Add function for generating validation signatures.

src/trusted/validator/caching/validation_signature.h

Index: src/trusted/validator/caching/validation_signature.h
diff --git a/src/trusted/validator/caching/validation_signature.h b/src/trusted/validator/caching/validation_signature.h
new file mode 100644
index 0000000000000000000000000000000000000000..772ac4edecda426b21a778bca3d882b3a2047b8c
--- /dev/null
+++ b/src/trusted/validator/caching/validation_signature.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_CACHING_VALIDATION_SIGNATURE_H_
+#define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_CACHING_VALIDATION_SIGNATURE_H_
+
+#include "native_client/src/include/nacl_base.h"
+#include "native_client/src/trusted/validator/cpufeatures.h"
+
+EXTERN_C_BEGIN
+
+struct HashingInterface;
+
+#define VALIDATION_SIGNATURE_MAX_LENGTH 32
+
+typedef struct {
+  const unsigned char *key;
+  unsigned int key_length;
+  const char *isa;
+  const char *version;
+  NaClCPUFeatures *cpu_features;
+} ValidationInfo;
+
+typedef struct {
+  unsigned char data[VALIDATION_SIGNATURE_MAX_LENGTH];
+  unsigned int length;
+} ValidationSignature;
+
+void GetValidationSignature(const HashingInterface *hashing,
+                            const ValidationInfo *info,
+                            const unsigned char *code,
+                            unsigned int code_length,
+                            ValidationSignature *sig);
+
+EXTERN_C_END
+
+#endif /* NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_CACHING_VALIDATION_SIGNATURE_H_ */