所有加密代码都在这里

AES加密方法

/**
 * AES加密
 * aesKey 加密Key
 */
+(NSData *)AESParmEncryptWithKey:(NSString *)AES_Key andEncryptData:(NSData *)encryptData  //加密
{
    NSString * kInitVector = [AES_Key copy]; //16位偏移，CBC模式才有
    NSData *initVector = [kInitVector dataUsingEncoding:NSUTF8StringEncoding];
    //公钥
    char keyPtr[kCCKeySizeAES128+1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [AES_Key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    //数据长度
    NSUInteger dataLength = encryptData.length;
    //加密输出缓冲区大小
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    //加密输出缓冲区
    void *buffer = malloc(bufferSize);
    //实际输出大小
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,//kCCEncrypt 代表加密 kCCDecrypt代表解密
                                          kCCAlgorithmAES,//加密算法
                                          kCCOptionPKCS7Padding,//CBC -> PKCS7Padding，ECB -> kCCOptionPKCS7Padding|kCCOptionECBMode
                                          keyPtr,
                                          kCCBlockSizeAES128,//密钥长度128
                                          initVector.bytes,//偏移字符串, ECB模式传NULL
                                          encryptData.bytes,//编码内容
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
    }
    free(buffer);
    return nil;
}

/**
 * AES加密
 * aesKey 加密Key
 */
+ (NSString *)AES_EncryptWithKey:(NSString *)AES_Key andEncryptText:(NSString *)encryptText
{
    AES_Key = [AESUtils checkAESKey:AES_Key];
    const char *cstr = [encryptText cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:encryptText.length];
    //对数据进行加密
    NSData *result = [AESUtils AESParmEncryptWithKey:AES_Key andEncryptData:data];
    //转换为2进制字符串
    if (result && result.length > 0) {
        Byte *datas = (Byte*)[result bytes];
        NSMutableString *output = [NSMutableString stringWithCapacity:result.length * 2];
        for(int i = 0; i < result.length; i++){
            [output appendFormat:@"%02x", datas[i]];
        }
        return output;
    }
    return nil;
}

AES解密方法

/**
 * AES解密
 * aesKey 加密Key
 */
+ (NSData *)AESParmDecryptWithKey:(NSString *)AES_Key andDecryptData:(NSData *)decryptData  //解密
{
    NSString * kInitVector = [AES_Key copy]; //16位偏移，CBC模式才有
    NSData *initVector = [kInitVector dataUsingEncoding:NSUTF8StringEncoding];
    //公钥
    char keyPtr[kCCKeySizeAES128+1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [AES_Key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    //数据长度
    NSUInteger dataLength = decryptData.length;
    //加密输出缓冲区大小
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    //加密输出缓冲区
    void *buffer = malloc(bufferSize);
    //实际输出大小
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,//kCCEncrypt 代表加密 kCCDecrypt代表解密
                                          kCCAlgorithmAES,//加密算法
                                          kCCOptionPKCS7Padding,//CBC -> PKCS7Padding，ECB -> kCCOptionPKCS7Padding|kCCOptionECBMode
                                          keyPtr,
                                          kCCBlockSizeAES128,//密钥长度128
                                          initVector.bytes,//偏移字符串,, ECB模式传NULL
                                          decryptData.bytes,//编码内容
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesDecrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }
    free(buffer);
    return nil;
}

/**
 * AES解密
 * aesKey 加密Key
 */
+ (NSString *)AES_DecryptWithKey:(NSString *)AES_Key andDecryptText:(NSString *)decryptText
{
    AES_Key = [AESUtils checkAESKey:AES_Key];    
    //转换为2进制Data
    NSMutableData *data = [NSMutableData dataWithCapacity:decryptText.length / 2];
    unsigned char whole_byte;
    char byte_chars[3] = {'\0','\0','\0'};
    int i;
    for (i=0; i < [decryptText length] / 2; i++) {
        byte_chars[0] = [decryptText characterAtIndex:i*2];
        byte_chars[1] = [decryptText characterAtIndex:i*2+1];
        whole_byte = strtol(byte_chars, NULL, 16);
        [data appendBytes:&whole_byte length:1];
    }
    
    //对数据进行解密
    NSData* result = [AESUtils AESParmDecryptWithKey:AES_Key andDecryptData:data];
    if (result && result.length > 0) {
        return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
    }
    return nil;
}

/**
 * 加密key检查
 * aesKey 加密Key
 */
+ (NSString *)checkAESKey:(NSString *)AES_Key
{
    if (AES_Key.length < 16) {
        NSMutableArray *array = [NSMutableArray arrayWithArray:@[AES_Key]];
        while (array.count <= 16 - AES_Key.length) {
            [array insertObject:@"0" atIndex:0];
        }
        AES_Key = [array componentsJoinedByString:@""];
    }
    return AES_Key;
}

Demo地址Demo
如有错误请指出。