对称加密算法代码演练
/**
* 终端测试指令
*
* 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
*/
#import "ViewController.h"
#import "EncryptionTools.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//AES - ECB 加密
NSString * key = @"wt";
NSString * pwd = [[EncryptionTools sharedEncryptionTools] encryptString:@"hello" keyString:key iv:nil];
NSLog(@"加密: %@",pwd);
//解密
NSLog(@"解密: %@",[[EncryptionTools sharedEncryptionTools] decryptString:pwd keyString:key iv:nil]);
//AES - CBC 加密
uint8_t iv[8] = {2,3,4,5,6,7,0,0}; //直接影响加密结果!
NSData * ivData = [NSData dataWithBytes:iv length:sizeof(iv)];
NSString * pwd2 =[[EncryptionTools sharedEncryptionTools] encryptString:@"hello" keyString:key iv:ivData];
NSLog(@"CBC加密: %@",pwd2);
NSLog(@"CBC解密: %@", [[EncryptionTools sharedEncryptionTools] decryptString:pwd2 keyString:key iv:ivData]);
//DES - ECB 加密
[EncryptionTools sharedEncryptionTools].algorithm = kCCAlgorithmDES;
NSString * pwd3 = [[EncryptionTools sharedEncryptionTools] encryptString:@"hello" keyString:key iv:nil];
NSLog(@"DES 加密%@",pwd3);
NSLog(@"DES 解密: %@", [[EncryptionTools sharedEncryptionTools] decryptString:pwd3 keyString:key iv:nil]);
}
@end
对称加密算法工具类说明:
EncryptionTools.h
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonCrypto.h>
@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
EncryptionTools.m
#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
/*
kCCOptionPKCS7Padding CBC 的加密方式
kCCOptionPKCS7Padding | kCCOptionECBMode ECB 的加密方式
*/
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 对称加密算法的核心函数(加密/解密)
参数:
1.kCCEncrypt 加密/kCCDecrypt 解密
2.加密算法,默认使用的是 AES/DES
3.加密选项 ECB/CBC
kCCOptionPKCS7Padding CBC 的加密方式
kCCOptionPKCS7Padding | kCCOptionECBMode ECB 的加密方式
4.加密密钥
5.密钥长度
6.iv 初始化向量,ECB 不需要指定
7.加密的数据
8.加密的数据的长度
9.密文的内存地址
10.密文缓冲区的大小
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