ModEnc is currently in Maintenance Mode: Changes could occur at any given moment, without advance warning.
Difference between revisions of "XWIS:APGAR"
From ModEnc
m (True pw) |
|||
| (2 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
| − | APGAR is a token sent by a C&C game to tell XWIS | + | APGAR is a token sent by a C&C game to tell XWIS the players' password. The password is encrypted using a weak algorithm. This is a one-way encryption, i.e. you cannot find the original password from it's encrypted form. |
| + | |||
| + | Pseudo-code to calculate the password from an 8 letter input: | ||
| + | <pre> | ||
| + | function apgar(input) | ||
| + | lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" | ||
| + | out = "" | ||
| + | i = 1 | ||
| + | while (i <= 8) | ||
| + | left = ascii value of input[ i ] | ||
| + | right = ascii value of input[ length[input] - i ] | ||
| + | |||
| + | if left is odd | ||
| + | x = ((left * 2) XOR (left AND 1)) AND right | ||
| + | else | ||
| + | x = left XOR right | ||
| + | |||
| + | out += lookup[x AND 63] | ||
| + | i++ | ||
| + | |||
| + | return out | ||
| + | </pre> | ||
| + | |||
| + | A C++ implementation of this algorithm: | ||
| + | <pre> | ||
| + | std::string apgar(std::string input) { | ||
| + | std::string lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; | ||
| + | std::string out = ""; | ||
| + | int i = 0; | ||
| + | while (i < 8) { | ||
| + | unsigned char left = input[i]; | ||
| + | unsigned char right = input[input.length() - i]; | ||
| + | |||
| + | unsigned char x = left & 1 ? ((left << 1) ^ (left & 1)) & right : left ^ right; | ||
| + | |||
| + | out += lookup[x & 63]; | ||
| + | i++; | ||
| + | } | ||
| + | return out; | ||
| + | } | ||
| + | </pre> | ||
Example (decrypted password "reneproj"): | Example (decrypted password "reneproj"): | ||
| Line 5: | Line 45: | ||
apgar Ykbcaxop 0 | apgar Ykbcaxop 0 | ||
</pre> | </pre> | ||
| − | The closing zero seems to have | + | |
| + | The closing zero seems to have no special function. | ||
[[Category:XWIS Protocol]] | [[Category:XWIS Protocol]] | ||
Latest revision as of 00:06, 19 June 2008
APGAR is a token sent by a C&C game to tell XWIS the players' password. The password is encrypted using a weak algorithm. This is a one-way encryption, i.e. you cannot find the original password from it's encrypted form.
Pseudo-code to calculate the password from an 8 letter input:
function apgar(input)
lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
out = ""
i = 1
while (i <= 8)
left = ascii value of input[ i ]
right = ascii value of input[ length[input] - i ]
if left is odd
x = ((left * 2) XOR (left AND 1)) AND right
else
x = left XOR right
out += lookup[x AND 63]
i++
return out
A C++ implementation of this algorithm:
std::string apgar(std::string input) {
std::string lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
std::string out = "";
int i = 0;
while (i < 8) {
unsigned char left = input[i];
unsigned char right = input[input.length() - i];
unsigned char x = left & 1 ? ((left << 1) ^ (left & 1)) & right : left ^ right;
out += lookup[x & 63];
i++;
}
return out;
}
Example (decrypted password "reneproj"):
apgar Ykbcaxop 0
The closing zero seems to have no special function.
