iOS AES encryption \ decryption, 3DES encryption \ decryption

AES: Advanced Encryption Standard (Advanced Encryption Standard). In cryptography, also known as Rijndael encryption method, it is a block encryption standard adopted by the US federal government. This standard is used to replace the original DES, it has been widely analyzed and multi- used around the world. After a five-year selection process, the Advanced Encryption Standard on November 26, 2001 issued by the US National Institute of Standards and Technology (NIST) in the FIPS PUB 197, and became effective standards in 2002, May 26. In 2006, the Advanced Encryption Standard has become one of the most popular symmetric key encryption algorithm (Baidu can be found).

Step encryption: AES encryption string obtained through NSData type, then the type of the encrypted NSData Base64 transcoding obtain the final string.

Decryption steps of: Base64 string to be decrypted decoded and then decrypt the original string obtained.

First create a NSData + JKEncrypt category, finished the .h file as follows:

#import <Foundation/Foundation.h>

@interface NSData (JKEncrypt)

/**
 *  利用AES加密数据
 *
 *  @param key key
 *  @param iv  iv description
 *
 *  @return data
 */
- (NSData *)jk_encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv;
/**
 *  @brief  利用AES解密据
 *
 *  @param key key
 *  @param iv  iv
 *
 *  @return 解密后数据
 */
- (NSData *)jk_decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv;

/**
 *  利用3DES加密数据
 *
 *  @param key key
 *  @param iv  iv description
 *
 *  @return data
 */
- (NSData *)jk_encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv;
/**
 *  @brief   利用3DES解密数据
 *
 *  @param key key
 *  @param iv  iv
 *
 *  @return 解密后数据
 */
- (NSData *)jk_decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv;

.m file into the appropriate header files corresponding to this implementation and

#import "NSData+JKEncrypt.h"
#import <CommonCrypto/CommonCryptor.h>

@implementation NSData (JKEncrypt)


/**
 *  利用AES加密数据
 *
 *  @param key key
 *  @param iv  iv description
 *
 *  @return data
 */
- (NSData*)jk_encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {
    
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    
    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];
    
    CCCryptorStatus status = CCCrypt(kCCEncrypt,                    // kCCEncrypt or kCCDecrypt
                                     kCCAlgorithmAES128,
                                     kCCOptionPKCS7Padding,         // Padding option for CBC Mode
                                     keyData.bytes,
                                     keyData.length,
                                     iv.bytes,
                                     self.bytes,
                                     self.length,
                                     encryptedData.mutableBytes,    // encrypted data out
                                     encryptedData.length,
                                     &dataMoved);                   // total data moved
    
    if (status == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }
    
    return nil;
    
}
/**
 *  @brief  利用AES解密据
 *
 *  @param key key
 *  @param iv  iv
 *
 *  @return 解密后数据
 */
- (NSData*)jk_decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {
    
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    
    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];
    
    CCCryptorStatus result = CCCrypt(kCCDecrypt,                    // kCCEncrypt or kCCDecrypt
                                     kCCAlgorithmAES128,
                                     kCCOptionPKCS7Padding,         // Padding option for CBC Mode
                                     keyData.bytes,
                                     keyData.length,
                                     iv.bytes,
                                     self.bytes,
                                     self.length,
                                     decryptedData.mutableBytes,    // encrypted data out
                                     decryptedData.length,
                                     &dataMoved);                   // total data moved
    
    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }
    
    return nil;
    
}
/**
 *  利用3DES加密数据
 *
 *  @param key key
 *  @param iv  iv description
 *
 *  @return data
 */
- (NSData*)jk_encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {
    
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    
    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];
    
    CCCryptorStatus result = CCCrypt(kCCEncrypt,                    // kCCEncrypt or kCCDecrypt
                                     kCCAlgorithm3DES,
                                     kCCOptionPKCS7Padding,         // Padding option for CBC Mode
                                     keyData.bytes,
                                     keyData.length,
                                     iv.bytes,
                                     self.bytes,
                                     self.length,
                                     encryptedData.mutableBytes,    // encrypted data out
                                     encryptedData.length,
                                     &dataMoved);                   // total data moved
    
    if (result == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }
    
    return nil;
    
}
/**
 *  @brief   利用3DES解密数据
 *
 *  @param key key
 *  @param iv  iv
 *
 *  @return 解密后数据
 */
- (NSData*)jk_decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {
    
    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
    
    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];
    
    CCCryptorStatus result = CCCrypt(kCCDecrypt,                    // kCCEncrypt or kCCDecrypt
                                     kCCAlgorithm3DES,
                                     kCCOptionPKCS7Padding,         // Padding option for CBC Mode
                                     keyData.bytes,
                                     keyData.length,
                                     iv.bytes,
                                     self.bytes,
                                     self.length,
                                     decryptedData.mutableBytes,    // encrypted data out
                                     decryptedData.length,
                                     &dataMoved);                   // total data moved
    
    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }
    
    return nil;
    
}