diff options
Diffstat (limited to 'meta')
| -rw-r--r-- | meta/.gitignore | 1 | ||||
| -rw-r--r-- | meta/Makefile | 11 | ||||
| -rw-r--r-- | meta/encrypt.py | 10 | ||||
| -rw-r--r-- | meta/flag.bmp | bin | 0 -> 2074762 bytes | |||
| -rw-r--r-- | meta/flag.bmp.enc | bin | 0 -> 2074768 bytes | |||
| -rw-r--r-- | meta/recover.c | 150 | ||||
| -rw-r--r-- | meta/recover.py | 55 |
7 files changed, 227 insertions, 0 deletions
diff --git a/meta/.gitignore b/meta/.gitignore new file mode 100644 index 0000000..f3880fa --- /dev/null +++ b/meta/.gitignore @@ -0,0 +1 @@ +recover diff --git a/meta/Makefile b/meta/Makefile new file mode 100644 index 0000000..c3b984e --- /dev/null +++ b/meta/Makefile @@ -0,0 +1,11 @@ +CFLAGS = -g +LDLIBS = -lraylib + +all: recover + +clean: + rm -f recover + +recover: recover.c + +.PHONY: all clean diff --git a/meta/encrypt.py b/meta/encrypt.py new file mode 100644 index 0000000..5451f4a --- /dev/null +++ b/meta/encrypt.py @@ -0,0 +1,10 @@ +#!/usr/bin/env python3 + +from Crypto.Cipher import AES +import os, sys + +img_in = open(sys.argv[1], "rb").read() +img_in += b'\00' * (16 - (len(img_in) % 16)) +cipher = AES.new(os.urandom(16), AES.MODE_ECB) +img_out = cipher.encrypt(img_in) +open(sys.argv[1] + ".enc", "wb+").write(img_out) diff --git a/meta/flag.bmp b/meta/flag.bmp Binary files differnew file mode 100644 index 0000000..091c585 --- /dev/null +++ b/meta/flag.bmp diff --git a/meta/flag.bmp.enc b/meta/flag.bmp.enc Binary files differnew file mode 100644 index 0000000..4f7ecfe --- /dev/null +++ b/meta/flag.bmp.enc diff --git a/meta/recover.c b/meta/recover.c new file mode 100644 index 0000000..54574b6 --- /dev/null +++ b/meta/recover.c @@ -0,0 +1,150 @@ +#include "raylib.h" + +#include <err.h> +#include <string.h> +#include <stdio.h> +#include <stdint.h> +#include <stdbool.h> +#include <stdlib.h> + +#define BLOCKSIZE 16 +#define BESTN 4 + +struct block { + uint8_t data[BLOCKSIZE]; + uint32_t cnt; +}; + +uint8_t * +read_file(const char *filename, size_t *size) +{ + uint8_t *buf; + FILE *f; + + f = fopen(filename, "r"); + if (!f) err(1, "fopen"); + + fseek(f, 0, SEEK_END); + *size = ftell(f); + fseek(f, 0, SEEK_SET); + + buf = malloc(*size); + if (!buf) err(1, "malloc"); + + if (!fread(buf, *size, 1, f)) + err(1, "fread"); + + fclose(f); + + return buf; +} + +void +update(struct block *blocks, struct block *bestblocks, + size_t *blockslen, uint8_t *img, size_t imglen) +{ + struct block cmp, tmp; + size_t tmpcnt; + size_t i, k; + + memset(bestblocks, 0, BESTN * sizeof(struct block)); + *blockslen = 0; + for (i = 0; i < imglen - BLOCKSIZE + 1; i += BLOCKSIZE) { + for (k = 0; k < *blockslen; k++) { + if (!memcmp(blocks[k].data, &img[i], BLOCKSIZE)) { + blocks[k].cnt += 1; + break; + } + } + if (k == *blockslen) { + memcpy(blocks[k].data, &img[i], BLOCKSIZE); + blocks[k].cnt = 1; + *blockslen += 1; + } + + memcpy(&cmp, &blocks[k], sizeof(struct block)); + for (k = 0; k < BESTN; k++) { + if (cmp.cnt > bestblocks[k].cnt || !bestblocks[k].cnt) { + memcpy(&tmp, &bestblocks[k], sizeof(struct block)); + memcpy(&bestblocks[k], &cmp, sizeof(struct block)); + memcpy(&cmp, &tmp, sizeof(struct block)); + } + } + } +} + + +int +main(int argc, const char **argv) +{ + const int wwidth = 1920; + const int wheight = 1080; + struct block bestblocks[BESTN]; + struct block *blocks; + char textbuf[256]; + size_t blockslen; + size_t imgoff, imglen; + size_t width, height; + size_t x, y, pos, i; + uint8_t *img; + + if (argc < 2) return 1; + + img = read_file(argv[1], &imglen); + + blocks = malloc(imglen / BLOCKSIZE * sizeof(struct block)); + if (!blocks) err(1, "malloc"); + + InitWindow(wwidth, wheight, "bmpass"); + + update(blocks, bestblocks, &blockslen, img, imglen); + + width = wwidth; + imgoff = 0; + while (!WindowShouldClose()) { + if (IsKeyDown(KEY_LEFT) && width > 0) + width -= 1; + else if (IsKeyDown(KEY_RIGHT)) + width += 1; + else if (IsKeyDown(KEY_DOWN) && imgoff > 0) + imgoff -= BLOCKSIZE; + else if (IsKeyDown(KEY_UP)) + imgoff += BLOCKSIZE; + else if (IsKeyDown(KEY_ESCAPE)) + break; + + BeginDrawing(); + + ClearBackground(GRAY); + + height = (imglen - imgoff) / width; + for (y = 0; y < height; y++) { + if (y >= wheight) continue; + for (x = 0; x < width; x++) { + if (x >= wwidth) continue; + pos = (imgoff + y * width + x) + / BLOCKSIZE * BLOCKSIZE; + if (pos + BLOCKSIZE >= imglen) continue; + for (i = 0; i < BESTN; i++) { + if (!memcmp(bestblocks[i].data, + img + pos, BLOCKSIZE)) + break; + } + if (i != BESTN) + DrawPixel(x, wheight - 1 - y, BLACK); + else + DrawPixel(x, wheight - 1 - y, WHITE); + } + } + + snprintf(textbuf, sizeof(textbuf), "imgoff %lu", imgoff); + DrawText(textbuf, 10, wheight - 40, 20, BLACK); + + snprintf(textbuf, sizeof(textbuf), "width %lu", width); + DrawText(textbuf, 10, wheight - 20, 20, BLACK); + + EndDrawing(); + } + + CloseWindow(); +} diff --git a/meta/recover.py b/meta/recover.py new file mode 100644 index 0000000..72b3a6c --- /dev/null +++ b/meta/recover.py @@ -0,0 +1,55 @@ +#!/usr/bin/env python3 + +from pyray import * +import struct +import sys + +img_enc = open(sys.argv[1], "rb").read() + + +blocksize = 16 + +pix = img_enc[0x480:] # offset needs to be blocksize aligned +img_off = 0x0a + +print(len(pix) - img_off, 1920 * 1080) + +blocks = {} +for i in range(0, len(pix)-blocksize+1, blocksize): + block = pix[i:i+blocksize] + if block not in blocks: + blocks[block] = [] + blocks[block].append(i) +blocks_items = [(k,len(v)) for k,v in blocks.items()] +blocks_sorted = sorted(blocks_items, key=lambda x: x[1], reverse=True)[8:] +blocks_top = {k:v for k,v in blocks_sorted} + +imgbuf = [] +for i in range(0, len(pix)-blocksize+1, blocksize): + block = pix[i:i+blocksize] + if block not in blocks_top: + imgbuf += [Color(255, 255, 255, 255)] * blocksize + else: + imgbuf += [Color(0, 0, 0, 255)] * blocksize + +width = 1920 +init_window(1920, 1080, "bmpass") +while not window_should_close(): + while key := get_key_pressed(): + if key == KEY_LEFT: + width -= 1 + elif key == KEY_RIGHT: + width += 1 + elif key == KEY_UP and img_off > 0: + img_off -= 1 + elif key == KEY_DOWN: + img_off += 1 + begin_drawing() + clear_background(GRAY) + height = len(imgbuf) // width + for y in range(height): + for x in range(width): + draw_pixel(x, height - 1 - y, imgbuf[img_off + y * width + x]) + end_drawing() +close_window() + |
