/*
Windows XP CD Key Verification/Generator v0.03
by z22
Compile with OpenSSL libs, modify to suit your needs.
http://gnuwin32.sourceforge.net/packages/openssl.htm
History:
0.03 Stack corruptionerror on exit fixed (now pkey is large enough)
More Comments added
0.02 Changed name the *.cpp;
Fixed minor bugs & Make it compilable on VC++
0.01 First version compilable MingW
*/
#include "header.h"
/* Unpacks the Windows XP Product Key. */
void unpackXP(ul32 *serial, ul32 *hash, ul32 *sig, ul32 *raw) {
// We're assuming that the quantity of information within the product key is at most 114 bits.
// log2(24^25) = 114.
// Serial = Bits [0..30] -> 31 bits
if (serial)
serial[0] = raw[0] & 0x7fffffff;
// Hash (e) = Bits [31..58] -> 28 bits
if (hash)
hash[0] = ((raw[0] >> 31) | (raw[1] << 1)) & 0xfffffff;
// Signature (s) = Bits [59..113] -> 55 bits
if (sig) {
sig[0] = (raw[1] >> 27) | (raw[2] << 5);
sig[1] = (raw[2] >> 27) | (raw[3] << 5);
}
}
/* Packs the Windows XP Product Key. */
void packXP(ul32 *raw, const ul32 *serial, const ul32 *hash, const ul32 *sig) {
raw[0] = serial[0] | ((hash[0] & 1) << 31);
raw[1] = (hash[0] >> 1) | ((sig[0] & 0x1f) << 27);
raw[2] = (sig[0] >> 5) | (sig[1] << 27);
raw[3] = sig[1] >> 5;
}
/* Verify Product Key */
bool verifyXPKey(EC_GROUP *eCurve, EC_POINT *generator, EC_POINT *publicKey, char *cdKey) {
BN_CTX *context = BN_CTX_new();
// Convert Base24 CD-key to bytecode.
ul32 bKey[4]{};
ul32 pID, checkHash, sig[2];
unbase24(bKey, cdKey);
// Extract data, hash and signature from the bytecode.
unpackXP(&pID, &checkHash, sig, bKey);
// e = Hash
// s = Signature
BIGNUM *e, *s;
// Put hash word into BigNum e.
e = BN_new();
BN_set_word(e, checkHash);
// Reverse signature and create a new BigNum s.
endian((byte *)sig, sizeof(sig));
s = BN_bin2bn((byte *)sig, sizeof(sig), nullptr);
// Create x and y.
BIGNUM *x = BN_new();
BIGNUM *y = BN_new();
// Create 2 new points on the existing elliptic curve.
EC_POINT *u = EC_POINT_new(eCurve);
EC_POINT *v = EC_POINT_new(eCurve);
// EC_POINT_mul calculates r = generator * n + q * m.
// v = s * generator + e * (-publicKey)
// u = generator * s
EC_POINT_mul(eCurve, u, nullptr, generator, s, context);
// v = publicKey * e
EC_POINT_mul(eCurve, v, nullptr, publicKey, e, context);
// v += u
EC_POINT_add(eCurve, v, u, v, context);
// EC_POINT_get_affine_coordinates() sets x and y, either of which may be nullptr, to the corresponding coordinates of p.
// x = v.x; y = v.y;
EC_POINT_get_affine_coordinates(eCurve, v, x, y, context);
byte buf[FIELD_BYTES], md[SHA_DIGEST_LENGTH], t[4];
ul32 newHash;
SHA_CTX hContext;
// h = First32(SHA-1(pID || v.x || v.y)) >> 4
SHA1_Init(&hContext);
// Chop Product ID into 4 bytes.
t[0] = (pID & 0xff); // First 8 bits
t[1] = (pID & 0xff00) >> 8; // Second 8 bits
t[2] = (pID & 0xff0000) >> 16; // Third 8 bits
t[3] = (pID & 0xff000000) >> 24; // Fourth 8 bits
// Hash chunk of data.
SHA1_Update(&hContext, t, sizeof(t));
// Empty buffer, place v.x in little-endian.
memset(buf, 0, FIELD_BYTES);
BN_bn2bin(x, buf);
endian(buf, FIELD_BYTES);
// Hash chunk of data.
SHA1_Update(&hContext, buf, FIELD_BYTES);
// Empty buffer, place v.y in little-endian.
memset(buf, 0, FIELD_BYTES);
BN_bn2bin(y, buf);
endian(buf, FIELD_BYTES);
// Hash chunk of data.
SHA1_Update(&hContext, buf, FIELD_BYTES);
// Store the final message from hContext in md.
SHA1_Final(md, &hContext);
// h = First32(SHA-1(pID || v.x || v.y)) >> 4
newHash = (md[0] | (md[1] << 8) | (md[2] << 16) | (md[3] << 24)) >> 4;
newHash &= 0xfffffff;
BN_free(e);
BN_free(s);
BN_free(x);
BN_free(y);
BN_CTX_free(context);
EC_POINT_free(u);
EC_POINT_free(v);
// If we managed to generate a key with the same hash, the key is correct.
return newHash == checkHash;
}
/* Generate a valid Product Key. */
void generateXPKey(char *pKey, EC_GROUP *eCurve, EC_POINT *generator, BIGNUM *order, BIGNUM *privateKey, ul32 *pRaw) {
EC_POINT *r = EC_POINT_new(eCurve);
BN_CTX *ctx = BN_CTX_new();
BIGNUM *c = BN_new();
BIGNUM *s = BN_new();
BIGNUM *x = BN_new();
BIGNUM *y = BN_new();
ul32 bKey[4]{};
do {
ul32 hash = 0, sig[2]{};
memset(bKey, 0, 4);
// Generate a random number c consisting of 384 bits without any constraints.
BN_rand(c, FIELD_BITS, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY);
// r = generator * c;
EC_POINT_mul(eCurve, r, nullptr, generator, c, ctx);
// x = r.x; y = r.y;
EC_POINT_get_affine_coordinates(eCurve, r, x, y, ctx);
SHA_CTX hContext;
byte md[SHA_DIGEST_LENGTH]{}, buf[FIELD_BYTES]{}, t[4]{};
// h = (First-32(SHA1(pRaw, r.x, r.y)) >> 4
SHA1_Init(&hContext);
// Chop Raw Product Key into 4 bytes.
t[0] = (*pRaw & 0xff);
t[1] = (*pRaw & 0xff00) >> 8;
t[2] = (*pRaw & 0xff0000) >> 16;
t[3] = (*pRaw & 0xff000000) >> 24;
// Hash chunk of data.
SHA1_Update(&hContext, t, sizeof(t));
// Empty buffer, place r.x in little-endian
memset(buf, 0, FIELD_BYTES);
BN_bn2bin(x, buf);
endian(buf, FIELD_BYTES);
// Hash chunk of data.
SHA1_Update(&hContext, buf, FIELD_BYTES);
// Empty buffer, place r.y in little-endian.
memset(buf, 0, FIELD_BYTES);
BN_bn2bin(y, buf);
endian(buf, FIELD_BYTES);
// Hash chunk of data.
SHA1_Update(&hContext, buf, FIELD_BYTES);
// Store the final message from hContext in md.
SHA1_Final(md, &hContext);
// h = (First-32(SHA1(pRaw, r.x, r.y)) >> 4
hash = (md[0] | (md[1] << 8) | (md[2] << 16) | (md[3] << 24)) >> 4;
hash &= 0xfffffff;
/* s = privateKey * hash + c; */
// s = privateKey;
BN_copy(s, privateKey);
// s *= hash;
BN_mul_word(s, hash);
// BN_mod_add() adds a to b % m and places the non-negative result in r.
// s = |s + c % order|;
BN_mod_add(s, s, c, order, ctx);
// Convert s from BigNum back to bytecode and reverse the endianness.
BN_bn2bin(s, (byte *)sig);
endian((byte *)sig, BN_num_bytes(s));
// Pack product key.
packXP(bKey, pRaw, &hash, sig);
} while (bKey[3] >= 0x40000);
// ↑ ↑ ↑
// bKey[3] can't be longer than 18 bits, else the signature part will make
// the CD-key longer than 25 characters.
// Convert the key to Base24.
base24(pKey, bKey);
BN_free(c);
BN_free(s);
BN_free(x);
BN_free(y);
BN_CTX_free(ctx);
EC_POINT_free(r);
}