JSB '19 - P4
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Points:
17
Time limit:
2.5s
Memory limit:
64M
Author:
Problem type
Allowed languages
Java
Please output the flag.
Download the Java agent here.
Download the source code of the agent here.
You can test locally using the command java -javaagent:p4_agent.jar YourClass.
Source Code
File: Agent.java
import java.lang.instrument.*;
public class Agent {
public static void premain(final String agentArgs, final Instrumentation inst) {
// deja vu?
}
}
File: Secret.java
public class Secret {
String getFlag() {
int[] obfuscated = {252, 235, 249, 146, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143, 143};
byte[] deobfuscated = new byte[obfuscated.length];
for (int i = 0; i < obfuscated.length; i++) {
deobfuscated[i] = (byte) (obfuscated[i] ^ 191);
}
String flag = new String(deobfuscated);
return false ? flag : "NO U";
}
}
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