Refactor LoadFrmware() to avoid global variables, which don't work when running out of ROM

vboot_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 67 matching lines @@
 
 
 int VerifySignatureInside(const void* parent, uint64_t parent_size,
                           const VbSignature* sig) {
   return VerifyMemberInside(parent, parent_size,
                             sig, sizeof(VbSignature),
                             sig->sig_offset, sig->sig_size);
 }
 
 
+void PublicKeyInit(VbPublicKey* key, uint8_t* key_data, uint64_t key_size) {
+  key->key_offset = OffsetOf(key, key_data);
+  key->key_size = key_size;
+  key->algorithm = kNumAlgorithms; /* Key not present yet */
+  key->key_version = 0;
+}
+
+
+int PublicKeyCopy(VbPublicKey* dest, const VbPublicKey* src) {
+  if (dest->key_size < src->key_size)
+    return 1;
+
+  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;
 
   if (kNumAlgorithms <= key->algorithm) {
     debug("Invalid algorithm.\n");
     return NULL;
   }
   if (RSAProcessedKeySize(key->algorithm) != key->key_size) {
     debug("Wrong key size for algorithm\n");
     return NULL;
@@ skipping 214 matching lines @@
   /* Verify body signature is inside the block */
   if (VerifySignatureInside(preamble, preamble->preamble_size,
                             &preamble->body_signature)) {
     debug("Kernel body signature off end of preamble\n");
     return VBOOT_PREAMBLE_INVALID;
   }
 
   /* Success */
   return VBOOT_SUCCESS;
 }