--- a/libtommath/bn_mp_read_radix.c	Wed Feb 28 22:11:39 2018 +0800
+++ b/libtommath/bn_mp_read_radix.c	Thu Oct 15 19:55:15 2020 +0800
@@ -1,85 +1,79 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
 #ifdef BN_MP_READ_RADIX_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://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+#define MP_TOUPPER(c) ((((c) >= 'a') && ((c) <= 'z')) ? (((c) + 'A') - 'a') : (c))
 
 /* read a string [ASCII] in a given radix */
-int mp_read_radix (mp_int * a, const char *str, int radix)
+mp_err mp_read_radix(mp_int *a, const char *str, int radix)
 {
-  int     y, res, neg;
-  char    ch;
+   mp_err   err;
+   int      y;
+   mp_sign  neg;
+   unsigned pos;
+   char     ch;
 
-  /* zero the digit bignum */
-  mp_zero(a);
+   /* zero the digit bignum */
+   mp_zero(a);
 
-  /* make sure the radix is ok */
-  if ((radix < 2) || (radix > 64)) {
-    return MP_VAL;
-  }
+   /* make sure the radix is ok */
+   if ((radix < 2) || (radix > 64)) {
+      return MP_VAL;
+   }
 
-  /* if the leading digit is a 
-   * minus set the sign to negative. 
-   */
-  if (*str == '-') {
-    ++str;
-    neg = MP_NEG;
-  } else {
-    neg = MP_ZPOS;
-  }
+   /* if the leading digit is a
+    * minus set the sign to negative.
+    */
+   if (*str == '-') {
+      ++str;
+      neg = MP_NEG;
+   } else {
+      neg = MP_ZPOS;
+   }
 
-  /* set the integer to the default of zero */
-  mp_zero (a);
-  
-  /* process each digit of the string */
-  while (*str != '\0') {
-    /* if the radix <= 36 the conversion is case insensitive
-     * this allows numbers like 1AB and 1ab to represent the same  value
-     * [e.g. in hex]
-     */
-    ch = (radix <= 36) ? (char)toupper((int)*str) : *str;
-    for (y = 0; y < 64; y++) {
-      if (ch == mp_s_rmap[y]) {
+   /* set the integer to the default of zero */
+   mp_zero(a);
+
+   /* process each digit of the string */
+   while (*str != '\0') {
+      /* if the radix <= 36 the conversion is case insensitive
+       * this allows numbers like 1AB and 1ab to represent the same  value
+       * [e.g. in hex]
+       */
+      ch = (radix <= 36) ? (char)MP_TOUPPER((int)*str) : *str;
+      pos = (unsigned)(ch - '(');
+      if (mp_s_rmap_reverse_sz < pos) {
          break;
       }
-    }
+      y = (int)mp_s_rmap_reverse[pos];
 
-    /* if the char was found in the map 
-     * and is less than the given radix add it
-     * to the number, otherwise exit the loop. 
-     */
-    if (y < radix) {
-      if ((res = mp_mul_d (a, (mp_digit) radix, a)) != MP_OKAY) {
-         return res;
+      /* if the char was found in the map
+       * and is less than the given radix add it
+       * to the number, otherwise exit the loop.
+       */
+      if ((y == 0xff) || (y >= radix)) {
+         break;
+      }
+      if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {
+         return err;
+      }
+      if ((err = mp_add_d(a, (mp_digit)y, a)) != MP_OKAY) {
+         return err;
       }
-      if ((res = mp_add_d (a, (mp_digit) y, a)) != MP_OKAY) {
-         return res;
-      }
-    } else {
-      break;
-    }
-    ++str;
-  }
-  
-  /* set the sign only if a != 0 */
-  if (mp_iszero(a) != MP_YES) {
-     a->sign = neg;
-  }
-  return MP_OKAY;
+      ++str;
+   }
+
+   /* if an illegal character was found, fail. */
+   if (!((*str == '\0') || (*str == '\r') || (*str == '\n'))) {
+      mp_zero(a);
+      return MP_VAL;
+   }
+
+   /* set the sign only if a != 0 */
+   if (!MP_IS_ZERO(a)) {
+      a->sign = neg;
+   }
+   return MP_OKAY;
 }
 #endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */