// Copyright 2017 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 syntax = "proto2"; option optimize_for = LITE_RUNTIME; package crx_file; // A CRX₃ file is a binary file of the following format: // [4 octets]: "Cr24", a magic number. // [4 octets]: The version of the *.crx file format used (currently 3). // [4 octets]: N, little-endian, the length of the header section. // [N octets]: The header (the binary encoding of a CrxFileHeader). // [M octets]: The ZIP archive. // Clients should reject CRX₃ files that contain an N that is too large for the // client to safely handle in memory. message CrxFileHeader { // PSS signature with RSA public key. The public key is formatted as a // X.509 SubjectPublicKeyInfo block, as in CRX₂. In the common case of a // developer key proof, the first 128 bits of the SHA-256 hash of the // public key must equal the crx_id. repeated AsymmetricKeyProof sha256_with_rsa = 2; // ECDSA signature, using the NIST P-256 curve. Public key appears in // named-curve format. // The pinned algorithm will be this, at least on 2017-01-01. repeated AsymmetricKeyProof sha256_with_ecdsa = 3; // A verified contents file containing signatures over the archive contents. // The verified contents are encoded in UTF-8 and then GZIP-compressed. // Consult // https://source.chromium.org/chromium/chromium/src/+/main:extensions/browser/verified_contents.h // for information about the verified contents format. optional bytes verified_contents = 4; // The binary form of a SignedData message. We do not use a nested // SignedData message, as handlers of this message must verify the proofs // on exactly these bytes, so it is convenient to parse in two steps. // // All proofs in this CrxFile message are on the value // "CRX3 SignedData\x00" + signed_header_size + signed_header_data + // archive, where "\x00" indicates an octet with value 0, "CRX3 SignedData" // is encoded using UTF-8, signed_header_size is the size in octets of the // contents of this field and is encoded using 4 octets in little-endian // order, signed_header_data is exactly the content of this field, and // archive is the remaining contents of the file following the header. optional bytes signed_header_data = 10000; } message AsymmetricKeyProof { optional bytes public_key = 1; optional bytes signature = 2; } message SignedData { // This is simple binary, not UTF-8 encoded mpdecimal; i.e. it is exactly // 16 bytes long. optional bytes crx_id = 1; }