Skip to content
  1. Jun 18, 2018
  2. Jun 13, 2018
    • Matt Caswell's avatar
      Add blinding to an ECDSA signature · 949ff366
      Matt Caswell authored
      
      
      Keegan Ryan (NCC Group) has demonstrated a side channel attack on an
      ECDSA signature operation. During signing the signer calculates:
      
      s:= k^-1 * (m + r * priv_key) mod order
      
      The addition operation above provides a sufficient signal for a
      flush+reload attack to derive the private key given sufficient signature
      operations.
      
      As a mitigation (based on a suggestion from Keegan) we add blinding to
      the operation so that:
      
      s := k^-1 * blind^-1 (blind * m + blind * r * priv_key) mod order
      
      Since this attack is a localhost side channel only no CVE is assigned.
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      949ff366
  3. Jun 12, 2018
  4. Jun 09, 2018
  5. Jun 02, 2018
  6. May 31, 2018
  7. May 29, 2018
  8. May 23, 2018
  9. May 21, 2018
  10. May 18, 2018
  11. May 17, 2018
    • Matt Caswell's avatar
      Make BN_GF2m_mod_arr more constant time · 7e5292ba
      Matt Caswell authored
      
      
      Experiments have shown that the lookup table used by BN_GF2m_mod_arr
      introduces sufficient timing signal to recover the private key for an
      attacker with access to cache timing information on the victim's host.
      This only affects binary curves (which are less frequently used).
      
      No CVE is considered necessary for this issue.
      
      The fix is to replace the lookup table with an on-the-fly calculation of
      the value from the table instead, which can be performed in constant time.
      
      Thanks to Youngjoo Shin for reporting this issue.
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      (Merged from https://github.com/openssl/openssl/pull/6270)
      
      (cherry picked from commit b336ce57)
      7e5292ba
  12. May 14, 2018
  13. May 12, 2018
  14. May 11, 2018
  15. May 05, 2018
  16. May 04, 2018
  17. May 03, 2018
  18. May 02, 2018
  19. May 01, 2018
  20. Apr 27, 2018
  21. Apr 26, 2018
  22. Apr 25, 2018