From a402b462e9efcb9cb2dad34eb1350288e5d91211 Mon Sep 17 00:00:00 2001
From: Francois Perrad <francois.perrad@gadz.org>
Date: Wed, 29 May 2019 12:23:08 +0200
Subject: [PATCH] refactor with goto

---
 bn_mp_addmod.c          |  5 +++--
 bn_mp_export.c          | 10 +++++-----
 bn_mp_expt_u32.c        | 11 ++++++-----
 bn_mp_exptmod.c         |  7 +++----
 bn_mp_fwrite.c          | 11 ++++++-----
 bn_mp_mod.c             |  4 ++--
 bn_mp_mulmod.c          |  5 +++--
 bn_mp_radix_size.c      | 10 ++++++----
 bn_mp_sqrmod.c          |  5 +++--
 bn_mp_submod.c          |  5 +++--
 bn_mp_to_radix.c        |  6 ++++--
 bn_mp_to_unsigned_bin.c |  8 +++++---
 12 files changed, 49 insertions(+), 38 deletions(-)

diff --git a/bn_mp_addmod.c b/bn_mp_addmod.c
index 2636e2a..1dcfb67 100644
--- a/bn_mp_addmod.c
+++ b/bn_mp_addmod.c
@@ -14,10 +14,11 @@ mp_err mp_addmod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
    }
 
    if ((err = mp_add(a, b, &t)) != MP_OKAY) {
-      mp_clear(&t);
-      return err;
+      goto LBL_ERR;
    }
    err = mp_mod(&t, c, d);
+
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_export.c b/bn_mp_export.c
index c9de48b..9dea54e 100644
--- a/bn_mp_export.c
+++ b/bn_mp_export.c
@@ -53,19 +53,19 @@ mp_err mp_export(void *rop, size_t *countp, int order, size_t size,
          *byte = (unsigned char)((j == ((size - nail_bytes) - 1u)) ? (t.dp[0] & odd_nail_mask) : (t.dp[0] & 0xFFuL));
 
          if ((err = mp_div_2d(&t, (j == ((size - nail_bytes) - 1u)) ? (int)(8u - odd_nails) : 8, &t, NULL)) != MP_OKAY) {
-            mp_clear(&t);
-            return err;
+            goto LBL_ERR;
          }
       }
    }
 
-   mp_clear(&t);
-
    if (countp != NULL) {
       *countp = count;
    }
+   err = MP_OKAY;
 
-   return MP_OKAY;
+LBL_ERR:
+   mp_clear(&t);
+   return err;
 }
 
 #endif
diff --git a/bn_mp_expt_u32.c b/bn_mp_expt_u32.c
index 4ec725e..2ab67ba 100644
--- a/bn_mp_expt_u32.c
+++ b/bn_mp_expt_u32.c
@@ -21,16 +21,14 @@ mp_err mp_expt_u32(const mp_int *a, uint32_t b, mp_int *c)
       /* if the bit is set multiply */
       if ((b & 1u) != 0u) {
          if ((err = mp_mul(c, &g, c)) != MP_OKAY) {
-            mp_clear(&g);
-            return err;
+            goto LBL_ERR;
          }
       }
 
       /* square */
       if (b > 1u) {
          if ((err = mp_sqr(&g, &g)) != MP_OKAY) {
-            mp_clear(&g);
-            return err;
+            goto LBL_ERR;
          }
       }
 
@@ -38,8 +36,11 @@ mp_err mp_expt_u32(const mp_int *a, uint32_t b, mp_int *c)
       b >>= 1;
    }
 
+   err = MP_OKAY;
+
+LBL_ERR:
    mp_clear(&g);
-   return MP_OKAY;
+   return err;
 }
 
 #endif
diff --git a/bn_mp_exptmod.c b/bn_mp_exptmod.c
index ceb8e86..bc4b643 100644
--- a/bn_mp_exptmod.c
+++ b/bn_mp_exptmod.c
@@ -32,18 +32,17 @@ mp_err mp_exptmod(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y)
 
       /* first compute 1/G mod P */
       if ((err = mp_invmod(G, P, &tmpG)) != MP_OKAY) {
-         mp_clear_multi(&tmpG, &tmpX, NULL);
-         return err;
+         goto LBL_ERR;
       }
 
       /* now get |X| */
       if ((err = mp_abs(X, &tmpX)) != MP_OKAY) {
-         mp_clear_multi(&tmpG, &tmpX, NULL);
-         return err;
+         goto LBL_ERR;
       }
 
       /* and now compute (1/G)**|X| instead of G**X [X < 0] */
       err = mp_exptmod(&tmpG, &tmpX, P, Y);
+LBL_ERR:
       mp_clear_multi(&tmpG, &tmpX, NULL);
       return err;
    }
diff --git a/bn_mp_fwrite.c b/bn_mp_fwrite.c
index 5b4719f..eaa5d06 100644
--- a/bn_mp_fwrite.c
+++ b/bn_mp_fwrite.c
@@ -20,17 +20,18 @@ mp_err mp_fwrite(const mp_int *a, int radix, FILE *stream)
    }
 
    if ((err = mp_to_radix(a, buf, (size_t)len, radix)) != MP_OKAY) {
-      MP_FREE_BUFFER(buf, (size_t)len);
-      return err;
+      goto LBL_ERR;
    }
 
    if (fwrite(buf, (size_t)len, 1uL, stream) != 1uL) {
-      MP_FREE_BUFFER(buf, (size_t)len);
-      return MP_ERR;
+      err = MP_ERR;
+      goto LBL_ERR;
    }
+   err = MP_OKAY;
 
+LBL_ERR:
    MP_FREE_BUFFER(buf, (size_t)len);
-   return MP_OKAY;
+   return err;
 }
 #endif
 
diff --git a/bn_mp_mod.c b/bn_mp_mod.c
index 18b4e6b..8fbfe08 100644
--- a/bn_mp_mod.c
+++ b/bn_mp_mod.c
@@ -14,8 +14,7 @@ mp_err mp_mod(const mp_int *a, const mp_int *b, mp_int *c)
    }
 
    if ((err = mp_div(a, b, NULL, &t)) != MP_OKAY) {
-      mp_clear(&t);
-      return err;
+      goto LBL_ERR;
    }
 
    if (MP_IS_ZERO(&t) || (t.sign == b->sign)) {
@@ -25,6 +24,7 @@ mp_err mp_mod(const mp_int *a, const mp_int *b, mp_int *c)
       err = mp_add(b, &t, c);
    }
 
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_mulmod.c b/bn_mp_mulmod.c
index 763f923..160d162 100644
--- a/bn_mp_mulmod.c
+++ b/bn_mp_mulmod.c
@@ -14,10 +14,11 @@ mp_err mp_mulmod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
    }
 
    if ((err = mp_mul(a, b, &t)) != MP_OKAY) {
-      mp_clear(&t);
-      return err;
+      goto LBL_ERR;
    }
    err = mp_mod(&t, c, d);
+
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_radix_size.c b/bn_mp_radix_size.c
index 6d7f912..339b21b 100644
--- a/bn_mp_radix_size.c
+++ b/bn_mp_radix_size.c
@@ -48,16 +48,18 @@ mp_err mp_radix_size(const mp_int *a, int radix, int *size)
    /* fetch out all of the digits */
    while (!MP_IS_ZERO(&t)) {
       if ((err = mp_div_d(&t, (mp_digit)radix, &t, &d)) != MP_OKAY) {
-         mp_clear(&t);
-         return err;
+         goto LBL_ERR;
       }
       ++digs;
    }
-   mp_clear(&t);
 
    /* return digs + 1, the 1 is for the NULL byte that would be required. */
    *size = digs + 1;
-   return MP_OKAY;
+   err = MP_OKAY;
+
+LBL_ERR:
+   mp_clear(&t);
+   return err;
 }
 
 #endif
diff --git a/bn_mp_sqrmod.c b/bn_mp_sqrmod.c
index b3c44e5..626ea2c 100644
--- a/bn_mp_sqrmod.c
+++ b/bn_mp_sqrmod.c
@@ -14,10 +14,11 @@ mp_err mp_sqrmod(const mp_int *a, const mp_int *b, mp_int *c)
    }
 
    if ((err = mp_sqr(a, &t)) != MP_OKAY) {
-      mp_clear(&t);
-      return err;
+      goto LBL_ERR;
    }
    err = mp_mod(&t, b, c);
+
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_submod.c b/bn_mp_submod.c
index 61c2d0f..5ebd374 100644
--- a/bn_mp_submod.c
+++ b/bn_mp_submod.c
@@ -14,10 +14,11 @@ mp_err mp_submod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
    }
 
    if ((err = mp_sub(a, b, &t)) != MP_OKAY) {
-      mp_clear(&t);
-      return err;
+      goto LBL_ERR;
    }
    err = mp_mod(&t, c, d);
+
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_to_radix.c b/bn_mp_to_radix.c
index c75ee5b..d6e8fcc 100644
--- a/bn_mp_to_radix.c
+++ b/bn_mp_to_radix.c
@@ -52,8 +52,7 @@ mp_err mp_to_radix(const mp_int *a, char *str, size_t maxlen, int radix)
          break;
       }
       if ((err = mp_div_d(&t, (mp_digit)radix, &t, &d)) != MP_OKAY) {
-         mp_clear(&t);
-         return err;
+         goto LBL_ERR;
       }
       *str++ = mp_s_rmap[d];
       ++digs;
@@ -67,6 +66,9 @@ mp_err mp_to_radix(const mp_int *a, char *str, size_t maxlen, int radix)
    /* append a NULL so the string is properly terminated */
    *str = '\0';
 
+   err = MP_OKAY;
+
+LBL_ERR:
    mp_clear(&t);
    return err;
 }
diff --git a/bn_mp_to_unsigned_bin.c b/bn_mp_to_unsigned_bin.c
index 093b01a..bc6372c 100644
--- a/bn_mp_to_unsigned_bin.c
+++ b/bn_mp_to_unsigned_bin.c
@@ -22,12 +22,14 @@ mp_err mp_to_unsigned_bin(const mp_int *a, unsigned char *b)
       b[x++] = (unsigned char)(t.dp[0] | ((t.dp[1] & 1u) << 7));
 #endif
       if ((err = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
-         mp_clear(&t);
-         return err;
+         goto LBL_ERR;
       }
    }
    s_mp_reverse(b, x);
+   err = MP_OKAY;
+
+LBL_ERR:
    mp_clear(&t);
-   return MP_OKAY;
+   return err;
 }
 #endif