Given the following code
Code:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
int main(void)
{
char buf[1024];
char **arr1 = NULL;
char **arr2 = NULL;
char **arr3 = NULL;
char **arr4 = NULL;
int size1 = 0;
int size2 = 0;
int size3 = 0;
int size4 = 0;
FILE * f1, *f2;
f1 = fopen("shadow.txt", "r");
f2 = fopen("mytab24112.txt", "r");
// Allocate memory for shadow.txt
while(fgets(buf, 1024, f1))
{
size1++;
arr1 = realloc(arr1, sizeof(char*) * size1);
arr1[size1 - 1] = strdup(buf);
}
// Allocate memory for mytab2411.txt
while(fgets(buf, 1024, f2))
{
size2++;
arr2 = realloc(arr2, sizeof(char*) * size2);
arr2[size2 - 1] = strdup(buf);
}
size3++;
arr3 = realloc(arr3, sizeof(char*) * size3);
arr3[size3 - 1] = strdup(buf);
size4++;
arr4 = realloc(arr4, sizeof(char*) * size4);
arr4[size4 - 1] = strdup(buf);
char line[1000]; //Allocate max number of characters in a line
char hash[1000]; // Allocate max number of characters in a hash (substring of a line) for shadow.txt
char * hash2; // Define hash for mytab24112.txt
char md5[5]= "$1$$"; // Define string to be searched for md5 in shadow.txt
char sha512[5]="$6$$"; // Define string to be searched for sha512 in shadow.txt
char *ret; // Used for shadow.txt
char *ret2; // Used for shadow.txt
char del='$'; // Delimiter for displaying all hashes in mytab24112.txt
char * del2; // Delimiter for displaying password text in mytab24112.txt
char word[sizeof(line)];
// Read shadow.txt line by line
for(int i = 0; i < size1; i++) {
memset(hash, '\0', sizeof(hash));
strcpy(line, arr1[i]);
// Search for md5 in shadow.txt
md5[4]='\0';
ret = strstr(line, md5);
// Search for sha512 in shadow.txt
sha512[4]='\0';
ret2 = strstr(line, sha512);
// Copies md5 hash to the variable hash if md5 is detected in shadow.txt
if (ret){
strncpy(hash, line+5, 26);
hash[26] = '\0';
}
// Copies sha512 hash to the variable hash if sha512 is detected in shadow.txt
else if (ret2){
strncpy(hash, line+5, 90);
hash[90] = '\0';
}
// Read mytab2411.txt line by line
for(int j = 0; j < size2; j++){
strcpy(line, arr2[j]);
// Returns all hashes from mytab24112.txt using delimiter '$'
hash2=strchr(line,del);
for(int a = 0; a < size3; a++)
for(int b = 0; b < size4; b++){
strcpy(arr3[a],hash);
strcpy(arr4[b],hash2);
printf("Hash in shadow:%s\n",arr3[a]);
printf("Hash in mytab24112:%s\n",arr4[b]);
//Compare hash (arr3[a]) and hash 2 (arr4[b])
int result = strcmp(arr3[a],arr4[b]);
printf("%d\n",result);
} //End of "for(int a = 0; a < size3; a++)" and "for(int b = 0; b < size4; b++)" loop
}// End of "for(int j = 0; j < size2; j++)" loop
}// End of "for (int i = 0; i < size1; i++)" loop
return 0;
}//End of main
and the following files
shadow.txt
Code:
pyc1:$1$$Tnq7a6/C1wwyKyt0V/.BP/:17482:0:99999:7:::
pyc2:$6$$/xMg2/4CZwMUbah4IhNwCjqzZf0/OByfs6UHmq32jFbsdpbDw9bhLttC7n/bAVlM2NwJ7hBQ3d0H47leLXE6g1:17482:0:99999:7:::
pyc3:$1$$zZQKNjRd94GHyYOwXuStf0:17482:0:99999:7:::
pyc4:$6$iKYSRG68$STdY8TCgoCaNfSUcyCwSBlVekdjs0P3qXtwxSbgpQpMUnHJRRSHOT5amoR24IqZBTPNWuIfO.uhZEnGLuE4q/.:17482:0:99999:7:::
pyc5:$6$$FDqvMBbQOCyKP9uBL8E6TAEupCh72v.3/ow4fZ5HpZ/0NS7LBifFS9nJdzc/u2OEhUnRF9yC4Lw23hHjD1EmD.:17482:0:99999:7:::
pyc6:$6$$LfCuhKecDtIfX77LOTWD1PjhF1IC0hBzjxckEthmoT8mVbxKH3qJzFgEi/P9GN1mptR4WPiwuh69X/41M6pHW1:17482:0:99999:7:::
mytab24112.txt
Code:
apple:$1$$Tnq7a6/C1wwyKyt0V/.BP/
orange:$6$$/xMg2/4CZwMUbah4IhNwCjqzZf0/OByfs6UHmq32jFbsdpbDw9bhLttC7n/bAVlM2NwJ7hBQ3d0H47leLXE6g1
banana:$1$$zZQKNjRd94GHyYOwXuStf0
a:$1$$Ij31LCAysPM23KuPlm1wA/
a:$6$$ek/ucQg0IM8SQLyD2D66mpoW0vAF26eA0/pqoN95V.F0nZh1IFuENNo0OikacRkDBk5frNqziMYMdVVrQ0o.51
aah:$1$$bh5o1cAKfH43fc/B1.AjF0
aah:$6$$jdxDww2LkNSlQPmWe5iDRAoBBT5IXa9241nN2bcm2Aukdrr4iH27Y6dj801MjLFaDQxbDBNxY4jvlXdIemiCY/
aahed:$1$$zA2Ef92JR9W7kqAf8Km5B0
aahed:$6$$mYQU7f3NL9Dysccvwv2BAyiCb/gxh9lN1gGnC9sa2uwHGX9VVb7jp3b7u/EZbdObqWrRFgiOLcRn7PEW1cOcz.
why is it that "strcmp(arr3[a],arr4[b])" returns "-10" instead of "0" despite matching strings (First 3 lines from shadow.txt and mytab24112.txt should match)? How should I solve this problem?
A few important lines from the output
Code:
Hash in shadow:$1$$Tnq7a6/C1wwyKyt0V/.BP/
Hash in mytab24112:$1$$Tnq7a6/C1wwyKyt0V/.BP/
-10
Hash in shadow:$6$$/xMg2/4CZwMUbah4IhNwCjqzZf0/OByfs6UHmq32jFbsdpbDw9bhLttC7n/bAVlM2NwJ7hBQ3d0H47leLXE6g1
Hash in mytab24112:$6$$/xMg2/4CZwMUbah4IhNwCjqzZf0/OByfs6UHmq32jFbsdpbDw9bhLttC7n/bAVlM2NwJ7hBQ3d0H47leLXE6g1
-10
Hash in shadow:$1$$zZQKNjRd94GHyYOwXuStf0
Hash in mytab24112:$1$$zZQKNjRd94GHyYOwXuStf0
-10