@aikidosec/firewall/helpers/mapIPv4ToIPv6.js

Zen by Aikido is an embedded Web Application Firewall that autonomously protects Node.js apps against common and critical attacks

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = mapIPv4ToIPv6;
/**
 * Maps an IPv4 address to an IPv6 address.
 * e.g. 127.0.0.0/8 -> ::ffff:127.0.0.0/104
 */
function mapIPv4ToIPv6(ip) {
    if (!ip.includes("/")) {
        // No CIDR suffix, assume /32
        return `::ffff:${ip}/128`;
    }
    const parts = ip.split("/");
    const suffix = Number.parseInt(parts[1], 10);
    // we add 96 to the suffix, since ::ffff: already is 96 bits, so the 32 remaining bits are decided by the IPv4 address
    return `::ffff:${parts[0]}/${suffix + 96}`;
}