1. Changed a memset to 0 of some mp_ints with mp_inits()

2. For alt-ecc, implemented the function fp_init_copy()
3. Added an fp_init() for the temp fp_int in fp_sub_d()

wolfcrypt/src/ecc.c

@@ -2088,8 +2088,8 @@ int wc_ecc_verify_hash(const byte* sig, word32 siglen, const byte* hash,
     * If either of those don't allocate correctly, none of
     * the rest of this function will execute, and everything
     * gets cleaned up at the end. */
-   XMEMSET(&r, 0, sizeof(r));
-   XMEMSET(&s, 0, sizeof(s));
+   mp_init(&r);
+   mp_init(&s);
    if (err == MP_OKAY) 
        err = DecodeECC_DSA_Sig(sig, siglen, &r, &s);
 

wolfcrypt/src/tfm.c

@@ -1829,6 +1829,7 @@ void fp_reverse (unsigned char *s, int len)
 void fp_sub_d(fp_int *a, fp_digit b, fp_int *c)
 {
    fp_int tmp;
+   fp_init(&tmp);
    fp_set(&tmp, b);
    fp_sub(a, &tmp, c);
 }
@@ -1983,6 +1984,14 @@ void fp_copy(fp_int *a, fp_int* b)
         XMEMCPY(b->dp, a->dp, a->used * sizeof(fp_digit));
     }
 }
+
+void fp_init_copy(fp_int *a, fp_int* b)
+{
+    if (a != b) {
+        fp_init(a);
+        fp_copy(b, a);
+    }
+}
 #endif
 
 /* fast math conversion */

wolfssl/wolfcrypt/tfm.h

@@ -375,10 +375,11 @@ void fp_set(fp_int *a, fp_digit b);
 /* copy from a to b */
 #ifndef ALT_ECC_SIZE
     #define fp_copy(a, b)  (void)(((a) != (b)) ? ((void)XMEMCPY((b), (a), sizeof(fp_int))) : (void)0)
+    #define fp_init_copy(a, b) fp_copy(b, a)
 #else
     void fp_copy(fp_int *a, fp_int *b);
+    void fp_init_copy(fp_int *a, fp_int *b);
 #endif
-#define fp_init_copy(a, b) fp_copy(b, a)
 
 /* clamp digits */
 #define fp_clamp(a)   { while ((a)->used && (a)->dp[(a)->used-1] == 0) --((a)->used); (a)->sign = (a)->used ? (a)->sign : FP_ZPOS; }