问题
I am making a HTTP
POST
request to my server from my C++
application via sockets
, I will be XORing
the POST
values from my C++
application before they are sent to my server. Once these XORed
POST
values are sent to my server I am going to need to be able to 'decrypt' them before processing the values on my server.
My C++
application currently is XORing
strings
like so
char *XOR(char *string)
{
//key = 0x10
char buffer[1000] = { 0 };
for (int i = 0; i < strlen(string); i++)
buffer[i] = string[i] ^ 0x10;
buffer[strlen(string)] = 0x00;
return buffer;
//yes I know, this function could be written much better. But that is not the point of this question...
}
Now in PHP
I am using this function to XOR
a string
function XOR($string, $key)
{
for($i = 0; $i < strlen($string); $i++)
$string[$i] = ($string[$i] ^ $key[$i % strlen($key)]);
return $string;
}
I have tried calling it like this
$decryptedValue = XOR($_POST['postParam1'], "16");
And like this
$decryptedValue = XOR($_POST['postParam1'], 16);
But the value stored in $decryptedValue
never matches up with the XORed
value sent from C++
application
For example if I XOR
"test"
in my C++
application with key as 0x10
the return value is
0x64, 0x75, 0x63, 0x64
But If I XOR
"test"
on my server the return value is
0x45, 0x53, 0x42, 0x42
回答1:
You need to convert your character to an integer with ord
, then XOR it with $key
(not using key as a string), then convert it back to a character with chr
. Otherwise, it XOR's the string value with a string containing "16"
, which clearly doesn't achieve the same result.
function encrypt($string, $key)
{
for($i = 0; $i < strlen($string); $i++)
$string[$i] = chr(ord($string[$i]) ^ $key);
return $string;
}
(My version of PHP thinks XOR is a keyword, so I renamed the function to encrypt).
To test:
encrypt("test", 16);
来源:https://stackoverflow.com/questions/48899919/xor-a-string-in-php-with-key-is-an-integer