Implement chrome.platformKeys.getKeyPair().

chrome/browser/extensions/api/platform_keys/platform_keys_api.cc

 // 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.
 
 #include "chrome/browser/extensions/api/platform_keys/platform_keys_api.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
+#include "base/values.h"
 #include "chrome/browser/chromeos/platform_keys/platform_keys.h"
 #include "chrome/browser/chromeos/platform_keys/platform_keys_service.h"
 #include "chrome/browser/chromeos/platform_keys/platform_keys_service_factory.h"
 #include "chrome/common/extensions/api/platform_keys_internal.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/cert/x509_certificate.h"
 
 namespace extensions {
 
 namespace api_pk = api::platform_keys;
 namespace api_pki = api::platform_keys_internal;
 
+namespace {
+
+const char kErrorAlgorithmNotSupported[] = "Algorithm not supported.";
+
+// Builds a partial WebCrypto Algorithm object from the parameters available in
+// |key_info|. This doesn't include sign/hash parameters and thus isn't
+// complete.
+// For RSA, the default public exponent 65537 is assumed.
+void BuildWebCryptoAlgorithmDictionary(
+    const chromeos::platform_keys::PublicKeyInfo& key_info,
+    base::DictionaryValue* algorithm) {
+  algorithm->SetStringWithoutPathExpansion("name", "RSASSA-PKCS1-v1_5");
+  algorithm->SetIntegerWithoutPathExpansion("modulusLength",
+                                            key_info.modulus_length_bits);
+
+  // Equals 65537.
+  const char defaultPublicExponent[] = {0x01, 0x00, 0x01};
+  algorithm->SetWithoutPathExpansion(
+      "publicExponent",
+      base::BinaryValue::CreateWithCopiedBuffer(
+          defaultPublicExponent, arraysize(defaultPublicExponent)));
+}
+
+}  // namespace
+
 namespace platform_keys {
 
 const char kErrorInvalidToken[] = "The token is not valid.";
-const char kErrorAlgorithmNotSupported[] = "Algorithm not supported.";
 const char kTokenIdUser[] = "user";
 const char kTokenIdSystem[] = "system";
 
 // Returns whether |token_id| references a known Token.
 bool ValidateToken(const std::string& token_id,
                    std::string* platform_keys_token_id) {
   platform_keys_token_id->clear();
   if (token_id == kTokenIdUser) {
     *platform_keys_token_id = chromeos::platform_keys::kTokenIdUser;
     return true;
@@ skipping 10 matching lines @@
   if (platform_keys_token_id == chromeos::platform_keys::kTokenIdUser)
     return kTokenIdUser;
   if (platform_keys_token_id == chromeos::platform_keys::kTokenIdSystem)
     return kTokenIdSystem;
 
   return std::string();
 }
 
 }  // namespace platform_keys
 
+PlatformKeysInternalGetPublicKeyFunction::
+    ~PlatformKeysInternalGetPublicKeyFunction() {
+}
+
+ExtensionFunction::ResponseAction
+PlatformKeysInternalGetPublicKeyFunction::Run() {
+  scoped_ptr<api_pki::GetPublicKey::Params> params(
+      api_pki::GetPublicKey::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params);
+
+  const std::vector<char>& cert_der = params->certificate;
+  scoped_refptr<net::X509Certificate> cert_x509 =
+      net::X509Certificate::CreateFromBytes(vector_as_array(&cert_der),
+                                            cert_der.size());

[Ryan Sleevi, 2015/02/03 01:44:50]

SECURITY BUG: Validate that |cert_x509| is valid here, before doing anything
else. With your code as written, you would end up crashing at a NULL pointer
deref.

[pneubeck (no reviews), 2015/02/03 20:15:00]

Done.

+
+  chromeos::platform_keys::PublicKeyInfo info;
+  if (!chromeos::platform_keys::GetPublicKey(cert_x509, &info) ||
+      info.key_type != net::X509Certificate::kPublicKeyTypeRSA) {
+    return RespondNow(Error(kErrorAlgorithmNotSupported));
+  }
+
+  api_pki::GetPublicKey::Results::Algorithm algorithm;
+  BuildWebCryptoAlgorithmDictionary(info, &algorithm.additional_properties);
+
+  return RespondNow(ArgumentList(api_pki::GetPublicKey::Results::Create(
+      info.public_key_spki_der, algorithm)));
+}
+
 PlatformKeysInternalSelectClientCertificatesFunction::
     ~PlatformKeysInternalSelectClientCertificatesFunction() {
 }
 
 ExtensionFunction::ResponseAction
 PlatformKeysInternalSelectClientCertificatesFunction::Run() {
   scoped_ptr<api_pki::SelectClientCertificates::Params> params(
       api_pki::SelectClientCertificates::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params);
 
@@ skipping 21 matching lines @@
     OnSelectedCertificates(scoped_ptr<net::CertificateList> matches,
                            const std::string& error_message) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   if (!error_message.empty()) {
     Respond(Error(error_message));
     return;
   }
   DCHECK(matches);
   std::vector<linked_ptr<api_pk::Match>> result_matches;
   for (const scoped_refptr<net::X509Certificate>& match : *matches) {
+    chromeos::platform_keys::PublicKeyInfo key_info;
+    if (!chromeos::platform_keys::GetPublicKey(match, &key_info)) {
+      LOG(ERROR) << "Could not retrieve public key info.";
+      continue;
+    }
+    if (key_info.key_type != net::X509Certificate::kPublicKeyTypeRSA) {
+      LOG(ERROR) << "Skipping unsupported certificate with non-RSA key.";
+      continue;
+    }
+
     linked_ptr<api_pk::Match> result_match(new api_pk::Match);
     std::string der_encoded_cert;
     net::X509Certificate::GetDEREncoded(match->os_cert_handle(),
                                         &der_encoded_cert);
     result_match->certificate.assign(der_encoded_cert.begin(),
                                      der_encoded_cert.end());
+
+    BuildWebCryptoAlgorithmDictionary(
+        key_info, &result_match->key_algorithm.additional_properties);
     result_matches.push_back(result_match);
   }
   Respond(ArgumentList(
       api_pki::SelectClientCertificates::Results::Create(result_matches)));
 }
 
 PlatformKeysInternalSignFunction::~PlatformKeysInternalSignFunction() {
 }
 
 ExtensionFunction::ResponseAction PlatformKeysInternalSignFunction::Run() {
   scoped_ptr<api_pki::Sign::Params> params(
       api_pki::Sign::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params);
   std::string platform_keys_token_id;
-  if (!platform_keys::ValidateToken(params->token_id, &platform_keys_token_id))
+  if (!params->token_id.empty() &&
+      !platform_keys::ValidateToken(params->token_id,
+                                    &platform_keys_token_id)) {
     return RespondNow(Error(platform_keys::kErrorInvalidToken));
+  }
 
   chromeos::platform_keys::HashAlgorithm hash_algorithm;
-  if (params->hash_algorithm_name == "SHA-1")
+  if (params->hash_algorithm_name == "none")
+    hash_algorithm = chromeos::platform_keys::HASH_ALGORITHM_NONE;
+  else if (params->hash_algorithm_name == "SHA-1")
     hash_algorithm = chromeos::platform_keys::HASH_ALGORITHM_SHA1;
   else if (params->hash_algorithm_name == "SHA-256")
     hash_algorithm = chromeos::platform_keys::HASH_ALGORITHM_SHA256;
   else if (params->hash_algorithm_name == "SHA-384")
     hash_algorithm = chromeos::platform_keys::HASH_ALGORITHM_SHA384;
   else if (params->hash_algorithm_name == "SHA-512")
     hash_algorithm = chromeos::platform_keys::HASH_ALGORITHM_SHA512;
   else
-    return RespondNow(Error(platform_keys::kErrorAlgorithmNotSupported));
+    return RespondNow(Error(kErrorAlgorithmNotSupported));
 
   chromeos::PlatformKeysService* service =
       chromeos::PlatformKeysServiceFactory::GetForBrowserContext(
           browser_context());
   DCHECK(service);
 
   service->Sign(
       platform_keys_token_id,
       std::string(params->public_key.begin(), params->public_key.end()),
       hash_algorithm, std::string(params->data.begin(), params->data.end()),
       extension_id(),
       base::Bind(&PlatformKeysInternalSignFunction::OnSigned, this));
   return RespondLater();
 }
 
 void PlatformKeysInternalSignFunction::OnSigned(
     const std::string& signature,
     const std::string& error_message) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   if (error_message.empty())
     Respond(ArgumentList(api_pki::Sign::Results::Create(
         std::vector<char>(signature.begin(), signature.end()))));
   else
     Respond(Error(error_message));
 }
 
 }  // namespace extensions