Fix error handling, NULL checks, and TLS padding

Author: JeremiahM37

src/wp_aes_aead.c

@@ -488,7 +488,9 @@ static int wp_aead_set_param_tag(wp_AeadCtx* ctx,
     if (ok && ((sz == 0) || ((p->data != NULL) && ctx->enc))) {
         ok = 0;
     }
-    ctx->tagLen = sz;
+    if (ok) {
+        ctx->tagLen = sz;
+    }
 
     WOLFPROV_LEAVE(WP_LOG_COMP_AES, __FILE__ ":" WOLFPROV_STRINGIZE(__LINE__), ok);
     return ok;
@@ -1122,7 +1124,7 @@ static int wp_aesgcm_dinit(wp_AeadCtx *ctx, const unsigned char *key,
             ok = 0;
         }
     }
-    if (ok) {
+    if (ok && (iv != NULL)) {
         XMEMCPY(ctx->iv, iv, ivLen);
         ctx->ivState = IV_STATE_BUFFERED;
         ctx->ivSet = 0;

src/wp_kbkdf.c

@@ -623,7 +623,9 @@ static int wp_kdf_kbkdf_derive(wp_KbkdfCtx* ctx, unsigned char* key,
             ok = 0;
         }
         else {
-            XMEMCPY(k_i, ctx->iv, ctx->ivLen);
+            if (ctx->ivLen > 0) {
+                XMEMCPY(k_i, ctx->iv, ctx->ivLen);
+            }
             k_i_len = ctx->ivLen;
             /* Prep [L]2 */
             wp_c32toa((word32)(keyLen * 8), (byte *)&beL);