[PATCH 0/2] Fixes for gcry_cipher_gettag crashes

[Peter Wu]

Hi,

As reported earlier[1], some modes can result in a buffer overrun when
improperly used. These patches avoid relying on the user-supplied input.

Poly1305 was introduced this cycle (1.7.0), but GCM was introduced in 1.6.0.
Maybe a backport is appropriate?

One crash is not fixed, that is the crash when setkey is not invoked before
using the GCM ciphers (introduced in the 1.7.0 cycle). Either these functions
should check that the key is present, or they should initialize the ghash table
earlier. Affected functions:

    _gcry_cipher_gcm_encrypt
    _gcry_cipher_gcm_decrypt
    _gcry_cipher_gcm_authenticate
    _gcry_cipher_gcm_initiv
    (via _gcry_cipher_gcm_setiv)
    _gcry_cipher_gcm_tag
    (via _gcry_cipher_gcm_get_tag, _gcry_cipher_gcm_check_tag)

Kind regards,
Peter

 [1]: https://lists.gnupg.org/pipermail/gcrypt-devel/2016-March/003753.html

Peter Wu (2):
  Fix buffer overrun in gettag for GCM
  Fix buffer overrun in gettag for Poly1305

 cipher/cipher-gcm.c      | 4 ++--
 cipher/cipher-poly1305.c | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

-- 
2.7.4