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[MS-RDPBCGR].pdf : username with smartcard logon RRS feed

  • Question

  • Hello

    I need more information about the smartcard logon procedure.

    My scenario is the following:

    The PIN code is entered by the user before the RDP connection is established.
    And when the RDP session is established, this PIN code is given as the 'Password' in the TS_INFO_PACKET (and the flag 'INFO_PASSWORD_IS_SC_PIN' is set).
    This works perfectly but the logon process is long (in addition the username/password fields are briefly displayed!)

    With MS RDP client, this process is faster. And I noticed, in addition of the PIN code, the username is also given in the TS_INFO_PACKET. But this username is unusual. It's like '@@B1bmKxo5HLFGD4y44OL4gE7UFabG'.

    Could you explain me what is this username format and how the MS RDP Client manages to get it (from LDAP, from the smartcard...)

    Thank you
    Vincent

    Wednesday, January 27, 2016 11:04 AM

Answers

  • Hi Vincent:

    Can you please send me decrypted network captures for both scenarios i.e. Windows client and your client?

    You can send it to my attention to dochelp at Microsoft dot com.


    Regards, Obaid Farooqi

    • Marked as answer by vincent dedieu Friday, February 26, 2016 10:16 AM
    Tuesday, February 16, 2016 7:43 PM
    Owner
  • Forum update:

    This issue is resolved. The document MS-RDPBCGR is modified as follows:

    The description for UserName field in section "2.2.1.11.1.1  Info Packet (TS_INFO_PACKET)" is modified and the new description addresses the question posed above. Here is the text for convenience. Please always refer to document directly for the latest content.

    "

    UserName (variable): Variable-length logon user name of the user (the length in bytes is given by
    the cbUserName field). The maximum length allowed by RDP 4.0 servers is 44 bytes (including
    the mandatory null terminator), while all other versions of RDP servers allow a maximum length of
    512 bytes (including the mandatory null terminator). The field MUST contain at least a null
    terminator character in Windows-1252 or Unicode format (depending on the presence of the
    INFO_UNICODE flag). The contents of the UserName field SHOULD be ignored if the
    INFO_PASSWORD_IS_SC_PIN (0x00040000) flag is specified in the flags field.

    "


    Regards, Obaid Farooqi

    Tuesday, May 3, 2016 7:39 PM
    Owner

All replies

  • Hi Vincent,

    Thank you for your question.  An engineer from the protocols team will contact you soon.


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team

    Wednesday, January 27, 2016 2:50 PM
    Moderator
  • Hi Vincent:

    I'll help you with this case and will be in touch as soon as I have an answer.


    Regards, Obaid Farooqi

    Tuesday, February 2, 2016 5:30 PM
    Owner
  • Hi Vincent:

    Can you please send me decrypted network captures for both scenarios i.e. Windows client and your client?

    You can send it to my attention to dochelp at Microsoft dot com.


    Regards, Obaid Farooqi

    • Marked as answer by vincent dedieu Friday, February 26, 2016 10:16 AM
    Tuesday, February 16, 2016 7:43 PM
    Owner
  • Forum update:

    This issue is resolved. The document MS-RDPBCGR is modified as follows:

    The description for UserName field in section "2.2.1.11.1.1  Info Packet (TS_INFO_PACKET)" is modified and the new description addresses the question posed above. Here is the text for convenience. Please always refer to document directly for the latest content.

    "

    UserName (variable): Variable-length logon user name of the user (the length in bytes is given by
    the cbUserName field). The maximum length allowed by RDP 4.0 servers is 44 bytes (including
    the mandatory null terminator), while all other versions of RDP servers allow a maximum length of
    512 bytes (including the mandatory null terminator). The field MUST contain at least a null
    terminator character in Windows-1252 or Unicode format (depending on the presence of the
    INFO_UNICODE flag). The contents of the UserName field SHOULD be ignored if the
    INFO_PASSWORD_IS_SC_PIN (0x00040000) flag is specified in the flags field.

    "


    Regards, Obaid Farooqi

    Tuesday, May 3, 2016 7:39 PM
    Owner