gif_seg.py

#!/usr/bin/env python3

DESCRIPTION = "Set rendered hex value in SPQ's 'segments display' GIF hashquine."

# Ange Albertini 2023

from collisions import *
from argparse import ArgumentParser
import random
import hashlib

HEX_BASE = 16
MD5_LEN = 32

HEADER_S = 85376
HEADER_MD5 = '6cc83e8357bd1a75b9f2005ba6fab928'

#  1
# 2 3
#  4
# 5 6
#  7
display = {
    '0': '1110111',
    '1': '0010010',
    '2': '1011101',
    '3': '1011011',
    '4': '0111010',
    '5': '1101011',
    '6': '1101111',
    '7': '1010010',
    '8': '1111111',
    '9': '1111011',
    'a': '1111110',
    'b': '0101111',
    'c': '1100101',
    'd': '0011111',
    'e': '1101101',
    'f': '1101100',
}


def test_segments():
    for l in display:
        segments = display[l]
        print(l)
        print(" - " if segments[0] == '1' else "   ")
        print("|" if segments[1] == '1' else ' ', end=' ')
        print("|" if segments[2] == '1' else ' ')
        print(" - " if segments[3] == '1' else "   ")
        print("|" if segments[4] == '1' else ' ', end=' ')
        print("|" if segments[5] == '1' else ' ')
        print(" - " if segments[6] == '1' else "   ")
        print()


block_indexes = [
    86, 92, 98, 104, 110, 116, 122, 128, 134, 140, 145, 151, 156, 161, 167,
    172, 178, 184, 189, 195, 201, 206, 212, 217, 222, 228, 233, 239, 245, 251,
    256, 262, 267, 273, 278, 284, 289, 295, 301, 307, 312, 317, 323, 328, 334,
    339, 344, 350, 356, 362, 368, 374, 380, 385, 391, 397, 403, 409, 414, 420,
    426, 432, 437, 443, 448, 453, 459, 465, 471, 476, 481, 486, 492, 498, 504,
    510, 516, 521, 527, 533, 539, 545, 551, 556, 562, 568, 573, 579, 584, 589,
    595, 601, 607, 613, 618, 624, 629, 634, 640, 645, 651, 656, 661, 666, 671,
    676, 682, 688, 694, 699, 704, 709, 715, 721, 727, 733, 739, 745, 750, 755,
    760, 765, 771, 776, 782, 788, 793, 799, 805, 811, 817, 823, 828, 833, 838,
    844, 850, 855, 861, 866, 872, 877, 882, 887, 893, 898, 904, 909, 914, 919,
    925, 931, 937, 943, 948, 953, 959, 964, 969, 975, 981, 986, 992, 997, 1003,
    1009, 1014, 1019, 1024, 1030, 1036, 1042, 1047, 1053, 1059, 1064, 1070,
    1076, 1081, 1086, 1092, 1097, 1103, 1108, 1114, 1120, 1125, 1131, 1137,
    1143, 1149, 1155, 1161, 1167, 1172, 1177, 1182, 1187, 1193, 1198, 1204,
    1210, 1215, 1220, 1225, 1231, 1236, 1242, 1248, 1253, 1259, 1264, 1269,
    1274, 1280, 1286, 1291, 1297, 1303, 1309, 1314, 1320, 1326, 1332
]


def main():
    parser = ArgumentParser(description=DESCRIPTION)
    parser.add_argument('-v',
                        '--value',
                        type=str,
                        nargs='?',
                        const=random,
                        help='Hex value to encode (random if not specified)')

    parser.add_argument("filename")
    args = parser.parse_args()

    fn = args.filename
    with open(fn, "rb") as f:
        data = bytearray(f.read())

    assert hashlib.md5(data[:HEADER_S]).hexdigest() == HEADER_MD5
    if args.value is not None:
        if args.value == random:
            hex_value = "".join(
                [random.choice("0123456789abcdef") for _ in range(MD5_LEN)])
            print("Encoding random value: %s" % hex_value)
        else:
            hex_value = "%032x" % int(args.value, HEX_BASE)
            hex_value = hex_value[:MD5_LEN]
            print("Encoding requested value: `%s` (len:%i)" %
                  (hex_value, len(hex_value)))
    else:
        hex_value = hashlib.md5(data).hexdigest()
        print("Encoding file MD5: `%s` (len:%i)" % (hex_value, len(hex_value)))

    for letter_index, letter in enumerate(hex_value):
        for segment_index, segment in enumerate(display[letter]):
            block_index = letter_index * 7 + segment_index
            data = setFastCollbySize(data,
                                     block_indexes[block_index],
                                     bSmaller=(segment != '1'),
                                     DIFF_BYTE=0x7B)

    with open("output.gif", "wb") as f:
        f.write(data)


if __name__ == '__main__':
    main()