iOS开发 单AES加密/解密

+(NSData *)AES256ParmEncryptWithKey:(NSString *)key Encrypttext:(NSData *)text  //加密
{
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [text length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,

                                          keyPtr, kCCBlockSizeAES128,

                                          NULL,

                                          [text bytes], dataLength,

                                          buffer, bufferSize,

                                          &numBytesEncrypted);

    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

    }
    free(buffer);
    
    return nil;
}

+ (NSData *)AES256ParmDecryptWithKey:(NSString *)key Decrypttext:(NSData *)text  //解密
{
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [text length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCBlockSizeAES128,
                                          NULL,
                                          [text bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesDecrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }
    free(buffer);
    return nil;
}

+(NSString *) aes256_encrypt:(NSString *)key Encrypttext:(NSString *)text
{
    const char *cstr = [text cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:text.length];
    //对数据进行加密
    NSData *result = [LanAES AES256ParmEncryptWithKey:key Encrypttext: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;
}

+(NSString *) aes256_decrypt:(NSString *)key Decrypttext:(NSString *)text
{
    // 转换为2进制Data
    NSMutableData *data = [NSMutableData dataWithCapacity:text.length / 2];
    unsigned char whole_byte;
    char byte_chars[3] = {'\0','\0','\0'};
    int i;
    for (i=0; i < [text length] / 2; i++) {
        byte_chars[0] = [text characterAtIndex:i*2];
        byte_chars[1] = [text 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 = [LanAES  AES256ParmDecryptWithKey:key Decrypttext:data];
    if (result && result.length > 0) {
        return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
    }
    return nil;
}