merge from main

--HG--
branch : fuzz

1 files changed, 75 insertions, 88 deletions

diff --git a/libtommath/bn_mp_gcd.c b/libtommath/bn_mp_gcd.c
index b0be8fb..53029ba 100644
--- a/libtommath/bn_mp_gcd.c
+++ b/libtommath/bn_mp_gcd.c
@@ -1,105 +1,92 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
 #ifdef BN_MP_GCD_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, tstdenis82@gmail.com, http://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
 
 /* Greatest Common Divisor using the binary method */
-int mp_gcd (mp_int * a, mp_int * b, mp_int * c)
+mp_err mp_gcd(const mp_int *a, const mp_int *b, mp_int *c)
 {
-  mp_int  u, v;
-  int     k, u_lsb, v_lsb, res;
+   mp_int  u, v;
+   int     k, u_lsb, v_lsb;
+   mp_err err;
 
-  /* either zero than gcd is the largest */
-  if (mp_iszero (a) == MP_YES) {
-    return mp_abs (b, c);
-  }
-  if (mp_iszero (b) == MP_YES) {
-    return mp_abs (a, c);
-  }
+   /* either zero than gcd is the largest */
+   if (MP_IS_ZERO(a)) {
+      return mp_abs(b, c);
+   }
+   if (MP_IS_ZERO(b)) {
+      return mp_abs(a, c);
+   }
 
-  /* get copies of a and b we can modify */
-  if ((res = mp_init_copy (&u, a)) != MP_OKAY) {
-    return res;
-  }
+   /* get copies of a and b we can modify */
+   if ((err = mp_init_copy(&u, a)) != MP_OKAY) {
+      return err;
+   }
 
-  if ((res = mp_init_copy (&v, b)) != MP_OKAY) {
-    goto LBL_U;
-  }
+   if ((err = mp_init_copy(&v, b)) != MP_OKAY) {
+      goto LBL_U;
+   }
 
-  /* must be positive for the remainder of the algorithm */
-  u.sign = v.sign = MP_ZPOS;
+   /* must be positive for the remainder of the algorithm */
+   u.sign = v.sign = MP_ZPOS;
 
-  /* B1.  Find the common power of two for u and v */
-  u_lsb = mp_cnt_lsb(&u);
-  v_lsb = mp_cnt_lsb(&v);
-  k     = MIN(u_lsb, v_lsb);
+   /* B1.  Find the common power of two for u and v */
+   u_lsb = mp_cnt_lsb(&u);
+   v_lsb = mp_cnt_lsb(&v);
+   k     = MP_MIN(u_lsb, v_lsb);
 
-  if (k > 0) {
-     /* divide the power of two out */
-     if ((res = mp_div_2d(&u, k, &u, NULL)) != MP_OKAY) {
-        goto LBL_V;
-     }
+   if (k > 0) {
+      /* divide the power of two out */
+      if ((err = mp_div_2d(&u, k, &u, NULL)) != MP_OKAY) {
+         goto LBL_V;
+      }
 
-     if ((res = mp_div_2d(&v, k, &v, NULL)) != MP_OKAY) {
-        goto LBL_V;
-     }
-  }
+      if ((err = mp_div_2d(&v, k, &v, NULL)) != MP_OKAY) {
+         goto LBL_V;
+      }
+   }
 
-  /* divide any remaining factors of two out */
-  if (u_lsb != k) {
-     if ((res = mp_div_2d(&u, u_lsb - k, &u, NULL)) != MP_OKAY) {
-        goto LBL_V;
-     }
-  }
+   /* divide any remaining factors of two out */
+   if (u_lsb != k) {
+      if ((err = mp_div_2d(&u, u_lsb - k, &u, NULL)) != MP_OKAY) {
+         goto LBL_V;
+      }
+   }
 
-  if (v_lsb != k) {
-     if ((res = mp_div_2d(&v, v_lsb - k, &v, NULL)) != MP_OKAY) {
-        goto LBL_V;
-     }
-  }
+   if (v_lsb != k) {
+      if ((err = mp_div_2d(&v, v_lsb - k, &v, NULL)) != MP_OKAY) {
+         goto LBL_V;
+      }
+   }
 
-  while (mp_iszero(&v) == MP_NO) {
-     /* make sure v is the largest */
-     if (mp_cmp_mag(&u, &v) == MP_GT) {
-        /* swap u and v to make sure v is >= u */
-        mp_exch(&u, &v);
-     }
-     
-     /* subtract smallest from largest */
-     if ((res = s_mp_sub(&v, &u, &v)) != MP_OKAY) {
-        goto LBL_V;
-     }
-     
-     /* Divide out all factors of two */
-     if ((res = mp_div_2d(&v, mp_cnt_lsb(&v), &v, NULL)) != MP_OKAY) {
-        goto LBL_V;
-     } 
-  } 
+   while (!MP_IS_ZERO(&v)) {
+      /* make sure v is the largest */
+      if (mp_cmp_mag(&u, &v) == MP_GT) {
+         /* swap u and v to make sure v is >= u */
+         mp_exch(&u, &v);
+      }
 
-  /* multiply by 2**k which we divided out at the beginning */
-  if ((res = mp_mul_2d (&u, k, c)) != MP_OKAY) {
-     goto LBL_V;
-  }
-  c->sign = MP_ZPOS;
-  res = MP_OKAY;
-LBL_V:mp_clear (&u);
-LBL_U:mp_clear (&v);
-  return res;
+      /* subtract smallest from largest */
+      if ((err = s_mp_sub(&v, &u, &v)) != MP_OKAY) {
+         goto LBL_V;
+      }
+
+      /* Divide out all factors of two */
+      if ((err = mp_div_2d(&v, mp_cnt_lsb(&v), &v, NULL)) != MP_OKAY) {
+         goto LBL_V;
+      }
+   }
+
+   /* multiply by 2**k which we divided out at the beginning */
+   if ((err = mp_mul_2d(&u, k, c)) != MP_OKAY) {
+      goto LBL_V;
+   }
+   c->sign = MP_ZPOS;
+   err = MP_OKAY;
+LBL_V:
+   mp_clear(&u);
+LBL_U:
+   mp_clear(&v);
+   return err;
 }
 #endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */