Sanitize data before providing it to the CDM

media/cdm/json_web_key.cc

 // Copyright 2013 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 "media/cdm/json_web_key.h"
 
 #include "base/base64.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/json/string_escape.h"
@@ skipping 84 matching lines @@
   std::string escaped_str =
       base::EscapeBytesAsInvalidJSONString(input.substr(0, 65), false);
   if (escaped_str.length() <= 64u)
     return escaped_str;
 
   // This may end up truncating an escaped character, but the first part of
   // the string should provide enough information.
   return escaped_str.substr(0, 61).append("...");
 }
 
+static scoped_ptr<base::DictionaryValue> CreateJSONDictionary(
+    const uint8* key,
+    int key_length,
+    const uint8* key_id,
+    int key_id_length) {
+  scoped_ptr<base::DictionaryValue> jwk(new base::DictionaryValue());
+  jwk->SetString(kKeyTypeTag, kKeyTypeOct);
+  jwk->SetString(kKeyTag, EncodeBase64Url(key, key_length));
+  jwk->SetString(kKeyIdTag, EncodeBase64Url(key_id, key_id_length));
+  return jwk.Pass();
+}
+
 std::string GenerateJWKSet(const uint8* key, int key_length,
                            const uint8* key_id, int key_id_length) {
-  // Both |key| and |key_id| need to be base64 encoded strings in the JWK.
-  std::string key_base64 = EncodeBase64Url(key, key_length);
-  std::string key_id_base64 = EncodeBase64Url(key_id, key_id_length);
-
   // Create the JWK, and wrap it into a JWK Set.
-  scoped_ptr<base::DictionaryValue> jwk(new base::DictionaryValue());
-  jwk->SetString(kKeyTypeTag, kKeyTypeOct);
-  jwk->SetString(kKeyTag, key_base64);
-  jwk->SetString(kKeyIdTag, key_id_base64);
   scoped_ptr<base::ListValue> list(new base::ListValue());
-  list->Append(jwk.release());
+  list->Append(
+      CreateJSONDictionary(key, key_length, key_id, key_id_length).release());
   base::DictionaryValue jwk_set;
   jwk_set.Set(kKeysTag, list.release());
 
   // Finally serialize |jwk_set| into a string and return it.
   std::string serialized_jwk;
+  JSONStringValueSerializer serializer(&serialized_jwk);
+  serializer.Serialize(jwk_set);
+  return serialized_jwk;
+}
+
+std::string GenerateJWKSet(const KeyIdAndKeyPairs& keys,
+                           MediaKeys::SessionType session_type) {
+  scoped_ptr<base::ListValue> list(new base::ListValue());
+  for (const auto& key_pair : keys) {
+    list->Append(CreateJSONDictionary(
+                     reinterpret_cast<const uint8*>(key_pair.second.data()),
+                     key_pair.second.length(),
+                     reinterpret_cast<const uint8*>(key_pair.first.data()),
+                     key_pair.first.length())
+                     .release());
+  }
+
+  base::DictionaryValue jwk_set;
+  jwk_set.Set(kKeysTag, list.release());
+  switch (session_type) {
+    case MediaKeys::TEMPORARY_SESSION:
+      jwk_set.SetString(kTypeTag, kTemporarySession);
+      break;
+    case MediaKeys::PERSISTENT_LICENSE_SESSION:
+      jwk_set.SetString(kTypeTag, kPersistentLicenseSession);
+      break;
+    case MediaKeys::PERSISTENT_RELEASE_MESSAGE_SESSION:
+      jwk_set.SetString(kTypeTag, kPersistentReleaseMessageSession);
+      break;
+  }
+
+  // Finally serialize |jwk_set| into a string and return it.
+  std::string serialized_jwk;
   JSONStringValueSerializer serializer(&serialized_jwk);
   serializer.Serialize(jwk_set);
   return serialized_jwk;
 }
 
 // Processes a JSON Web Key to extract the key id and key value. Sets |jwk_key|
 // to the id/value pair and returns true on success.
 static bool ConvertJwkToKeyPair(const base::DictionaryValue& jwk,
                                 KeyIdAndKeyPair* jwk_key) {
   std::string type;
@@ skipping 257 matching lines @@
     DVLOG(1) << "Invalid '" << kKeyIdsTag << "' value: " << encoded_key;
     return false;
   }
 
   std::vector<uint8> result(decoded_string.begin(), decoded_string.end());
   first_key->swap(result);
   return true;
 }
 
 }  // namespace media