Refactor CRX verification in preparation to support CRX₃ files.

components/crx_file/crx_verifier.h

+// Copyright 2017 The Chromium 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 COMPONENTS_CRX_FILE_CRX_VERIFIER_H_
+#define COMPONENTS_CRX_FILE_CRX_VERIFIER_H_
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+namespace base {
+class FilePath;
+}  // namespace base
+
+namespace crx_file {
+
+enum class VerifierFormat {
+  CRX2_OR_CRX3,               // Accept Crx2 or Crx3.
+  CRX3,                       // Accept only Crx3.
+  CRX3_WITH_PUBLISHER_PROOF,  // Accept only Crx3 with a publisher proof.
+};
+
+enum class VerifierResult {
+  OK_FULL,   // The file verifies as a correct full CRX file.
+  OK_DELTA,  // The file verifies as a correct differential CRX file.
+  ERROR_FILE_NOT_READABLE,      // Cannot open the CRX file.
+  ERROR_HEADER_INVALID,         // Failed to parse or understand CRX header.
+  ERROR_EXPECTED_HASH_INVALID,  // Expected hash is not well-formed.
+  ERROR_FILE_HASH_FAILED,       // The file's actual hash != the expected hash.
+  ERROR_SIGNATURE_INITIALIZATION_FAILED,  // A signature or key is malformed.
+  ERROR_SIGNATURE_VERIFICATION_FAILED,    // A signature doesn't match.
+  ERROR_REQUIRED_PROOF_MISSING,           // RequireKeyProof was unsatisfied.
+};
+
+// Verify the file at |crx_path| as a valid Crx of |format|. The Crx must be
+// well-formed, contain no invalid proofs, match the |required_file_hash| (if
+// non-empty), and contain a proof with each of the |required_key_hashes|.
+// If and only if this function returns OK_FULL or OK_DELTA, and only if
+// |public_key| / |crx_id| are non-null, they will be updated to contain the
+// public key (PEM format, without the header/footer) and crx id (encoded in
+// base16 using the characters [a-p]).
+VerifierResult Verify(
+    const base::FilePath& crx_path,
+    const VerifierFormat& format,
+    const std::vector<std::vector<uint8_t>>& required_key_hashes,
+    const std::vector<uint8_t>& required_file_hash,
+    std::string* public_key,
+    std::string* crx_id);
+
+}  // namespace crx_file
+
+#endif  // COMPONENTS_CRX_FILE_CRX_VERIFIER_H_