1// Copyright 2023 Google LLC 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15syntax = "proto2"; 16 17package securegcm; 18 19option optimize_for = LITE_RUNTIME; 20option java_package = "com.google.security.cryptauth.lib.securegcm"; 21option java_outer_classname = "UkeyProto"; 22 23message Ukey2Message { 24 enum Type { 25 UNKNOWN_DO_NOT_USE = 0; 26 ALERT = 1; 27 CLIENT_INIT = 2; 28 SERVER_INIT = 3; 29 CLIENT_FINISH = 4; 30 } 31 32 optional Type message_type = 1; // Identifies message type 33 optional bytes message_data = 2; // Actual message, to be parsed according to 34 // message_type 35} 36 37message Ukey2Alert { 38 enum AlertType { 39 // Framing errors 40 BAD_MESSAGE = 1; // The message could not be deserialized 41 BAD_MESSAGE_TYPE = 2; // message_type has an undefined value 42 INCORRECT_MESSAGE = 3; // message_type received does not correspond to 43 // expected type at this stage of the protocol 44 BAD_MESSAGE_DATA = 4; // Could not deserialize message_data as per 45 // value inmessage_type 46 47 // ClientInit and ServerInit errors 48 BAD_VERSION = 100; // version is invalid; server cannot find 49 // suitable version to speak with client. 50 BAD_RANDOM = 101; // Random data is missing or of incorrect 51 // length 52 BAD_HANDSHAKE_CIPHER = 102; // No suitable handshake ciphers were found 53 BAD_NEXT_PROTOCOL = 103; // The next protocol is missing, unknown, or 54 // unsupported 55 BAD_PUBLIC_KEY = 104; // The public key could not be parsed 56 57 // Other errors 58 INTERNAL_ERROR = 200; // An internal error has occurred. error_message 59 // may contain additional details for logging 60 // and debugging. 61 } 62 63 optional AlertType type = 1; 64 optional string error_message = 2; 65} 66 67enum Ukey2HandshakeCipher { 68 RESERVED = 0; 69 P256_SHA512 = 100; // NIST P-256 used for ECDH, SHA512 used for 70 // commitment 71 CURVE25519_SHA512 = 200; // Curve 25519 used for ECDH, SHA512 used for 72 // commitment 73} 74 75message Ukey2ClientInit { 76 optional int32 version = 1; // highest supported version for rollback 77 // protection 78 optional bytes random = 2; // random bytes for replay/reuse protection 79 80 // One commitment (hash of ClientFinished containing public key) per supported 81 // cipher 82 message CipherCommitment { 83 optional Ukey2HandshakeCipher handshake_cipher = 1; 84 optional bytes commitment = 2; 85 } 86 repeated CipherCommitment cipher_commitments = 3; 87 88 // Next protocol that the client wants to speak. 89 optional string next_protocol = 4; 90 // Next protocols the client can speak. 91 repeated string next_protocols = 5; 92} 93 94message Ukey2ServerInit { 95 optional int32 version = 1; // highest supported version for rollback 96 // protection 97 optional bytes random = 2; // random bytes for replay/reuse protection 98 99 // Selected Cipher and corresponding public key 100 optional Ukey2HandshakeCipher handshake_cipher = 3; 101 optional bytes public_key = 4; 102 // The server-selected next_protocol string based on the Ukey2ClientInit's 103 // next_protocol string and other_next_protocols array. 104 optional string selected_next_protocol = 5; 105} 106 107message Ukey2ClientFinished { 108 optional bytes public_key = 1; // public key matching selected handshake 109 // cipher 110} 111