iOS 抑或算法总结（XOR）

方法1:

／／ 加密

-(NSString *)obfuscate:(NSData *)string withKey:(NSString *)key

{

     NSData *data = string;

     char *dataPtr = (char *) [data bytes];

 　 char *keyData = (char *) [[key dataUsingEncoding:NSUTF8StringEncoding] bytes];

     char *keyPtr = keyData;

     int keyIndex = 0;

     for (int x = 0; x < [data length]; x++){

 　　   *dataPtr = *dataPtr++ ^ *keyPtr++;

          if (++keyIndex == [key length]) keyIndex = 0, keyPtr = keyData;

}

      return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

}

／／解密

 -(NSString*)encodeString:(NSString*)data :(NSString*)key

{

    NSString *result=[NSString string];

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

        int chData = [data characterAtIndex:i];

        for(int j=0;j<[key length];j++){

            int chKey = [key characterAtIndex:j];

            chData = chData^chKey;

        }

        result=[NSString stringWithFormat:@"%@%@",result,[NSString stringWithFormat:@"%c",chData]];

    }

    return result;

}

方法2:

// 客户端内置私钥
static NSString const *privateKey = @"jwef37c9111210854f5986fc9ebb5548b2ae";

// 加密
- (NSData *)xor_encrypt
{
    // 获取key的长度
    NSInteger length = privateKey.length;
    // 将OC字符串转换为C字符串
    const char *keys = [privateKey cStringUsingEncoding:NSASCIIStringEncoding];
    unsigned char cKey[length];
    memcpy(cKey, keys, length);
    // 数据初始化，空间未分配 配合使用 appendBytes
    NSMutableData *encryptData = [[NSMutableData alloc] initWithCapacity:length];
    // 获取字节指针
    const Byte *point = self.bytes;
    for (int i = 0; i < self.length; i++) {
        int l = i % length;                     // 算出当前位置字节，要和密钥的异或运算的密钥字节
        char c = cKey[l];
        Byte b = (Byte) ((point[i]) ^ c);       // 异或运算
        [encryptData appendBytes:&b length:1];  // 追加字节
    }
    return encryptData.copy;
}
@end

// 解密

- (NSData *)xor_decrypt
{
    return [self xor_encrypt];
}