endianness_v2_temp

endianness_v2/sol.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+from pwn import *
+
+with open("challengefile", "rb") as f:
+    file = f.read()
+
+log.info(f"length: {len(file)}")
+
+reorder = b""
+
+for i in range(len(file)//4):
+    reorder += file[i+3:i+4] + file[i+2:i+3] + file[i+1:i+2] + file[i:i+1]
+
+log.hexdump(reorder)
+

flag_printer/flag_printer.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+import galois
+import numpy as np
+MOD = 7514777789
+
+points = []
+
+for line in open('encoded.txt', 'r').read().strip().split('\n'):
+    x, y = line.split(' ')
+    points.append((int(x), int(y)))
+
+GF = galois.GF(MOD)
+print(GF.properties)
+
+matrix = []
+solution = []
+for point in points:
+    x, y = point
+    solution.append(GF(y % MOD))
+
+    row = []
+    for i in range(3):
+        row.append(GF((x ** i) % MOD))
+    
+    matrix.append(GF(row))
+
+print('solving')
+open('output.bmp', 'wb').write(bytearray(np.linalg.lstsq(GF(matrix), GF(solution)).tolist()[:-1]))

flag_printer/sol.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+from sage.all import *
+MOD = 7514777789
+
+ring=GF(MOD)
+
+points = []
+for line in open('encoded.txt', 'r').read().strip().split('\n'):
+    x, y = line.split(' ')
+    points.append((int(x), int(y)))
+
+print("building matrices")
+
+solution = []
+M = []
+for point in points:
+    x, y = point
+    solution.append(ring(y % MOD))
+
+    row = []
+    for i in range(3):
+        row.append(pow(x, i, MOD))
+    M.append(row)
+
+print("converting matrices")
+
+solution = vector(solution)
+M = Matrix(M, base_ring=GF(MOD))
+
+print('solving')
+open('output.bmp', 'wb').write(bytearray(M.solve_right(solution).tolist()[:-1]))

poweranalysis_part_1/sol.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+from pwn import *
+import matplotlib.pyplot as plt
+
+address = "saturn.picoctf.net"
+port = 63821
+
+def fetch_data(message):
+    conn = remote(address, port, level="warn")
+    conn.recvuntil(b"hex: ")
+    conn.sendline(message)
+    conn.recvuntil(b"[")
+    list_string = conn.recvuntil(b"]", drop=True)
+    conn.close()
+    return [int(s.strip()) for s in list_string.split(b',')]
+
+data_array = []
+P = log.progress("fetching timing data")
+for i in range(16):
+    P.status(f"{i+1}/16")
+    data_array.append(fetch_data(b"00112233445566778899aabbccddeeff"))
+P.success("16/16 all data fetched")
+
+data = [0]*len(data_array[0])
+for i in range(len(data_array)):
+    slice = data_array[i]
+    for j, n in enumerate(slice):
+        data[j] += n
+
+plt.plot(data)
+plt.show()
+