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authorSteffen Jaeckel <s@jaeckel.eu>2020-05-26 17:36:47 +0200
committerGitHub <noreply@github.com>2020-05-26 23:36:47 +0800
commitb4bd23b4d2a4c640880b49069e02cd598dd03416 (patch)
treefb480b4e501cc69b305de95fb15259aa6afa1963 /libtommath/bn_mp_from_ubin.c
parent724e61f8ae9e9f216b0252e41c5ebd5d64ad79a6 (diff)
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.
Diffstat (limited to 'libtommath/bn_mp_from_ubin.c')
-rw-r--r--libtommath/bn_mp_from_ubin.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/libtommath/bn_mp_from_ubin.c b/libtommath/bn_mp_from_ubin.c
new file mode 100644
index 0000000..7f73cbc
--- /dev/null
+++ b/libtommath/bn_mp_from_ubin.c
@@ -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