Skip to content
  • Home Home Home, current page.
  • Moments Moments Moments, current page.

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
BRIAN_____'s profile
Brian Smith
Brian Smith
Brian Smith
@BRIAN_____

Tweets

Brian Smith

@BRIAN_____

Code farmer. Security, crypto, performance, networking, usability. Rust, C++, C, Haskell, DSLs, etc. *ring*, webpki, crypto-bench, mozilla::pkix.

Honolulu & San Francisco
briansmith.org
Joined April 2008

Tweets

  • © 2018 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Tim Dierks‏ @tdierks 17 Sep 2017
      Replying to @BRIAN_____

      DER ≠ ASN.1. I've written a handful of BER/DER encoders and decoders without coming near implementing ASN.1. DER is a decent TLV format.

      1 reply 1 retweet 0 likes
    2. Brian Smith‏ @BRIAN_____ 17 Sep 2017
      Replying to @tdierks

      I agree DER is a decent TLV format. However, it seems wrong to require parsing the DER at all just for 1 field that happens to be ASN.1 DER.

      1 reply 0 retweets 0 likes
    3. Tim Dierks‏ @tdierks 17 Sep 2017
      Replying to @BRIAN_____

      I don't know a lot about the U2F spec, but I agree that it should probably have lengths of its own for convenience and layer separation.

      1 reply 0 retweets 1 like
    4. Tim Dierks‏ @tdierks 17 Sep 2017
      Replying to @tdierks @BRIAN_____

      That said, isn't it just: it should start with 30 82, then the next two bytes are the length of the rest?

      1 reply 0 retweets 0 likes
    5. Brian Smith‏ @BRIAN_____ 17 Sep 2017
      Replying to @tdierks

      No, and that proves my point, I think. See also https://bugzilla.mozilla.org/show_bug.cgi?id=1064670 ….

      1 reply 0 retweets 0 likes
    6. Brian Smith‏ @BRIAN_____ 17 Sep 2017
      Replying to @BRIAN_____ @tdierks

      In particular, nothing requires overlong encodings to be rejected. I think that U2F spec could be updated to include that as an extra check.

      3 replies 0 retweets 1 like
    7. Brian Smith‏ @BRIAN_____ 17 Sep 2017
      Replying to @BRIAN_____ @tdierks

      Also, IIUC, attestation certificate can be (arguably, should be) < 256 bytes but not < 127 bytes, i.e. 0x30 0x81 <length byte> is allowed.

      1 reply 0 retweets 0 likes
    8. Tim Dierks‏ @tdierks 17 Sep 2017
      Replying to @BRIAN_____

      Yes, I don't know enough about the variety of certs actually seen here. I'm oversimplifying, unaware of general context.

      1 reply 0 retweets 0 likes
      Brian Smith‏ @BRIAN_____ 17 Sep 2017
      Replying to @tdierks

      If most certs are >= 256 bytes, probably safer for CA to always pad certs to >= 256 bytes, in case someone hard-coded 0x30 0x82 <len> <len>.

      9:02 PM - 17 Sep 2017
      1 reply 0 retweets 0 likes
        1. New conversation
        2. Tim Dierks‏ @tdierks 17 Sep 2017
          Replying to @BRIAN_____

          By my math, a P-256 cert signed with P-256 ECDSA is 235 bytes before you put in subject, issuer, serial number, or extensions.

          1 reply 0 retweets 0 likes
        3. Tim Dierks‏ @tdierks 17 Sep 2017
          Replying to @tdierks @BRIAN_____

          Unless I'm missing context, I'd be surprised to see one under 256 bytes in the wild.

          1 reply 0 retweets 0 likes
        4. Brian Smith‏ @BRIAN_____ 17 Sep 2017
          Replying to @tdierks

          Here's one that I think may be valid & reasonable that's 251 bytes: https://goo.gl/L2yCos . But usually there will be at least 1 extn.

          0 replies 0 retweets 0 likes
        5. End of conversation

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2018 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Cookies
        • Ads info