diff bn_mp_read_signed_bin.c @ 282:91fbc376f010 libtommath-orig libtommath-0.35

Import of libtommath 0.35 From ltm-0.35.tar.bz2 SHA1 of 3f193dbae9351e92d02530994fa18236f7fde01c
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:16:18 +0000
parents
children 97db060d0ef5
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bn_mp_read_signed_bin.c	Wed Mar 08 13:16:18 2006 +0000
@@ -0,0 +1,38 @@
+#include <tommath.h>
+#ifdef BN_MP_READ_SIGNED_BIN_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.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, [email protected], http://math.libtomcrypt.org
+ */
+
+/* read signed bin, big endian, first byte is 0==positive or 1==negative */
+int
+mp_read_signed_bin (mp_int * a, unsigned char *b, int c)
+{
+  int     res;
+
+  /* read magnitude */
+  if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
+    return res;
+  }
+
+  /* first byte is 0 for positive, non-zero for negative */
+  if (b[0] == 0) {
+     a->sign = MP_ZPOS;
+  } else {
+     a->sign = MP_NEG;
+  }
+
+  return MP_OKAY;
+}
+#endif