investigative reversing 1/2

investigative_reversing_1/sol.py

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+#!/home/maxime/.pyvenv/bin/python3
+
+with open("mystery.png", 'rb') as f1, open("mystery2.png", 'rb') as f2, open("mystery3.png", 'rb') as f3:
+    img1 = f1.read()
+    img2 = f2.read()
+    img3 = f3.read()
+
+    contents1 = img1[-16:]
+    contents2 = img2[-2:]
+    contents3 = img3[-8:]
+
+    flag = ['']*26
+
+    flag[0] = chr(contents2[0] - 21)
+    flag[1] = chr(contents3[0])
+    flag[2] = chr(contents3[1])
+    flag_3_offset = 0
+    flag[4] = chr(contents1[0])
+    flag[5] = chr(contents3[2])
+
+    for i in range(6, 10):
+        flag_3_offset -= 1
+        flag[i] = chr(contents1[1+i-6])
+    
+    flag[3] = chr(contents2[1] + flag_3_offset)
+
+    for i in range(10, 15):
+        flag[i] = chr(contents3[3+i-10])
+
+    for i in range(15, 26):
+        flag[i] = chr(contents1[5+i-15])
+
+    print(''.join(flag))
+