Code/net/minecraft/world/entity/player/ProfilePublicKey.java

package net.minecraft.world.entity.player;

import com.mojang.serialization.Codec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import com.mojang.serialization.codecs.RecordCodecBuilder.Instance;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.security.PublicKey;
import java.time.Duration;
import java.time.Instant;
import java.util.Arrays;
import java.util.UUID;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.chat.Component;
import net.minecraft.network.chat.ThrowingComponent;
import net.minecraft.util.Crypt;
import net.minecraft.util.ExtraCodecs;
import net.minecraft.util.SignatureValidator;

public record ProfilePublicKey(ProfilePublicKey.Data data) {
    public static final Component EXPIRED_PROFILE_PUBLIC_KEY = Component.translatable("multiplayer.disconnect.expired_public_key");
    private static final Component INVALID_SIGNATURE = Component.translatable("multiplayer.disconnect.invalid_public_key_signature");
    public static final Duration EXPIRY_GRACE_PERIOD = Duration.ofHours(8L);
    public static final Codec<ProfilePublicKey> TRUSTED_CODEC = ProfilePublicKey.Data.CODEC.xmap(ProfilePublicKey::new, ProfilePublicKey::data);

    public static ProfilePublicKey createValidated(SignatureValidator p_243373_, UUID p_243390_, ProfilePublicKey.Data p_243374_) throws ProfilePublicKey.ValidationException {
        if (!p_243374_.validateSignature(p_243373_, p_243390_)) {
            throw new ProfilePublicKey.ValidationException(INVALID_SIGNATURE);
        } else {
            return new ProfilePublicKey(p_243374_);
        }
    }

    public SignatureValidator createSignatureValidator() {
        return SignatureValidator.from(this.data.key, "SHA256withRSA");
    }

    public record Data(Instant expiresAt, PublicKey key, byte[] keySignature) {
        private static final int MAX_KEY_SIGNATURE_SIZE = 4096;
        public static final Codec<ProfilePublicKey.Data> CODEC = RecordCodecBuilder.create(
            p_219814_ -> p_219814_.group(
                    ExtraCodecs.INSTANT_ISO8601.fieldOf("expires_at").forGetter(ProfilePublicKey.Data::expiresAt),
                    Crypt.PUBLIC_KEY_CODEC.fieldOf("key").forGetter(ProfilePublicKey.Data::key),
                    ExtraCodecs.BASE64_STRING.fieldOf("signature_v2").forGetter(ProfilePublicKey.Data::keySignature)
                )
                .apply(p_219814_, ProfilePublicKey.Data::new)
        );

        public Data(FriendlyByteBuf p_219809_) {
            this(p_219809_.readInstant(), p_219809_.readPublicKey(), p_219809_.readByteArray(4096));
        }

        public void write(FriendlyByteBuf p_219816_) {
            p_219816_.writeInstant(this.expiresAt);
            p_219816_.writePublicKey(this.key);
            p_219816_.writeByteArray(this.keySignature);
        }

        boolean validateSignature(SignatureValidator p_240296_, UUID p_240297_) {
            return p_240296_.validate(this.signedPayload(p_240297_), this.keySignature);
        }

        private byte[] signedPayload(UUID p_240267_) {
            byte[] abyte = this.key.getEncoded();
            byte[] abyte1 = new byte[24 + abyte.length];
            ByteBuffer bytebuffer = ByteBuffer.wrap(abyte1).order(ByteOrder.BIG_ENDIAN);
            bytebuffer.putLong(p_240267_.getMostSignificantBits())
                .putLong(p_240267_.getLeastSignificantBits())
                .putLong(this.expiresAt.toEpochMilli())
                .put(abyte);
            return abyte1;
        }

        public boolean hasExpired() {
            return this.expiresAt.isBefore(Instant.now());
        }

        public boolean hasExpired(Duration p_243376_) {
            return this.expiresAt.plus(p_243376_).isBefore(Instant.now());
        }

        @Override
        public boolean equals(Object p_219822_) {
            return !(p_219822_ instanceof ProfilePublicKey.Data profilepublickey$data)
                ? false
                : this.expiresAt.equals(profilepublickey$data.expiresAt)
                    && this.key.equals(profilepublickey$data.key)
                    && Arrays.equals(this.keySignature, profilepublickey$data.keySignature);
        }
    }

    public static class ValidationException extends ThrowingComponent {
        public ValidationException(Component p_243378_) {
            super(p_243378_);
        }
    }
}