r239613 - in /trunk: gcc/fortran/ChangeLog gcc/...

[jb@gcc.gnu.org]

Author: jb
Date: Fri Aug 19 14:19:51 2016
New Revision: 239613

URL: https://gcc.gnu.org/viewcvs?rev=239613&root=gcc&view=rev
Log:
Use a XOR cipher instead of byte shuffling to protect against bad seeds.

libgfortran:
2016-08-19  Janne Blomqvist  <jb@gcc.gnu.org>

        * intrinsics/random.c (xor_keys): New array with "secret" keys.
        (scramble_seed): XOR given seed with xor_keys array rather than
        shuffling bytes.
        (unscramble_seed): Remove function.
        (random_seed_i4): Use new scramble_seed.
        (random_seed_i8): Likewise.

frontend:
2016-08-19  Janne Blomqvist  <jb@gcc.gnu.org>

        * intrinsics.texi (RANDOM_NUMBER): Remove reference to
        init_random_seed in example.
        (RANDOM_SEED): Remove warning to not set all seed values to 0.

Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/intrinsic.texi
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/intrinsics/random.c