X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/551a4acb84abdf14340214d90188e33e8c657b6f..4d9b8cfde347c30066cdcf1002fb6d4b02bdc808:/sshbn.c

diff --git a/sshbn.c b/sshbn.c
index cbd710d5..a5e0552f 100644
--- a/sshbn.c
+++ b/sshbn.c
@@ -607,6 +607,7 @@ static void internal_add_shifted(BignumInt *number,
     addend = (BignumDblInt)n << bshift;
 
     while (addend) {
+        assert(word <= number[0]);
 	addend += number[word];
 	number[word] = (BignumInt) addend & BIGNUM_INT_MASK;
 	addend >>= BIGNUM_INT_BITS;
@@ -1322,6 +1323,12 @@ int bignum_cmp(Bignum a, Bignum b)
     int amax = a[0], bmax = b[0];
     int i;
 
+    /* Annoyingly we have two representations of zero */
+    if (amax == 1 && a[amax] == 0)
+        amax = 0;
+    if (bmax == 1 && b[bmax] == 0)
+        bmax = 0;
+
     assert(amax == 0 || a[amax] != 0);
     assert(bmax == 0 || b[bmax] != 0);