root@localhost$

root@localhost$

total 3 -rw-r----- 1 root root 2235 Dec 11 11:58 VaultDoor7.java root@localhost$

import java.util.*; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; import java.security.*; class VaultDoor7 { public static void main(String args[]) { VaultDoor7 vaultDoor = new VaultDoor7(); 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!"); } } // Each character can be represented as a byte value using its // ASCII encoding. Each byte contains 8 bits, and an int contains // 32 bits, so we can "pack" 4 bytes into a single int. Here's an // example: if the hex string is "01ab", then those can be // represented as the bytes {0x30, 0x31, 0x61, 0x62}. When those // bytes are represented as binary, they are: // // 0x30: 00110000 // 0x31: 00110001 // 0x61: 01100001 // 0x62: 01100010 // // If we put those 4 binary numbers end to end, we end up with 32 // bits that can be interpreted as an int. // // 00110000001100010110000101100010 -> 808542562 // // Since 4 chars can be represented as 1 int, the 32 character password can // be represented as an array of 8 ints. // // - Minion #7816 public int[] passwordToIntArray(String hex) { int[] x = new int[8]; byte[] hexBytes = hex.getBytes(); for (int i=0; i<8; i++) { x[i] = hexBytes[i*4] << 24 | hexBytes[i*4+1] << 16 | hexBytes[i*4+2] << 8 | hexBytes[i*4+3]; } return x; } public boolean checkPassword(String password) { if (password.length() != 32) { return false; } int[] x = passwordToIntArray(password); return x[0] == 1096770097 && x[1] == 1952395366 && x[2] == 1600270708 && x[3] == 1601398833 && x[4] == 1716808014 && x[5] == 1734304867 && x[6] == 942695730 && x[7] == 942748212; } } root@localhost$

bash: nano: command not found root@localhost$

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7f0458391720>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7f0458391a50>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x78ae1dac59f0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x78ae1dac5d20>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7cece20dd9c0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7cece20ddcf0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7fef9e64d510>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7fef9e64d840>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x79159d21d5d0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x79159d21d900>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7cf3c5581270>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7cf3c55815a0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/python3/

root@localhost$

bash: nano: command not found root@localhost$

bash: nano: command not found root@localhost$

bash: nano: command not found root@localhost$

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7fd5ae9e94b0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7fd5ae9e97e0>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/

root@localhost$

bash: nano: command not found root@localhost$

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7ed873651600>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/ WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7ed873651930>: Failed to establish a new connection: [Errno 101] Network is unreachable')': /simple/bitstring/

bash: nano: command not found root@localhost$

bash: nano: command not found root@localhost$

bash: nano: command not found root@localhost$