File indexing completed on 2024-04-21 15:00:43

 /*
     This file is part of the KDE libraries
     SPDX-FileCopyrightText: 2004 Szombathelyi György <gyurco@freemail.hu>
 
     The implementation is based on the documentation and sample code
     at https://davenport.sourceforge.net/ntlm.html
     The DES encryption functions are from libntlm
     at https://gitlab.com/gsasl/libntlm/
 
     SPDX-License-Identifier: LGPL-2.0-only
 */
 
 #include "kntlm.h"
 #include "des.h"
 
 #include <cstring>
 
 #include <QCryptographicHash>
 #include <QDate>
 #include <QRandomGenerator>
 #include <QtEndian>
 
 static const char NTLM_SIGNATURE[] = "NTLMSSP";
 
 static constexpr int NTLM_BLOB_SIZE = 28;
 
 static QByteArray QString2UnicodeLE(const QString &target)
 {
     QByteArray unicode(target.length() * 2, 0);
 
     for (int i = 0; i < target.length(); i++) {
         ((quint16 *)unicode.data())[i] = qToLittleEndian(target[i].unicode());
     }
 
     return unicode;
 }
 
 static QString UnicodeLE2QString(const QChar *data, uint len)
 {
     QString ret;
 
     for (uint i = 0; i < len; i++) {
         ret += qFromLittleEndian(data[i].unicode());
     }
 
     return ret;
 }
 
 static QByteArray getBuf(const QByteArray &buf, const KNTLM::SecBuf &secbuf)
 {
     quint32 offset = qFromLittleEndian(secbuf.offset);
     quint16 len = qFromLittleEndian(secbuf.len);
 
     // watch for buffer overflows
     if (offset > (quint32)buf.size() || offset + len > (quint32)buf.size()) {
         return QByteArray();
     }
 
     return QByteArray(buf.data() + offset, len);
 }
 
 static void addBuf(QByteArray &buf, KNTLM::SecBuf &secbuf, const QByteArray &data)
 {
     quint32 offset = (buf.size() + 1) & 0xfffffffe;
     quint16 len = data.size();
     quint16 maxlen = data.size();
 
     secbuf.offset = qToLittleEndian((quint32)offset);
     secbuf.len = qToLittleEndian(len);
     secbuf.maxlen = qToLittleEndian(maxlen);
     buf.resize(offset + len);
     memcpy(buf.data() + offset, data.data(), data.size());
 }
 
 static QString getString(const QByteArray &buf, const KNTLM::SecBuf &secbuf, bool unicode)
 {
     // watch for buffer overflows
     quint32 offset = qFromLittleEndian((quint32)secbuf.offset);
     quint16 len = qFromLittleEndian(secbuf.len);
 
     if (offset > (quint32)buf.size() || offset + len > (quint32)buf.size()) {
         return QString();
     }
 
     const char *c = buf.data() + offset;
 
     if (unicode) {
         return UnicodeLE2QString((QChar *)c, len >> 1);
     }
 
     return QString::fromLatin1(c, len);
 }
 
 static void addString(QByteArray &buf, KNTLM::SecBuf &secbuf, const QString &str, bool unicode = false)
 {
     if (unicode) {
         addBuf(buf, secbuf, QString2UnicodeLE(str));
         return;
     }
 
     addBuf(buf, secbuf, str.toLatin1());
 }
 
 /*
  * turns a 56 bit key into the 64 bit, odd parity key and sets the key.
  * The key schedule ks is also set.
  */
 static void convertKey(unsigned char *key_56, void *ks)
 {
     unsigned char key[8];
 
     key[0] = key_56[0];
     key[1] = ((key_56[0] << 7) & 0xFF) | (key_56[1] >> 1);
     key[2] = ((key_56[1] << 6) & 0xFF) | (key_56[2] >> 2);
     key[3] = ((key_56[2] << 5) & 0xFF) | (key_56[3] >> 3);
     key[4] = ((key_56[3] << 4) & 0xFF) | (key_56[4] >> 4);
     key[5] = ((key_56[4] << 3) & 0xFF) | (key_56[5] >> 5);
     key[6] = ((key_56[5] << 2) & 0xFF) | (key_56[6] >> 6);
     key[7] = (key_56[6] << 1) & 0xFF;
 
     for (unsigned char &b : key) {
         const bool needsParity = ((((b >> 7) ^ (b >> 6) ^ (b >> 5) ^ (b >> 4) ^ (b >> 3) ^ (b >> 2) ^ (b >> 1)) & 0x01) == 0);
 
         if (needsParity) {
             b |= 0x01;
         } else {
             b &= 0xfe;
         }
     }
 
     ntlm_des_set_key((DES_KEY *)ks, (char *)&key, sizeof(key));
     memset(&key, 0, sizeof(key));
 }
 
 static QByteArray createBlob(const QByteArray &targetinfo)
 {
     QByteArray blob(NTLM_BLOB_SIZE + 4 + targetinfo.size(), 0);
 
     KNTLM::Blob *bl = (KNTLM::Blob *)blob.data();
     bl->signature = qToBigEndian((quint32)0x01010000);
     quint64 now = QDateTime::currentSecsSinceEpoch();
     now += (quint64)3600 * (quint64)24 * (quint64)134774;
     now *= (quint64)10000000;
     bl->timestamp = qToLittleEndian(now);
 
     for (unsigned char &b : bl->challenge) {
         b = QRandomGenerator::global()->bounded(0xff);
     }
 
     memcpy(blob.data() + NTLM_BLOB_SIZE, targetinfo.data(), targetinfo.size());
     return blob;
 }
 
 static QByteArray hmacMD5(const QByteArray &data, const QByteArray &key)
 {
     QByteArray ipad(64, 0x36);
     QByteArray opad(64, 0x5c);
 
     Q_ASSERT(key.size() <= 64);
 
     for (int i = qMin(key.size(), 64) - 1; i >= 0; i--) {
         ipad.data()[i] ^= key[i];
         opad.data()[i] ^= key[i];
     }
 
     QByteArray content(ipad + data);
 
     QCryptographicHash md5(QCryptographicHash::Md5);
     md5.addData(content);
     content = opad + md5.result();
 
     md5.reset();
     md5.addData(content);
 
     return md5.result();
 }
 
 /*************************************** KNTLM implementation ***************************************/
 
 bool KNTLM::getNegotiate(QByteArray &negotiate, const QString &domain, const QString &workstation, quint32 flags)
 {
     QByteArray rbuf(sizeof(Negotiate), 0);
 
     memcpy(rbuf.data(), NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE));
     ((Negotiate *)rbuf.data())->msgType = qToLittleEndian((quint32)1);
 
     if (!domain.isEmpty()) {
         flags |= Negotiate_Domain_Supplied;
         addString(rbuf, ((Negotiate *)rbuf.data())->domain, domain);
     }
 
     if (!workstation.isEmpty()) {
         flags |= Negotiate_WS_Supplied;
         addString(rbuf, ((Negotiate *)rbuf.data())->workstation, workstation);
     }
 
     ((Negotiate *)rbuf.data())->flags = qToLittleEndian(flags);
     negotiate = rbuf;
     return true;
 }
 
 bool KNTLM::getAuth(QByteArray &auth,
                     const QByteArray &challenge,
                     const QString &user,
                     const QString &password,
                     const QString &domain,
                     const QString &workstation,
                     AuthFlags authflags)
 {
     QByteArray rbuf(sizeof(Auth), 0);
     Challenge *ch = (Challenge *)challenge.data();
     QByteArray response;
     const uint chsize = challenge.size();
     bool unicode = false;
     QString dom;
 
     // challenge structure too small
     if (chsize < 32) {
         return false;
     }
 
     unicode = qFromLittleEndian(ch->flags) & Negotiate_Unicode;
 
     // If the domain is NULL (i.e. QString()) use the target domain. If the domain is empty
     // (i.e. QString("")) use an empty domain.
     if (domain.isNull()) {
         dom = getString(challenge, ch->targetName, unicode);
     } else {
         dom = domain;
     }
 
     memcpy(rbuf.data(), NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE));
     ((Auth *)rbuf.data())->msgType = qToLittleEndian((quint32)3);
     ((Auth *)rbuf.data())->flags = ch->flags;
     QByteArray targetInfo;
     if (chsize >= sizeof(Challenge)) {
         targetInfo = getBuf(challenge, ch->targetInfo);
     }
 
     if (!(authflags & Force_V1)
         && ((authflags & Force_V2) //
             || (!targetInfo.isEmpty() && (qFromLittleEndian(ch->flags) & Negotiate_Target_Info))) /* may support NTLMv2 */) {
         bool ret = false;
 
         if (qFromLittleEndian(ch->flags) & Negotiate_NTLM) {
             if (targetInfo.isEmpty()) {
                 return false;
             }
 
             response = getNTLMv2Response(dom, user, password, targetInfo, ch->challengeData);
             addBuf(rbuf, ((Auth *)rbuf.data())->ntResponse, response);
             ret = true;
         }
 
         if (authflags & Add_LM) {
             response = getLMv2Response(dom, user, password, ch->challengeData);
             addBuf(rbuf, ((Auth *)rbuf.data())->lmResponse, response);
             ret = true;
         }
 
         if (!ret) {
             return false;
         }
     } else { // if no targetinfo structure and NTLMv2 or LMv2 not forced, or v1 forced, try the older methods
         bool ret = false;
 
         if (qFromLittleEndian(ch->flags) & Negotiate_NTLM) {
             response = getNTLMResponse(password, ch->challengeData);
             addBuf(rbuf, ((Auth *)rbuf.data())->ntResponse, response);
             ret = true;
         }
 
         if (authflags & Add_LM) {
             response = getLMResponse(password, ch->challengeData);
             addBuf(rbuf, ((Auth *)rbuf.data())->lmResponse, response);
             ret = true;
         }
 
         if (!ret) {
             return false;
         }
     }
 
     if (!dom.isEmpty()) {
         addString(rbuf, ((Auth *)rbuf.data())->domain, dom, unicode);
     }
 
     addString(rbuf, ((Auth *)rbuf.data())->user, user, unicode);
 
     if (!workstation.isEmpty()) {
         addString(rbuf, ((Auth *)rbuf.data())->workstation, workstation, unicode);
     }
 
     auth = rbuf;
     return true;
 }
 
 QByteArray KNTLM::getLMResponse(const QString &password, const unsigned char *challenge)
 {
     QByteArray hash;
     QByteArray answer;
 
     hash = lmHash(password);
     hash.resize(21);
     memset(hash.data() + 16, 0, 5);
     answer = lmResponse(hash, challenge);
     hash.fill(0);
     return answer;
 }
 
 QByteArray KNTLM::lmHash(const QString &password)
 {
     QByteArray keyBytes(14, 0);
     QByteArray hash(16, 0);
     DES_KEY ks;
     const char *magic = "KGS!@#$%";
 
     strncpy(keyBytes.data(), password.toUpper().toLocal8Bit().constData(), 14);
 
     convertKey((unsigned char *)keyBytes.data(), &ks);
     ntlm_des_ecb_encrypt(magic, 8, &ks, (unsigned char *)hash.data());
 
     convertKey((unsigned char *)keyBytes.data() + 7, &ks);
     ntlm_des_ecb_encrypt(magic, 8, &ks, (unsigned char *)hash.data() + 8);
 
     keyBytes.fill(0);
     memset(&ks, 0, sizeof(ks));
 
     return hash;
 }
 
 QByteArray KNTLM::lmResponse(const QByteArray &hash, const unsigned char *challenge)
 {
     DES_KEY ks;
     QByteArray answer(24, 0);
 
     convertKey((unsigned char *)hash.data(), &ks);
     ntlm_des_ecb_encrypt(challenge, 8, &ks, (unsigned char *)answer.data());
 
     convertKey((unsigned char *)hash.data() + 7, &ks);
     ntlm_des_ecb_encrypt(challenge, 8, &ks, (unsigned char *)answer.data() + 8);
 
     convertKey((unsigned char *)hash.data() + 14, &ks);
     ntlm_des_ecb_encrypt(challenge, 8, &ks, (unsigned char *)answer.data() + 16);
 
     memset(&ks, 0, sizeof(ks));
     return answer;
 }
 
 QByteArray KNTLM::getNTLMResponse(const QString &password, const unsigned char *challenge)
 {
     QByteArray hash = ntlmHash(password);
     hash.resize(21);
     memset(hash.data() + 16, 0, 5);
     QByteArray answer = lmResponse(hash, challenge);
     hash.fill(0);
     return answer;
 }
 
 QByteArray KNTLM::ntlmHash(const QString &password)
 {
     QByteArray unicode;
     unicode = QString2UnicodeLE(password);
 
     return QCryptographicHash::hash(unicode, QCryptographicHash::Md4);
 }
 
 QByteArray KNTLM::getNTLMv2Response(const QString &target,
                                     const QString &user,
                                     const QString &password,
                                     const QByteArray &targetInformation,
                                     const unsigned char *challenge)
 {
     QByteArray hash = ntlmv2Hash(target, user, password);
     QByteArray blob = createBlob(targetInformation);
     return lmv2Response(hash, blob, challenge);
 }
 
 QByteArray KNTLM::getLMv2Response(const QString &target, const QString &user, const QString &password, const unsigned char *challenge)
 {
     QByteArray hash = ntlmv2Hash(target, user, password);
     QByteArray clientChallenge(8, 0);
 
     for (uint i = 0; i < 8; i++) {
         clientChallenge.data()[i] = QRandomGenerator::global()->bounded(0xff);
     }
 
     return lmv2Response(hash, clientChallenge, challenge);
 }
 
 QByteArray KNTLM::ntlmv2Hash(const QString &target, const QString &user, const QString &password)
 {
     const QByteArray hash = ntlmHash(password);
     const QByteArray key = QString2UnicodeLE(user.toUpper() + target);
     return hmacMD5(key, hash);
 }
 
 QByteArray KNTLM::lmv2Response(const QByteArray &hash, const QByteArray &clientData, const unsigned char *challenge)
 {
     QByteArray data(8 + clientData.size(), 0);
     memcpy(data.data(), challenge, 8);
     memcpy(data.data() + 8, clientData.data(), clientData.size());
 
     QByteArray mac = hmacMD5(data, hash);
     mac.resize(16 + clientData.size());
     memcpy(mac.data() + 16, clientData.data(), clientData.size());
     return mac;
 }