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Diffstat (limited to 'data/extensions/jsr@javascriptrestrictor/wrappingS-EME.js')
| -rw-r--r-- | data/extensions/jsr@javascriptrestrictor/wrappingS-EME.js | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/data/extensions/jsr@javascriptrestrictor/wrappingS-EME.js b/data/extensions/jsr@javascriptrestrictor/wrappingS-EME.js new file mode 100644 index 0000000..822ef1d --- /dev/null +++ b/data/extensions/jsr@javascriptrestrictor/wrappingS-EME.js @@ -0,0 +1,83 @@ +/** \file + * \brief This file contains wrappers for the EME standard + * + * \see https://developer.mozilla.org/en-US/docs/Web/API/Navigator/requestMediaKeySystemAccess + * + * \author Copyright (C) 2022 Libor Polcak + * + * \license SPDX-License-Identifier: GPL-3.0-or-later + */ +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. +// + +/** \file + * \ingroup wrappers + * + * `Navigator.requestMediaKeySystemAccess()` provides access to `MediaKeySystemAccess` object that + * allows to query supported encryption mechanisms and other information about the system. + * + * For example, visit https://www.fit.vutbr.cz/~polcak/jsr/hdcp/ and try a different browser or + * computer. + * + * \see https://w3c.github.io/encrypted-media/ + * \see https://developer.mozilla.org/en-US/docs/Web/API/Navigator/requestMediaKeySystemAccess + * \see https://developer.mozilla.org/en-US/docs/Web/API/MediaKeySystemAccess + * \see https://developer.mozilla.org/en-US/docs/Web/API/MediaKeySystemAccess/getConfiguration + * + * We provide two modes of protection: + * + * 1. Strict approach prevents accessing the API. + * 2. Farbling approach changes the output to a non-existing key system with 12.5% probability. + */ + +/* + * Create private namespace + */ +(function() { + var helping_code = `var approach = args[0];`; + var wrappers = [ + { + parent_object: "Navigator.prototype", + parent_object_property: "requestMediaKeySystemAccess", + wrapped_objects: [{ + original_name: "Navigator.prototype.requestMediaKeySystemAccess", + wrapped_name: "origMKSA", + }], + helping_code: helping_code, + wrapping_function_args: "keySystem, queriedConfigs, ...args", + wrapping_function_body: ` + if (approach == 2) { + return new Promise(() => {}); // Never resolves + } + else if (approach == 1) { + keySystem = "org.jshelter"; + return origMKSA.call(this, keySystem, queriedConfigs, ...args); + } + else { + var eme_prng = alea(domainHash, "requestMediaKeySystemAccess", keySystem); + var rnd = eme_prng.get_bits(3); + if (rnd == 0) { + keySystem = "org.jshelter"; + return origMKSA.call(this, keySystem, queriedConfigs, ...args); + } + else { + return origMKSA.call(this, keySystem, queriedConfigs, ...args); + } + } + `, + }, + ] + add_wrappers(wrappers); +})() |