** Description changed:

  [IMPACT]
  libgcrypt20 is not a FIPS certified library. On a machine running FIPS 
enabled kernel, the library by default goes into FIPS mode if 
/proc/sys/crypto/fips_enabled=1. FIPS mode is not a configurable compile option 
currently in the library. Hence FIPS code paths are always executed on a FIPS 
enabled machine. In FIPS mode, it runs self tests and integrity checks and it 
looks for quality entropy from /dev/random.
  
  On encrypted installations, cryptsetup uses libgcrypt20. During boot on
  an encrypted machine running in FIPS mode, cryptsetup invokes libgcrypt
  and it stalls looking for quality entropy from /dev/random. This results
  in significant delays during startup. The issue was reported by a FIPS
  customer.
  
- This issue impacts xenial's version of libgcrypt. In later version of
- libgcrypt in Bionic, the entropy device is a global configurable option
- via /etc/gcrypt/random.conf config file. The config setting "only-
- urandom" can be used to set the entropy device to /dev/urandom globally
- in libgcrypt.
- 
  lsb_release -rd
  Description:  Ubuntu 16.04.3 LTS
  Release:      16.04
  
  version - 1.6.5-2ubuntu0.3
  
  [FIX]
- Get entropy from /dev/urandom device in FIPS mode. This does not block.
+ Disable the two self tests that require entropy from /dev/random during boot 
in FIPS mode.
  
  [TEST]
  Tested on a VM installed with xenial desktop iso and one with xenial server 
iso. Enabled full disk encryption during install. Tested with and without FIPS. 
No delays were observed during boot after the fix patch was applied.
  
  With FIPS enabled on encrypted install, without the patch fix, the boot
  stalls before and after prompting for decryption password.
  
  [REGRESSION POTENTIAL]
- The regression potential for this is small. This patch does not take away 
current functionality. It changes the entropy device in FIPS mode to 
/dev/urandom to get faster entropy.
+ The regression potential for this is small. The two self tests disabled does 
not impact any other functionality available in fips mode and non-fips mode of 
the library.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1748310

Title:
  [SRU][xenial]boot stalls looking for entropy in FIPS mode

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libgcrypt20/+bug/1748310/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to