Add additional sanity checks to RSA verification code.

firmware/lib/vboot_common.c

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Common functions between firmware and kernel verified boot.
  * (Firmware portion)
  */
 
 
 #include "vboot_common.h"
@@ skipping 89 matching lines @@
   dest->key_size = src->key_size;
   dest->algorithm = src->algorithm;
   dest->key_version = src->key_version;
   Memcpy(GetPublicKeyData(dest), GetPublicKeyDataC(src), src->key_size);
   return 0;
 }
 
 
 RSAPublicKey* PublicKeyToRSA(const VbPublicKey* key) {
   RSAPublicKey *rsa;
+  int key_size;
 
   if (kNumAlgorithms <= key->algorithm) {
     VBDEBUG(("Invalid algorithm.\n"));
     return NULL;
   }
-  if (RSAProcessedKeySize((int)key->algorithm) != (int)key->key_size) {
+  if (!RSAProcessedKeySize((int)key->algorithm, &key_size) ||
+      key_size != (int)key->key_size) {
     VBDEBUG(("Wrong key size for algorithm\n"));
     return NULL;
   }
 
   rsa = RSAPublicKeyFromBuf(GetPublicKeyDataC(key), (int)key->key_size);
   if (!rsa)
     return NULL;
 
   rsa->algorithm = (int)key->algorithm;
   return rsa;
@@ skipping 231 matching lines @@
   /* Verify body signature is inside the block */
   if (VerifySignatureInside(preamble, preamble->preamble_size,
                             &preamble->body_signature)) {
     VBDEBUG(("Kernel body signature off end of preamble\n"));
     return VBOOT_PREAMBLE_INVALID;
   }
 
   /* Success */
   return VBOOT_SUCCESS;
 }