+ work so far

meow
Dominika 2022-02-09 03:58:56 +01:00
commit e0b1d39d78
8 changed files with 695 additions and 0 deletions

BIN
icon.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 810 B

241
mc.sh Executable file
View File

@ -0,0 +1,241 @@
#!/bin/bash
state=''
dyed=0
keepalive=0
pos=(0 0 0)
players=()
TEMP=/dev/shm/witchcraft/
mkdir -p $TEMP $TEMP/players $TEMP/world
source src/log.sh
source src/int.sh
source src/packet.sh
source src/hooks.sh
function keep_alive() {
while true; do
sleep 5
log "sending keepalive"
echo '092100000000000000ff' | xxd -p -r
done
}
function position_delta() {
local deltaX
local deltaY
local deltaZ
# pos[0]=0
# pos[1]=0
# pos[2]=0
pos_old[0]=0
pos_old[1]=0
pos_old[2]=0
while true; do
sleep 0.1
for i in $(ls "$TEMP/players/"); do
if [[ "$i" != "$nick" ]]; then
pos[0]=$(cat $TEMP/players/$i/position | awk -F, '{print($1)}') # idk, floating point broke
pos[1]=$(cat $TEMP/players/$i/position | awk -F, '{print($2)}')
pos[2]=$(cat $TEMP/players/$i/position | awk -F, '{print($3)}')
log "posX: ${pos[0]}"
deltaX=$((((${pos[0]}*32) - (${pos_old[0]}*32)) * 128))
deltaY=$(((${pos[1]}*32 - ${pos_old[1]}*32) * 128))
deltaZ=$(((${pos[2]}*32 - ${pos_old[2]}*32) * 128))
if [[ $deltaX != 0 || $deltaY != 0 || $deltaZ != 0 ]]; then
pkt_position $deltaX $deltaY $deltaZ $(cat $TEMP/players/$i/eid)
fi
pos_old=("${pos[@]}")
fi
done
done
}
function handle_broadcast() {
while true; do
for i in $(ls "$TEMP/players/"); do
if [[ "$i" != "$nick" ]]; then
if [[ -f $TEMP/players/$i/broadcast ]]; then
packet="$(cat $TEMP/players/$i/broadcast)"
if [[ "$last" != "$packet" ]]; then
cat $TEMP/players/$i/broadcast
last="$packet"
fi
else
last=''
fi
fi
done
sleep 1
done
}
function spawn_players() {
for i in $(ls "$TEMP/players/"); do # fite me
if [[ $i != $nick && ${players[@]} != *"$i"* ]]; then
log "name: $i EID: $eid"
pkt_playerinfo_add $i $(cat $TEMP/players/$i/eid)
pkt_spawnplayer $(cat $TEMP/players/$i/eid)
players+=("$nick")
fi
done
}
while true; do
len=$(varint2int)
a=$(dd count=$len bs=1 status=none | xxd -p)
if [[ "$a" == '' ]]; then
log "connection dyed"
pkill -P $$
pkt_chatmessage "- $nick" "00000000000000000000000000000000" > $TEMP/players/$nick/broadcast
sleep 1
rm -R "$TEMP/players/$nick"
exit
fi
if [[ -f /tmp/block ]]; then
res="$(encode_position 10 -10 10)"
res+="01"
log "$res"
echo -n "$(hexpacket_len "$res")0c$res" | xxd -p -r
rm -R /tmp/block
fi
if [[ -f /tmp/spawn ]]; then
spawn_players
rm /tmp/spawn
fi
if [[ $a == "00"* ]]; then
log "responding to 00; state: $state"
if [[ "$state" == '01' ]]; then
log "status response"
#json='{"version":{"name":"1.18.1","protocol":757},"players":{"max":100,"online":5,"sample":[{"name":"uwu","id":"4566e69f-c907-48ee-8d71-d7ba5aa00d20"}]},"description":{"text":"Hello world"}}'
json='{"version":{"name":"§a§kaaa§aUwU§kaaa","protocol":756},"players":{"max":1,"online":0,"sample":[]},"description":{"text":"§aUwU"},"favicon":"data:image/png;base64,'"$(base64 -w0 icon.png)"'"}'
res="$(str_len "$json")$(echo -n "$json" | xxd -p)"
echo "$(hexpacket_len "$res")00$res" | xxd -p -r
state=''
elif [[ "$state" == '02' ]]; then
nick=$(cut -c 5- <<< "$a" | xxd -p -r | grep -Poh '[A-Za-z0-9_-]*')
eid=$(printf "%02x" $RANDOM)
mkdir -p $TEMP/players/$nick
echo -n $eid > $TEMP/players/$nick/eid
pkt_chatmessage "+ $nick" "00000000000000000000000000000000" > $TEMP/players/$nick/broadcast
log "login response"
if [[ $keepalive == 0 ]]; then
hook_keepalive
keepalive=1
fi
# random uuid string len string (nick)
res="0000000000000000000000000000$eid$(str_len "$nick")$(echo -n "$nick" | xxd -p)"
log "$(hexpacket_len "$res")02$res"
echo -n "$(hexpacket_len "$res")02$res" | xxd -p -r
res="$(encode_position 0 0 0)"
res+="00000000" # angle as float
echo -n "$(hexpacket_len "$res")4B$res" | xxd -p -r
log "sent spawn position"
#res="00000000" # entity id (0 or -2147483648, idk)
#res+="00" # not hardcore
#res+="00" # survival mode
#res+="01" # ... as previously seen on Creative Mode (ignored)
#res+="01" # one dimension
#res+="13$(echo -n "minecraft:overworld" | xxd -p)"
#res+="0a000000" # dimension codec
#res+="0a000000" # dimension
#res+="13$(echo -n "minecraft:overworld" | xxd -p)" # dimension being spawned into
#res+="0000000000000000" # beginning of sha256 of seed
#res+="0f" # max players (ignored)
#res+="02" # view distance (min 2 chunks)
#res+="02" # simulation distance
#res+="00" # reduced debug info? (false)
#res+="00" # enable respawn screen
#res+="00" # is debug (surprisingly, no)
#res+="01" # is flat (yeah, sure)
#rhexlog "$(hexpacket_len "$res")26$res"
#echo -n "$(hexpacket_len "$res")26$res" | xxd -p -r
#log "sent join game"
cat nbt_
log "sent (hardcoded) join game"
# send inventory (0x14)
res="00" # inventory id
res+="00" # state
res+="09" # item count
for i in {1..9}; do
res+="01 0$i 7f 00" # stone block
done
res+="01 00 01 00" # again, for held
echo -n "$(hexpacket_len "$res")14$res" | xxd -p -r
log "sent inventory"
pkt_pos
source src/palette.sh
hook_chunks
spawn_players
state=''
else
if [[ $a == *"01" ]]; then # 01 - next state: status
log 'set status'
state='01'
else # 02 - next state: login
log 'set login'
state='02'
fi
fi
elif [[ $a == "01"* ]]; then
log "responding to 01"
echo "$len$a" | xxd -p -r
log "bye"
exit
elif [[ $a == "0f"* ]]; then
log "received keepalive"
date "+%s" > $TEMP/players/$nick/ping
elif [[ $a == "11"* ]]; then
pos[0]=$(from_ieee754 $(cut -c 3-18 <<< "$a"))
pos[1]=$(from_ieee754 $(cut -c 19-34 <<< "$a"))
pos[2]=$(from_ieee754 $(cut -c 35-50 <<< "$a"))
echo "${pos[0]},${pos[1]},${pos[2]}" > $TEMP/players/$nick/position
hook_move
elif [[ $a == "12"* ]]; then
hook_move
elif [[ $a == "13"* ]]; then
hook_move
elif [[ $a == "1a"* ]]; then
hook_dig
elif [[ $a == "2c"* ]]; then
hook_swing
elif [[ $a == "2e"* ]]; then
hook_block
elif [[ $a == "03"* ]]; then
if [[ $((0x$(cut -c 3-4 <<< "$a"))) -lt 127 ]]; then # lazy varint check
msg=$(cut -c 5- <<< "$a" | xxd -p -r)
else
msg=$(cut -c 3- <<< "$a" | xxd -p -r)
fi
hook_chat
else
log "unknown data from client"
rhexlog "$a"
fi
done

BIN
nbt_ Normal file

Binary file not shown.

60
src/hooks.sh Normal file
View File

@ -0,0 +1,60 @@
#!/usr/bin/env bash
# hooks.sh - dummy hooks functions
# on player dig
function hook_dig() {
log "received Player Dig"
rhexlog $a
}
# on player arm swing
function hook_swing() {
log "received Arm Swing"
}
# on player block placement
function hook_block() {
log "received Player Block Placement"
rhexlog $a
}
# on chat message
# msg available as $msg
function hook_chat() {
chatlog "$nick: $msg"
pkt_chatmessage "$nick: $msg" "0000000000000000000000000000$eid"
pkt_chatmessage "$nick: $msg" "0000000000000000000000000000$eid" > $TEMP/players/$nick/broadcast
}
# on move/move+rotation/rotation
# X/Y/Z available as ${pos[0]} through ${pos[2]}
function hook_move() {
log "received Player Position"
}
# after login, join; intended for loading chunks
function hook_chunks() {
pkt_chunk FFFFFFFF FFFFFFFF
pkt_chunk FFFFFFFF 00000000
pkt_chunk FFFFFFFF 00000001
pkt_chunk 00000000 FFFFFFFF
pkt_chunk 00000000 00000000
pkt_chunk 00000000 00000001
pkt_chunk 00000001 FFFFFFFF
pkt_chunk 00000001 00000000
pkt_chunk 00000001 00000001
pkt_chunk FFFFFFFF 00000002
pkt_chunk 00000000 00000002
pkt_chunk 00000001 00000002
}
# during login; useful for disabling all multiplayer functionality
function hook_keepalive() {
keep_alive &
# sleep probably only needed for testing
sleep 1 && position_delta &
sleep 1 && handle_broadcast &
}

144
src/int.sh Normal file
View File

@ -0,0 +1,144 @@
#!/usr/bin/env bash
# int.sh - int conversion functions, and other numeric functions
# int2varint(int)
function int2varint() {
# very proud of my implementation; haven't seen anyone use a modulo for this ;p
local a
local b
local c
local out
out=$(printf '%02x' "$1")
if [[ $1 -lt 128 ]]; then
:
elif [[ $1 -lt 16384 ]]; then
a=$(($1%128))
b=$(($1/128))
out=$(printf "%02x" $((a+128)))$(printf "%02x" $b)
elif [[ $1 -lt $((128*128*128)) ]]; then
a=$(($1%128))
c=$((($1/128)%128))
b=$(($1/16384))
out=$(printf "%02x" $((a+128)))$(printf "%02x" $((c+128)))$(printf "%02x" $b)
fi
echo -n "$out"
}
# varint2int() <<< varint
function varint2int() {
local x
local uwu
local out
out=""
x=1
while true; do
uwu=$(dd count=1 bs=1 status=none | xxd -p)
out=$((out+((0x$uwu&127)*x)))
x=$((x*128))
if [[ $((0x$uwu>>7)) == 0 ]]; then
break
fi
done
echo -n "$out"
}
# parse_position(Position)
# https://wiki.vg/Protocol#Position
function parse_position() {
x=$((0x$1 >> 38))
y=$((0x$1 & 0xFFF))
z=$(((0x$1 >> 12) & 0x3FFFFFF))
[[ $x -gt 33554431 ]] && x=$((x-67108864))
[[ $y -gt 2047 ]] && y=$((y-4095))
[[ $z -gt 33554431 ]] && z=$((z-67108864))
}
# encode_position(x, y, z)
function encode_position() {
local x
local y
local z
x=$1
y=$2
z=$3
[[ $x -lt 33554433 ]] && x=$((x+67108864))
[[ $y -lt 2049 ]] && y=$((y+4095))
[[ $z -lt 33554433 ]] && z=$((z+67108864))
printf "%016x" $((((x & 0x3FFFFFF)<<38) | ((z & 0x3FFFFFF)<<12) | (y & 0xFFF)))
}
# packet_len(packet)
function packet_len() {
int2varint $((($(echo -n "$1" | wc -c)+1)))
}
# hexpacket_len(hexpacket)
function hexpacket_len() {
int2varint $((($(echo -n "$1" | xxd -p -r | wc -c)+1)))
}
# str_len(string)
function str_len() {
int2varint $(echo -n "$1" | wc -c)
}
# hexstrl_len(hexstring)
function hexstr_len() {
int2varint $(echo -n "$1" | xxd -p -r | wc -c)
}
# hex2bin(hexstring)
function hex2bin() {
# \o/
echo -n "$1" | sed -E 's/0/0000/g;s/1/0001/g;s/2/0010/g;s/3/0011/g;s/4/0100/g;s/5/0101/g;s/6/0110/g;s/7/0111/g;s/8/1000/g;s/9/1001/g;s/a/1010/g;s/b/1011/g;s/c/1100/g;s/d/1101/g;s/e/1110/g;s/f/1111/g'
}
# from_ieee754(hexstring)
function from_ieee754() {
local sign
local exponent
local asdf
local exponent_
local val
val=$(hex2bin "$1")
sign=$(cut -c 1 <<< $val)
exponent=$(cut -c 2-12 <<< $val)
asdf=$(cut -c 13- <<< $val | sed -E 's/./,&/g;s/,//' | tr -d '\n' | awk -F , \
'{
power_count=-1
x=0;
for(i=1; i<=NF; i++) {
x=(x + ($i * (2 ** power_count)))
power_count=power_count-1;
}
print(x+1)
}')
exponent_=$((2#$exponent))
if [[ $sign == 0 ]]; then
echo "$asdf $exponent_" | awk '{print (int($1 * (2 ** ($2 - 1023))))}'
else
echo "$asdf $exponent_" | awk '{print -(int($1 * (2 ** ($2 - 1023))))}'
fi
}
# to_short(number)
function to_short() {
if [[ $1 -lt 0 && $1 -gt -32769 ]]; then
printf "%04x" $(($1+65536))
elif [[ $1 -lt 32768 && $1 -gt -1 ]]; then
printf "%04x" $1
elif [[ $1 -lt -32768 ]]; then
printf "8000"
elif [[ $1 -gt 32767 ]]; then
printf "7FFF"
fi
}

21
src/log.sh Normal file
View File

@ -0,0 +1,21 @@
#!/usr/bin/env bash
# log.sh - logging functions
function log() {
echo "[INFO] $@" >&2
}
function warn() {
echo "[WARN] $@" >&2
}
function err() {
echo "[FAIL] $@" >&2
}
function chatlog() {
echo "[CHAT] $@" >&2
}
function hexlog() {
echo -n "$@" | xxd >&2
}
function rhexlog() {
echo -n "$@" | xxd -p -r | xxd >&2
}

189
src/packet.sh Normal file
View File

@ -0,0 +1,189 @@
#!/usr/bin/env bash
# packet.sh - play state packets
function pkt_pos() {
res="0000001000000000" # X
res+="0000000000000000" # Y
res+="0000000000000000" # Z
res+="00000000" # yaw
res+="00000000" # pitch
res+="00" # bit field; all absolute
res+="00" # teleport id (?)
res+="00" # dismount vehicle?
echo -n "$(hexpacket_len "$res")38$res" | xxd -p -r
log "sent player look and position"
}
function pkt_chunk() {
# palettes are really cool once you figure them out :3
# https://wiki.vg/Protocol#Chunk_Data_And_Update_Light
local chunk
res="$1" # chunk X
res+="$2" # chunk Z
# here goes the scary NBT field
# nbt tag MOTION_BLOCKING len light data for a superflat map
res+="0a00000c000f 4d4f54494f4e5f424c4f434b494e47 00000025 010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804010080402010080401008040201008040100804020100804 0000000020100804 00"
chunk="ffff" # amount of blocks, doesnt matter
chunk+="08" # palette - bits per block
chunk+="$(int2varint ${#palette[@]})" # palette - entries amount
chunk+="${palette[@]}"
#res+="0f af0b 01 00"
chunk+="8002" # len of next array
l=$(echo -n "8002" | xxd -p -r | varint2int)
for (( i=0; i<$((l*8)); i++ )); do
chunk+="01" # third entry of palette
done
chunk+="0001" # biome palette
for i in {1..26}; do
chunk+="0000000000000001" # set biome
done
res+="$(int2varint $(hexstr_len "$chunk"))" # Data len
res+="$chunk" # Chunk data itself
res+="00 01 00 00 00 00 00 00" # empty bitsets and light arrays
echo -n "$(hexpacket_len "$res")22$res" | xxd -p -r
log "sending chunk data"
}
# pkt_effect(x, y, z, effect_id)
function pkt_effect() {
res="$(printf '%08x' $4)"
res+="$(encode_position $1 $2 $3)"
res+="00000000"
res+="00"
echo -n "$(hexpacket_len "$res")23$res" | xxd -p -r
log "sending effect"
}
# pkt_playerinfo(name, eid)
function pkt_playerinfo_add() {
res="00" # add player
res+="01" # total players
res+="0000000000000000000000000000$2" # random UUID
res+="$(str_len "$1")$(echo -n "$1" | xxd -p)"
res+="00" # array len; can be zero, but no skins then
res+="01" # gamemode: creative
res+="01" # ping: 1ms
res+="00" # has display name: false
echo -n "$(hexpacket_len "$res")36$res" | xxd -p -r
log "sent playerinfo"
}
# pkt_spawnplayer(eid)
function pkt_spawnplayer() {
res="$(int2varint $((0x$1)))" # entity id
res+="0000000000000000000000000000$1" # a really badly made UUID
res+="00 00 00 00 00 00 00 00" # X
res+="00 00 00 00 00 00 00 00" # Y
res+="00 00 00 00 00 00 00 00" # Z
res+="00" # Angle (256 steps)
res+="00" # Pitch (...)
echo -n "$(hexpacket_len "$res")04$res" | xxd -p -r
rhexlog "$(hexpacket_len "$res")04$res"
log "sent spawnplayer"
}
# pkt_position(deltaX, deltaY, deltaZ, eid)
function pkt_position() {
local deltaX
local deltaY
local deltaZ
local stepX
local stepY
local stepZ
local n
deltaX=$1
deltaY=$2
deltaZ=$3
stepX=0
stepY=0
stepZ=0
while true; do
n=false
if [[ $deltaX -gt 32767 ]]; then
stepX=32767
deltaX=$((deltaX-32767))
n=true
fi
if [[ $deltaX -lt -32768 ]]; then
stepX=-32768
deltaX=$((deltaX+32768))
n=true
fi
if [[ $deltaY -gt 32767 ]]; then
stepY=32767
deltaY=$((deltaY-32767))
n=true
fi
if [[ $deltaY -lt -32768 ]]; then
stepY=-32768
deltaY=$((deltaY+32768))
n=true
fi
if [[ $deltaZ -gt 32767 ]]; then
stepZ=32767
deltaX=$((deltaZ-32767))
n=true
fi
if [[ $deltaZ -lt -32768 ]]; then
stepZ=-32768
deltaZ=$((deltaZ+32768))
n=true
fi
[[ $n == false ]] && break
pkt_position $stepX $stepY $stepZ
done
res="$(int2varint $((0x$4)))" # entity ID
res+="$(to_short $deltaX)"
res+="$(to_short $deltaY)"
res+="$(to_short $deltaZ)"
res+="00" # on ground
echo -n "$(hexpacket_len "$res")29$res" | xxd -p -r
}
# pkt_chatmessage(msg, sender_uuid)
function pkt_chatmessage() {
local msg
local json
local res
msg=$(sed -E 's/"//g;s@\\@@g' <<< "$1")
json='{"text":"'"$msg"'"}'
res="$(str_len "$json")$(echo -n "$json" | xxd -p)"
res+="00" # position: chat box
res+="$2"
echo -n "$(hexpacket_len "$res")0F$res" | xxd -p -r
}
# pkt_title(msg)
function pkt_title() {
local txt
txt='{"text":"'"$1"'"}'
res="$(str_len "$txt")$(echo -n "$txt" | xxd -p)"
echo -n "$(hexpacket_len "$res")5a$res" | xxd -p -r
}

40
src/palette.sh Normal file
View File

@ -0,0 +1,40 @@
#!/bin/bash
# palette.sh - up to 255 block definitions
# maps first 32 IDs to pre-flattening IDs, just for fun; rest is rather random
# empty blocks (00) is what I can't easily implement :(
# https://minecraft.fandom.com/wiki/Java_Edition_data_values/Pre-flattening/Block_IDs
palette=()
palette+=("00") # air
palette+=("01") # stone
palette+=("09") # grass
palette+=("0a") # dirt
palette+=("0e") # cobblestone
palette+=("0f") # planks
palette+=("15") # sapling
palette+=("21") # bedrock
palette+=("00") #
palette+=("31") # water
palette+=("00") #
palette+=("41") # lava
palette+=("42") # sand
palette+=("44") # gravel
palette+=("45") # gold ore
palette+=("47") # iron ore
palette+=("49") # coal ore
palette+=("4d") # wood
palette+=("9401") # leaves
palette+=("8402") # sponge
palette+=("8602") # glass
palette+=("8702") # lapis ore
palette+=("8902")
palette+=("00") #
palette+=("9602") # sandstone
palette+=("00") #
palette+=("00") #
palette+=("00") #
palette+=("00") #
palette+=("00") #
palette+=("f60a") # grass