Porting SecureSocket to use BoringSSL on OSX

runtime/bin/security_context_linux.cc

Index: runtime/bin/security_context_linux.cc
diff --git a/runtime/bin/security_context_linux.cc b/runtime/bin/security_context_linux.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2985fff4808f2053b988911f2918e86b6cd2d6e0
--- /dev/null
+++ b/runtime/bin/security_context_linux.cc
@@ -0,0 +1,84 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#if !defined(DART_IO_DISABLED) && !defined(DART_IO_SECURE_SOCKET_DISABLED)
+
+#include "platform/globals.h"
+#if defined(HOST_OS_LINUX)
+
+#include "bin/security_context.h"
+
+#include <openssl/bio.h>
+#include <openssl/ssl.h>
+#include <openssl/x509.h>
+
+#include "bin/directory.h"
+#include "bin/file.h"
+#include "bin/log.h"
+#include "bin/secure_socket_filter.h"
+#include "bin/secure_socket_utils.h"
+
+namespace dart {
+namespace bin {
+
+// The security context won't necessarily use the compiled-in root certificates,
+// but since there is no way to update the size of the allocation after creating
+// the weak persistent handle, we assume that it will. Note that when the
+// root certs aren't compiled in, |root_certificates_pem_length| is 0.
+const intptr_t SSLCertContext::kApproximateSize =
+    sizeof(SSLCertContext) + root_certificates_pem_length;
+
+const char* commandline_root_certs_file = NULL;
+const char* commandline_root_certs_cache = NULL;
+
+void SSLCertContext::TrustBuiltinRoots() {
+  // First, try to use locations specified on the command line.
+  if (commandline_root_certs_file != NULL) {
+    LoadRootCertFile(commandline_root_certs_file);
+    return;
+  }
+
+  if (commandline_root_certs_cache != NULL) {
+    LoadRootCertCache(commandline_root_certs_cache);
+    return;
+  }
+
+  // On Linux, we use the compiled-in trusted certs as a last resort. First,
+  // we try to find the trusted certs in various standard locations. A good
+  // discussion of the complexities of this endeavor can be found here:
+  //
+  // https://www.happyassassin.net/2015/01/12/a-note-about-ssltls-trusted-certificate-stores-and-platforms/
+  const char* bundle = "/etc/pki/tls/certs/ca-bundle.crt";
+  const char* cachedir = "/etc/ssl/certs";
+  if (File::Exists(bundle)) {
+    LoadRootCertFile(bundle);
+    return;
+  }
+
+  if (Directory::Exists(cachedir) == Directory::EXISTS) {
+    LoadRootCertCache(cachedir);
+    return;
+  }
+
+  // Fall back on the compiled-in certs if the standard locations don't exist,
+  // or we aren't on Linux.
+  if (SSL_LOG_STATUS) {
+    Log::Print("Trusting compiled-in roots\n");
+  }
+  AddCompiledInCerts();
+}
+
+
+void SSLCertContext::RegisterCallbacks(SSL* ssl) {
+  // No callbacks to register for implementations using BoringSSL's built-in
+  // verification mechanism.
+}
+
+}  // namespace bin
+}  // namespace dart
+
+#endif  // defined(HOST_OS_LINUX)
+
+#endif  // !defined(DART_IO_DISABLED) &&
+        // !defined(DART_IO_SECURE_SOCKET_DISABLED)