fuckme.go

package main

import (
	"encoding/hex"
	"fmt"

	"github.com/JulianDuniec/crc7"
)

func main() {
	/*
		1) Take your id1
			24A90106478089A4534C303800035344

		2) Split it into u16 chunks
			24A9 0106 4780 89A4 534C 3038 0003 5344

		3) Reverse them backwards
			5344 0003 3038 534C 89A4 4780 0106 24A9

		4) Endian flip each of those chunks
			4453 0300 3830 4C53 A489 8047 0601 A924

		5) Shuffle them around with the table on 3dbrew (backwards!)
			0601 A924 A489 8047 3830 4C53 4453 0300

		6) Join them together
			0601A924A489804738304C5344530300 <-- cid
	*/
	id1s := "24A90106478089A4534C303800035344"
	id1, err := hex.DecodeString(id1s)
	if err != nil {
		return
	}
	var chunks [8][2]byte
	for i := 0; i < 8; i++ {
		chunks[i][0] = id1[i*2]
		chunks[i][1] = id1[(i*2)+1]
	}
	var rchunks [8][2]byte
	for i := 0; i < 8; i++ {
		rchunks[7-i] = chunks[i]
	}
	var echunks [8][2]byte
	for i := 0; i < 8; i++ {
		echunks[i][0] = rchunks[i][1]
		echunks[i][1] = rchunks[i][0]
	}
	var schunks [8][2]byte
	/* 3dbrew:
	Input CID u16 index	Output CID u16 index
	6					0
	7					1
	4					2
	5					3
	2					4
	3					5
	0					6
	1					7
	*/
	schunks[6] = echunks[0]
	schunks[7] = echunks[1]
	schunks[4] = echunks[2]
	schunks[5] = echunks[3]
	schunks[2] = echunks[4]
	schunks[3] = echunks[5]
	schunks[0] = echunks[6]
	schunks[1] = echunks[7]
	var cid [16]byte
	for i := 0; i < 8; i++ {
		fmt.Println(i, i*2, (i*2)+1, rchunks[i][0], rchunks[i][1])
		cid[i*2] = rchunks[i][0]
		cid[(i*2)+1] = rchunks[i][1]
	}
	hash := crc7.ComputeHash(cid[:])
	fmt.Println(hex.EncodeToString(cid[:]), schunks, echunks, hash)
}