refactor wc_AesDelete, wc_curve25519_delete, wc_ed25519_delete, wc_HashDelete, and wc_DeleteRsaKey to take two arguments, the first a required pointer to the object, the second an optional pointer to the pointer to be zeroed upon successful deletion, for the benefit of calling from C# without unsafe code.

wrapper/CSharp/wolfSSL_CSharp/wolfCrypt.cs: update for new calling conventions around wc_AesNew, wc_curve25519_new, wc_ed25519_new, wc_HashNew, and wc_NewRsaKey, and the corresponding delete functions.

Author: douzzer

wolfcrypt/src/aes.c

@@ -10542,7 +10542,7 @@ int wc_Gmac(const byte* key, word32 keySz, byte* iv, word32 ivSz,
                                   authTag, authTagSz, authIn, authInSz);
 
 #ifdef WOLFSSL_SMALL_STACK
-    wc_AesDelete(&aes);
+    wc_AesDelete(aes, NULL);
 #else
     wc_AesFree(aes);
 #endif
@@ -10582,7 +10582,7 @@ int wc_GmacVerify(const byte* key, word32 keySz,
 
     }
 #ifdef WOLFSSL_SMALL_STACK
-    wc_AesDelete(&aes);
+    wc_AesDelete(aes, NULL);
 #else
     wc_AesFree(aes);
 #endif
@@ -11318,13 +11318,14 @@ Aes* wc_AesNew(void* heap, int devId, int *result_code)
     return aes;
 }
 
-int wc_AesDelete(Aes** aes)
+int wc_AesDelete(Aes *aes, Aes** aes_p)
 {
-    if ((aes == NULL) || (*aes == NULL))
+    if (aes == NULL)
         return BAD_FUNC_ARG;
-    wc_AesFree(*aes);
-    XFREE(*aes, (*aes)->heap, DYNAMIC_TYPE_AES);
-    *aes = NULL;
+    wc_AesFree(aes);
+    XFREE(aes, aes->heap, DYNAMIC_TYPE_AES);
+    if (aes_p != NULL)
+        *aes_p = NULL;
     return 0;
 }
 #endif /* !WC_NO_CONSTRUCTORS */
@@ -14028,7 +14029,7 @@ static WARN_UNUSED_RESULT int AesSivCipher(
     }
 
 #ifdef WOLFSSL_SMALL_STACK
-    wc_AesDelete(&aes);
+    wc_AesDelete(aes, NULL);
 #else
     wc_AesFree(aes);
 #endif

wolfcrypt/src/curve25519.c

@@ -678,12 +678,13 @@ curve25519_key* wc_curve25519_new(void* heap, int devId, int *result_code)
     return key;
 }
 
-int wc_curve25519_delete(curve25519_key** key) {
-    if ((key == NULL) || (*key == NULL))
+int wc_curve25519_delete(curve25519_key* key, curve25519_key** key_p) {
+    if (key == NULL)
         return BAD_FUNC_ARG;
-    wc_curve25519_free(*key);
-    XFREE(*key, (*key)->heap, DYNAMIC_TYPE_CURVE25519);
-    *key = NULL;
+    wc_curve25519_free(key);
+    XFREE(key, key->heap, DYNAMIC_TYPE_CURVE25519);
+    if (key_p != NULL)
+        *key_p = NULL;
     return 0;
 }
 #endif /* !WC_NO_CONSTRUCTORS */

wolfcrypt/src/ed25519.c

@@ -991,12 +991,13 @@ ed25519_key* wc_ed25519_new(void* heap, int devId, int *result_code)
     return key;
 }
 
-int wc_ed25519_delete(ed25519_key** key) {
-    if ((key == NULL) || (*key == NULL))
+int wc_ed25519_delete(ed25519_key* key, ed25519_key** key_p) {
+    if (key == NULL)
         return BAD_FUNC_ARG;
-    wc_ed25519_free(*key);
-    XFREE(*key, (*key)->heap, DYNAMIC_TYPE_ED25519);
-    *key = NULL;
+    wc_ed25519_free(key);
+    XFREE(key, key->heap, DYNAMIC_TYPE_ED25519);
+    if (key_p != NULL)
+        *key_p = NULL;
     return 0;
 }
 #endif /* !WC_NO_CONSTRUCTORS */

wolfcrypt/src/hash.c

@@ -710,15 +710,16 @@ wc_HashAlg* wc_HashNew(enum wc_HashType type, void* heap, int devId,
     return hash;
 }
 
-int wc_HashDelete(wc_HashAlg **hash) {
+int wc_HashDelete(wc_HashAlg *hash, wc_HashAlg **hash_p) {
     int ret;
-    if ((hash == NULL) || (*hash == NULL))
+    if (hash == NULL)
         return BAD_FUNC_ARG;
-    ret = wc_HashFree(*hash, (*hash)->type);
+    ret = wc_HashFree(hash, hash->type);
     if (ret < 0)
         return ret;
-    XFREE(*hash, (*hash)->heap, DYNAMIC_TYPE_HASHES);
-    *hash = NULL;
+    XFREE(hash, hash->heap, DYNAMIC_TYPE_HASHES);
+    if (hash_p != NULL)
+        *hash_p = NULL;
     return 0;
 }
 #endif /* !WC_NO_CONSTRUCTORS */

wolfcrypt/src/rsa.c

@@ -176,13 +176,14 @@ RsaKey* wc_NewRsaKey(void* heap, int devId, int *result_code)
     return key;
 }
 
-int wc_DeleteRsaKey(RsaKey** key)
+int wc_DeleteRsaKey(RsaKey* key, RsaKey** key_p)
 {
-    if ((key == NULL) || (*key == NULL))
+    if (key == NULL)
         return BAD_FUNC_ARG;
-    wc_FreeRsaKey(*key);
-    XFREE(*key, (*key)->heap, DYNAMIC_TYPE_RSA);
-    *key = NULL;
+    wc_FreeRsaKey(key);
+    XFREE(key, key->heap, DYNAMIC_TYPE_RSA);
+    if (key_p != NULL)
+        *key_p = NULL;
     return 0;
 }
 #endif /* !WC_NO_CONSTRUCTORS */