From: Mark Wooding <mdw@distorted.org.uk>
Date: Mon, 12 Sep 2016 21:32:37 +0000 (+0100)
Subject: math/mpmont.c: Make REDC coefficient as long as the modulus.
X-Git-Tag: 2.3.0~33
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/362c3d18594a017c064fe5d6439e56dff8c9f30c

math/mpmont.c: Make REDC coefficient as long as the modulus.

We'll have trouble later if it's too short.
---

diff --git a/math/mpmont.c b/math/mpmont.c
index b95e1cfe..a86623b2 100644
--- a/math/mpmont.c
+++ b/math/mpmont.c
@@ -209,6 +209,7 @@ int mpmont_create(mpmont *mm, mp *m)
   mp_build(&r, r2->v + n, r2->vl);
   mm->mi = mp_modinv(MP_NEW, m, &r);
   mm->mi = mp_sub(mm->mi, &r, mm->mi);
+  MP_ENSURE(mm->mi, n);
 
   /* --- Discover the values %$R \bmod m$% and %$R^2 \bmod m$% --- */