Generates passwords for DS Tekuteku Diary - ＤＳてくてく日記

tekutekupass.py

# Generates passwords for DS Tekuteku Diary - ＤＳてくてく日記
# TODO figure out all the unknown bits, clean up the code
import datetime

outfname = "tekuteku_pass.txt"

# sample password
# さ そ め す き に
# ひ い あ お め こ
# 2008-05-10 3032 steps

# Edit these two lines
steps = 3032 # 0 - 1,048,575
date = datetime.date(2008, 5, 10) # Valid dates are 2000-01-01 through today's date

unk2_7 = 1 # 1 bit (0-1)
unk2_6 = 0 # 1 bit (0-1)
unk2_5 = 0 # 1 bit (0-1)
unk2_4 = 0 # 1 bit (0-1)

unkthing = 1 # ??? 6 bits (0-63) Related to which creature you receive.

unk5_7 = 0 # 1 bit (0-1)
unk5_6 = 0 # 1 bit (0-1)
unk5_5 = 0 # 1 bit (0-1)

unk6 = 0 # 2 bits (0-3)


day = (date - datetime.date(2000, 1, 1)).days # day offset from 2000-01-01 (0-32767)
unk2_7654 = (unk2_7 << 3) | (unk2_6 << 2) | (unk2_5 << 1) | unk2_4
unk5_765 = (unk5_7 << 2) | (unk5_6 << 1) | unk5_5

passbytes = [0, 0, 0, 0, 0, 0, 0]
passbytes[0] = steps & 0xFF
passbytes[1] = (steps >> 8) & 0xFF
passbytes[2] = (unk2_7654 << 4) | (steps >> 16)
passbytes[3] = day & 0xFF
passbytes[4] = ((day >> 8) & 0x7F) | ((unkthing & 0x1) << 7)
passbytes[5] = (unkthing >> 1) | (unk5_765 << 5)
passbytes[6] = unk6

# Calc checksum
chk = 0
for num in passbytes:
    chk = (chk + num) & 0xFF

dec = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
dec[0] = passbytes[0] & 0x1F
dec[1] = (passbytes[0] >> 5) | ((passbytes[1] & 3) << 3)
dec[2] = (passbytes[1] >> 2) & 0x1F
dec[3] = (passbytes[1] >> 7) | ((passbytes[2] & 0x1F) << 1)
dec[4] = (passbytes[2] >> 4) | ((passbytes[3] & 1) << 4)
dec[5] = (passbytes[3] >> 1) & 0x1F
dec[6] = (passbytes[3] >> 6) | ((passbytes[4] & 7) << 2)
dec[7] = (passbytes[4] >> 3) & 0x1F
dec[8] = (passbytes[5]) & 0x1F
dec[9] = (passbytes[5] >> 5) | ((passbytes[6] & 3) << 3)

cipherstate = chk
enc = [chk&0xF, (chk>>4)&0xF]
for num in dec:
    cipherstate = (cipherstate * 0x6d + 0xa15) & 0x7FFF
    enc.append((num + (cipherstate & 0x1F)) & 0x1F)

charsordered = ["あ", "え", "い", "お", "う", "か", "け", "き", "こ", "く", "さ", "せ", "し", "そ", "す", "た", "て", "ち", "と", "つ", "な", "ね", "に", "の", "ぬ", "は", "へ", "ひ", "ほ", "ふ", "ま", "め"]
with open(outfname, "w", encoding="utf-8") as f:
    f.write("Date: %s\nSteps: %d\n  " % (date.strftime("%Y-%m-%d"), steps))
    for i, num in enumerate(enc):
        if i == 6:
            f.write("\n  ")
        f.write("%s " % charsordered[num])

Online version that's easier to use. Generated from my Python script using Grok.
https://windwakr.github.io/tekuteku/passgen.html

unk2_7 = quota reached message
unk2_5 = late at night message? Makes your gel more "cool" looking?
unk5_7 = day start message or something?
unk5_6 = congratulations on clearing something
unk5_5 = goodbye message

Still don't understand how the gel selection is fully encoded.