Record when certificates signed with md[2,4,5] are encountered on OS X.

R=wtc@chromium.org
BUG=101123



Review URL: http://codereview.chromium.org/8374019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@108308 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 93 insertions, 27 deletions

diff --git a/net/base/x509_certificate_mac.cc b/net/base/x509_certificate_mac.cc
index 44acddf..93bf74b 100644
--- a/net/base/x509_certificate_mac.cc
+++ b/net/base/x509_certificate_mac.cc
@@ -286,6 +286,77 @@ OSStatus CreateTrustPolicies(const std::string& hostname,
   return noErr;
 }
 
+// Saves some information about the certificate chain |cert_chain| in
+// |*verify_result|. The caller MUST initialize |*verify_result| before
+// calling this function.
+void GetCertChainInfo(CFArrayRef cert_chain,
+                      CSSM_TP_APPLE_EVIDENCE_INFO* chain_info,
+                      CertVerifyResult* verify_result) {
+  SecCertificateRef verified_cert = NULL;
+  std::vector<SecCertificateRef> verified_chain;
+  for (CFIndex i = 0, count = CFArrayGetCount(cert_chain); i < count; ++i) {
+    SecCertificateRef chain_cert = reinterpret_cast<SecCertificateRef>(
+        const_cast<void*>(CFArrayGetValueAtIndex(cert_chain, i)));
+    if (i == 0) {
+      verified_cert = chain_cert;
+    } else {
+      verified_chain.push_back(chain_cert);
+    }
+
+    if ((chain_info[i].StatusBits & CSSM_CERT_STATUS_IS_IN_ANCHORS) ||
+        (chain_info[i].StatusBits & CSSM_CERT_STATUS_IS_ROOT)) {
+      // The current certificate is either in the user's trusted store or is
+      // a root (self-signed) certificate. Ignore the signature algorithm for
+      // these certificates, as it is meaningless for security. We allow
+      // self-signed certificates (i == 0 & IS_ROOT), since we accept that
+      // any security assertions by such a cert are inherently meaningless.
+      continue;
+    }
+
+    CSSMFields cssm_fields;
+    OSStatus status = GetCertFields(chain_cert, &cssm_fields);
+    if (status)
+      continue;
+    CSSM_FIELD_PTR fields = cssm_fields.fields;
+    for (size_t field = 0; field < cssm_fields.num_of_fields; ++field) {
+      if (!CSSMOIDEqual(&fields[field].FieldOid,
+                        &CSSMOID_X509V1SignatureAlgorithm)) {
+        continue;
+      }
+
+      CSSM_X509_ALGORITHM_IDENTIFIER* signature_algorithm =
+          reinterpret_cast<CSSM_X509_ALGORITHM_IDENTIFIER*>(
+              fields[field].FieldValue.Data);
+      // Match the behaviour of OS X system tools and defensively check that
+      // sizes are appropriate. This would indicate a critical failure of the
+      // OS X certificate library, but based on history, it is best to play it
+      // safe.
+      if (!signature_algorithm || (fields[field].FieldValue.Length !=
+          sizeof(CSSM_X509_ALGORITHM_IDENTIFIER))) {
+        break;
+      }
+      CSSM_OID_PTR alg_oid = &signature_algorithm->algorithm;
+      if (CSSMOIDEqual(alg_oid, &CSSMOID_MD2WithRSA)) {
+        verify_result->has_md2 = true;
+        if (i != 0)
+          verify_result->has_md2_ca = true;
+      } else if (CSSMOIDEqual(alg_oid, &CSSMOID_MD4WithRSA)) {
+        verify_result->has_md4 = true;
+      } else if (CSSMOIDEqual(alg_oid, &CSSMOID_MD5WithRSA)) {
+        verify_result->has_md5 = true;
+        if (i != 0)
+          verify_result->has_md5_ca = true;
+      }
+      break;
+    }
+  }
+  if (!verified_cert)
+    return;
+
+  verify_result->verified_cert =
+      X509Certificate::CreateFromHandle(verified_cert, verified_chain);
+}
+
 // Gets the issuer for a given cert, starting with the cert itself and
 // including the intermediate and finally root certificates (if any).
 // This function calls SecTrust but doesn't actually pay attention to the trust
@@ -830,22 +901,7 @@ int X509Certificate::VerifyInternal(const std::string& hostname,
     return NetErrorFromOSStatus(status);
   ScopedCFTypeRef<CFArrayRef> scoped_completed_chain(completed_chain);
 
-  SecCertificateRef verified_cert = NULL;
-  std::vector<SecCertificateRef> verified_chain;
-  for (CFIndex i = 0, count = CFArrayGetCount(completed_chain);
-       i < count; ++i) {
-    SecCertificateRef chain_cert = reinterpret_cast<SecCertificateRef>(
-        const_cast<void*>(CFArrayGetValueAtIndex(completed_chain, i)));
-    if (i == 0) {
-      verified_cert = chain_cert;
-    } else {
-      verified_chain.push_back(chain_cert);
-    }
-  }
-  if (verified_cert) {
-    verify_result->verified_cert = CreateFromHandle(verified_cert,
-                                                    verified_chain);
-  }
+  GetCertChainInfo(scoped_completed_chain.get(), chain_info, verify_result);
 
   // Evaluate the results
   OSStatus cssm_result;
diff --git a/net/base/x509_certificate_unittest.cc b/net/base/x509_certificate_unittest.cc
index c0240ea..21416b1 100644
--- a/net/base/x509_certificate_unittest.cc
+++ b/net/base/x509_certificate_unittest.cc
@@ -1489,8 +1489,8 @@ TEST_P(X509CertificateNameVerifyTest, VerifyHostname) {
 INSTANTIATE_TEST_CASE_P(, X509CertificateNameVerifyTest,
                         testing::ValuesIn(kNameVerifyTestData));
 
-// Not implemented on Mac or OpenSSL - http://crbug.com/101123
-#if defined(USE_NSS) || defined(OS_WIN)
+// Not implemented on OpenSSL - http://crbug.com/101123
+#if defined(USE_NSS) || defined(OS_WIN) || defined(OS_MACOSX)
 
 struct WeakDigestTestData {
   const char* root_cert_filename;
@@ -1574,8 +1574,10 @@ TEST_P(X509CertificateWeakDigestTest, Verify) {
 const WeakDigestTestData kVerifyRootCATestData[] = {
   { "weak_digest_md5_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_sha1_ee.pem", false, false, false, false, false },
+#if !defined(OS_MACOSX)  // MD4 is not supported.
   { "weak_digest_md4_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_sha1_ee.pem", false, false, false, false, false },
+#endif
   { "weak_digest_md2_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_sha1_ee.pem", false, false, false, false, false },
 };
@@ -1586,10 +1588,11 @@ INSTANTIATE_TEST_CASE_P(VerifyRoot, X509CertificateWeakDigestTest,
 const WeakDigestTestData kVerifyIntermediateCATestData[] = {
   { "weak_digest_sha1_root.pem", "weak_digest_md5_intermediate.pem",
     "weak_digest_sha1_ee.pem", true, false, false, true, false },
-// NSS does not support MD4 and does not enable MD2 by policy.
-#if !defined(USE_NSS)
+#if !defined(USE_NSS) && !defined(OS_MACOSX)  // MD4 is not supported.
   { "weak_digest_sha1_root.pem", "weak_digest_md4_intermediate.pem",
     "weak_digest_sha1_ee.pem", false, true, false, false, false },
+#endif
+#if !defined(USE_NSS)  // MD2 is disabled by default.
   { "weak_digest_sha1_root.pem", "weak_digest_md2_intermediate.pem",
     "weak_digest_sha1_ee.pem", false, false, true, false, true },
 #endif
@@ -1601,10 +1604,11 @@ INSTANTIATE_TEST_CASE_P(VerifyIntermediate, X509CertificateWeakDigestTest,
 const WeakDigestTestData kVerifyEndEntityTestData[] = {
   { "weak_digest_sha1_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_md5_ee.pem", true, false, false, false, false },
-// NSS does not support MD4 and does not enable MD2 by policy.
-#if !defined(USE_NSS)
+#if !defined(USE_NSS) && !defined(OS_MACOSX)  // MD4 is not supported.
   { "weak_digest_sha1_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_md4_ee.pem", false, true, false, false, false },
+#endif
+#if !defined(USE_NSS)  // MD2 is disabled by default.
   { "weak_digest_sha1_root.pem", "weak_digest_sha1_intermediate.pem",
     "weak_digest_md2_ee.pem", false, false, true, false, false },
 #endif
@@ -1625,8 +1629,10 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(MAYBE_VerifyEndEntity,
 const WeakDigestTestData kVerifyIncompleteIntermediateTestData[] = {
   { NULL, "weak_digest_md5_intermediate.pem", "weak_digest_sha1_ee.pem",
     true, false, false, true, false },
+#if !defined(OS_MACOSX)  // MD4 is not supported.
   { NULL, "weak_digest_md4_intermediate.pem", "weak_digest_sha1_ee.pem",
     false, true, false, false, false },
+#endif
   { NULL, "weak_digest_md2_intermediate.pem", "weak_digest_sha1_ee.pem",
     false, false, true, false, true },
 };
@@ -1647,8 +1653,10 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
 const WeakDigestTestData kVerifyIncompleteEETestData[] = {
   { NULL, "weak_digest_sha1_intermediate.pem", "weak_digest_md5_ee.pem",
     true, false, false, false, false },
+#if !defined(OS_MACOSX)  // MD4 is not supported.
   { NULL, "weak_digest_sha1_intermediate.pem", "weak_digest_md4_ee.pem",
     false, true, false, false, false },
+#endif
   { NULL, "weak_digest_sha1_intermediate.pem", "weak_digest_md2_ee.pem",
     false, false, true, false, false },
 };
@@ -1671,10 +1679,12 @@ const WeakDigestTestData kVerifyMixedTestData[] = {
     "weak_digest_md2_ee.pem", true, false, true, true, false },
   { "weak_digest_sha1_root.pem", "weak_digest_md2_intermediate.pem",
     "weak_digest_md5_ee.pem", true, false, true, false, true },
+#if !defined(OS_MACOSX)  // MD4 is not supported.
   { "weak_digest_sha1_root.pem", "weak_digest_md4_intermediate.pem",
     "weak_digest_md2_ee.pem", false, true, true, false, false },
+#endif
 };
-// NSS does not support MD4 and does not enable MD2 by policy, making all
+// NSS does not support MD4 and does not enable MD2 by default, making all
 // permutations invalid.
 #if defined(USE_NSS)
 #define MAYBE_VerifyMixed DISABLED_VerifyMixed
@@ -1686,6 +1696,6 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
     X509CertificateWeakDigestTest,
     testing::ValuesIn(kVerifyMixedTestData));
 
-#endif  // defined(USE_NSS) || defined(OS_WIN)
+#endif  // defined(USE_NSS) || defined(OS_WIN) || defined(OS_MACOSX)
 
 }  // namespace net
diff --git a/net/base/x509_certificate_win.cc b/net/base/x509_certificate_win.cc
index 4f0d40c..4905b0b 100644
--- a/net/base/x509_certificate_win.cc
+++ b/net/base/x509_certificate_win.cc
@@ -315,9 +315,9 @@ bool CertSubjectCommonNameHasNull(PCCERT_CONTEXT cert) {
   return false;
 }
 
-// Saves some information about the certificate chain chain_context in
-// *verify_result.  The caller MUST initialize *verify_result before calling
-// this function.
+// Saves some information about the certificate chain |chain_context| in
+// |*verify_result|. The caller MUST initialize |*verify_result| before
+// calling this function.
 void GetCertChainInfo(PCCERT_CHAIN_CONTEXT chain_context,
                       CertVerifyResult* verify_result) {
   if (chain_context->cChain == 0)