1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MEDIA_CDM_JSON_WEB_KEY_H_ 6 #define MEDIA_CDM_JSON_WEB_KEY_H_ 7 8 #include <string> 9 #include <utility> 10 #include <vector> 11 12 #include "base/basictypes.h" 13 #include "media/base/media_export.h" 14 #include "media/base/media_keys.h" 15 16 namespace media { 17 18 // The ClearKey license request format (ref: 19 // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#clear-key) 20 // is a JSON object containing the following members: 21 // "kids" : An array of key IDs. Each element of the array is the base64url 22 // encoding of the octet sequence containing the key ID value. 23 // "type" : The requested SessionType. 24 // An example: 25 // { "kids":["67ef0gd8pvfd0","77ef0gd8pvfd0"], "type":"temporary" } 26 27 // The ClearKey license format is a JSON Web Key (JWK) Set containing 28 // representation of the symmetric key to be used for decryption. 29 // For each JWK in the set, the parameter values are as follows: 30 // "kty" (key type) : "oct" (octet sequence) 31 // "alg" (algorithm) : "A128KW" (AES key wrap using a 128-bit key) 32 // "k" (key value) : The base64url encoding of the octet sequence 33 // containing the symmetric key value. 34 // "kid" (key ID) : The base64url encoding of the octet sequence 35 // containing the key ID value. 36 // The JSON object may have an optional "type" member value, which may be 37 // any of the SessionType values. If not specified, the default value of 38 // "temporary" is used. 39 // A JSON Web Key Set looks like the following in JSON: 40 // { "keys": [ JWK1, JWK2, ... ], "type":"temporary" } 41 // A symmetric keys JWK looks like the following in JSON: 42 // { "kty":"oct", 43 // "alg":"A128KW", 44 // "kid":"AQIDBAUGBwgJCgsMDQ4PEA", 45 // "k":"FBUWFxgZGhscHR4fICEiIw" } 46 47 // There may be other properties specified, but they are ignored. 48 // Ref: http://tools.ietf.org/html/draft-ietf-jose-json-web-key and: 49 // http://tools.ietf.org/html/draft-jones-jose-json-private-and-symmetric-key 50 51 // Vector of [key_id, key_value] pairs. Values are raw binary data, stored in 52 // strings for convenience. 53 typedef std::pair<std::string, std::string> KeyIdAndKeyPair; 54 typedef std::vector<KeyIdAndKeyPair> KeyIdAndKeyPairs; 55 56 // Converts a single |key|, |key_id| pair to a JSON Web Key Set. 57 MEDIA_EXPORT std::string GenerateJWKSet(const uint8* key, int key_length, 58 const uint8* key_id, int key_id_length); 59 60 // Extracts the JSON Web Keys from a JSON Web Key Set. If |input| looks like 61 // a valid JWK Set, then true is returned and |keys| and |session_type| are 62 // updated to contain the values found. Otherwise return false. 63 MEDIA_EXPORT bool ExtractKeysFromJWKSet(const std::string& jwk_set, 64 KeyIdAndKeyPairs* keys, 65 MediaKeys::SessionType* session_type); 66 67 // Create a license request message for the |key_id| and |session_type| 68 // specified. Currently ClearKey generates a message for each key individually, 69 // so no need to take a list of |key_id|'s. |license| is updated to contain the 70 // resulting JSON string. 71 MEDIA_EXPORT void CreateLicenseRequest(const uint8* key_id, 72 int key_id_length, 73 MediaKeys::SessionType session_type, 74 std::vector<uint8>* license); 75 76 // Extract the first key from the license request message. Returns true if 77 // |license| is a valid license request and contains at least one key, 78 // otherwise false and |first_key| is not touched. 79 MEDIA_EXPORT bool ExtractFirstKeyIdFromLicenseRequest( 80 const std::vector<uint8>& license, 81 std::vector<uint8>* first_key); 82 83 } // namespace media 84 85 #endif // MEDIA_CDM_JSON_WEB_KEY_H_ 86