libwinpr-sspi: simplify NTLM header and fields read/write

diff --git a/include/winpr/wtypes.h b/include/winpr/wtypes.h
index 94d5ac4..1311132 100644 (file)
--- a/include/winpr/wtypes.h
+++ b/include/winpr/wtypes.h
@@ -54,6 +54,14 @@ typedef float FLOAT;
 typedef unsigned char UCHAR, *PUCHAR;
 typedef short SHORT;
 
+#ifndef FALSE
+#define FALSE                  0
+#endif
+
+#ifndef TRUE
+#define TRUE                   1
+#endif
+
 typedef void* HANDLE, *LPHANDLE;
 typedef DWORD HCALL;
 typedef int INT, *LPINT;

diff --git a/winpr/sspi/NTLM/ntlm.h b/winpr/sspi/NTLM/ntlm.h
index 904d8d8..3a6e06e 100644 (file)
--- a/winpr/sspi/NTLM/ntlm.h
+++ b/winpr/sspi/NTLM/ntlm.h
@@ -136,14 +136,21 @@ struct _NTLM_VERSION_INFO
 };
 typedef struct _NTLM_VERSION_INFO NTLM_VERSION_INFO;
 
-struct _NTLM_MESSAGE_FIELD
+struct _NTLM_MESSAGE_FIELDS
 {
        UINT16 Len;
        UINT16 MaxLen;
        PBYTE Buffer;
        UINT32 BufferOffset;
 };
-typedef struct _NTLM_MESSAGE_FIELD NTLM_MESSAGE_FIELD;
+typedef struct _NTLM_MESSAGE_FIELDS NTLM_MESSAGE_FIELDS;
+
+struct _NTLM_MESSAGE_HEADER
+{
+       BYTE Signature[8];
+       UINT32 MessageType;
+};
+typedef struct _NTLM_MESSAGE_HEADER NTLM_MESSAGE_HEADER;
 
 struct _NTLM_NEGOTIATE_MESSAGE
 {
@@ -151,8 +158,8 @@ struct _NTLM_NEGOTIATE_MESSAGE
        UINT32 MessageType;
        UINT32 NegotiateFlags;
        NTLM_VERSION_INFO Version;
-       NTLM_MESSAGE_FIELD DomainName;
-       NTLM_MESSAGE_FIELD Workstation;
+       NTLM_MESSAGE_FIELDS DomainName;
+       NTLM_MESSAGE_FIELDS Workstation;
 };
 typedef struct _NTLM_NEGOTIATE_MESSAGE NTLM_NEGOTIATE_MESSAGE;
 
@@ -163,8 +170,8 @@ struct _NTLM_CHALLENGE_MESSAGE
        UINT32 NegotiateFlags;
        BYTE ServerChallenge[8];
        NTLM_VERSION_INFO Version;
-       NTLM_MESSAGE_FIELD TargetName;
-       NTLM_MESSAGE_FIELD TargetInfo;
+       NTLM_MESSAGE_FIELDS TargetName;
+       NTLM_MESSAGE_FIELDS TargetInfo;
 };
 typedef struct _NTLM_CHALLENGE_MESSAGE NTLM_CHALLENGE_MESSAGE;
 
@@ -174,12 +181,12 @@ struct _NTLM_AUTHENTICATE_MESSAGE
        UINT32 MessageType;
        UINT32 NegotiateFlags;
        NTLM_VERSION_INFO Version;
-       NTLM_MESSAGE_FIELD DomainName;
-       NTLM_MESSAGE_FIELD UserName;
-       NTLM_MESSAGE_FIELD Workstation;
-       NTLM_MESSAGE_FIELD LmChallengeResponse;
-       NTLM_MESSAGE_FIELD NtChallengeResponse;
-       NTLM_MESSAGE_FIELD EncryptedRandomSessionKey;
+       NTLM_MESSAGE_FIELDS DomainName;
+       NTLM_MESSAGE_FIELDS UserName;
+       NTLM_MESSAGE_FIELDS Workstation;
+       NTLM_MESSAGE_FIELDS LmChallengeResponse;
+       NTLM_MESSAGE_FIELDS NtChallengeResponse;
+       NTLM_MESSAGE_FIELDS EncryptedRandomSessionKey;
        BYTE MessageIntegrityCheck[16];
 };
 typedef struct _NTLM_AUTHENTICATE_MESSAGE NTLM_AUTHENTICATE_MESSAGE;

diff --git a/winpr/sspi/NTLM/ntlm_message.c b/winpr/sspi/NTLM/ntlm_message.c
index 214f226..cb8cedc 100644 (file)
--- a/winpr/sspi/NTLM/ntlm_message.c
+++ b/winpr/sspi/NTLM/ntlm_message.c
@@ -29,7 +29,7 @@
 
 #include "ntlm_message.h"
 
-static const char NTLM_SIGNATURE[] = "NTLMSSP";
+static const char NTLM_SIGNATURE[8] = "NTLMSSP\0";
 
 static const char* const NTLM_NEGOTIATE_STRINGS[] =
 {
@@ -86,6 +86,58 @@ void ntlm_print_negotiate_flags(UINT32 flags)
        printf("}\n");
 }
 
+void ntlm_read_message_header(PStream s, NTLM_MESSAGE_HEADER* header)
+{
+       StreamRead(s, header->Signature, sizeof(NTLM_SIGNATURE));
+       StreamRead_UINT32(s, header->MessageType);
+}
+
+void ntlm_write_message_header(PStream s, NTLM_MESSAGE_HEADER* header)
+{
+       StreamWrite(s, header->Signature, sizeof(NTLM_SIGNATURE));
+       StreamWrite_UINT32(s, header->MessageType);
+}
+
+void ntlm_populate_message_header(NTLM_MESSAGE_HEADER* header, UINT32 MessageType)
+{
+       CopyMemory(header->Signature, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE));
+       header->MessageType = MessageType;
+}
+
+BOOL ntlm_validate_message_header(PStream s, NTLM_MESSAGE_HEADER* header, UINT32 MessageType)
+{
+       if (memcmp(header->Signature, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE)) != 0)
+       {
+               printf("Unexpected NTLM signature: %s, expected:%s\n", header->Signature, NTLM_SIGNATURE);
+               return FALSE;
+       }
+
+       if (header->MessageType != MessageType)
+       {
+               printf("Unexpected NTLM message type: %d, expected: %d\n", header->MessageType, MessageType);
+               return FALSE;
+       }
+
+       return TRUE;
+}
+
+void ntlm_read_message_fields(PStream s, NTLM_MESSAGE_FIELDS* fields)
+{
+       StreamRead_UINT16(s, fields->Len); /* Len (2 bytes) */
+       StreamRead_UINT16(s, fields->MaxLen); /* MaxLen (2 bytes) */
+       StreamRead_UINT32(s, fields->BufferOffset); /* BufferOffset (4 bytes) */
+}
+
+void ntlm_write_message_fields(PStream s, NTLM_MESSAGE_FIELDS* fields)
+{
+       if (fields->MaxLen < 1)
+               fields->MaxLen = fields->Len;
+
+       StreamWrite_UINT16(s, fields->Len); /* Len (2 bytes) */
+       StreamWrite_UINT16(s, fields->MaxLen); /* MaxLen (2 bytes) */
+       StreamWrite_UINT32(s, fields->BufferOffset); /* BufferOffset (4 bytes) */
+}
+
 SECURITY_STATUS ntlm_read_NegotiateMessage(NTLM_CONTEXT* context, PSecBuffer buffer)
 {
        PStream s;
@@ -95,17 +147,9 @@ SECURITY_STATUS ntlm_read_NegotiateMessage(NTLM_CONTEXT* context, PSecBuffer buf
        ZeroMemory(&message, sizeof(message));
        s = PStreamAllocAttach(buffer->pvBuffer, buffer->cbBuffer);
 
-       StreamRead(s, message.Signature, 8);
-       StreamRead_UINT32(s, message.MessageType);
+       ntlm_read_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
-       if (memcmp(message.Signature, NTLM_SIGNATURE, 8) != 0)
-       {
-               printf("Unexpected NTLM signature: %s, expected:%s\n", message.Signature, NTLM_SIGNATURE);
-               PStreamFreeDetach(s);
-               return SEC_E_INVALID_TOKEN;
-       }
-
-       if (message.MessageType != MESSAGE_TYPE_NEGOTIATE)
+       if (!ntlm_validate_message_header(s, (NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_NEGOTIATE))
        {
                PStreamFreeDetach(s);
                return SEC_E_INVALID_TOKEN;
@@ -118,16 +162,12 @@ SECURITY_STATUS ntlm_read_NegotiateMessage(NTLM_CONTEXT* context, PSecBuffer buf
        /* only set if NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED is set */
 
        /* DomainNameFields (8 bytes) */
-       StreamRead_UINT16(s, message.DomainName.Len); /* DomainNameLen */
-       StreamRead_UINT16(s, message.DomainName.MaxLen); /* DomainNameMaxLen */
-       StreamRead_UINT32(s, message.DomainName.BufferOffset); /* DomainNameBufferOffset */
+       ntlm_read_message_fields(s, &(message.DomainName));
 
        /* only set if NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED is set */
 
        /* WorkstationFields (8 bytes) */
-       StreamRead_UINT16(s, message.Workstation.Len); /* WorkstationLen */
-       StreamRead_UINT16(s, message.Workstation.MaxLen); /* WorkstationMaxLen */
-       StreamRead_UINT32(s, message.Workstation.BufferOffset); /* WorkstationBufferOffset */
+       ntlm_read_message_fields(s, &(message.Workstation));
 
        if (message.NegotiateFlags & NTLMSSP_NEGOTIATE_VERSION)
        {
@@ -164,8 +204,10 @@ SECURITY_STATUS ntlm_write_NegotiateMessage(NTLM_CONTEXT* context, PSecBuffer bu
        ZeroMemory(&message, sizeof(message));
        s = PStreamAllocAttach(buffer->pvBuffer, buffer->cbBuffer);
 
-       StreamWrite(s, NTLM_SIGNATURE, 8); /* Signature (8 bytes) */
-       StreamWrite_UINT32(s, MESSAGE_TYPE_NEGOTIATE); /* MessageType */
+       ntlm_populate_message_header((NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_NEGOTIATE);
+
+       /* Message Header (12 bytes) */
+       ntlm_write_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
        if (context->ntlm_v2)
        {
@@ -207,16 +249,12 @@ SECURITY_STATUS ntlm_write_NegotiateMessage(NTLM_CONTEXT* context, PSecBuffer bu
        /* only set if NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED is set */
 
        /* DomainNameFields (8 bytes) */
-       StreamWrite_UINT16(s, 0); /* DomainNameLen */
-       StreamWrite_UINT16(s, 0); /* DomainNameMaxLen */
-       StreamWrite_UINT32(s, 0); /* DomainNameBufferOffset */
+       ntlm_write_message_fields(s, &(message.DomainName));
 
        /* only set if NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED is set */
 
        /* WorkstationFields (8 bytes) */
-       StreamWrite_UINT16(s, 0); /* WorkstationLen */
-       StreamWrite_UINT16(s, 0); /* WorkstationMaxLen */
-       StreamWrite_UINT32(s, 0); /* WorkstationBufferOffset */
+       ntlm_write_message_fields(s, &(message.Workstation));
 
        if (message.NegotiateFlags & NTLMSSP_NEGOTIATE_VERSION)
        {
@@ -266,17 +304,9 @@ SECURITY_STATUS ntlm_read_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer buf
        ZeroMemory(&message, sizeof(message));
        s = PStreamAllocAttach(buffer->pvBuffer, buffer->cbBuffer);
 
-       StreamRead(s, message.Signature, 8);
-       StreamRead_UINT32(s, message.MessageType);
+       ntlm_read_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
-       if (memcmp(message.Signature, NTLM_SIGNATURE, 8) != 0)
-       {
-               printf("Unexpected NTLM signature: %s, expected:%s\n", message.Signature, NTLM_SIGNATURE);
-               PStreamFreeDetach(s);
-               return SEC_E_INVALID_TOKEN;
-       }
-
-       if (message.MessageType != MESSAGE_TYPE_CHALLENGE)
+       if (!ntlm_validate_message_header(s, (NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_CHALLENGE))
        {
                PStreamFreeDetach(s);
                return SEC_E_INVALID_TOKEN;
@@ -285,9 +315,7 @@ SECURITY_STATUS ntlm_read_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer buf
        StartOffset = StreamGetPointer(s) - 12;
 
        /* TargetNameFields (8 bytes) */
-       StreamRead_UINT16(s, message.TargetName.Len); /* TargetNameLen (2 bytes) */
-       StreamRead_UINT16(s, message.TargetName.MaxLen); /* TargetNameMaxLen (2 bytes) */
-       StreamRead_UINT32(s, message.TargetName.BufferOffset); /* TargetNameBufferOffset (4 bytes) */
+       ntlm_read_message_fields(s, &(message.TargetName));
 
        StreamRead_UINT32(s, context->NegotiateFlags); /* NegotiateFlags (4 bytes) */
 
@@ -299,9 +327,7 @@ SECURITY_STATUS ntlm_read_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer buf
        StreamSeek(s, 8); /* Reserved (8 bytes), should be ignored */
 
        /* TargetInfoFields (8 bytes) */
-       StreamRead_UINT16(s, message.TargetInfo.Len); /* TargetInfoLen (2 bytes) */
-       StreamRead_UINT16(s, message.TargetInfo.MaxLen); /* TargetInfoMaxLen (2 bytes) */
-       StreamRead_UINT32(s, message.TargetInfo.BufferOffset); /* TargetInfoBufferOffset (4 bytes) */
+       ntlm_read_message_fields(s, &(message.TargetInfo));
 
        /* only present if NTLMSSP_NEGOTIATE_VERSION is set */
 
@@ -466,8 +492,10 @@ SECURITY_STATUS ntlm_write_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer bu
        ZeroMemory(&message, sizeof(message));
        s = PStreamAllocAttach(buffer->pvBuffer, buffer->cbBuffer);
 
-       StreamWrite(s, NTLM_SIGNATURE, 8); /* Signature (8 bytes) */
-       StreamWrite_UINT32(s, MESSAGE_TYPE_CHALLENGE); /* MessageType */
+       ntlm_populate_message_header((NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_CHALLENGE);
+
+       /* Message Header (12 bytes) */
+       ntlm_write_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
        if (context->NegotiateFlags & NTLMSSP_REQUEST_TARGET)
        {
@@ -502,9 +530,7 @@ SECURITY_STATUS ntlm_write_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer bu
        message.TargetInfo.BufferOffset = message.TargetName.BufferOffset + message.TargetName.Len;
 
        /* TargetNameFields (8 bytes) */
-       StreamWrite_UINT16(s, message.TargetName.Len); /* TargetNameLen (2 bytes) */
-       StreamWrite_UINT16(s, message.TargetName.Len); /* TargetNameMaxLen (2 bytes) */
-       StreamWrite_UINT32(s, message.TargetName.BufferOffset); /* TargetNameBufferOffset (4 bytes) */
+       ntlm_write_message_fields(s, &(message.TargetName));
 
        StreamWrite_UINT32(s, context->NegotiateFlags); /* NegotiateFlags (4 bytes) */
 
@@ -512,9 +538,7 @@ SECURITY_STATUS ntlm_write_ChallengeMessage(NTLM_CONTEXT* context, PSecBuffer bu
        StreamZero(s, 8); /* Reserved (8 bytes), should be ignored */
 
        /* TargetInfoFields (8 bytes) */
-       StreamWrite_UINT16(s, message.TargetInfo.Len); /* TargetInfoLen (2 bytes) */
-       StreamWrite_UINT16(s, message.TargetInfo.Len); /* TargetInfoMaxLen (2 bytes) */
-       StreamWrite_UINT32(s, message.TargetInfo.BufferOffset); /* TargetInfoBufferOffset (4 bytes) */
+       ntlm_write_message_fields(s, &(message.TargetInfo));
 
        /* only present if NTLMSSP_NEGOTIATE_VERSION is set */
 
@@ -574,55 +598,35 @@ SECURITY_STATUS ntlm_read_AuthenticateMessage(NTLM_CONTEXT* context, PSecBuffer
        ZeroMemory(&message, sizeof(message));
        s = PStreamAllocAttach(buffer->pvBuffer, buffer->cbBuffer);
 
-       StreamRead(s, message.Signature, 8);
-       StreamRead_UINT32(s, message.MessageType);
-
-       if (memcmp(message.Signature, NTLM_SIGNATURE, 8) != 0)
-       {
-               printf("Unexpected NTLM signature: %s, expected:%s\n", message.Signature, NTLM_SIGNATURE);
-               PStreamFreeDetach(s);
-               return SEC_E_INVALID_TOKEN;
-       }
+       ntlm_read_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
-       if (message.MessageType != MESSAGE_TYPE_AUTHENTICATE)
+       if (!ntlm_validate_message_header(s, (NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_AUTHENTICATE))
        {
                PStreamFreeDetach(s);
                return SEC_E_INVALID_TOKEN;
        }
 
        /* LmChallengeResponseFields (8 bytes) */
-       StreamRead_UINT16(s, message.LmChallengeResponse.Len); /* LmChallengeResponseLen */
-       StreamRead_UINT16(s, message.LmChallengeResponse.MaxLen); /* LmChallengeResponseMaxLen */
-       StreamRead_UINT32(s, message.LmChallengeResponse.BufferOffset); /* LmChallengeResponseBufferOffset */
+       ntlm_read_message_fields(s, &(message.LmChallengeResponse));
 
        /* NtChallengeResponseFields (8 bytes) */
-       StreamRead_UINT16(s, message.NtChallengeResponse.Len); /* NtChallengeResponseLen */
-       StreamRead_UINT16(s, message.NtChallengeResponse.MaxLen); /* NtChallengeResponseMaxLen */
-       StreamRead_UINT32(s, message.NtChallengeResponse.BufferOffset); /* NtChallengeResponseBufferOffset */
+       ntlm_read_message_fields(s, &(message.NtChallengeResponse));
 
        /* only set if NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED is set */
 
        /* DomainNameFields (8 bytes) */
-       StreamRead_UINT16(s, message.DomainName.Len); /* DomainNameLen */
-       StreamRead_UINT16(s, message.DomainName.MaxLen); /* DomainNameMaxLen */
-       StreamRead_UINT32(s, message.DomainName.BufferOffset); /* DomainNameBufferOffset */
+       ntlm_read_message_fields(s, &(message.DomainName));
 
        /* UserNameFields (8 bytes) */
-       StreamRead_UINT16(s, message.UserName.Len); /* UserNameLen */
-       StreamRead_UINT16(s, message.UserName.MaxLen); /* UserNameMaxLen */
-       StreamRead_UINT32(s, message.UserName.BufferOffset); /* UserNameBufferOffset */
+       ntlm_read_message_fields(s, &(message.UserName));
 
        /* only set if NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED is set */
 
        /* WorkstationFields (8 bytes) */
-       StreamRead_UINT16(s, message.Workstation.Len); /* WorkstationLen */
-       StreamRead_UINT16(s, message.Workstation.MaxLen); /* WorkstationMaxLen */
-       StreamRead_UINT32(s, message.Workstation.BufferOffset); /* WorkstationBufferOffset */
+       ntlm_read_message_fields(s, &(message.Workstation));
 
        /* EncryptedRandomSessionKeyFields (8 bytes) */
-       StreamRead_UINT16(s, message.EncryptedRandomSessionKey.Len); /* EncryptedRandomSessionKeyLen */
-       StreamRead_UINT16(s, message.EncryptedRandomSessionKey.MaxLen); /* EncryptedRandomSessionKeyMaxLen */
-       StreamRead_UINT32(s, message.EncryptedRandomSessionKey.BufferOffset); /* EncryptedRandomSessionKeyBufferOffset */
+       ntlm_read_message_fields(s, &(message.EncryptedRandomSessionKey));
 
        StreamRead_UINT32(s, message.NegotiateFlags); /* NegotiateFlags (4 bytes) */
 
@@ -900,42 +904,32 @@ SECURITY_STATUS ntlm_write_AuthenticateMessage(NTLM_CONTEXT* context, PSecBuffer
        message.NtChallengeResponse.BufferOffset = message.LmChallengeResponse.BufferOffset + message.LmChallengeResponse.Len;
        message.EncryptedRandomSessionKey.BufferOffset = message.NtChallengeResponse.BufferOffset + message.NtChallengeResponse.Len;
 
-       StreamWrite(s, NTLM_SIGNATURE, 8); /* Signature (8 bytes) */
-       StreamWrite_UINT32(s, MESSAGE_TYPE_AUTHENTICATE); /* MessageType */
+       ntlm_populate_message_header((NTLM_MESSAGE_HEADER*) &message, MESSAGE_TYPE_AUTHENTICATE);
+
+       /* Message Header (12 bytes) */
+       ntlm_write_message_header(s, (NTLM_MESSAGE_HEADER*) &message);
 
        /* LmChallengeResponseFields (8 bytes) */
-       StreamWrite_UINT16(s, message.LmChallengeResponse.Len); /* LmChallengeResponseLen */
-       StreamWrite_UINT16(s, message.LmChallengeResponse.Len); /* LmChallengeResponseMaxLen */
-       StreamWrite_UINT32(s, message.LmChallengeResponse.BufferOffset); /* LmChallengeResponseBufferOffset */
+       ntlm_write_message_fields(s, &(message.LmChallengeResponse));
 
        /* NtChallengeResponseFields (8 bytes) */
-       StreamWrite_UINT16(s, message.NtChallengeResponse.Len); /* NtChallengeResponseLen */
-       StreamWrite_UINT16(s, message.NtChallengeResponse.Len); /* NtChallengeResponseMaxLen */
-       StreamWrite_UINT32(s, message.NtChallengeResponse.BufferOffset); /* NtChallengeResponseBufferOffset */
+       ntlm_write_message_fields(s, &(message.NtChallengeResponse));
 
        /* only set if NTLMSSP_NEGOTIATE_DOMAIN_SUPPLIED is set */
 
        /* DomainNameFields (8 bytes) */
-       StreamWrite_UINT16(s, message.DomainName.Len); /* DomainNameLen */
-       StreamWrite_UINT16(s, message.DomainName.Len); /* DomainNameMaxLen */
-       StreamWrite_UINT32(s, message.DomainName.BufferOffset); /* DomainNameBufferOffset */
+       ntlm_write_message_fields(s, &(message.DomainName));
 
        /* UserNameFields (8 bytes) */
-       StreamWrite_UINT16(s, message.UserName.Len); /* UserNameLen */
-       StreamWrite_UINT16(s, message.UserName.Len); /* UserNameMaxLen */
-       StreamWrite_UINT32(s, message.UserName.BufferOffset); /* UserNameBufferOffset */
+       ntlm_write_message_fields(s, &(message.UserName));
 
        /* only set if NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED is set */
 
        /* WorkstationFields (8 bytes) */
-       StreamWrite_UINT16(s, message.Workstation.Len); /* WorkstationLen */
-       StreamWrite_UINT16(s, message.Workstation.Len); /* WorkstationMaxLen */
-       StreamWrite_UINT32(s, message.Workstation.BufferOffset); /* WorkstationBufferOffset */
+       ntlm_write_message_fields(s, &(message.Workstation));
 
        /* EncryptedRandomSessionKeyFields (8 bytes) */
-       StreamWrite_UINT16(s, message.EncryptedRandomSessionKey.Len); /* EncryptedRandomSessionKeyLen */
-       StreamWrite_UINT16(s, message.EncryptedRandomSessionKey.Len); /* EncryptedRandomSessionKeyMaxLen */
-       StreamWrite_UINT32(s, message.EncryptedRandomSessionKey.BufferOffset); /* EncryptedRandomSessionKeyBufferOffset */
+       ntlm_write_message_fields(s, &(message.EncryptedRandomSessionKey));
 
        StreamWrite_UINT32(s, message.NegotiateFlags); /* NegotiateFlags (4 bytes) */