merkle-tree-lib/dist/hash/strategies/TaggedSha256Strategy.js

Merkle Tree implementation with BIP340 tagged hash support.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.TaggedSha256Strategy = void 0;
const crypto_1 = require("crypto");
/**
 * TaggedSha256Strategy - Implementation of HashStrategy using BIP-0340 tagged SHA-256
 * This implements tagged hashing as defined in BIP-0340: SHA256(SHA256(tag) || SHA256(tag) || msg)
 */
class TaggedSha256Strategy {
    /**
     * Initialize with a specific tag
     *
     * @param tag - Tag string to use for domain separation
     */
    constructor(tag) {
        this.tag = tag;
        this.tagHash = (0, crypto_1.createHash)('sha256').update(tag, 'utf8').digest();
    }
    /**
     * Calculate a tagged SHA-256 hash for the input data
     *
     * @param data - The data to hash
     * @returns The computed tagged SHA-256 hash as a Buffer
     */
    hash(data) {
        const dataBuffer = typeof data === 'string' ? Buffer.from(data, 'utf8') : data;
        // Apply the tagged hash: SHA256(tagHash || tagHash || msg)
        return (0, crypto_1.createHash)('sha256')
            .update(this.tagHash)
            .update(this.tagHash)
            .update(dataBuffer)
            .digest();
    }
    /**
     * Get the algorithm name including the tag
     *
     * @returns A descriptive string with the algorithm and tag
     */
    getAlgorithmName() {
        return `Tagged-SHA-256(${this.tag})`;
    }
    /**
     * Get the tag used for this strategy
     *
     * @returns The tag string
     */
    getTag() {
        return this.tag;
    }
    /**
     * Get the pre-computed tag hash
     *
     * @returns The tag hash as a Buffer
     */
    getTagHash() {
        return this.tagHash;
    }
}
exports.TaggedSha256Strategy = TaggedSha256Strategy;