VBoot Reference: Refactor Part 2 - Crypto Libraries

Removing multiple top level includes - now padding.h, rsa.h and sha.h are used internally and cryptolib.h must be used instead for all modules that wish to use crypto functions.

I am trying to separate refactors involving code movement from one file to another, and the movement of files themselves into separate CLs so that it's clear what changed.

Review URL: http://codereview.chromium.org/1574005

include/file_keys.h

@@ -8,7 +8,7 @@
 #ifndef VBOOT_REFERENCE_FILE_KEYS_H_
 #define VBOOT_REFERENCE_FILE_KEYS_H_
 
-#include "rsa.h"
+#include "cryptolib.h"
 
 /* Read file named [input_file] into a buffer and stores the length into
  * [len].
@@ -25,6 +25,12 @@ uint8_t* BufferFromFile(const char* input_file, uint64_t* len);
  */
 RSAPublicKey* RSAPublicKeyFromFile(const char* input_file);
 
+/* Returns the appropriate digest for the data in [input_file]
+ * based on the signature [algorithm].
+ * Caller owns the returned digest and must free it.
+ */
+uint8_t* DigestFile(char* input_file, int sig_algorithm);
+
 /* Helper function to invoke external program to calculate signature on
  * [input_file] using private key [key_file] and signature algorithm
  * [algorithm].