ADD week 4

02-Easy4/E4.txt

@@ -0,0 +1,26 @@
+1. Was this executable stripped?
+yes
+
+2. How are the password checking functionalities entangled with the operating system?
+
+
+3. What is the algorithm used to check the validity of a password?
+
+
+4. Can you break this password checker, i.e., implementing a generator of valid passwords? You must send 16 different valid passwords by email to pascal+sre25@mod-p.ch before Mar. 24th, 2025, 12h00 CET to validate this lab and get 5 points.
+3A3A3A3A3A3A
+3A4B5C6D7E8F
+SaSaSaSaSaSa
+SaTbUcVdWeXf
++9+9+9+9+9+9
++99GGUUccq4B
+!//==KKYYggu
+>L3AGUES3AN\
+HVESDRHVESDR
+8F7E6D5C4B3A
+XfWeVdUcTbSa
+4BcqUcGU9G+9
+guYgKY=K/=!/
+N\3AESGU3A>L
+DRESHVDRESHV
+#1HVESLZP^#1

02-Easy4/code.c

@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+
+static char* input_pw;
+static char return_check_pw;
+
+
+
+void check_pw(void) {
+  uint8_t bVar1;
+  char *pcVar2;
+  char *pcVar3;
+
+  bVar1 = 0;
+  pcVar2 = input_pw;
+  do {
+    pcVar3 = pcVar2 + 2;
+    bVar1 = bVar1 | ((pcVar2[1] - 14) - pcVar2[0]);
+    pcVar2 = pcVar3;
+  } while (input_pw + 12 != pcVar3);
+  return_check_pw = (int)(char)bVar1;
+  return;
+}
+
+void print_check_pw(void) {
+  if (return_check_pw != 0) {
+    fwrite("\nWrong password ! Try again...\n\n",1,0x20,stderr);
+    return;
+  }
+  fprintf(stderr,"\nCongratulations ! A right password is indeed %s :-)\n\n",input_pw);
+  return;
+}
+
+
+uint64_t main(int param_1,char* *param_2) {
+  char *__s;
+  size_t sVar1;
+
+  if (param_1 == 2) {
+    __s = (char *)param_2[1];
+    sVar1 = strlen(__s);
+    if (sVar1 == 12) {
+      input_pw = __s;
+      signal(10,check_pw);
+      signal(12,print_check_pw);
+      kill(0,10);
+      kill(0,12);
+      return 0;
+    }
+    fwrite("\nWrong password ! Try again...\n\n",1,0x20,stderr);
+  } else {
+    fwrite("\nMSE-SRE Challenge E4 --- Enjoy !\n",1,0x22,stderr);
+    fwrite("\nWhat I need is 1024 passwords passing the check!\n",1,0x32,stderr);
+    fprintf(stderr,"\nUsage: %s <password>\n\n",*param_2);
+  }
+  return 1;
+}