@waku/core/dist/lib/message_hash/message_hash.js

TypeScript implementation of the Waku v2 protocol

import { sha256 } from "@noble/hashes/sha256";
import { isDefined } from "@waku/utils";
import { bytesToHex, concat, numberToBytes, utf8ToBytes } from "@waku/utils/bytes";
/**
 * Deterministic Message Hashing as defined in
 * [14/WAKU2-MESSAGE](https://rfc.vac.dev/spec/14/#deterministic-message-hashing)
 *
 * Computes a SHA-256 hash of the concatenation of pubsub topic, payload, content topic, meta, and timestamp.
 *
 * @param pubsubTopic - The pubsub topic string
 * @param message - The message to be hashed
 * @returns A Uint8Array containing the SHA-256 hash
 *
 * @example
 * ```typescript
 * import { messageHash } from "@waku/core";
 *
 * const pubsubTopic = "/waku/2/default-waku/proto";
 * const message = {
 *   payload: new Uint8Array([1, 2, 3, 4]),
 *   contentTopic: "/waku/2/default-content/proto",
 *   meta: new Uint8Array([5, 6, 7, 8]),
 *   timestamp: new Date()
 * };
 *
 * const hash = messageHash(pubsubTopic, message);
 * ```
 */
export function messageHash(pubsubTopic, message) {
    const pubsubTopicBytes = utf8ToBytes(pubsubTopic);
    const contentTopicBytes = utf8ToBytes(message.contentTopic);
    const timestampBytes = tryConvertTimestampToBytes(message.timestamp);
    const bytes = concat([
        pubsubTopicBytes,
        message.payload,
        contentTopicBytes,
        message.meta,
        timestampBytes
    ].filter(isDefined));
    return sha256(bytes);
}
function tryConvertTimestampToBytes(timestamp) {
    if (!timestamp) {
        return;
    }
    let bigIntTimestamp;
    if (typeof timestamp === "bigint") {
        bigIntTimestamp = timestamp;
    }
    else {
        bigIntTimestamp = BigInt(timestamp.valueOf()) * 1000000n;
    }
    return numberToBytes(bigIntTimestamp);
}
/**
 * Computes a deterministic message hash and returns it as a hexadecimal string.
 * This is a convenience wrapper around messageHash that converts the result to a hex string.
 *
 * @param pubsubTopic - The pubsub topic string
 * @param message - The message to be hashed
 * @returns A string containing the hex representation of the SHA-256 hash
 *
 * @example
 * ```typescript
 * import { messageHashStr } from "@waku/core";
 *
 * const pubsubTopic = "/waku/2/default-waku/proto";
 * const message = {
 *   payload: new Uint8Array([1, 2, 3, 4]),
 *   contentTopic: "/waku/2/default-content/proto",
 *   meta: new Uint8Array([5, 6, 7, 8]),
 *   timestamp: new Date()
 * };
 *
 * const hashString = messageHashStr(pubsubTopic, message);
 * console.log(hashString); // e.g. "a1b2c3d4..."
 * ```
 */
export function messageHashStr(pubsubTopic, message) {
    const hash = messageHash(pubsubTopic, message);
    const hashStr = bytesToHex(hash);
    return hashStr;
}
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