Move bn_add_words() and bn_sub_words from bn_asm.c to bn_add.c.

These are wrapped with #ifndef HAVE_BN_ADD_WORDS/HAVE_BN_SUB_WORDS, which
are defined for architectures that provide their own assembly versions.

1 files changed, 158 insertions, 1 deletions

diff --git a/src/lib/libcrypto/bn/bn_add.c b/src/lib/libcrypto/bn/bn_add.c
index 3352e0e1d5..b3fed564e9 100644
--- a/src/lib/libcrypto/bn/bn_add.c
+++ b/src/lib/libcrypto/bn/bn_add.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_add.c,v 1.17 2023/01/20 04:49:48 jsing Exp $ */
+/* $OpenBSD: bn_add.c,v 1.18 2023/01/23 10:31:03 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -56,12 +56,169 @@
  * [including the GNU Public Licence.]
  */
 
+#include <assert.h>
 #include <stdio.h>
 
 #include <openssl/err.h>
 
 #include "bn_local.h"
 
+#ifndef HAVE_BN_ADD_WORDS
+#ifdef BN_LLONG
+BN_ULONG
+bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
+{
+        BN_ULLONG ll = 0;
+
+        assert(n >= 0);
+        if (n <= 0)
+                return ((BN_ULONG)0);
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n & ~3) {
+                ll += (BN_ULLONG)a[0] + b[0];
+                r[0] = (BN_ULONG)ll & BN_MASK2;
+                ll >>= BN_BITS2;
+                ll += (BN_ULLONG)a[1] + b[1];
+                r[1] = (BN_ULONG)ll & BN_MASK2;
+                ll >>= BN_BITS2;
+                ll += (BN_ULLONG)a[2] + b[2];
+                r[2] = (BN_ULONG)ll & BN_MASK2;
+                ll >>= BN_BITS2;
+                ll += (BN_ULLONG)a[3] + b[3];
+                r[3] = (BN_ULONG)ll & BN_MASK2;
+                ll >>= BN_BITS2;
+                a += 4;
+                b += 4;
+                r += 4;
+                n -= 4;
+        }
+#endif
+        while (n) {
+                ll += (BN_ULLONG)a[0] + b[0];
+                r[0] = (BN_ULONG)ll & BN_MASK2;
+                ll >>= BN_BITS2;
+                a++;
+                b++;
+                r++;
+                n--;
+        }
+        return ((BN_ULONG)ll);
+}
+#else /* !BN_LLONG */
+BN_ULONG
+bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
+{
+        BN_ULONG c, l, t;
+
+        assert(n >= 0);
+        if (n <= 0)
+                return ((BN_ULONG)0);
+
+        c = 0;
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n & ~3) {
+                t = a[0];
+                t = (t + c) & BN_MASK2;
+                c = (t < c);
+                l = (t + b[0]) & BN_MASK2;
+                c += (l < t);
+                r[0] = l;
+                t = a[1];
+                t = (t + c) & BN_MASK2;
+                c = (t < c);
+                l = (t + b[1]) & BN_MASK2;
+                c += (l < t);
+                r[1] = l;
+                t = a[2];
+                t = (t + c) & BN_MASK2;
+                c = (t < c);
+                l = (t + b[2]) & BN_MASK2;
+                c += (l < t);
+                r[2] = l;
+                t = a[3];
+                t = (t + c) & BN_MASK2;
+                c = (t < c);
+                l = (t + b[3]) & BN_MASK2;
+                c += (l < t);
+                r[3] = l;
+                a += 4;
+                b += 4;
+                r += 4;
+                n -= 4;
+        }
+#endif
+        while (n) {
+                t = a[0];
+                t = (t + c) & BN_MASK2;
+                c = (t < c);
+                l = (t + b[0]) & BN_MASK2;
+                c += (l < t);
+                r[0] = l;
+                a++;
+                b++;
+                r++;
+                n--;
+        }
+        return ((BN_ULONG)c);
+}
+#endif /* !BN_LLONG */
+#endif
+
+#ifndef HAVE_BN_SUB_WORDS
+BN_ULONG
+bn_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
+{
+        BN_ULONG t1, t2;
+        int c = 0;
+
+        assert(n >= 0);
+        if (n <= 0)
+                return ((BN_ULONG)0);
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
+        while (n&~3) {
+                t1 = a[0];
+                t2 = b[0];
+                r[0] = (t1 - t2 - c) & BN_MASK2;
+                if (t1 != t2)
+                        c = (t1 < t2);
+                t1 = a[1];
+                t2 = b[1];
+                r[1] = (t1 - t2 - c) & BN_MASK2;
+                if (t1 != t2)
+                        c = (t1 < t2);
+                t1 = a[2];
+                t2 = b[2];
+                r[2] = (t1 - t2 - c) & BN_MASK2;
+                if (t1 != t2)
+                        c = (t1 < t2);
+                t1 = a[3];
+                t2 = b[3];
+                r[3] = (t1 - t2 - c) & BN_MASK2;
+                if (t1 != t2)
+                        c = (t1 < t2);
+                a += 4;
+                b += 4;
+                r += 4;
+                n -= 4;
+        }
+#endif
+        while (n) {
+                t1 = a[0];
+                t2 = b[0];
+                r[0] = (t1 - t2 - c) & BN_MASK2;
+                if (t1 != t2)
+                        c = (t1 < t2);
+                a++;
+                b++;
+                r++;
+                n--;
+        }
+        return (c);
+}
+#endif
+
 int
 BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
 {