From 9dc6dd0572102a2fa27df28ba4d66728827eb03d Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Mon, 16 Sep 2013 15:57:01 +0200 Subject: Fix bug in mpi_tdiv_q_2exp. * mpi/mpi-internal.h (MPN_COPY_INCR): Make it work. -- This bug has been with us since the version 0.0.0 of GnuPG. Fortunately it only affects an optimized code path which is rarely used in practice: If the shift size matches the size of a limb (i.e.. 32 or 64); this is is_prime in primegen.c. Over there the Rabin-Miller test may fail with a probability of 2^-31 (that is if the to be tested prime - 1 has the low 32 bits cleared). In practice the probability is even much less because we first do a Fermat test on the randomly generated candidates which sorts out the majority of composite numbers. The bug in MPN_COPY_INCR was found by Sven Bjorn. Signed-off-by: Werner Koch (back ported from Libgcrypt commit 7f7a5ef59962ae1a819b5060f9b781469bfe27d5) --- mpi/mpi-internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mpi/mpi-internal.h b/mpi/mpi-internal.h index c1df30ad8..46da08d0d 100644 --- a/mpi/mpi-internal.h +++ b/mpi/mpi-internal.h @@ -104,7 +104,7 @@ typedef int mpi_size_t; /* (must be a signed type) */ do { \ mpi_size_t _i; \ for( _i = 0; _i < (n); _i++ ) \ - (d)[_i] = (d)[_i]; \ + (d)[_i] = (s)[_i]; \ } while (0) #define MPN_COPY_DECR( d, s, n ) \ -- cgit v1.2.3