3 ms·

We moved to: time(NULL) * getpid() * clock() Thanks!

by justintocci 11y ago

joelthelion 11y ago
That's still not a good idea. Use your OS' random source.
- justintocci 11y ago
  We wanted to avoid anything controversial. Do we need to make this configurable to make everyone happy? https://www.schneier.com/blog/archives/2013/10/insecurities_in.html https://www.schneier.com/blog/archives/2013/10/insecurities_...
  - MrRadar 11y ago
    Even if it isn't perfect /dev/random is a hell of a lot more random than just taking the current time stamp and PID. Edit: For reference, this is exactly how the Netscape's original SSL implementation was broken: https://web.archive.org/web/20141214141822/http://www.cs.berkeley.edu/~daw/papers/ddj-netscape.html https://web.archive.org/web/20141214141822/http://www.cs.ber...
    - justintocci 11y ago
      Understood. Working on it now.
      - justintocci 11y ago
        Fixed!
Canada 11y ago
Still weak. Read the seed value from /dev/urandom or get it from CryptGenRandom if you're on Windows. I think it's also best to use #ifdef to prevent those hardcoded debugging keys from being included in production builds. That is, if you still need to keep them at all. edit: joelthelion: You are mistaken. It's not the 1990s anymore. Use the non-blocking /dev/urandom, not /dev/random. (I can't seem to reply directly to you)
- joelthelion 11y ago
  /dev/random, not /dev/urandom, if I'm not mistaken.
  - MrRadar 11y ago
    That's somewhat debatable: http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ But really either will be way better than anything you could homebrew.
  - DanBC 11y ago
    (EDIT: I reread this and it sounds like I'm ranting at you. Sorry, I'm not, even though it does read like that.) This is why cryptography is doomed to fail. This /dev/random vs /dev/urandom (blocking vs non-blocking and whether it matters) is discussed frequently on HN, usually with very long threads, and yet it still comes up. If I want to remember whether there's an apostrophe in possessive its there's a cartoon to tell me. We need a good, accurate, fact-checked cartoon for urandom vs random. (It's one of the things I'd do if I had FU money.)
sgk284 11y ago
That is truly a horrible seed. Use /dev/random
- justintocci 11y ago
  I just made it so that it uses the first 4 bytes it gets from /dev/random, if it can't open /dev/random, it falls back to what we had before. --nunzio
  - alcari 11y ago
    Don't fall back. If you don't have a reasonable enough environment to get a PRNG, you should halt and complain very loudly. As for actually generating random numbers, here's a good explanation from 'tptacek: http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/ http://sockpuppet.org/blog/2014/02/25/safely-generate-random...
    - deleted 11y ago
      [deleted]
    - justintocci 11y ago
      I have finished the error message and pushed to Github. Thank you for your input. I will look at the link you have referenced soon. --nunzio
  - pmontra 11y ago
    Use /dev/urandom instead of /dev/random See http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ for the reasons

We moved to: time(NULL) * getpid() * clock() Thanks!

joelthelion 11y ago

That's still not a good idea. Use your OS' random source.

justintocci 11y ago
We wanted to avoid anything controversial. Do we need to make this configurable to make everyone happy? https://www.schneier.com/blog/archives/2013/10/insecurities_in.html https://www.schneier.com/blog/archives/2013/10/insecurities_...
- MrRadar 11y ago
  Even if it isn't perfect /dev/random is a hell of a lot more random than just taking the current time stamp and PID. Edit: For reference, this is exactly how the Netscape's original SSL implementation was broken: https://web.archive.org/web/20141214141822/http://www.cs.berkeley.edu/~daw/papers/ddj-netscape.html https://web.archive.org/web/20141214141822/http://www.cs.ber...
  - justintocci 11y ago
    Understood. Working on it now.
    - justintocci 11y ago
      Fixed!

Canada 11y ago

Still weak. Read the seed value from /dev/urandom or get it from CryptGenRandom if you're on Windows. I think it's also best to use #ifdef to prevent those hardcoded debugging keys from being included in production builds. That is, if you still need to keep them at all. edit: joelthelion: You are mistaken. It's not the 1990s anymore. Use the non-blocking /dev/urandom, not /dev/random. (I can't seem to reply directly to you)

joelthelion 11y ago
/dev/random, not /dev/urandom, if I'm not mistaken.
- MrRadar 11y ago
  That's somewhat debatable: http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ But really either will be way better than anything you could homebrew.
- DanBC 11y ago
  (EDIT: I reread this and it sounds like I'm ranting at you. Sorry, I'm not, even though it does read like that.) This is why cryptography is doomed to fail. This /dev/random vs /dev/urandom (blocking vs non-blocking and whether it matters) is discussed frequently on HN, usually with very long threads, and yet it still comes up. If I want to remember whether there's an apostrophe in possessive its there's a cartoon to tell me. We need a good, accurate, fact-checked cartoon for urandom vs random. (It's one of the things I'd do if I had FU money.)

sgk284 11y ago

That is truly a horrible seed. Use /dev/random

justintocci 11y ago
I just made it so that it uses the first 4 bytes it gets from /dev/random, if it can't open /dev/random, it falls back to what we had before. --nunzio
- alcari 11y ago
  Don't fall back. If you don't have a reasonable enough environment to get a PRNG, you should halt and complain very loudly. As for actually generating random numbers, here's a good explanation from 'tptacek: http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/ http://sockpuppet.org/blog/2014/02/25/safely-generate-random...
  - deleted 11y ago
    [deleted]
  - justintocci 11y ago
    I have finished the error message and pushed to Github. Thank you for your input. I will look at the link you have referenced soon. --nunzio
- pmontra 11y ago
  Use /dev/urandom instead of /dev/random See http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ for the reasons