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diff libtommath/bn_mp_from_ubin.c @ 1692:1051e4eea25a

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Update LibTomMath to 1.2.0 (#84) * update C files * update other files * update headers * update makefiles * remove mp_set/get_double() * use ltm 1.2.0 API * update ltm_desc * use bundled tommath if system-tommath is too old * XMALLOC etc. were changed to MP_MALLOC etc.
author Steffen Jaeckel <s@jaeckel.eu>
date Tue, 26 May 2020 17:36:47 +0200
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtommath/bn_mp_from_ubin.c	Tue May 26 17:36:47 2020 +0200
@@ -0,0 +1,39 @@
+#include "tommath_private.h"
+#ifdef BN_MP_FROM_UBIN_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+/* reads a unsigned char array, assumes the msb is stored first [big endian] */
+mp_err mp_from_ubin(mp_int *a, const unsigned char *buf, size_t size)
+{
+   mp_err err;
+
+   /* make sure there are at least two digits */
+   if (a->alloc < 2) {
+      if ((err = mp_grow(a, 2)) != MP_OKAY) {
+         return err;
+      }
+   }
+
+   /* zero the int */
+   mp_zero(a);
+
+   /* read the bytes in */
+   while (size-- > 0u) {
+      if ((err = mp_mul_2d(a, 8, a)) != MP_OKAY) {
+         return err;
+      }
+
+#ifndef MP_8BIT
+      a->dp[0] |= *buf++;
+      a->used += 1;
+#else
+      a->dp[0] = (*buf & MP_MASK);
+      a->dp[1] |= ((*buf++ >> 7) & 1u);
+      a->used += 2;
+#endif
+   }
+   mp_clamp(a);
+   return MP_OKAY;
+}
+#endif