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vault-door-5/VaultDoor5.java

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+import java.net.URLDecoder;
+import java.util.*;
+
+class VaultDoor5 {
+    public static void main(String args[]) {
+        VaultDoor5 vaultDoor = new VaultDoor5();
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Enter vault password: ");
+        String userInput = scanner.next();
+	String input = userInput.substring("picoCTF{".length(),userInput.length()-1);
+	if (vaultDoor.checkPassword(input)) {
+	    System.out.println("Access granted.");
+	} else {
+	    System.out.println("Access denied!");
+        }
+    }
+
+    // Minion #7781 used base 8 and base 16, but this is base 64, which is
+    // like... eight times stronger, right? Riiigghtt? Well that's what my twin
+    // brother Minion #2415 says, anyway.
+    //
+    // -Minion #2414
+    public String base64Encode(byte[] input) {
+        return Base64.getEncoder().encodeToString(input);
+    }
+
+    // URL encoding is meant for web pages, so any double agent spies who steal
+    // our source code will think this is a web site or something, defintely not
+    // vault door! Oh wait, should I have not said that in a source code
+    // comment?
+    //
+    // -Minion #2415
+    public String urlEncode(byte[] input) {
+        StringBuffer buf = new StringBuffer();
+        for (int i=0; i<input.length; i++) {
+            buf.append(String.format("%%%2x", input[i]));
+        }
+        return buf.toString();
+    }
+
+    public boolean checkPassword(String password) {
+        String urlEncoded = urlEncode(password.getBytes());
+        String base64Encoded = base64Encode(urlEncoded.getBytes());
+        String expected = "JTYzJTMwJTZlJTc2JTMzJTcyJTc0JTMxJTZlJTY3JTVm"
+                        + "JTY2JTcyJTMwJTZkJTVmJTYyJTYxJTM1JTY1JTVmJTM2"
+                        + "JTM0JTVmJTMwJTYyJTM5JTM1JTM3JTYzJTM0JTY2";
+        return base64Encoded.equals(expected);
+    }
+}

vault-door-5/sol.py

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+#!/home/maxime/.pyvenv/bin/python3
+from base64 import b64decode
+from urllib.parse import unquote
+
+S = "JTYzJTMwJTZlJTc2JTMzJTcyJTc0JTMxJTZlJTY3JTVm" + "JTY2JTcyJTMwJTZkJTVmJTYyJTYxJTM1JTY1JTVmJTM2" + "JTM0JTVmJTMwJTYyJTM5JTM1JTM3JTYzJTM0JTY2"
+S = b64decode(S)
+S = unquote(S)
+print(S)
+