RSA signature verification and SHA-1/256/512 reference implementation for verified boot.

src/platform/vboot_reference/common/utility_stub.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.
+ *
+ * Stub implementations of utility functions which call their linux-specific
+ * equivalents.
+ */
+
+#include "utility.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void* Malloc(size_t size) {
+  void* p = malloc(size);
+  if (!p) {
+    /* Fatal Error. We must abort. */
+    abort();
+  }
+  return p;
+}
+
+void Free(void* ptr) {
+  free(ptr);
+}
+
+void* Memcpy(void* dest, const void* src, size_t n) {
+  return memcpy(dest, src, n);
+}
+
+int SafeMemcmp(const void* s1, const void* s2, size_t n) {
+  int match = 1;
+  const unsigned char* us1 = s1;
+  const unsigned char* us2 = s2;
+  while (n--) {
+    if (*us1++ != *us2++)
+      match = 0;
+    else
+      match = 1;
+  }
+
+  return match;
+}