NosCore.Archive

Read/write support for the legacy NosTale .NOS archive format used by NScliData_*.NOS and friends (e.g. conststring.dat, langdata.dat).

The newer "NT Data" DEFLATE variant is not supported — this library targets the legacy layout only.

Install

dotnet add package NosCore.Archive

Usage

using NosCore.Archive;

// Read
var bytes = File.ReadAllBytes("NScliData_conststring_en.NOS");
List<NosArchive.Entry> entries = NosArchive.Read(bytes);

// Mutate an inner file
var conststring = entries.Single(e => e.Name == "conststring.dat");
var patched = new NosArchive.Entry(
    conststring.Id,
    conststring.Name,
    conststring.Unknown,
    Patch(conststring.Content));

// Write back
var replaced = entries.Select(e => e.Id == conststring.Id ? patched : e).ToList();
File.WriteAllBytes("NScliData_conststring_en.NOS", NosArchive.Write(replaced));

Layout

int32 fileCount
repeat fileCount times:
    int32   id
    int32   nameLen
    byte[]  name           (ASCII, nameLen bytes)
    int32   unknown        (preserve verbatim on round-trip)
    int32   encLen
    byte[]  enc            (XOR-obfuscated payload, encLen bytes)

The inner payload is XOR-obfuscated. NosArchive.Write emits the simple 0x33-XOR mode; NosArchive.Read handles both that and the packed-nibble mode produced by the real client.

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