Reimplement ItemStack Obfuscation

[Owen1212055]

Due to the amount of changes to items in the past updates, the previous configuration for obfuscation does not really fit today's representation of items.
This reimplements ItemStack obfuscation in a way that is built in mind to support the new 1.21.4 ItemModel format.

The following data components are obfuscated by default when enabled:

DataComponents.MAX_STACK_SIZE,
DataComponents.MAX_DAMAGE,
DataComponents.DAMAGE,
DataComponents.UNBREAKABLE,
DataComponents.CUSTOM_NAME,
DataComponents.ITEM_NAME,
DataComponents.LORE,
DataComponents.RARITY,
DataComponents.ENCHANTMENTS,
DataComponents.CAN_PLACE_ON,
DataComponents.CAN_BREAK,
DataComponents.ATTRIBUTE_MODIFIERS,
DataComponents.HIDE_ADDITIONAL_TOOLTIP,
DataComponents.HIDE_TOOLTIP,
DataComponents.REPAIR_COST,
DataComponents.USE_REMAINDER,
DataComponents.FOOD,
DataComponents.DAMAGE_RESISTANT
DataComponents.TOOL,
DataComponents.ENCHANTABLE,
DataComponents.REPAIRABLE,
DataComponents.GLIDER,
DataComponents.TOOLTIP_STYLE,
DataComponents.DEATH_PROTECTION,
DataComponents.STORED_ENCHANTMENTS,
DataComponents.MAP_ID,
DataComponents.POTION_CONTENTS,
DataComponents.SUSPICIOUS_STEW_EFFECTS,
DataComponents.WRITABLE_BOOK_CONTENT,
DataComponents.WRITTEN_BOOK_CONTENT,
DataComponents.CUSTOM_DATA,
DataComponents.ENTITY_DATA,
DataComponents.BUCKET_ENTITY_DATA,
DataComponents.BLOCK_ENTITY_DATA,
DataComponents.INSTRUMENT,
DataComponents.OMINOUS_BOTTLE_AMPLIFIER,
DataComponents.JUKEBOX_PLAYABLE,
DataComponents.LODESTONE_TRACKER,
DataComponents.FIREWORKS,
DataComponents.NOTE_BLOCK_SOUND,
DataComponents.BEES,
DataComponents.LOCK,
DataComponents.CONTAINER_LOOT

Unlike before, obfuscation for data components can now be configured on a per item model basis. So for example, items with the elytra item model will not obfuscate their damage component in order for their item model to properly read the damage value.

    items:
      all-models:
        also-obfuscate: []
        dont-obfuscate:
        - minecraft:lodestone_tracker
        sanitize-count: true
      enable-item-obfuscation: false
      model-overrides:
        minecraft:elytra:
          also-obfuscate: []
          dont-obfuscate:
          - minecraft:damage
          sanitize-count: true

Default Obfuscation Behavior

Patched data component values are either DROPPED or SANITIZED.
Most values are dropped, unless certain behavior restricts them from being just dropped.

Dropping (standard)

Dropping occurs when the type can be freely removed from the item without any visual/behavioral changes.
Examples:

• diamond_sword[max_damage=10] -> diamond_sword
  • Drop the modified value, (uses the original MC value)
• dirt[max_damage=10] -> dirt
  • Dirt doesnt use max damage, we can drop it

Sanitizing

Certain components have serious behavior changes when dropped. So these types are instead mutated.
For example:

• minecraft:diamond_sword[enchantments={levels:{"minecraft:sharpness":1, "minecraft:unbreaking":1}}] -> minecraft:diamond_sword[enchantments={levels:{"minecraft:frost_walker":1}}]
  • Enchantments now get obfuscated, but in order to retain their glint, we send a dummy enchantment.
    (when configured)
• minecraft:compass[lodestone_tracker={target: {dimension: "minecraft:overworld", pos: [I; 117, 160, -518]}}] -> minecraft:compass[lodestone_tracker={tracked: 0b}]
  • Retain the glow effect by keeping a dummy lodestone tracker

Tradeoff

The issue with this new system is that new types cannot be added, only removed/mutated.

Finally

Please provide any feedback on this new system, as this is a bit different and want to make sure that it is the best for people migrating from the old system. And additionally which new components people would like obfuscated by default.😄

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Download the paperclip jar for this pull request: paper-11817.zip

[MiniDigger]

(needs docs PR)

[Owen1212055]

This implementation has been dramatically simplified, and now supports dropping components. So for example, unbreaking is now hidden.

[Owen1212055]

PaperMC/docs#515

[ghost]

weird nitpick but why is it so complex? item obfuscation session, switching contexts, item obfuscation bindings, just seems like it might cause issues with maintenance in future (kind of like how anti-xray is complex, to a lesser extent though)

[lynxplay]

Indeed a weird nitpick.
We need a session as obfuscation is not enabled on every code path.
We need a context to pass context.