import type { Filter } from "../lib/modules/Lightweight-Directory-Access-Protocol-V3/Filter.ta.mjs";
/**
 * @summary Normalizes a Filter (mostly) as specified in ITU Recommendation X.501 (2019), Annex Q.
 * @description
 *
 * This function deviates from the rules described in Annex Q because following
 * those rules would open up an attack vector for denial-of-service, since the
 * normalization of boolean filter according to them could result in a
 * combinatorial explosion of new filters.
 *
 * This is the particular simplification that is dangerous:
 *
 * - "and { or {x,y,z}, p, q} is the same as or { and {x,p,q}, and {y,p,q}, and {z,p,q} }"
 *
 * The number of subfilters in the inner `or` is multiplied by all the other
 * subfilters in the `and`, which themselves may also be `or` subfilters. This
 * is handled by capping the number of filters that may be produced from such a
 * transformation. If the number exceeds this cap, the filter is left unchanged,
 * which means that this function may return a filter that is not perfectly
 * normalized.
 *
 * These are also a little dangerous:
 *
 * - "not { and {x,y,z} } is the same as or { not {x}, not {y}, not {z}}" doubles
 *   the number of filters within the inner `and`, although it subtracts by one.
 * - "not { or {x,y,z} } is the same as and { not {x}, not {y}, not {z} }" does
 *   the same.
 *
 * These normalizations are fine, because they do not produce more filters:
 *
 * - "not { not {x}} is the same as x"
 * - "and { and {x,y,z}, p, q } is the same as and { x,y,z,p,q }"
 * - "or { or {x,y,z}, p, q } is the same as or { x,y,z,p,q }"
 *
 * @param filter The filter to be normalized.
 * @param recursionTTL The recursion "time-to-live" hops: this number is
 *  decremented with each function invocation. If it reaches zero, recursion
 *  stops: no normalization occurs deeper beneath this. This is to prevent stack
 *  overflows from maliciously huge filters. Defaults to 20.
 * @returns A normalized filter.
 *
 * @function
 */
export declare function normalizeFilter(filter: Filter, recursionTTL?: number): Filter;
export default normalizeFilter;
//# sourceMappingURL=normalizeFilter.d.mts.map