chaingate/dist/utils/rlp.js

Multi-chain cryptocurrency SDK for TypeScript — unified API for Bitcoin, Ethereum, Litecoin, Dogecoin, Bitcoin Cash, Polygon, Arbitrum, and any EVM-compatible chain. Create wallets, query balances, send transactions, and manage tokens and NFTs across UTXO

"use strict";
/**
 * Minimal RLP (Recursive Length Prefix) encoder for EVM transaction serialization.
 *
 * Implements the RLP encoding scheme as specified in the Ethereum Yellow Paper,
 * Appendix B. Only encoding is needed — decoding is not required for transaction
 * construction.
 *
 * @see https://ethereum.org/en/developers/docs/data-structures-and-encoding/rlp/
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.rlpEncode = rlpEncode;
/**
 * RLP-encodes a single item or nested list of items.
 */
function rlpEncode(input) {
    if (input instanceof Uint8Array) {
        return encodeBytes(input);
    }
    return encodeList(input);
}
function encodeBytes(data) {
    // Single byte in [0x00, 0x7f] range encodes as itself.
    if (data.length === 1 && data[0] < 0x80) {
        return data;
    }
    // Short string: 0–55 bytes → prefix = 0x80 + length.
    if (data.length <= 55) {
        const out = new Uint8Array(1 + data.length);
        out[0] = 0x80 + data.length;
        out.set(data, 1);
        return out;
    }
    // Long string: >55 bytes → prefix = 0xb7 + len(len), then len, then data.
    const lenBytes = encodeLength(data.length);
    const out = new Uint8Array(1 + lenBytes.length + data.length);
    out[0] = 0xb7 + lenBytes.length;
    out.set(lenBytes, 1);
    out.set(data, 1 + lenBytes.length);
    return out;
}
function encodeList(items) {
    // Concatenate all encoded children.
    const encoded = items.map(rlpEncode);
    const totalLength = encoded.reduce((sum, e) => sum + e.length, 0);
    if (totalLength <= 55) {
        const out = new Uint8Array(1 + totalLength);
        out[0] = 0xc0 + totalLength;
        let offset = 1;
        for (const e of encoded) {
            out.set(e, offset);
            offset += e.length;
        }
        return out;
    }
    const lenBytes = encodeLength(totalLength);
    const out = new Uint8Array(1 + lenBytes.length + totalLength);
    out[0] = 0xf7 + lenBytes.length;
    out.set(lenBytes, 1);
    let offset = 1 + lenBytes.length;
    for (const e of encoded) {
        out.set(e, offset);
        offset += e.length;
    }
    return out;
}
/** Encodes a positive integer length as big-endian bytes (no leading zeros). */
function encodeLength(length) {
    const bytes = [];
    let remaining = length;
    while (remaining > 0) {
        bytes.unshift(remaining & 0xff);
        remaining >>= 8;
    }
    return new Uint8Array(bytes);
}