对称加密工具类

源文件

头文件

包含终端命令，可以验证加密结果是否正确

#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonCrypto.h>

/**
 *  终端测试指令
 * 其中 -k 是key的ascii码
 * 可以利用
 *  DES(ECB)加密
 *  $ echo -n hello | openssl enc -des-ecb -K 616263 -nosalt | base64
 *
  * DES(CBC)加密
 *  $ echo -n hello | openssl enc -des-cbc -iv 0102030405060708 -K 616263 -nosalt | base64
 *
 *  AES(ECB)加密
 *  $ echo -n hello | openssl enc -aes-128-ecb -K 616263 -nosalt | base64
 *
 *  AES(CBC)加密
 *  $ echo -n hello | openssl enc -aes-128-cbc -iv 0102030405060708 -K 616263 -nosalt | base64
 *
 *  DES(ECB)解密
 *  $ echo -n HQr0Oij2kbo= | base64 -D | openssl enc -des-ecb -K 616263 -nosalt -d
 *
 *  DES(CBC)解密
 *  $ echo -n alvrvb3Gz88= | base64 -D | openssl enc -des-cbc -iv 0102030405060708 -K 616263 -nosalt -d
 *
 *  AES(ECB)解密
 *  $ echo -n d1QG4T2tivoi0Kiu3NEmZQ== | base64 -D | openssl enc -aes-128-ecb -K 616263 -nosalt -d
 *
 *  AES(CBC)解密
 *  $ echo -n u3W/N816uzFpcg6pZ+kbdg== | base64 -D | openssl enc -aes-128-cbc -iv 0102030405060708 -K 616263 -nosalt -d
 *
 *  提示：
 *      1> 加密过程是先加密，再base64编码
 *      2> 解密过程是先base64解码，再解密
 */
@interface EncryptionTools : NSObject

+ (instancetype)sharedEncryptionTools;

/**
 @constant   kCCAlgorithmAES     高级加密标准，128位(默认)
 @constant   kCCAlgorithmDES     数据加密标准
 */
@property (nonatomic, assign) uint32_t algorithm;

/**
 *  加密字符串并返回base64编码字符串
 *
 *  @param string    要加密的字符串
 *  @param keyString 加密密钥
 *  @param iv        初始化向量(8个字节)
 *
 *  @return 返回加密后的base64编码字符串
 */
- (NSString *)encryptString:(NSString *)string keyString:(NSString *)keyString iv:(NSData *)iv;

/**
 *  解密字符串
 *
 *  @param string    加密并base64编码后的字符串
 *  @param keyString 解密密钥
 *  @param iv        初始化向量(8个字节)
 *
 *  @return 返回解密后的字符串
 */
- (NSString *)decryptString:(NSString *)string keyString:(NSString *)keyString iv:(NSData *)iv;

@end

体文件

#import "EncryptionTools.h"

@interface EncryptionTools()
@property (nonatomic, assign) int keySize;
@property (nonatomic, assign) int blockSize;
@end

@implementation EncryptionTools

+ (instancetype)sharedEncryptionTools {
    static EncryptionTools *instance;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[self alloc] init];
        instance.algorithm = kCCAlgorithmAES;
    });
    
    return instance;
}

- (void)setAlgorithm:(uint32_t)algorithm {
    _algorithm = algorithm;
    switch (algorithm) {
        case kCCAlgorithmAES:
            self.keySize = kCCKeySizeAES128;
            self.blockSize = kCCBlockSizeAES128;
            break;
        case kCCAlgorithmDES:
            self.keySize = kCCKeySizeDES;
            self.blockSize = kCCBlockSizeDES;
            break;
        default:
            break;
    }
}

- (NSString *)encryptString:(NSString *)string keyString:(NSString *)keyString iv:(NSData *)iv {
    
    // 设置秘钥
    NSData *keyData = [keyString dataUsingEncoding:NSUTF8StringEncoding];
    uint8_t cKey[self.keySize];
    bzero(cKey, sizeof(cKey));
    [keyData getBytes:cKey length:self.keySize];
    
    // 设置iv
    uint8_t cIv[self.blockSize];
    bzero(cIv, self.blockSize);
    int option = 0;
    if (iv) {
        [iv getBytes:cIv length:self.blockSize];
        option = kCCOptionPKCS7Padding;
    } else {
        option = kCCOptionPKCS7Padding | kCCOptionECBMode;
    }
    
    // 设置输出缓冲区
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    size_t bufferSize = [data length] + self.blockSize;
    void *buffer = malloc(bufferSize);
    
    // 开始加密
    size_t encryptedSize = 0;
    /*
     CCCrypt:对称加密的核心函数（加密、解密）
     参数:
     1:加密kCCEncrypt、解密kCCDecrypt
     2:加密算法 AES/DES 
     kCCAlgorithmAES     高级加密标准
     kCCAlgorithmDES     数据加密标准
     
     3.加密选项：ECB/CBC
     4.加密的密钥 
     5.密钥长度
     6.iv 初始化向量
     7.加密的长度
     8.加密的数据长度
     9.密文的内存地址
     10.密文缓冲区大小
     11.加密结果大小
     */
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          self.algorithm,
                                          option,
                                          cKey,
                                          self.keySize,
                                          cIv,
                                          [data bytes],
                                          [data length],
                                          buffer,
                                          bufferSize,
                                          &encryptedSize);
    
    NSData *result = nil;
    if (cryptStatus == kCCSuccess) {
        result = [NSData dataWithBytesNoCopy:buffer length:encryptedSize];
    } else {    
        free(buffer);
        NSLog(@"[错误] 加密失败|状态编码: %d", cryptStatus);
    }
    
    return [result base64EncodedStringWithOptions:0];
}

- (NSString *)decryptString:(NSString *)string keyString:(NSString *)keyString iv:(NSData *)iv {
    
    // 设置秘钥
    NSData *keyData = [keyString dataUsingEncoding:NSUTF8StringEncoding];
    uint8_t cKey[self.keySize];
    bzero(cKey, sizeof(cKey));
    [keyData getBytes:cKey length:self.keySize];
    
    // 设置iv
    uint8_t cIv[self.blockSize];
    bzero(cIv, self.blockSize);
    int option = 0;
    if (iv) {
        [iv getBytes:cIv length:self.blockSize];
        option = kCCOptionPKCS7Padding;
    } else {
        option = kCCOptionPKCS7Padding | kCCOptionECBMode;
    }
    
    // 设置输出缓冲区
    NSData *data = [[NSData alloc] initWithBase64EncodedString:string options:0];
    size_t bufferSize = [data length] + self.blockSize;
    void *buffer = malloc(bufferSize);
    
    // 开始解密
    size_t decryptedSize = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          self.algorithm,
                                          option,
                                          cKey,
                                          self.keySize,
                                          cIv,
                                          [data bytes],
                                          [data length],
                                          buffer,
                                          bufferSize,
                                          &decryptedSize);
    
    NSData *result = nil;
    if (cryptStatus == kCCSuccess) {
        result = [NSData dataWithBytesNoCopy:buffer length:decryptedSize];
    } else {
        free(buffer);
        NSLog(@"[错误] 解密失败|状态编码: %d", cryptStatus);
    }
    
    return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
}

@end

使用方法

AES - ECB 加密

每个加密块是一个独立的单元，当拆分后再拼接 不影响其他的加密单元

 //AES - ECB 加密
    NSString *key = @"LYJ";
    
    //iv 不需要向量
   //加密
   NSString *reslut =  [[EncryptionTools sharedEncryptionTools]encryptString:@"hello" keyString:key iv:nil];
     NSLog(@"加密结果：%@",reslut);
    
   //解密
    NSString *decryptString = [[EncryptionTools sharedEncryptionTools]decryptString:reslut keyString:key iv:nil];
    NSLog(@"解密结果：%@",decryptString);
    

//AES - CBC

加密单元不是独立，后面的加密依赖前面单元数据的加密，更加安全需要向量

 //AES - CBC
    uint8_t iv[8] = {1,2,3,4,5,6,7,8};
    NSData *ivData = [NSData dataWithBytes:iv length:sizeof(iv)];
    
    NSString *CBC_EncryptString = [[EncryptionTools sharedEncryptionTools]encryptString:@"liyanjun" keyString:key iv:ivData];
    
    NSLog(@"CBC加密字符串 %@",CBC_EncryptString);
    
    
    NSString *CBC_DecryptString = [[EncryptionTools sharedEncryptionTools]decryptString:CBC_EncryptString keyString:key iv:ivData];
    
    
    NSLog(@"CBC解密字符串 %@",CBC_DecryptString);

des 给工具类单例的一个参数设置一下值即可

 //DES - ECB
    [EncryptionTools sharedEncryptionTools].algorithm = kCCAlgorithmDES;
     NSString *DES_ECB_EncryptString =  [[EncryptionTools sharedEncryptionTools]encryptString:@"hello" keyString:key iv:nil];

    NSLog(@"DES_ECB加密字符串 %@",DES_ECB_EncryptString);

    NSString *ECB_CBC_DecryptString = [[EncryptionTools sharedEncryptionTools]decryptString:DES_ECB_EncryptString keyString:key iv:nil];
    NSLog(@"DES_ECB解密字符串 %@",ECB_CBC_DecryptString);