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MS-MICE: Stream Encryption RRS feed

  • Question

  • Hi,

    I'm new in this form and I'm trying to implement miracast over infrastructure with pin mode and stream encryption.

    At the moment I have successfully made the security handshake and I received the source ready message. Now I have to establish the rtp and uibc connection which are encrypted with the dtls keys.

    For me it is not clear what should I do now. Do I have to share the same dtls session (Port 7250) with the other new connections (rtp, uibc) (in my opinion not possible) or do I have  to extract the master secret, server random and client random from the dtls session and generate the 4 keys and use the keys to encrypt/decrypt the data? This is also difficult because I have to do the encryption/decryption depending on the cipher used in the session (in my case it was always ECDHE-RSA-AES256-SHA384 but this can be different). I can limit the supported cipher list but I don't know if all windows version will support this or do I have to export the keying material (with "EXTRACTOR-dtls_srtp"). Is it possible that the key changes during a established dtls session?

    I'm using openssl to make my implementation. Maybe somebody can give me a hint. The MS-MICE spec is not very helpful and it would be nice to describe these steps more in detail.

    Thank you

    Stefan

    Friday, August 2, 2019 12:35 PM

All replies

  • Hello Stefan,
    Thank you for this question. I will investigate this issue for you.

    Regards,
    Sreekanth Nadendla
    Microsoft Windows Open Specifications

    Friday, August 2, 2019 2:08 PM
    Moderator
  • Hello Stefan,
    Can you contact us by sending e-mail to dochelp at microsoft dot com?

    Regards,
    Sreekanth Nadendla
    Microsoft Windows Open Specifications
    Tuesday, August 6, 2019 6:20 PM
    Moderator
  • UPDATE 7 AUGUST 2019
    ----------------------------
    Suggested to review DTLS RFC with session resumption as focus. Since those details pertain to implementing DTLS, they will not be part of MS-MICE.


    Regards,
    Sreekanth Nadendla
    Microsoft Windows Open Specifications

    Friday, September 13, 2019 7:16 PM
    Moderator