iOS,信息加解密

AES加解密

// AESEncryptAndDecrypt.h文件

//
//  AESEncryptAndDecrypt.h
//  NSData扩展方法，用于处理aes加解密
//
//  Created by Vie on 16/4/7.
//  Copyright © 2016年 Vie. All rights reserved.
//

#import <Foundation/Foundation.h>
@class NSString;
@interface NSData (AES)
- (NSData *)AES256EncryptWithKey:(NSData *)key;   //加密

- (NSData *)AES256DecryptWithKey:(NSData *)key;   //解密
@end

// AESEncryptAndDecrypt.m文件

//
//  AESEncryptAndDecrypt.m
//  NSData扩展方法，用于处理aes加解密
//
//  Created by Vie on 16/4/7.
//  Copyright © 2016年 Vie. All rights reserved.
//

#import "AESEncryptAndDecrypt.h"
#import <CommonCrypto/CommonCryptor.h>
//static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
@implementation NSData (AES)
- (NSData *)AES256EncryptWithKey:(NSData *)key   //加密
{
    //AES256加密，密钥应该是32位的
    const void * keyPtr2 = [key bytes];
    char (*keyPtr)[32] = keyPtr2;
    //对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
    //所以在下边需要再加上一个块的大小
    NSUInteger dataLength = [self length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
                                          [key bytes], kCCKeySizeAES256,
                                          NULL,/* 初始化向量(可选) */
                                          [self bytes], dataLength,/*输入*/
                                          buffer, bufferSize,/* 输出 */
                                          &numBytesEncrypted);
    
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
    }
    free(buffer);//释放buffer
    return nil;
}

- (NSData *)AES256DecryptWithKey:(NSData *)key   //解密
{
    //同理，解密中，密钥也是32位的
    const void * keyPtr2 = [key bytes];
    char (*keyPtr)[32] = keyPtr2;
    //对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
    //所以在下边需要再加上一个块的大小
    NSUInteger dataLength = [self length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
                                          keyPtr, kCCKeySizeAES256,
                                          NULL,/* 初始化向量(可选) */
                                          [self bytes], dataLength,/* 输入 */
                                          buffer, bufferSize,/* 输出 */
                                          &numBytesDecrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }
    free(buffer);
    return nil;
}



@end

//使用

　//测试加密
    [self encryptBase64Key:@"74DhItW47MitqIBGOf8aosUllBdhlUxB7es64TKCsgU=" originalText:@"监察局时间长"];

　//测试解密
   [self decryptBase64Key:@"74DhItW47MitqIBGOf8aosUllBdhlUxB7es64TKCsgU=" cipherText:@"bWZMFt1I2H7wy25D9V3Ll26IdbOs+/NOlzaEqcUZ9L8="];

//运行结果

2017-02-16 11:08:03.984 aesDemo[16675:498435] 密文：bWZMFt1I2H7wy25D9V3Ll26IdbOs+/NOlzaEqcUZ9L8=
2017-02-16 11:08:03.987 aesDemo[16675:498435] 原文：监察局时间长