src/net/ssl/client_cert_identity.cc

// 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.

#include "net/ssl/client_cert_identity.h"

#include "base/bind.h"
#include "net/cert/x509_util.h"
#include "net/ssl/ssl_private_key.h"

namespace net {

namespace {

void IdentityOwningPrivateKeyCallback(
    std::unique_ptr<ClientCertIdentity> identity,
    const base::Callback<void(scoped_refptr<SSLPrivateKey>)>&
        private_key_callback,
    scoped_refptr<SSLPrivateKey> private_key) {
  private_key_callback.Run(std::move(private_key));
}

}  // namespace

ClientCertIdentity::ClientCertIdentity(scoped_refptr<net::X509Certificate> cert)
    : cert_(std::move(cert)) {}
ClientCertIdentity::~ClientCertIdentity() = default;

// static
void ClientCertIdentity::SelfOwningAcquirePrivateKey(
    std::unique_ptr<ClientCertIdentity> self,
    const base::Callback<void(scoped_refptr<SSLPrivateKey>)>&
        private_key_callback) {
  ClientCertIdentity* self_ptr = self.get();
  auto wrapped_private_key_callback =
      base::Bind(&IdentityOwningPrivateKeyCallback, base::Passed(&self),
                 private_key_callback);
  self_ptr->AcquirePrivateKey(wrapped_private_key_callback);
}

void ClientCertIdentity::SetIntermediates(
    std::vector<bssl::UniquePtr<CRYPTO_BUFFER>> intermediates) {
  // Allow UTF-8 inside PrintableStrings in client certificates. See
  // crbug.com/770323.
  // TODO(mattm): Perhaps X509Certificate should have a method to clone the
  // X509Certificate but with different intermediates, to avoid reparsing here
  // (and avoid needing to match the parsing options here with where the
  // X509Certificate was initially created.)
  X509Certificate::UnsafeCreateOptions options;
  options.printable_string_is_utf8 = true;
  cert_ = X509Certificate::CreateFromBufferUnsafeOptions(
      bssl::UpRef(cert_->cert_buffer()), std::move(intermediates), options);
  // |cert_->cert_buffer()| was already successfully parsed, so this should
  // never fail.
  DCHECK(cert_);
}

ClientCertIdentitySorter::ClientCertIdentitySorter()
    : now_(base::Time::Now()) {}

bool ClientCertIdentitySorter::operator()(
    const std::unique_ptr<ClientCertIdentity>& a_identity,
    const std::unique_ptr<ClientCertIdentity>& b_identity) const {
  X509Certificate* a = a_identity->certificate();
  X509Certificate* b = b_identity->certificate();
  DCHECK(a);
  DCHECK(b);

  // Certificates that are expired/not-yet-valid are sorted last.
  bool a_is_valid = now_ >= a->valid_start() && now_ <= a->valid_expiry();
  bool b_is_valid = now_ >= b->valid_start() && now_ <= b->valid_expiry();
  if (a_is_valid != b_is_valid)
    return a_is_valid && !b_is_valid;

  // Certificates with longer expirations appear as higher priority (less
  // than) certificates with shorter expirations.
  if (a->valid_expiry() != b->valid_expiry())
    return a->valid_expiry() > b->valid_expiry();

  // If the expiration dates are equivalent, certificates that were issued
  // more recently should be prioritized over older certificates.
  if (a->valid_start() != b->valid_start())
    return a->valid_start() > b->valid_start();

  // Otherwise, prefer client certificates with shorter chains.
  const auto& a_intermediates = a->intermediate_buffers();
  const auto& b_intermediates = b->intermediate_buffers();
  return a_intermediates.size() < b_intermediates.size();
}

}  // namespace net