散列函数
    
    	- (NSString *)hmacMD5StringWithKey:(NSString *)key {
        	const char *keyData = key.UTF8String;
        	const char *strData = self.UTF8String;
        	uint8_t buffer[CC_MD5_DIGEST_LENGTH];
    
        	CCHmac(kCCHmacAlgMD5, keyData, strlen(keyData), strData, strlen(strData), buffer);
    
        	return [self stringFromBytes:buffer length:CC_MD5_DIGEST_LENGTH];
    	}
    
    	/// 散列函数
    
    	- (NSString *)md5String {
        	const char *str = self.UTF8String;
        	uint8_t buffer[CC_MD5_DIGEST_LENGTH];
    
        	CC_MD5(str, (CC_LONG)strlen(str), buffer);
    
        	return [self stringFromBytes:buffer length:CC_MD5_DIGEST_LENGTH];
    	}
    
    	/// 助手方法
    
    	- (NSString *)stringFromBytes:(uint8_t *)bytes length:(int)length {
        	NSMutableString *strM = [NSMutableString string];
    
        	for (int i = 0; i < length; i++) {
            	[strM appendFormat:@"%02x", bytes[i]];
        	}
    
        	return [strM copy];
    	}
    

6、保存用户信息

• Objective-C

  • 明文保存

    	// 保存用户信息
    
    		NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];                 
    
    		[userDefaults setObject:self.usernameText.text forKey:@"userNameKey"];
    		[userDefaults setObject:self.pwdText.text forKey:@"userPwdKey"];
    
    		[userDefaults synchronize];
    
    	// 加载用户信息
    
    		NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    
    		self.usernameText.text = [userDefaults objectForKey:@"userNameKey"];
    		self.pwdText.text = [userDefaults objectForKey:@"userPwdKey"];
    

  • base64 编码保存

    	// NSString+Base64.m
    
    		// 对 ASCII 编码的字符串进行 base64 编码
    		- (NSString *)base64Encode {
    
        		NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];
        		return [data base64EncodedStringWithOptions:0];
    		}
    
    		// 对 base64 编码的字符串进行解码
    		- (NSString *)base64Decode {
    
        		NSData *data = [[NSData alloc] initWithBase64EncodedString:self options:0];
        		return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    		}
    
    	// 保存用户信息
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    
        	[userDefaults setObject:self.usernameText.text forKey:@"userNameKey"];
    
        	// 对密码进行 base64 编码
        	[userDefaults setObject:[self.pwdText.text base64Encode] forKey:@"userPwdKey"];
    
        	[userDefaults synchronize];
    
    	// 加载用户信息
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    
        	self.usernameText.text = [userDefaults objectForKey:@"userNameKey"];
    
        	// 对密码进行 base64 解码
        	self.pwdText.text = [[userDefaults objectForKey:@"userPwdKey"] base64Decode];
    

  • 钥匙串保存

    	// 添加第三方库文件
    	SSKeychain
    
    	// 包含头文件
    	#import "SSKeychain.h"
    
    	// 保存用户信息
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
        	[userDefaults setObject:self.usernameText.text forKey:@"userNameKey"];
        	[userDefaults synchronize];
    
        	// 将密码保存到钥匙串中
        	[SSKeychain setPassword:self.pwdText.text
      	                 forService:[NSBundle mainBundle].bundleIdentifier
      	                    account:self.usernameText.text];
    
    	// 加载用户信息
    
        	NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
        	self.usernameText.text = [userDefaults objectForKey:@"userNameKey"];
    
        	// 将密码从钥匙串中取出
        	self.pwdText.text = [SSKeychain passwordForService:[NSBundle mainBundle].bundleIdentifier
        	                                           account:self.usernameText.text];
    

7、SSKeychain/SAMKeychain 的使用

• GitHub 网址：https://github.com/soffes/SAMKeychain

• SSKeychain/SAMKeychain 使用 ARC

• Objective-C

  	// 添加第三方库文件
  	SSKeychain
  
  	// 包含头文件
  	#import "SSKeychain.h"
  
  	// 获取所有的账户信息
  
  		// 只有同一个开发者开发的应用程序，才能够互相看到账号
      	NSArray *allAccounts = [SSKeychain allAccounts];
  
  	// 获取指定服务名的账户信息
  
      	NSArray *accounts = [SSKeychain accountsForService:[NSBundle mainBundle].bundleIdentifier];
  
  	// 将密码保存到钥匙串中
  	/*
      	+ (BOOL)setPassword:(NSString *)password forService:(NSString *)serviceName account:(NSString *)account;
  
      	参数：
      		password   ：密码明文
      		serviceName：服务名，可以随便写，建议使用 bundleId，应用程序的唯一标示，每一个上架的应用程序，都有一个唯一的 bundleId
      		account    ：账户名（用户名）
   	*/
  
      	// 保存 NSString 格式的密码
  		[SSKeychain setPassword:self.pwdText.text
  		             forService:[NSBundle mainBundle].bundleIdentifier
  		                account:self.usernameText.text];    
  
      	NSData *pwdData = [self.pwdText.text dataUsingEncoding:NSUTF8StringEncoding];
  
      	// 保存 NSData 格式的密码
      	[SSKeychain setPasswordData:pwdData
      	                 forService:[NSBundle mainBundle].bundleIdentifier
      	                    account:self.usernameText.text];          
  
  	// 将密码从钥匙串中取出
  
  		// 获取 NSString 格式的密码
      	self.pwdText.text = [SSKeychain passwordForService:[NSBundle mainBundle].bundleIdentifier
      	                                           account:self.usernameText.text];
  
  		// 获取 NSData 格式的密码
      	NSData *pwdData1 = [SSKeychain passwordDataForService:[NSBundle mainBundle].bundleIdentifier
      	                                              account:self.usernameText.text];   
  
  	// 将密码从钥匙串中删除
  
      	[SSKeychain deletePasswordForService:[NSBundle mainBundle].bundleIdentifier
      	                             account:self.usernameText.text];