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Difference between revisions of "XWIS:APGAR"
From ModEnc
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− | APGAR is a token sent by a C&C game to tell XWIS the players' password. The password is encrypted using a weak algorithm. | + | 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. |
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+ | Pseudo-code to calculate the password from an 8 letter input: | ||
<pre> | <pre> | ||
− | + | function apgar(input) | |
lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" | lookup = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" | ||
out = "" | out = "" | ||
Line 22: | Line 21: | ||
return out | return out | ||
</pre> | </pre> | ||
− | |||
A C++ implementation of this algorithm: | A C++ implementation of this algorithm: | ||
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return out; | return out; | ||
} | } | ||
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</pre> | </pre> | ||
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apgar Ykbcaxop 0 | apgar Ykbcaxop 0 | ||
</pre> | </pre> | ||
+ | |||
The closing zero seems to have no special function. | 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.