Change the interface for parsing SignatureAlgorithm to take a

net/cert/internal/signature_algorithm.h

 // Copyright 2015 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 NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_
 #define NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "net/base/net_export.h"
 
 namespace net {
 
+class CertErrors;
+
 namespace der {
 class Input;
 }  // namespace der
 
 // The digest algorithm used within a signature.
 enum class DigestAlgorithm {
   Sha1,
   Sha256,
   Sha384,
   Sha512,
@@ skipping 52 matching lines @@
 // SignatureAlgorithm describes a signature algorithm and its parameters. This
 // corresponds to "AlgorithmIdentifier" from RFC 5280.
 class NET_EXPORT SignatureAlgorithm {
  public:
   ~SignatureAlgorithm();
 
   SignatureAlgorithmId algorithm() const { return algorithm_; }
   DigestAlgorithm digest() const { return digest_; }
 
   // Creates a SignatureAlgorithm by parsing a DER-encoded "AlgorithmIdentifier"
-  // (RFC 5280). Returns nullptr on failure.
-  static std::unique_ptr<SignatureAlgorithm> CreateFromDer(
-      const der::Input& algorithm_identifier);
+  // (RFC 5280). Returns nullptr on failure. If |errors| was non-null then
+  // error/warning information is output to it.
+  static std::unique_ptr<SignatureAlgorithm> Create(
+      const der::Input& algorithm_identifier,
+      CertErrors* errors);
 
   // Creates a new SignatureAlgorithm with the given type and parameters.
+  // Guaranteed to return non-null result.
   static std::unique_ptr<SignatureAlgorithm> CreateRsaPkcs1(
       DigestAlgorithm digest);
   static std::unique_ptr<SignatureAlgorithm> CreateEcdsa(
       DigestAlgorithm digest);
   static std::unique_ptr<SignatureAlgorithm> CreateRsaPss(
       DigestAlgorithm digest,
       DigestAlgorithm mgf1_hash,
       uint32_t salt_length);
 
   // The following methods retrieve the parameters for the signature algorithm.
@@ skipping 13 matching lines @@
   const SignatureAlgorithmId algorithm_;
   const DigestAlgorithm digest_;
   const std::unique_ptr<SignatureAlgorithmParameters> params_;
 
   DISALLOW_COPY_AND_ASSIGN(SignatureAlgorithm);
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_