question8

question8/check_pass.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+int check_pass(__uid_t user, char *pass) {
+
+    char * line = NULL;
+    size_t len = 0;
+    size_t read;
+
+    FILE *fp = fopen("/home/admin/passwd", "r");
+    if (fp == NULL) {
+        printf("fopen failed, errno = %d\n", errno);
+        exit(EXIT_FAILURE);
+    }
+
+    while ((read = getline(&line, &len, fp)) != -1) {
+        unsigned long i = 0;
+        while (i < len && line[i] != ':') {
+            i++;
+        }
+        char vOut[64];
+        snprintf(vOut, 64, "%d", user);
+        if (strncmp(vOut, line, i) == 0) {
+            if (strncmp(pass, &line[i+1], len-1-i) == 0) {
+                return 0;
+            }
+        }
+    }
+
+    fclose(fp);
+
+    return 1;
+}
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question8/check_pass.h

+int check_pass(__uid_t user, char *pass);
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question8/passwd

+lhomme:123456

question8/rmg.c

+#include <sys/stat.h>
+#include <string.h>
+#include <stdio.h>
+#include "check_pass.h"
+#include <unistd.h>
+#include <sys/types.h>
+
+int main(int argc, char* argv[]) {
+
+    struct stat buf;
+
+    if (argc == 2) {
+        stat(argv[1], &buf);
+
+        if (buf.st_gid == getgid()) {
+            printf("Entrez votre mot de passe : ");
+            char pass[64];
+            fgets(pass, 64, stdin);
+            if (check_pass(getuid(), pass) == 0) {
+                remove(argv[1]);
+                printf("Le fichier à bien été supprimé.\n");
+            } else {
+                printf("T'as pas le bon mot de passe.\n");
+            }
+        } else {
+            printf("T'as pas le bon groupe.\n");
+        }
+    }
+
+}
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