iOS 对称算法DES加解密-白红宇

#import "NSString+DES.h"

#import <CommonCrypto/CommonDigest.h>

#import <CommonCrypto/CommonCryptor.h>

@implementation NSString (DES)

(NSData *)jm_hexStringConvertToBytesData { //异常字符串 if (self.length % 2 != 0) { return nil; }

Byte bytes[1024*3] = {0};

int bytesIndex = 0;

for(int i = 0; i < [self length]; i++) {

int int_char;  /// 两位16进制数转化后的10进制数    unichar hex_charUpper = [self characterAtIndex:i]; ///两位16进制数中的第一位(高位*16)  int int_charUpper;  if(hex_charUpper >= '0' && hex_charUpper <='9') {      int_charUpper = (hex_charUpper - 48 ) * 16;   // 0 的Ascll - 48  } else if(hex_charUpper >= 'A' && hex_charUpper <= 'F') {      int_charUpper = (hex_charUpper - 55 ) * 16; /// A 的Ascll - 65  } else {      int_charUpper = (hex_charUpper - 87 ) * 16; // a 的Ascll - 97  }    i++;    unichar hex_charLower = [self characterAtIndex:i]; ///两位16进制数中的第二位(低位)  int int_charLower;  if(hex_charLower >= '0' && hex_charLower <= '9') {      int_charLower = (hex_charLower - 48); /// 0 的Ascll - 48  } else if(hex_charUpper >= 'A' && hex_charUpper <='F') {      int_charLower = (hex_charLower - 55); ///  A 的Ascll - 65  } else {      int_charLower = hex_charLower - 87; /// a 的Ascll - 97  }    int_char = int_charUpper + int_charLower;  bytes[bytesIndex] = int_char;  ///将转化后的数放入Byte数组里  bytesIndex++;复制代码

}

NSUInteger dataLength = self.length / 2;

NSData *data = [[NSData alloc] initWithBytes:bytes length:dataLength];

return data; }

(NSString *)jm_urlDecode {

NSString *decodedString = [self stringByRemovingPercentEncoding];

return decodedString; }

(NSString *)jm_urlEncode {

NSString encodedString = [self stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet characterSetWithCharactersInString:@"!'();:@&=+$,/?%#[]"]];

return encodedString; }

(NSString *)jm_encryptUseDESByKey:(NSString *)key iv:(NSString *)iv { NSString *ciphertext; NSString *encode = [self jm_urlEncode]; // NSLog(@"%s encode::%@", func, encode);

NSData *data = [encode dataUsingEncoding:NSUTF8StringEncoding];

NSUInteger dataLength = data.length;

NSUInteger bufferLength = 1024;

unsigned char buffer[bufferLength];

memset(buffer, 0, sizeof(char));

size_t numBytesEncrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding, [key UTF8String], kCCKeySizeDES, [iv UTF8String] , //iv向量 [data bytes], dataLength, buffer, bufferLength, &numBytesEncrypted);

if (cryptStatus == kCCSuccess) {
```
NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];  //NSLog(@"%s buffer::%s", __func__, buffer);  //NSLog(@"%s data::%@", __func__, data);    ciphertext = @"";  for (int index = 0; index < data.length; index++) {      char byte;      [data getBytes:&byte range:NSMakeRange(index, 1)];      NSString *text = [NSString stringWithFormat:@"%x", byte&0xff];            //不足两位，前面补0      if([text length] == 1) {          text = [NSString stringWithFormat:@"0%@", text];      }            ciphertext = [ciphertext stringByAppendingString:text];  }复制代码
```
}

NSLog(@"%s encryptText::%@", func, ciphertext); return ciphertext; }

(NSString *)jm_decryptUseDesByKey:(NSString *)key iv:(NSString *)iv { NSString *decryptText;

NSData *encryptData = [self jm_hexStringConvertToBytesData];

const char *textBytes = [encryptData bytes];

NSUInteger dataLength = encryptData.length;

NSUInteger bufferLength = dataLength + 0x8 & 0xfffffff8;

unsigned char buffer[bufferLength];

memset(buffer, 0, sizeof(char));

size_t numBytesEncrypted = 0;

//将encryptText转化为bytes CCCryptorStatus decryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding, [key UTF8String], kCCKeySizeDES, [iv UTF8String] , //iv向量 textBytes, dataLength, buffer, bufferLength, &numBytesEncrypted); if (decryptStatus == kCCSuccess ) {
```
NSLog(@"%s buffer::%s", __func__, buffer);    NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];    NSLog(@"%s data::%@", __func__, data);    decryptText = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];  NSLog(@"%s decryptText::%@", __func__, decryptText);    decryptText = [decryptText jm_urlDecode];  NSLog(@"%s decodeUrl::%@", __func__, decryptText);复制代码
```
}

return decryptText; }

@end