具体来说,我只想知道为什么在我的64位mac上,Swift编译器说某些类型(如Float80 )的对齐是16。为了检查类型的内存对齐要求,我使用alignof函数。
sizeof(Float80) // ~> 16 bytes, it only needs 10 bytes, but because of hardware design decisions it has to be a power of 2
strideof(Float80) // ~> 16 bytes, clear because it is exact on a power of 2, struct type
3 3DES + ECB algo密码密码有问题。下面是我使用的代码:
class func encryptPassword(pass: String) -> String {
let keyString = "123456789012345678901234"
let keyData: NSData! = (keyString as NSString).dataUsingEncoding(NSUTF8StringEncoding) as NSData!
let keyBytes = Unsa
我有一个加密工具对文件进行加密,当我研究加密文件时,发现它正在加密文件中写入.PEM的名称。
I found encryption logic is commonly used as below,
it supporting encryption of any file, it means RSA keys can not be use for encryption so here
it is creating a key(K) and encrypt it with RSA public key and then using key(K) for encrypting the file.
当我移动结构变量时,我想知道为什么结构的大小不同,我知道存在填充,但是在后台它所做的并不明显
struct test1 {
long y;
int a;
short int b;
short int t;
}
sizeof(struct test1) = 16
struct test2 {
long y;
short int b;
int a;
short int t;
}
sizeof(struct test2) = 24
struct test3 {
int a;
long y;
short i
我正在将png流到浏览器上,以便在img属性中使用。
def streamer():
with open(local_path) as fh:
while True:
rbuf = fh.read(READ_BUF_SIZE)
if not rbuf:
break
yield rbuf
我想做这样的事:
base64.b64encode(streamer())
但我不能对发电机进行编码。
我有一个用AES加密的文件。我使用以下NSData类别:
#import <CommonCrypto/CommonCryptor.h>
@implementation NSData (AES)
- (NSData *)AES256DecryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES256+1]; // room for terminator (
我不一定有问题,我更好奇。如果我将AES填充模式设置为PKCS7,并加密长度为128的byte[],则输出byte[]为144。
var input = new string('0', 128);
var inputBytes = Encoding.UTF8.GetBytes(input);
using var aes = Aes.Create();
Console.WriteLine(aes.BlockSize); // 128 (bits)
aes.Padding = PaddingMode.PKCS7;
using var encryptedMessageStre