Extension API enterprise.platformKeys.

chrome/renderer/resources/extensions/enterprise_platform_keys/subtle_crypto.js

+// Copyright 2014 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.
+
+var utils = require('utils');
+var internalAPI = require('enterprise.platformKeys.internalAPI');
+var intersect = require('enterprise.platformKeys.utils').intersect;
+var KeyPair = require('enterprise.platformKeys.KeyPair').KeyPair;
+var keyModule = require('enterprise.platformKeys.Key');
+var getSpki = keyModule.getSpki;
+var KeyUsage = keyModule.KeyUsage;
+
+// This error is thrown by the internal and public API's token functions and
+// must be rethrown by this custom binding. Keep this in sync with the C++ part
+// of this API.
+var errorInvalidToken = "The token is not valid.";
+
+// The following errors are specified in WebCrypto.
+// TODO(pneubeck): These should be DOMExceptions.
+function CreateNotSupportedError() {
+  return new Error('The algorithm is not supported');
+}
+
+function CreateInvalidAccessError() {
+  return new Error('The requested operation is not valid for the provided key');
+}
+
+function CreateDataError() {
+  return new Error('Data provided to an operation does not meet requirements');
+}
+
+function CreateSyntaxError() {
+  return new Error('A required parameter was missing our out-of-range');
+}
+
+function CreateOperationError() {
+  return new Error('The operation failed for an operation-specific reason');
+}
+
+// Catches an |internalErrorInvalidToken|. If so, forwards it to |reject| and
+// returns true.
+function catchInvalidTokenError(reject) {
+  if (chrome.runtime.lastError &&
+      chrome.runtime.lastError.message == errorInvalidToken) {
+    reject(chrome.runtime.lastError);
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Implementation of WebCrypto.SubtleCrypto used in enterprise.platformKeys.
+ * @param {string} tokenId The id of the backing Token.
+ * @constructor
+ */
+var SubtleCryptoImpl = function(tokenId) {
+  this.tokenId = tokenId;
+};
+
+SubtleCryptoImpl.prototype.generateKey =
+    function(algorithm, extractable, keyUsages) {
+  var subtleCrypto = this;
+  return new Promise(function(resolve, reject) {
+    // TODO(pneubeck): Apply the algorithm normalization of the WebCrypto
+    // implementation.
+
+    if (extractable) {
+      // Note: This deviates from WebCrypto.SubtleCrypto.
+      throw CreateNotSupportedError();
+    }
+    if (intersect(keyUsages, [KeyUsage.sign, KeyUsage.verify]).length !=
+        keyUsages.length) {
+      throw CreateDataError();
+    }
+    if (!algorithm.name) {
+      // TODO(pneubeck): It's not clear from the WebCrypto spec which error to
+      // throw here.
+      throw CreateSyntaxError();
+    }
+
+    if (algorithm.name != 'RSASSA-PKCS1-v1_5') {
+      // Note: This deviates from WebCrypto.SubtleCrypto.
+      throw CreateNotSupportedError();
+    }
+    if (!algorithm.modulusLength || !algorithm.publicExponent)
+      throw CreateSyntaxError();
+
+    internalAPI.generateKey(
+        subtleCrypto.tokenId, algorithm.modulusLength, function(spki) {
+          if (catchInvalidTokenError(reject))
+            return;
+          if (chrome.runtime.lastError) {
+            reject(CreateOperationError());
+            return;
+          }
+          resolve(new KeyPair(spki, algorithm, keyUsages));
+        });
+  });
+};
+
+SubtleCryptoImpl.prototype.sign = function(algorithm, key, dataView) {
+  var subtleCrypto = this;
+  return new Promise(function(resolve, reject) {
+    if (key.type != 'private' || key.usages.indexOf(KeyUsage.sign) == -1)
+      throw CreateInvalidAccessError();
+
+    // Create an ArrayBuffer that equals the dataView. Note that dataView.buffer
+    // might contain more data than dataView.
+    var data = dataView.buffer.slice(dataView.byteOffset,
+                                     dataView.byteOffset + dataView.byteLength);
+    internalAPI.sign(
+        subtleCrypto.tokenId, getSpki(key), data, function(signature) {
+          if (catchInvalidTokenError(reject))
+            return;
+          if (chrome.runtime.lastError) {
+            reject(CreateOperationError());
+            return;
+          }
+          resolve(signature);
+        });
+  });
+};
+
+SubtleCryptoImpl.prototype.exportKey = function(format, key) {
+  return new Promise(function(resolve, reject) {
+    if (format == 'pkcs8') {
+      // Either key.type is not 'private' or the key is not extractable. In both
+      // cases the error is the same.
+      throw CreateInvalidAccessError();
+    } else if (format == 'spki') {
+      if (key.type != 'public')
+        throw CreateInvalidAccessError();
+      resolve(getSpki(key));
+    } else {
+      // TODO(pneubeck): It should be possible to export to format 'jwk'.
+      throw CreateNotSupportedError();
+    }
+  });
+};
+
+exports.SubtleCrypto =
+    utils.expose('SubtleCrypto',
+                 SubtleCryptoImpl,
+                 {functions:['generateKey', 'sign', 'exportKey']});