[PATCH 1/2] MPILIB: Fix comparison of negative MPIs

Rasmus Villemoes
2014-12-06T00:00:58Z

If u and v both represent negative integers and their limb counts
happen to differ, mpi_cmp will always return a positive value - this
is obviously bogus. u is smaller than v if and only if it is larger in
absolute value.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
lib/mpi/mpi-cmp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
index 1871e7b61ca0..3801694240d8 100644
--- a/lib/mpi/mpi-cmp.c
+++ b/lib/mpi/mpi-cmp.c
@@ -57,7 +57,7 @@ int mpi_cmp(MPI u, MPI v)
if (usize != vsize && !u->sign && !v->sign)
return usize - vsize;
if (usize != vsize && u->sign && v->sign)
- return vsize + usize;
+ return vsize - usize;
if (!usize)
return 0;
cmp = mpihelp_cmp(u->d, v->d, usize);
--
2.1.3