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

src/platform/vboot_reference/utils/file_keys.c

Index: src/platform/vboot_reference/utils/file_keys.c
diff --git a/src/platform/vboot_reference/utils/file_keys.c b/src/platform/vboot_reference/utils/file_keys.c
index 8a8a2cb2c0f1b605d8236e4ecb98b12f69d147f7..bcba749a4bb92c1d629959db629a3138d5d07453 100644
--- a/src/platform/vboot_reference/utils/file_keys.c
+++ b/src/platform/vboot_reference/utils/file_keys.c
@@ -15,6 +15,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include "padding.h"
 #include "rsa_utility.h"
 #include "utility.h"
 
@@ -55,3 +56,41 @@ RSAPublicKey* RSAPublicKeyFromFile(char* input_file) {
   Free(buf);
   return key;
 }
+
+uint8_t* SignatureFile(char* input_file, char* key_file, int algorithm) {
+  char* sign_utility = "./sign_data.sh";
+  char* cmd;  /* Command line to invoke. */
+  int cmd_len;
+  FILE* cmd_out;  /* File descriptor to command output. */
+  uint8_t* signature = NULL;
+  int signature_size = siglen_map[algorithm] * sizeof(uint32_t);
+
+  /* Build command line:
+   * sign_data.sh <algorithm> <key file> <input file>
+   */
+  cmd_len = (strlen(sign_utility) + 1 + /* +1 for space. */
+             2 + 1 + /* For [algorithm]. */
+             strlen(key_file) + 1 + /* +1 for space. */
+             strlen(input_file) +
+             1);  /* For the trailing '\0'. */
+  cmd = (char*) Malloc(cmd_len);
+  snprintf(cmd, cmd_len, "%s %d %s %s", sign_utility, algorithm, key_file,
+           input_file);
+  cmd_out = popen(cmd, "r");
+  Free(cmd);
+  if (!cmd_out) {
+    fprintf(stderr, "Couldn't execute: %s\n", cmd);
+    return NULL;
+  }
+
+  signature = (uint8_t*) Malloc(signature_size);
+  if (fread(signature, signature_size, 1, cmd_out) != 1) {
+    fprintf(stderr, "Couldn't read signature.\n");
+    pclose(cmd_out);
+    Free(signature);
+    return NULL;
+  }
+
+  pclose(cmd_out);
+  return signature;
+}