364 lines
12 KiB
C++

/**
* This file is a part of the UMSKT Project
*
* Copyleft (C) 2019-2024 UMSKT Contributors (et.al.)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @FileCreated by Andrew on 01/06/2023
* @Maintainer Andrew
*
* @History {
* Algorithm was initially written and open sourced by z22
* and uploaded to GitHub by TheMCHK in August of 2019
*
* Endermanch (Andrew) rewrote the algorithm in May of 2023
* }
*/
#include "BINK2002.h"
/**
* Packs a Windows Server 2003-like Product Key.
*
* @param pRaw *QWORD[2] raw product key output
**/
BOOL BINK2002::Pack(QWORD *pRaw)
{
// AuthInfo [113..104] <- Signature [103..42] <- Hash [41..11] <- Channel ID [10..1] <- Upgrade [0]
pRaw[0] = FIRSTNBITS(info.Signature, 22) << 42 | (QWORD)info.Hash << 11 | info.ChannelID << 1 | info.isUpgrade;
pRaw[1] = FIRSTNBITS(info.AuthInfo, 10) << 40 | NEXTSNBITS(info.Signature, 40, 22);
return true;
}
/**
* Unpacks a Windows Server 2003-like Product Key.
*
* @param pRaw *QWORD[2] raw product key input
**/
BOOL BINK2002::Unpack(QWORD *pRaw)
{
// We're assuming that the quantity of information within the product key is at most 114 bits.
// log2(24^25) = 114.
// Upgrade = Bit 0
info.isUpgrade = FIRSTNBITS(pRaw[0], 1);
// Channel ID = Bits [1..10] -> 10 bits
info.ChannelID = NEXTSNBITS(pRaw[0], 10, 1);
// Hash = Bits [11..41] -> 31 bits
info.Hash = NEXTSNBITS(pRaw[0], 31, 11);
// Signature = Bits [42..103] -> 62 bits
// The quad-word signature overlaps AuthInfo in bits 104 and 105,
// hence Microsoft employs a secret technique called: Signature = HIDWORD(Signature) >> 2 | LODWORD(Signature)
info.Signature = NEXTSNBITS(pRaw[1], 30, 10) << 32 | FIRSTNBITS(pRaw[1], 10) << 22 | NEXTSNBITS(pRaw[0], 22, 42);
// AuthInfo = Bits [104..113] -> 10 bits
info.AuthInfo = NEXTSNBITS(pRaw[1], 10, 40);
return true;
}
/**
* Generates a Windows Server 2003-like Product Key.
*
* @param info
* @param pKey
* @return
*/
BOOL BINK2002::Generate(std::string &pKey)
{
BN_CTX *numContext = BN_CTX_new();
BIGNUM *c = BN_CTX_get(numContext), *e = BN_CTX_get(numContext), *s = BN_CTX_get(numContext),
*x = BN_CTX_get(numContext), *y = BN_CTX_get(numContext);
QWORD pRaw[2];
// Data segment of the RPK.
DWORD pData = info.ChannelID << 1 | info.isUpgrade;
BOOL noSquare;
do
{
EC_POINT *r = EC_POINT_new(eCurve);
// Generate a random number c consisting of 512 bits without any constraints.
BN_rand(c, FIELD_BITS_2003, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY);
// R = cG
EC_POINT_mul(eCurve, r, nullptr, genPoint, c, numContext);
// Acquire its coordinates.
// x = R.x; y = R.y;
EC_POINT_get_affine_coordinates(eCurve, r, x, y, numContext);
BYTE msgDigest[SHA_DIGEST_LENGTH], msgBuffer[SHA_MSG_LENGTH_2003], xBin[FIELD_BYTES_2003],
yBin[FIELD_BYTES_2003];
// Convert resulting point coordinates to bytes.
UMSKT::BN_bn2lebin(x, xBin, FIELD_BYTES_2003);
UMSKT::BN_bn2lebin(y, yBin, FIELD_BYTES_2003);
// Assemble the first SHA message.
msgBuffer[0x00] = 0x79;
msgBuffer[0x01] = (pData & 0x00FF);
msgBuffer[0x02] = (pData & 0xFF00) >> 8;
memcpy(&msgBuffer[3], xBin, FIELD_BYTES_2003);
memcpy(&msgBuffer[3 + FIELD_BYTES_2003], yBin, FIELD_BYTES_2003);
// pHash = SHA1(79 || Channel ID || R.x || R.y)
SHA1(msgBuffer, SHA_MSG_LENGTH_2003, msgDigest);
// Translate the byte digest into a 32-bit integer - this is our computed hash.
// Truncate the hash to 31 bits.
info.Hash = BYDWORD(msgDigest) & BITMASK(31);
// Assemble the second SHA message.
msgBuffer[0x00] = 0x5D;
msgBuffer[0x01] = (pData & 0x00FF);
msgBuffer[0x02] = (pData & 0xFF00) >> 8;
msgBuffer[0x03] = (info.Hash & 0x000000FF);
msgBuffer[0x04] = (info.Hash & 0x0000FF00) >> 8;
msgBuffer[0x05] = (info.Hash & 0x00FF0000) >> 16;
msgBuffer[0x06] = (info.Hash & 0xFF000000) >> 24;
msgBuffer[0x07] = (info.AuthInfo & 0x00FF);
msgBuffer[0x08] = (info.AuthInfo & 0xFF00) >> 8;
msgBuffer[0x09] = 0x00;
msgBuffer[0x0A] = 0x00;
// newSignature = SHA1(5D || Channel ID || Hash || AuthInfo || 00 00)
SHA1(msgBuffer, 11, msgDigest);
// Translate the byte digest into a 64-bit integer - this is our computed intermediate signature.
// As the signature is only 62 bits long at most, we have to truncate it by shifting the high DWORD right 2
// bits (per spec).
QWORD iSignature = NEXTSNBITS(BYDWORD(&msgDigest[4]), 30, 2) << 32 | BYDWORD(msgDigest);
BN_lebin2bn((BYTE *)&iSignature, sizeof(iSignature), e);
/*
*
* Scalars:
* c = Random multiplier
* e = Intermediate Signature
* s = Signature
* n = Order of G
* k = Private Key
*
* Points:
* G(x, y) = Generator (Base Point)
* R(x, y) = Random derivative of the generator
* K(x, y) = Public Key
*
* Equation:
* s(sG + eK) = R (mod p)
* ↓ K = kG; R = cG ↓
*
* s(sG + ekG) = cG (mod p)
* s(s + ek)G = cG (mod p)
* ↓ G cancels out, the scalar arithmetic shrinks to order n ↓
*
* s(s + ek) = c (mod n)
* s² + (ek)s - c = 0 (mod n)
* ↓ This is a quadratic equation in respect to the signature ↓
*
* s = (-ek ± √((ek)² + 4c)) / 2 (mod n)
*/
// e = ek (mod n)
BN_mod_mul(e, e, privateKey, genOrder, numContext);
// s = e
BN_copy(s, e);
// s = (ek (mod n))²
BN_mod_sqr(s, s, genOrder, numContext);
// c *= 4 (c <<= 2)
BN_lshift(c, c, 2);
// s += c
BN_add(s, s, c);
// Around half of numbers modulo a prime are not squares -> BN_sqrt_mod fails about half of the times,
// hence if BN_sqrt_mod returns NULL, we need to restart with a different seed.
// s = √((ek)² + 4c (mod n))
noSquare = BN_mod_sqrt(s, s, genOrder, numContext) == nullptr;
// s = -ek + √((ek)² + 4c) (mod n)
BN_mod_sub(s, s, e, genOrder, numContext);
// If s is odd, add order to it.
// The order is a prime, so it can't be even.
if (BN_is_odd(s))
{
// s = -ek + √((ek)² + 4c) + n
BN_add(s, s, genOrder);
}
// s /= 2 (s >>= 1)
BN_rshift1(s, s);
// Translate resulting scalar into a 64-bit integer (the byte order is little-endian).
BN_bn2lebinpad(s, (BYTE *)&info.Signature, BN_num_bytes(s));
// Pack product key.
Pack(pRaw);
fmt::print(UMSKT::debug, "Generation results:\n");
fmt::print(UMSKT::debug, "{:>10}: {:b}\n", "Upgrade", (bool)info.isUpgrade);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Channel ID", info.ChannelID);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Hash", info.Hash);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Signature", info.Signature);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "AuthInfo", info.AuthInfo);
fmt::print(UMSKT::debug, "\n");
EC_POINT_free(r);
} while (info.Signature > BITMASK(62) || noSquare);
// ↑ ↑ ↑
// The signature can't be longer than 62 bits, else it will
// overlap with the AuthInfo segment next to it.
// Convert bytecode to Base24 CD-key.
base24(pKey, (BYTE *)pRaw);
BN_CTX_free(numContext);
return true;
}
/**
* Validates a Windows Server 2003-like Product Key.
*
* @param pKey
**/
BOOL BINK2002::Validate(std::string &pKey)
{
BN_CTX *context = BN_CTX_new();
QWORD bKey[2];
// Convert Base24 CD-key to bytecode.
unbase24((BYTE *)bKey, &pKey[0]);
// Extract product key segments from bytecode.
Unpack(bKey);
DWORD pData = info.ChannelID << 1 | info.isUpgrade;
fmt::print(UMSKT::debug, "Validation results:\n");
fmt::print(UMSKT::debug, "{:>10}: {:b}\n", "Upgrade", (bool)info.isUpgrade);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Channel ID", info.ChannelID);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Hash", info.Hash);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "Signature", info.Signature);
fmt::print(UMSKT::debug, "{:>10}: {:d}\n", "AuthInfo", info.AuthInfo);
fmt::print(UMSKT::debug, "\n");
BYTE msgDigest[SHA_DIGEST_LENGTH], msgBuffer[SHA_MSG_LENGTH_2003], xBin[FIELD_BYTES_2003], yBin[FIELD_BYTES_2003];
// Assemble the first SHA message.
msgBuffer[0x00] = 0x5D;
msgBuffer[0x01] = (pData & 0x00FF);
msgBuffer[0x02] = (pData & 0xFF00) >> 8;
msgBuffer[0x03] = (info.Hash & 0x000000FF);
msgBuffer[0x04] = (info.Hash & 0x0000FF00) >> 8;
msgBuffer[0x05] = (info.Hash & 0x00FF0000) >> 16;
msgBuffer[0x06] = (info.Hash & 0xFF000000) >> 24;
msgBuffer[0x07] = (info.AuthInfo & 0x00FF);
msgBuffer[0x08] = (info.AuthInfo & 0xFF00) >> 8;
msgBuffer[0x09] = 0x00;
msgBuffer[0x0A] = 0x00;
// newSignature = SHA1(5D || Channel ID || Hash || AuthInfo || 00 00)
SHA1(msgBuffer, 11, msgDigest);
// Translate the byte digest into a 64-bit integer - this is our computed intermediate signature.
// As the signature is only 62 bits long at most, we have to truncate it by shifting the high DWORD right 2 bits
// (per spec).
QWORD iSignature = NEXTSNBITS(BYDWORD(&msgDigest[4]), 30, 2) << 32 | BYDWORD(msgDigest);
/*
*
* Scalars:
* e = Hash
* s = Schnorr Signature
*
* Points:
* G(x, y) = Generator (Base Point)
* K(x, y) = Public Key
*
* Equation:
* P = s(sG + eK)
*
*/
BIGNUM *e = BN_lebin2bn((BYTE *)&iSignature, sizeof(iSignature), nullptr),
*s = BN_lebin2bn((BYTE *)&info.Signature, sizeof(info.Signature), nullptr);
BIGNUM *x = BN_CTX_get(context), *y = BN_CTX_get(context);
// Create 2 points on the elliptic curve.
EC_POINT *p = EC_POINT_new(eCurve), *t = EC_POINT_new(eCurve);
// t = sG
EC_POINT_mul(eCurve, t, nullptr, genPoint, s, context);
// p = eK
EC_POINT_mul(eCurve, p, nullptr, pubPoint, e, context);
// p += t
EC_POINT_add(eCurve, p, t, p, context);
// p *= s
EC_POINT_mul(eCurve, p, nullptr, p, s, context);
// x = p.x; y = p.y;
EC_POINT_get_affine_coordinates(eCurve, p, x, y, context);
// Convert resulting point coordinates to bytes.
UMSKT::BN_bn2lebin(x, xBin, FIELD_BYTES_2003);
UMSKT::BN_bn2lebin(y, yBin, FIELD_BYTES_2003);
// Assemble the second SHA message.
msgBuffer[0x00] = 0x79;
msgBuffer[0x01] = (pData & 0x00FF);
msgBuffer[0x02] = (pData & 0xFF00) >> 8;
memcpy((void *)&msgBuffer[3], (void *)xBin, FIELD_BYTES_2003);
memcpy((void *)&msgBuffer[3 + FIELD_BYTES_2003], (void *)yBin, FIELD_BYTES_2003);
// compHash = SHA1(79 || Channel ID || p.x || p.y)
SHA1(msgBuffer, SHA_MSG_LENGTH_2003, msgDigest);
// Translate the byte digest into a 32-bit integer - this is our computed hash.
// Truncate the hash to 31 bits.
DWORD compHash = BYDWORD(msgDigest) & BITMASK(31);
BN_free(s);
BN_free(e);
EC_POINT_free(p);
EC_POINT_free(t);
BN_CTX_free(context);
// If the computed hash checks out, the key is valid.
return compHash == info.Hash;
}