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crack.c

@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <cs50.h>
+#include <string.h>
+#include <crypt.h>
+int main(int argc, string argv[])
+{
+
+    if (argc != 2)
+    {
+        //To check if the user entered two arguments in the command line.
+        printf("Usage: ./crack hash\n");
+        return 1; // exit code to end the program (not like other exit codes).
+    }
+    // array to compare those letters in crypt function .
+    string alphapaticalLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    int alphaL = strlen(alphapaticalLetters);
+    string hashedS = argv[1];
+    // to manipulate salt charecters .
+    char *salt = malloc(3 * sizeof(char));
+    // initialize the salt with values from input in the command line.
+    salt[0] = hashedS[0];
+    salt[1] = hashedS[1];
+    // to end initialization of salt
+    salt[2] = '\0';
+    //to hold password cracking .
+    char crack[4];
+
+
+    for (int frthHash = 0; frthHash < alphaL; frthHash++)
+    {
+
+        crack[3] = hashedS[frthHash];
+        if (strcmp(crypt(crack, salt), hashedS) == 0)
+        {
+            printf("%s\n", crack);
+            return 0;
+        }
+        for (int trdHash = 0; trdHash < alphaL; trdHash++)
+        {
+            crack[2] = hashedS[trdHash];
+            if (strcmp(crypt(crack, salt), hashedS) == 0)
+            {
+                printf("%s\n", crack);
+                return 0;
+            }
+            for (int sndHash = 0 ; sndHash < alphaL; sndHash++)
+            {
+                crack[1] = hashedS[sndHash];
+                if (strcmp(crypt(crack, salt), hashedS) == 0)
+                {
+                    printf("%s\n", crack);
+                    return 0;
+                }
+                for (int fstHash = 0; fstHash < alphaL; fstHash++)
+                {
+                    crack[0] = hashedS[fstHash];
+                    if (strcmp(crypt(crack, salt), hashedS) == 0)
+                    {
+                        printf("%s\n", crack);
+                        return 0;
+                    }
+                }
+            }
+        }
+    }
+    printf("The password can not be cracked.\n");
+    return 2; //end the problem with this exit code to makr differentation between other exit code.
+    free(salt); //give the taken space back to the memory(by malloc function).
+}