Vboot Reference: Add the "real" reference firmware verification function (VerifyFirmware).

src/platform/vboot_reference/include/rsa_utility.h

 /* 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.
  *
  * Some utility functions for use with RSA signature verification.
  */
 
 #ifndef VBOOT_REFERENCE_RSA_UTILITY_H_
 #define VBOOT_REFERENCE_RSA_UTILITY_H_
 
 #include "rsa.h"
 
 /* Returns the size of a pre-processed RSA public key in bytes with algorithm
  * [algorithm]. */
 int RSAProcessedKeySize(int algorithm);
 
+/* Deep free the contents of [key]. */
+void RSAPublicKeyFree(RSAPublicKey* key);
+
 /* Create a RSAPublic key structure from binary blob [buf] of length
- * [len]. */
-RSAPublicKey* RSAPublicKeyFromBuf(uint8_t* buf, int len);
+ * [len].
+ *
+ * Caller owns the returned key and must free it.
+ */
+RSAPublicKey* RSAPublicKeyFromBuf(const uint8_t* buf, int len);
+
+/* Perform RSA signature verification on [buf] of length [len] against expected
+ * signature [sig] using signature algorithm [algorithm]. The public key used
+ * for verification can either be in the form of a pre-process key blob
+ * [key_blob] or RSAPublicKey structure [key]. One of [key_blob] or [key] must
+ * be non-NULL, and the other NULL or the function will fail.
+ *
+ * Returns 1 on verification success, 0 on verification failure or invalid
+ * arguments.
+ *
+ * Note: This function is for use in the firmware and assumes all pointers point
+ * to areas in the memory of the right size.
+ *
+ */
+int RSAVerifyBinary_f(const uint8_t* key_blob,
+                      const RSAPublicKey* key,
+                      const uint8_t* buf,
+                      int len,
+                      const uint8_t* sig,
+                      int algorithm);
 
 #endif  /* VBOOT_REFERENCE_RSA_UTILITY_H_ */