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Be the first to email me and win a prize!
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import java.nio.charset.StandardCharsets; | |
import java.security.MessageDigest; | |
import java.security.NoSuchAlgorithmException; | |
import java.util.Random; | |
public class CrackMe1 { | |
public static void main(String[] args) throws Exception { | |
long sleepy = 1; | |
while (true) { | |
Thread.sleep(sleepy++); | |
long seed = new Random().nextLong(); | |
Random rnd = new Random(seed); | |
final int range = 26; | |
String prefix = ""; | |
for (int i = 0; i < 80; i++) { | |
int v = rnd.nextInt(range) + 1; | |
char c = (char) ('`' + v); | |
prefix += c; | |
} | |
prefix = prefix.replace("s", "-"); | |
String[] preconditions = prefix.split("-"); | |
if (preconditions.length != 3) { | |
continue; | |
} | |
if (!preconditions[0].equals("xgjv")) { | |
continue; | |
} | |
if (!preconditions[1].equals("xceg")) { | |
continue; | |
} | |
if (!preconditions[2].equals("rtakdmavlctjtnfdwicmliizylrfqynpbolgexazdutylgzrbyrcybzgdmjydylzhrbiml")) { | |
continue; | |
} | |
String suffix = ""; | |
for (int i = 0; i < 20; i++) { | |
int v = rnd.nextInt(range) + 1; | |
char c = (char) ('`' + v); | |
suffix += c; | |
} | |
suffix = suffix.replace("s", "-"); | |
if (SHA256(suffix).startsWith("e9")) { | |
System.out.println("Be the first to email '" + suffix.substring(0, 15) | |
+ "@ben-holland.com' and include a solution summary to claim a prize!"); | |
break; | |
} | |
} | |
} | |
private static String SHA256(String input) throws NoSuchAlgorithmException { | |
MessageDigest digest = MessageDigest.getInstance("SHA-256"); | |
byte[] hash = digest.digest(input.getBytes(StandardCharsets.UTF_8)); | |
StringBuffer hexString = new StringBuffer(); | |
for (int i = 0; i < hash.length; i++) { | |
String hex = Integer.toHexString(0xff & hash[i]); | |
if (hex.length() == 1) { | |
hexString.append('0'); | |
} | |
hexString.append(hex); | |
} | |
return hexString.toString(); | |
} | |
} |
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