iOS 笔记之_时间戳 + DES 加密

iOS 时间戳 + DES 加密

• 时间戳

NSDate* date = [NSDate dateWithTimeIntervalSinceNow:0];
NSTimeInterval a=[date timeIntervalSince1970]*1000;
NSString *timeString = [NSString stringWithFormat:@"%f", a];
NSString *timeStamp = [timeString substringToIndex:13];

• DES 加密解密

#import "ViewController.h"
@interface ViewController ()

@end

@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    //加密内容
     NSString *plainText = @"helloWorld";
    NSLog(@"加密内容:%@",plainText);
    //秘钥
    NSString *seckey = @"seckey";
    NSString *result = [self encryptUseDES:plainText Andkey:seckey];
    NSLog(@"加密结果:%@",result);
    
    NSString *decresult = [self decryptUseDES:result Andkey:seckey];
    NSLog(@"解密结果:%@",decresult);
}

//加密
-(NSString *) encryptUseDES:(NSString *)clearText Andkey:(NSString *)key
{
    NSString *ciphertext = nil;
    NSData *textData = [clearText dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [textData length];
    
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void * buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          [key UTF8String], kCCBlockSizeDES,
                                          NULL,
                                          [textData bytes]  , dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    
    if (cryptStatus == kCCSuccess) {
        NSLog(@"DES加密成功");
        
        NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
        ciphertext = [self stringWithHexBytes2:data];
        
    }else{
        NSLog(@"DES加密失败");
    }
    
    free(buffer);
    return ciphertext;
}

-(NSString *) decryptUseDES:(NSString *)plainText Andkey:(NSString *)key
{
    NSString *cleartext = nil;
    NSData *textData = [self parseHexToByteArray:plainText];
    NSUInteger dataLength = [textData length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    
    
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          [key UTF8String], kCCKeySizeDES,
                                          NULL,
                                          [textData bytes]  , dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        NSLog(@"DES解密成功");
        
        NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
        cleartext = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }else{
        NSLog(@"DES解密失败");
    }
    
    free(buffer);
    return cleartext;
}

//nsdata转成16进制字符串
- (NSString*)stringWithHexBytes2:(NSData *)sender {
    static const char hexdigits[] = "0123456789ABCDEF";
    const size_t numBytes = [sender length];
    const unsigned char* bytes = [sender bytes];
    char *strbuf = (char *)malloc(numBytes * 2 + 1);
    char *hex = strbuf;
    NSString *hexBytes = nil;
    
    for (int i = 0; i<numBytes; ++i) {
        const unsigned char c = *bytes++;
        *hex++ = hexdigits[(c >> 4) & 0xF];
        *hex++ = hexdigits[(c ) & 0xF];
    }
    
    *hex = 0;
    hexBytes = [NSString stringWithUTF8String:strbuf];
    
    free(strbuf);
    return hexBytes;
}


/*
 将16进制数据转化成NSData 数组
 */
-(NSData*) parseHexToByteArray:(NSString*) hexString
{
    int j=0;
    Byte bytes[hexString.length];
    for(int i=0;i<[hexString length];i++)
    {
        int int_ch;  /// 两位16进制数转化后的10进制数
        unichar hex_char1 = [hexString characterAtIndex:i]; ////两位16进制数中的第一位(高位*16)
        int int_ch1;
        if(hex_char1 >= '0' && hex_char1 <='9')
            int_ch1 = (hex_char1-48)*16;   //// 0 的Ascll - 48
        else if(hex_char1 >= 'A' && hex_char1 <='F')
            int_ch1 = (hex_char1-55)*16; //// A 的Ascll - 65
        else
            int_ch1 = (hex_char1-87)*16; //// a 的Ascll - 97
        i++;
        unichar hex_char2 = [hexString characterAtIndex:i]; ///两位16进制数中的第二位(低位)
        int int_ch2;
        if(hex_char2 >= '0' && hex_char2 <='9')
            int_ch2 = (hex_char2-48); //// 0 的Ascll - 48
        else if(hex_char2 >= 'A' && hex_char1 <='F')
            int_ch2 = hex_char2-55; //// A 的Ascll - 65
        else
            int_ch2 = hex_char2-87; //// a 的Ascll - 97
        
        int_ch = int_ch1+int_ch2;
        bytes[j] = int_ch;  ///将转化后的数放入Byte数组里
        j++;
    }
    
    NSData *newData = [[NSData alloc] initWithBytes:bytes length:hexString.length/2];
    return newData;
}
@end

就酱...

加密内容:helloWorld
DES加密成功
加密结果:F6F8FDCDA4FD6B837E34C208AB6BA36C
DES解密成功
解密结果:helloWorld