qauthenticator.cpp

奇趣公司比较新的qt/emd版本

/*
 * NTLM message flags.
 *
 * Copyright (c) 2004 Andrey Panin <[e-mail]>
 *
 * This software is released under the MIT license.
 */

/*
 * Indicates that Unicode strings are supported for use in security
 * buffer data. 
 */
#define NTLMSSP_NEGOTIATE_UNICODE 0x00000001 

/*
 * Indicates that OEM strings are supported for use in security buffer data.
 */
#define NTLMSSP_NEGOTIATE_OEM 0x00000002 

/*
 * Requests that the server's authentication realm be included in the
 * Type 2 message. 
 */
#define NTLMSSP_REQUEST_TARGET 0x00000004 

/*
 * Specifies that authenticated communication between the client and server
 * should carry a digital signature (message integrity). 
 */
#define NTLMSSP_NEGOTIATE_SIGN 0x00000010 

/*
 * Specifies that authenticated communication between the client and server
 * should be encrypted (message confidentiality).
 */
#define NTLMSSP_NEGOTIATE_SEAL 0x00000020 

/*
 * Indicates that datagram authentication is being used. 
 */
#define NTLMSSP_NEGOTIATE_DATAGRAM 0x00000040 

/*
 * Indicates that the LAN Manager session key should be
 * used for signing and sealing authenticated communications.
 */
#define NTLMSSP_NEGOTIATE_LM_KEY 0x00000080 

/*
 * Indicates that NTLM authentication is being used. 
 */
#define NTLMSSP_NEGOTIATE_NTLM 0x00000200 

/*
 * Sent by the client in the Type 1 message to indicate that the name of the
 * domain in which the client workstation has membership is included in the
 * message. This is used by the server to determine whether the client is
 * eligible for local authentication. 
 */
#define NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED 0x00001000 

/*
 * Sent by the client in the Type 1 message to indicate that the client
 * workstation's name is included in the message. This is used by the server
 * to determine whether the client is eligible for local authentication.
 */
#define NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED 0x00002000 

/*
 * Sent by the server to indicate that the server and client are on the same
 * machine. Implies that the client may use the established local credentials
 * for authentication instead of calculating a response to the challenge.
 */
#define NTLMSSP_NEGOTIATE_LOCAL_CALL 0x00004000 

/*
 * Indicates that authenticated communication between the client and server
 * should be signed with a "dummy" signature. 
 */
#define NTLMSSP_NEGOTIATE_ALWAYS_SIGN 0x00008000 

/*
 * Sent by the server in the Type 2 message to indicate that the target
 * authentication realm is a domain.
 */
#define NTLMSSP_TARGET_TYPE_DOMAIN 0x00010000 

/*
 * Sent by the server in the Type 2 message to indicate that the target
 * authentication realm is a server. 
 */
#define NTLMSSP_TARGET_TYPE_SERVER 0x00020000 

/*
 * Sent by the server in the Type 2 message to indicate that the target
 * authentication realm is a share. Presumably, this is for share-level
 * authentication. Usage is unclear. 
 */
#define NTLMSSP_TARGET_TYPE_SHARE 0x00040000 

/*
 * Indicates that the NTLM2 signing and sealing scheme should be used for
 * protecting authenticated communications. Note that this refers to a
 * particular session security scheme, and is not related to the use of
 * NTLMv2 authentication.
 */ 
#define NTLMSSP_NEGOTIATE_NTLM2 0x00080000 

/*
 * Sent by the server in the Type 2 message to indicate that it is including
 * a Target Information block in the message. The Target Information block
 * is used in the calculation of the NTLMv2 response.
 */
#define NTLMSSP_NEGOTIATE_TARGET_INFO 0x00800000 

/*
 * Indicates that 128-bit encryption is supported. 
 */
#define NTLMSSP_NEGOTIATE_128 0x20000000 

/*
 * Indicates that the client will provide an encrypted master session key in
 * the "Session Key" field of the Type 3 message. This is used in signing and
 * sealing, and is RC4-encrypted using the previous session key as the
 * encryption key.
 */
#define NTLMSSP_NEGOTIATE_KEY_EXCHANGE 0x40000000 

/*
 * Indicates that 56-bit encryption is supported.
 */
#define NTLMSSP_NEGOTIATE_56 0x80000000 


/* usage:
   // fill up ctx with what we know.
   QByteArray response = qNtlmPhase1(ctx);
   // send response (b64 encoded??)
   // get response from server (b64 decode?)
   Phase2Block pb;
   qNtlmDecodePhase2(response, pb);
   response = qNtlmPhase3(ctx, pb);
   // send response (b64 encoded??)
*/

/*
   TODO:
    - Fix unicode handling
    - add v2 handling
*/

class QNtlmBuffer {
public:
    QNtlmBuffer() : len(0), maxLen(0), offset(0) {}
    quint16 len;
    quint16 maxLen;
    quint32 offset;
    enum { Size = 8 };
};

class QNtlmPhase1BlockBase
{
public:
    char magic[8];
    quint32 type;
    quint32 flags;
    QNtlmBuffer domain;
    QNtlmBuffer workstation;
    enum { Size = 32 };
};

// ################# check paddings
class QNtlmPhase2BlockBase
{
public:
    char magic[8];
    quint32 type;
    QNtlmBuffer targetName;
    quint32 flags;
    unsigned char challenge[8];
    quint32 context[2];
    QNtlmBuffer targetInfo;
    enum { Size = 48 };
};

class QNtlmPhase3BlockBase {
public:
    char magic[8];
    quint32 type;
    QNtlmBuffer lmResponse;
    QNtlmBuffer ntlmResponse;
    QNtlmBuffer domain;
    QNtlmBuffer user;
    QNtlmBuffer workstation;
    QNtlmBuffer sessionKey;
    quint32 flags;
    enum { Size = 64 };
};

static void qStreamNtlmBuffer(QDataStream& ds, const QByteArray& s)
{
    ds.writeRawData(s.constData(), s.size());
}


static void qStreamNtlmString(QDataStream& ds, const QString& s, bool unicode)
{
    if (!unicode) {
        qStreamNtlmBuffer(ds, s.toLatin1());
        return;
    }
    const ushort *d = s.utf16();
    for (int i = 0; i < s.length(); ++i) 
        ds << d[i];
}



static int qEncodeNtlmBuffer(QNtlmBuffer& buf, int offset, const QByteArray& s)
{
    buf.len = s.size();
    buf.maxLen = buf.len;
    buf.offset = (offset + 1) & ~1;
    return buf.offset + buf.len;
}


static int qEncodeNtlmString(QNtlmBuffer& buf, int offset, const QString& s, bool unicode)
{
    if (!unicode)
        return qEncodeNtlmBuffer(buf, offset, s.toLatin1());
    buf.len = 2 * s.length();
    buf.maxLen = buf.len;
    buf.offset = (offset + 1) & ~1;
    return buf.offset + buf.len;
}


static QDataStream& operator<<(QDataStream& s, const QNtlmBuffer& b)
{
    s << b.len << b.maxLen << b.offset;
    return s;
}

static QDataStream& operator>>(QDataStream& s, QNtlmBuffer& b)
{
    s >> b.len >> b.maxLen >> b.offset;
    return s;
}


class QNtlmPhase1Block : public QNtlmPhase1BlockBase
{  // request
public:
    QNtlmPhase1Block() {
        qstrncpy(magic, "NTLMSSP", 8);
        type = 1;
        flags = NTLMSSP_NEGOTIATE_UNICODE | NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_REQUEST_TARGET;
    }

    // extracted
    QString domainStr, workstationStr;
};


class QNtlmPhase2Block : public QNtlmPhase2BlockBase
{  // challenge
public:
    QNtlmPhase2Block() {
        magic[0] = 0;
        type = 0xffffffff;
    }

    // extracted
    QString targetNameStr, targetInfoStr;
};



class QNtlmPhase3Block : public QNtlmPhase3BlockBase {  // response
public:
    QNtlmPhase3Block() {
        qstrncpy(magic, "NTLMSSP", 8);
        type = 3;
        flags = NTLMSSP_NEGOTIATE_UNICODE | NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_TARGET_INFO;
    }

    // extracted
    QByteArray lmResponseBuf, ntlmResponseBuf;
    QString domainStr, userStr, workstationStr, sessionKeyStr;
};


static QDataStream& operator<<(QDataStream& s, const QNtlmPhase1Block& b) {
    bool unicode = (b.flags & NTLMSSP_NEGOTIATE_UNICODE);
    
    s.writeRawData(b.magic, sizeof(b.magic));
    s << b.type;
    s << b.flags;
    s << b.domain;
    s << b.workstation;
    if (!b.domainStr.isEmpty()) 
        qStreamNtlmString(s, b.domainStr, unicode);
    if (!b.workstationStr.isEmpty()) 
        qStreamNtlmString(s, b.workstationStr, unicode);
    return s;
}


static QDataStream& operator<<(QDataStream& s, const QNtlmPhase3Block& b) {
    bool unicode = (b.flags & NTLMSSP_NEGOTIATE_UNICODE);
    s.writeRawData(b.magic, sizeof(b.magic));
    s << b.type;
    s << b.lmResponse;
    s << b.ntlmResponse;
    s << b.domain;
    s << b.user;
    s << b.workstation;
    s << b.sessionKey;
    s << b.flags;

    if (!b.domainStr.isEmpty()) 
        qStreamNtlmString(s, b.domainStr, unicode);

    qStreamNtlmString(s, b.userStr, unicode);

    if (!b.workstationStr.isEmpty()) 
        qStreamNtlmString(s, b.workstationStr, unicode);

    // Send auth info
    qStreamNtlmBuffer(s, b.lmResponseBuf);
    qStreamNtlmBuffer(s, b.ntlmResponseBuf);
    

    return s;
}


static QByteArray qNtlmPhase1()
{
    QByteArray rc;
    QDataStream ds(&rc, QIODevice::WriteOnly);
    ds.setByteOrder(QDataStream::LittleEndian);
    QNtlmPhase1Block pb;
    ds << pb;
    return rc;
}


static QByteArray qStringAsUcs2Le(const QString& src)
{
    QByteArray rc(2*src.length(), 0);
    const unsigned short *s = src.utf16();
    unsigned short *d = (unsigned short*)rc.data();
    for (int i = 0; i < src.length(); ++i) {
        d[i] = qToLittleEndian(s[i]);
    }
    return rc;
}


static QString qStringFromUcs2Le(const QByteArray& src)
{
    Q_ASSERT(src.size() % 2 == 0);
    unsigned short *d = (unsigned short*)src.data();
    for (int i = 0; i < src.length() / 2; ++i) {
        d[i] = qFromLittleEndian(d[i]);
    }
    return QString((const QChar *)src.data(), src.size()/2);
}


static QByteArray qEncodeNtlmResponse(const QAuthenticatorPrivate *ctx, const QNtlmPhase2Block& ch)
{
    QCryptographicHash md4(QCryptographicHash::Md4);
    QByteArray asUcs2Le = qStringAsUcs2Le(ctx->password);
    md4.addData(asUcs2Le.data(), asUcs2Le.size());

    unsigned char md4hash[22];
    memset(md4hash, 0, sizeof(md4hash));
    QByteArray hash = md4.result();
    Q_ASSERT(hash.size() == 16);
    memcpy(md4hash, hash.constData(), 16);

    QByteArray rc(24, 0);
    deshash((unsigned char *)rc.data(), md4hash, (unsigned char *)ch.challenge);
    deshash((unsigned char *)rc.data() + 8, md4hash + 7, (unsigned char *)ch.challenge);
    deshash((unsigned char *)rc.data() + 16, md4hash + 14, (unsigned char *)ch.challenge);

    hash.fill(0);
    return rc;
}


static QByteArray qEncodeLmResponse(const QAuthenticatorPrivate *ctx, const QNtlmPhase2Block& ch)
{
    QByteArray hash(21, 0);
    QByteArray key(14, 0);
    qstrncpy(key.data(), ctx->password.toUpper().toLatin1(), 14);
    const char *block = "KGS!@#$%";

    deshash((unsigned char *)hash.data(), (unsigned char *)key.data(), (unsigned char *)block);
    deshash((unsigned char *)hash.data() + 8, (unsigned char *)key.data() + 7, (unsigned char *)block);
    key.fill(0);

    QByteArray rc(24, 0);
    deshash((unsigned char *)rc.data(), (unsigned char *)hash.data(), ch.challenge);
    deshash((unsigned char *)rc.data() + 8, (unsigned char *)hash.data() + 7, ch.challenge);
    deshash((unsigned char *)rc.data() + 16, (unsigned char *)hash.data() + 14, ch.challenge);

    hash.fill(0);
    return rc;
}


static bool qNtlmDecodePhase2(const QByteArray& data, QNtlmPhase2Block& ch)
{
    Q_ASSERT(QNtlmPhase2BlockBase::Size == sizeof(QNtlmPhase2BlockBase));
    if (data.size() < QNtlmPhase2BlockBase::Size) 
        return false;

    
    QDataStream ds(data);
    ds.setByteOrder(QDataStream::LittleEndian);
    if (ds.readRawData(ch.magic, 8) < 8)
        return false;
    if (strncmp(ch.magic, "NTLMSSP", 8) != 0)
        return false;
    
    ds >> ch.type;
    if (ch.type != 2)
        return false;
    
    ds >> ch.targetName;
    ds >> ch.flags;
    if (ds.readRawData((char *)ch.challenge, 8) < 8)
        return false;
    ds >> ch.context[0] >> ch.context[1];
    ds >> ch.targetInfo;

    if (ch.targetName.len > 0) {
        if (ch.targetName.len + ch.targetName.offset >= (unsigned)data.size()) 
            return false;

        ch.targetNameStr = qStringFromUcs2Le(data.mid(ch.targetName.offset, ch.targetName.len));
    }

    if (ch.targetInfo.len > 0) {
        // UNUSED right now
    }

    return true;
}


static QByteArray qNtlmPhase3(QAuthenticatorPrivate *ctx, const QByteArray& phase2data)
{
    QNtlmPhase2Block ch;
    if (!qNtlmDecodePhase2(phase2data, ch))
        return QByteArray();
    
    QByteArray rc;
    QDataStream ds(&rc, QIODevice::WriteOnly);
    ds.setByteOrder(QDataStream::LittleEndian);
    QNtlmPhase3Block pb;

    bool unicode = ch.flags & NTLMSSP_NEGOTIATE_UNICODE;

    ctx->realm = ch.targetNameStr;

    pb.flags = NTLMSSP_NEGOTIATE_NTLM;
    if (unicode)
        pb.flags |= NTLMSSP_NEGOTIATE_UNICODE;
    else
        pb.flags |= NTLMSSP_NEGOTIATE_OEM;
    

    int offset = QNtlmPhase3BlockBase::Size;
    Q_ASSERT(QNtlmPhase3BlockBase::Size == sizeof(QNtlmPhase3BlockBase));
    
    offset = qEncodeNtlmString(pb.domain, offset, ctx->realm, unicode);
    pb.domainStr = ctx->realm;
    
    offset = qEncodeNtlmString(pb.user, offset, ctx->user, unicode);
    pb.userStr = ctx->user;

    offset = qEncodeNtlmString(pb.workstation, offset, ctx->workstation, unicode);
    pb.workstationStr = ctx->workstation;

    // Get LM response
    pb.lmResponseBuf = qEncodeLmResponse(ctx, ch);
    offset = qEncodeNtlmBuffer(pb.lmResponse, offset, pb.lmResponseBuf);
    
    // Get NTLM response
    pb.ntlmResponseBuf = qEncodeNtlmResponse(ctx, ch);
    offset = qEncodeNtlmBuffer(pb.ntlmResponse, offset, pb.ntlmResponseBuf);


    // Encode and send
    ds << pb;

    return rc;
}