- Safely escape user input with mysql_real_escape_string

- fixed some memory leaks

common.c

@@ -124,7 +124,7 @@ int
 member(char *gr) {
   char *username;
 
-  char *group;
+  char group[65];
   struct group *g;
 
   struct passwd *p;
@@ -141,11 +141,8 @@ member(char *gr) {
   username = p->pw_name;
  
   /* Copy string, but cut at '_' */
-  group = strdup(gr);
+  strncpy(group, gr, 64);
-  if (group == NULL) {
+  group[64] = '\0';
-    fprintf(stderr, "Couldn't allocate memory. Terminating."); 
-    exit(1);
-  }
 
   // ettersom man kan få inn gruppenavn med underscore i, må man rett og
   // slett prøve seg fram for å sjekke om det er en gruppe personen er med
@@ -170,9 +167,9 @@ member(char *gr) {
     if (g) { 
       /* Check if user is member of group */
       while(*g->gr_mem != NULL) {
-        char * member = *g->gr_mem; 
+        char * member = *g->gr_mem++; 
 #if DEBUG
-        printf("Medlem: %s\n", *g->gr_mem);
+        printf("Medlem: %s\n", member);
 #endif
 
         if (strcmp(member,username) == 0) {
@@ -180,8 +177,6 @@ member(char *gr) {
           printf("You have access to '%s'\n", gr);
 #endif
           return 1;              /* OK */
-        } else {
-          *g->gr_mem++;
         }
       } 
 #if DEBUG
@@ -222,7 +217,7 @@ char **get_group_names(int *numgroups)
     return NULL;
   }
 
-  grouplist = malloc(sizeof(char *));
+  grouplist = malloc(33 * sizeof(char *));
   real_nr_groups = 0;
 
   for (i = 0; i < nr_groups; i++) {
@@ -230,9 +225,7 @@ char **get_group_names(int *numgroups)
 
     /* Go to next grp if it doesn't have a name */
     if (g != NULL) {
-      grouplist = (char **) realloc(grouplist, (real_nr_groups+2) * sizeof(char *));
+      grouplist[real_nr_groups++] = strdup(g->gr_name);
-      grouplist[real_nr_groups] = strdup(g->gr_name);
-      real_nr_groups++;
     } else {
       fprintf(stderr, "Omitting gid %d, no entry in group-file.\n", gids[i]);
     }
@@ -250,3 +243,10 @@ reload(MYSQL *pmysql)
 {
   return mysql_reload(pmysql);
 }
+
+/* same as strcpy, but returns a pointer to the end of dest instead of start */
+char *strmov(char *dest, const char *src) {
+  while ((*dest++ = *src++))
+    ;
+  return dest-1;
+}

mysql-admutils.h

@@ -33,6 +33,9 @@ version(void);
 extern int
 read_config_file(void);
 
+/* same as strcpy, but returns a pointer to the end of dest instead of start */
+extern char *strmov(char *, const char *);
+
 
 #ifdef _mysql_h
 

mysql-dbadm.c

@@ -23,12 +23,6 @@
 const char dbname_validchars[] =
   "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
 
-/* same as strcpy, but returns a pointer to the end of dest instead of start */
-char *strmov(char *dest, const char *src) {
-  while ((*dest++ = *src++))
-    ;
-  return dest-1;
-}
 
 /* Returns true if dbname contains only characters in dbname_validchars. */
 int dbname_isclean(char* dbname) {

mysql-useradm.c

@@ -37,32 +37,50 @@ usage()
 int
 is_password_set(MYSQL *pmysql, const char *user)
 {
-  char query[1024];
+  char query[1024], *end;
   MYSQL_RES *res;
   int rows;
   MYSQL_ROW row;
+  int check = 0;
+
+  end = strmov(query, "SELECT password FROM user WHERE user='");
+  end += mysql_real_escape_string(pmysql, end, user, strlen(user));
+  *end++ = '\'';
+  *end = '\0';
 
-  sprintf(query, "select password from user where user = '%s'", user);
   if (mysql_query(pmysql, query))
     dberror(pmysql, "Failed to look up password for user '%s'.", user);
   res = mysql_store_result(pmysql);
   rows = mysql_num_rows(res);
-  if (rows == 0)
+
-    return -1;
   if (rows > 1)
+  {
+    mysql_free_result(res);
     return dberror(NULL, "Query for password for user '%s' gave %d results!", 
                    user, rows);
+  }
+  else if (rows < 1) {
+    mysql_free_result(res);
+    return -1;
+  }
+
   row = mysql_fetch_row(res);
-  return (row[0] && (strlen(row[0]) > 0));
+  check = (row[0] && (strlen(row[0]) > 0));
+  mysql_free_result(res);
+
+  return check;
 }
 
 
 int
 create(MYSQL *pmysql, const char *user)
 {
-  char query[1024];
+  char query[1024], *end;
+
+  end = strmov(query, "INSERT INTO user (host, user) VALUES ('%', '");
+  end += mysql_real_escape_string(pmysql, end, user, strlen(user));
+  end = strmov(end, "')");
 
-  sprintf(query, "insert into user (host, user) values ('%%', '%s')", user);
   if (mysql_query(pmysql, query))
     return dberror(pmysql, "Failed to create user '%s'.", user);
 
@@ -73,9 +91,13 @@ create(MYSQL *pmysql, const char *user)
 int
 delete(MYSQL *pmysql, const char *user)
 {
-  char query[1024];
+  char query[1024], *end;
+
+  end = strmov(query, "DELETE FROM user WHERE user='");
+  end += mysql_real_escape_string(pmysql, end, user, strlen(user));
+  *end++ = '\'';
+  *end = '\0';
 
-  sprintf(query, "delete from user where user = '%s'", user);
   if (mysql_query(pmysql, query))
     return dberror(pmysql, "Failed to delete user '%s'.", user);
 
@@ -87,40 +109,13 @@ int
 passwd(MYSQL *pmysql, const char *user)
 {
   char prompt[1024];
-  char query[1024];
+  char query[1024], *end;
   char *password, *confirm_password;
-  MYSQL_RES *res;
-  int rows;
-  MYSQL_ROW row;
 
-  /*
+  if (is_password_set(pmysql, user) == -1) /* no such mysql user */
-  if (is_password_set(pmysql, user))
+    return dberror(NULL, "User '%s' does not exist."
-    {
+                         " You must create it first.\n", user);
-      sprintf(prompt, "(current) MySQL password for user '%s': ", user);
+
-      password = getpass(prompt);
-      sprintf(query, "select password = password('%s') from user "
-              "where user = '%s'", password, user);
-      if (mysql_query(pmysql, query))
-        return dberror(pmysql, "Failed to check old password for user '%s'.",
-                       user);
-      res = mysql_store_result(pmysql);
-      rows = mysql_num_rows(res);
-      if (rows == 0)
-        return dberror(NULL, "Check for old password for user '%s' "
-                       "returned empty.", user);
-      if (rows > 1)
-        return dberror(NULL, "Check for old password for user '%s' "
-                       "returned more than one row!", user);
-      row = mysql_fetch_row(res);
-      if (strcmp(row[0], "1") != 0)
-        {
-          fprintf(stderr, "%s: Wrong password entered for user '%s'.\n", 
-                  program_name, user);
-          return 1;
-        }
-    }
-  */
-  
   sprintf(prompt, "New MySQL password for user '%s': ", user);
   password = getpass(prompt);
   confirm_password = strdup(password);
@@ -133,11 +128,16 @@ passwd(MYSQL *pmysql, const char *user)
     }
   free(confirm_password);
 
-  sprintf(query, "update user set password = password('%s') "
+  end = strmov(query, "UPDATE user SET password = PASSWORD('");
-          "where user = '%s'", password, user);
+  end += mysql_real_escape_string(pmysql, end, password, strlen(password));
+  end = strmov(end, "') WHERE user='");
+  end += mysql_real_escape_string(pmysql, end, user, strlen(user));
+  *end++ = '\'';
+  *end = '\0';
+  
   if (mysql_query(pmysql, query))
     return dberror(pmysql, "Failed to set new password for user '%s'.", user);
-  if (mysql_affected_rows(pmysql) > 1)
+  if (mysql_affected_rows(pmysql) != 1)
     dberror(NULL, "%d rows affected by password update for user '%s'!", 
             mysql_affected_rows(pmysql), user);
 
@@ -170,7 +170,7 @@ show(MYSQL *pmysql, const char *user)
 char **
 list(MYSQL *pmysql)
 {
-  char query[4096];
+  char query[4096], *end;
   char **usrgroups, **cp;
   MYSQL_RES *res;
   int rows, numgroups;
@@ -180,18 +180,27 @@ list(MYSQL *pmysql)
   struct passwd *p;
 
   p = getpwuid(getuid());
-  sprintf(query, "select user from user where user='%s' or user like '%s\\_%%'",
+  
-          p->pw_name, p->pw_name);
+  end = strmov(query, "SELECT user FROM user WHERE user='");
-//   sprintf(query, "select user from user where user='myhr' or user like 'myhr\\_%%'");
+  end += mysql_real_escape_string(pmysql, end, p->pw_name, strlen(p->pw_name));
+  end = strmov(end, "' OR user LIKE '");
+  end += mysql_real_escape_string(pmysql, end, p->pw_name, strlen(p->pw_name));
+  end = strmov(end, "\\_%'");
 
   numgroups = 0;
 
   usrgroups = get_group_names(&numgroups);
   cp = usrgroups;
   while (*cp) {
-    sprintf(&query[strlen(query)], " or user='%s' or user like '%s\\_%%'", *cp, *cp);
+    end = strmov(end, " OR user='");
+    end += mysql_real_escape_string(pmysql, end, *cp, strlen(*cp));
+    end = strmov(end, "' OR user LIKE '");
+    end += mysql_real_escape_string(pmysql, end, *cp, strlen(*cp));
+    end = strmov(end, "\\_%'");
+    free(*cp);
     cp++;
   }
+  free(usrgroups);
 
 #ifdef DEBUG
   printf("about to run query: %s\n", query);
@@ -218,6 +227,8 @@ list(MYSQL *pmysql)
 
   userlist[i] = NULL;
 
+  mysql_free_result(res);
+
   return userlist;
 }
 
@@ -229,7 +240,7 @@ main(int argc, char *argv[])
   MYSQL mysql;
   mysql_init(&mysql);
   char **dblist, **p;
-  char *user;
+  char user[65];
 
   program_name = argv[0];
 
@@ -262,7 +273,7 @@ main(int argc, char *argv[])
   else
     return wrong_use("unrecognized command '%s'.", argv[1]); /* XXX */
 
-  /* all other than show requires at lease one USER argument. */
+  /* all other than show requires at least one USER argument. */
   if ((command != c_show) && (argc < 3))
     return wrong_use(NULL);
 
@@ -288,7 +299,6 @@ main(int argc, char *argv[])
       free(dblist);
     }
   else {
-    user = malloc(64);
     /* for each supplied database name, perform the requested action */
 
     for (i = 2; i < argc; i++) {