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authorjan.nijtmans <nijtmans@users.sourceforge.net>2019-02-01 20:00:04 (GMT)
committerjan.nijtmans <nijtmans@users.sourceforge.net>2019-02-01 20:00:04 (GMT)
commit04ed7f99daa6ac1ca3e5a2903fc7c9325cd4d581 (patch)
treef20c21e7a9b452eeab3f8cace2601ec59404aed7 /libtommath/bn_mp_tc_xor.c
parent99be2974c327e7b37412b3f6c11681bffc3abb31 (diff)
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Update libtommath to latest stable release (1.1.0)
Diffstat (limited to 'libtommath/bn_mp_tc_xor.c')
-rw-r--r--libtommath/bn_mp_tc_xor.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/libtommath/bn_mp_tc_xor.c b/libtommath/bn_mp_tc_xor.c
new file mode 100644
index 0000000..cdb1d40
--- /dev/null
+++ b/libtommath/bn_mp_tc_xor.c
@@ -0,0 +1,90 @@
+#include "tommath_private.h"
+#ifdef BN_MP_TC_XOR_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * SPDX-License-Identifier: Unlicense
+ */
+
+/* two complement xor */
+int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
+{
+ int res = MP_OKAY, bits, abits, bbits;
+ int as = mp_isneg(a), bs = mp_isneg(b);
+ mp_int *mx = NULL, _mx, acpy, bcpy;
+
+ if ((as != MP_NO) || (bs != MP_NO)) {
+ abits = mp_count_bits(a);
+ bbits = mp_count_bits(b);
+ bits = MAX(abits, bbits);
+ res = mp_init_set_int(&_mx, 1uL);
+ if (res != MP_OKAY) {
+ goto end;
+ }
+
+ mx = &_mx;
+ res = mp_mul_2d(mx, bits + 1, mx);
+ if (res != MP_OKAY) {
+ goto end;
+ }
+
+ if (as != MP_NO) {
+ res = mp_init(&acpy);
+ if (res != MP_OKAY) {
+ goto end;
+ }
+
+ res = mp_add(mx, a, &acpy);
+ if (res != MP_OKAY) {
+ mp_clear(&acpy);
+ goto end;
+ }
+ a = &acpy;
+ }
+ if (bs != MP_NO) {
+ res = mp_init(&bcpy);
+ if (res != MP_OKAY) {
+ goto end;
+ }
+
+ res = mp_add(mx, b, &bcpy);
+ if (res != MP_OKAY) {
+ mp_clear(&bcpy);
+ goto end;
+ }
+ b = &bcpy;
+ }
+ }
+
+ res = mp_xor(a, b, c);
+
+ if ((as != bs) && (res == MP_OKAY)) {
+ res = mp_sub(c, mx, c);
+ }
+
+end:
+ if (a == &acpy) {
+ mp_clear(&acpy);
+ }
+
+ if (b == &bcpy) {
+ mp_clear(&bcpy);
+ }
+
+ if (mx == &_mx) {
+ mp_clear(mx);
+ }
+
+ return res;
+}
+#endif
+
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */