NBT obfuscating

NBT obfuscating

#BioForge #BioForge_V2_0 #Build_V0_54T #AddonDevelopment #LegacyUpdated

#Extra

The mod uses NBT obfuscation to prevent players from reading or tampering with sensitive item data (blood samples, infection strains, medical records, etc.) via commands like /data get or inventory viewers.

• All blood data (type, amount, source UUID) is stored in an obfuscated format.
• Infection strain data (pathogen, symptoms, colony ID) is similarly protected.
• Clipboard and Medical Report data are also obfuscated.

Without obfuscation, a player could cheat by inspecting an item’s NBT to determine blood type without testing reagents, or copy infection strains without using a swab.

How It Works

The NbtObfuscator class encrypts data using a combination of:

• XOR encryption with a derived key stream.
• Random salt (UUID) per write.
• Checksum (Adler‑32 style) to detect corruption.
• Flag byte to quickly verify if data exists.

Data is stored in the item’s CompoundTag under special keys:

• bf_s0, bf_s1 - salt (XOR‑masked)
• bf_p - encrypted payload (byte array)
• bf_c - checksum
• bf_f - flag (derived from salt)

The keys are non‑descriptive to avoid easy discovery.

Two Write Modes

1. Random salt (normal)

• Every write generates a new random UUID as salt.
• Used for most items (needles, swabs, petri dishes, etc.).
• Produces different obfuscated output even for identical plaintext - prevents pattern recognition.

2. Deterministic salt

• Used for infected crop drops (writeStringDeterministic).
• Salt is derived from the plaintext (SHA‑256 hash).
• Ensures that identical infection strains always produce the same obfuscated bytes. This allows drops from the same infected crop type to be stackable (identical NBT).

API (for developers)

Writing data

// Write blood sample data
NbtObfuscator.write(tag, amount, typeName, sourceName, subjectUUID);

// Write arbitrary string (random salt)
NbtObfuscator.writeString(tag, payload);

// Write arbitrary string (deterministic salt)
NbtObfuscator.writeStringDeterministic(tag, payload);

Reading data

// Read blood sample data (returns ObfuscatedData record)
ObfuscatedData data = NbtObfuscator.read(tag);

// Read arbitrary string
String payload = NbtObfuscator.readString(tag);

Checking presence

if (NbtObfuscator.hasData(tag)) { ... }

Clearing

NbtObfuscator.clear(tag);