[refactor] Extract the CertVerifyResult assignment of has_md2, has_md4,

net/cert/x509_certificate_ios.cc

 // Copyright (c) 2016 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.
 
 #include "net/cert/x509_certificate.h"
 
 #include <CommonCrypto/CommonDigest.h>
 #include <Security/Security.h>
 
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 340 matching lines @@
     case EVP_PKEY_EC:
       *type = kPublicKeyTypeECDSA;
       break;
     case EVP_PKEY_DH:
       *type = kPublicKeyTypeDH;
       break;
   }
   *size_bits = EVP_PKEY_bits(key);
 }
 
+// static
+X509Certificate::SignatureHashAlgorithm
+X509Certificate::GetSignatureHashAlgorithm(OSCertHandle cert_handle) {
+  bssl::UniquePtr<X509> cert = OSCertHandleToOpenSSL(cert_handle);
+  if (!cert)
+    return kSignatureHashAlgorithmOther;
+
+  // TODO(eroman): This duplicates code with x509_certificate_openssl.cc
+  int sig_alg = OBJ_obj2nid(cert->sig_alg->algorithm);
+  if (sig_alg == NID_md2WithRSAEncryption)
+    return kSignatureHashAlgorithmMd2;
+  if (sig_alg == NID_md4WithRSAEncryption)
+    return kSignatureHashAlgorithmMd4;
+  if (sig_alg == NID_md5WithRSAEncryption || sig_alg == NID_md5WithRSA)
+    return kSignatureHashAlgorithmMd5;
+  if (sig_alg == NID_sha1WithRSAEncryption || sig_alg == NID_dsaWithSHA ||
+      sig_alg == NID_dsaWithSHA1 || sig_alg == NID_dsaWithSHA1_2 ||
+      sig_alg == NID_sha1WithRSA || sig_alg == NID_ecdsa_with_SHA1) {
+    return kSignatureHashAlgorithmSha1;
+  }
+  return kSignatureHashAlgorithmOther;
+}
+
 bool X509Certificate::SupportsSSLClientAuth() const {
   return false;
 }
 
 CFMutableArrayRef X509Certificate::CreateOSCertChainForCert() const {
   CFMutableArrayRef cert_list =
       CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);
   if (!cert_list)
     return nullptr;
 
@@ skipping 66 matching lines @@
     return false;
   bssl::UniquePtr<EVP_PKEY> scoped_key(X509_get_pubkey(cert.get()));
   if (!scoped_key)
     return false;
   if (!X509_verify(cert.get(), scoped_key.get()))
     return false;
   return X509_check_issued(cert.get(), cert.get()) == X509_V_OK;
 }
 
 }  // namespace net