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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | 1x 1x 1x 1x 1x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 6x 6x 6x 2x 2x 2x 2x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x | import { BufferReader, BufferWriter } from '@node-dlc/bufio';
import { math, verify } from 'bip-schnorr';
import { MessageType } from '../MessageType';
import { IDlcMessage } from './DlcMessage';
/**
* In order to make it possible to hold oracles accountable in cases where
* they do not release a signature for an event outcome, there needs to be
* a proof that an oracle has committed to a given outcome. This proof is
* given in a so-called oracle announcement, which contains an oracle event
* together with the oracle public key and a signature over its serialization,
* which must be valid with respect to the specified public key.
*
* This also makes it possible for users to obtain oracle event information
* from an un-trusted peer while being guaranteed that it originates from a
* given oracle.
*/
export class OracleAttestationV0 implements IDlcMessage {
public static type = MessageType.OracleAttestationV0;
/**
* Deserializes an oracle_announcement_v0 message
* @param buf
*/
public static deserialize(buf: Buffer): OracleAttestationV0 {
const instance = new OracleAttestationV0();
const reader = new BufferReader(buf);
reader.readBigSize(); // read type
instance.length = reader.readBigSize();
const eventIdLength = reader.readBigSize();
const eventIdBuf = reader.readBytes(Number(eventIdLength));
instance.eventId = eventIdBuf.toString();
instance.oraclePubkey = reader.readBytes(32);
const numSignatures = reader.readUInt16BE();
for (let i = 0; i < numSignatures; i++) {
const signature = reader.readBytes(64);
instance.signatures.push(signature);
}
while (!reader.eof) {
const outcomeLen = reader.readBigSize();
const outcomeBuf = reader.readBytes(Number(outcomeLen));
instance.outcomes.push(outcomeBuf.toString());
}
return instance;
}
/**
* The type for oracle_announcement_v0 message. oracle_announcement_v0 = 55332
*/
public type = OracleAttestationV0.type;
public length: bigint;
public eventId: string;
public oraclePubkey: Buffer;
public signatures: Buffer[] = [];
public outcomes: string[] = [];
public validate(): void {
Iif (this.signatures.length !== this.outcomes.length) {
throw Error('signature and outcome length must be the same');
}
// Verify attestation outcome signatures
for (let i = 0; i < this.signatures.length; i++) {
const msg = math.taggedHash(
'DLC/oracle/attestation/v0',
this.outcomes[i],
);
verify(this.oraclePubkey, msg, this.signatures[i]);
}
}
/**
* Converts oracle_attestation_v0 to JSON
*/
public toJSON(): OracleAttestationV0JSON {
return {
type: this.type,
eventId: this.eventId,
oraclePubkey: this.oraclePubkey.toString('hex'),
signatures: this.signatures.map((sig) => sig.toString('hex')),
outcomes: this.outcomes,
};
}
/**
* Serializes the oracle_announcement_v0 message into a Buffer
*/
public serialize(): Buffer {
const writer = new BufferWriter();
writer.writeBigSize(this.type);
const dataWriter = new BufferWriter();
dataWriter.writeBigSize(this.eventId.length);
dataWriter.writeBytes(Buffer.from(this.eventId));
dataWriter.writeBytes(this.oraclePubkey);
dataWriter.writeUInt16BE(this.signatures.length);
for (const signature of this.signatures) {
dataWriter.writeBytes(signature);
}
for (const outcome of this.outcomes) {
dataWriter.writeBigSize(outcome.length);
dataWriter.writeBytes(Buffer.from(outcome));
}
writer.writeBigSize(dataWriter.size);
writer.writeBytes(dataWriter.toBuffer());
return writer.toBuffer();
}
}
export interface OracleAttestationV0JSON {
type: number;
eventId: string;
oraclePubkey: string;
signatures: string[];
outcomes: string[];
}
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