menu/libmenu/passwords.c

   1 /* -*- c -*- ------------------------------------------------------------- *
   2  *
   3  *   Copyright 2004-2005 Murali Krishnan Ganapathy - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Bostom MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 #include "passwords.h"
  14 #include "des.h"
  15 #include "string.h"
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include "tui.h"
  19
  20 #define MAX_LINE 512
  21 // Max line length in a pwdfile
  22 p_pwdentry userdb[MAX_USERS]; // Array of pointers
  23 int numusers; // Actual number of users
  24
  25 // returns true or false, i.e. 1 or 0
  26 char authenticate_user(const char * username, const char* pwd)
  27 {
  28   char salt[12];
  29   int  i;
  30
  31   for (i=0; i< numusers; i++) {
  32     if (userdb[i] == NULL) continue;
  33     if (strcmp(username,userdb[i]->username)==0) {
  34       strcpy(salt, userdb[i]->pwdhash);
  35       salt[2] = '\0';
  36       if (strcmp(userdb[i]->pwdhash,crypt(pwd,salt))==0) return 1;
  37     }
  38   }
  39   return 0;
  40 }
  41
  42 // Does user USERNAME  have permission PERM
  43 char isallowed(const char *username, const char *perm)
  44 {
  45   int i;
  46   char *dperm;
  47   char *tmp;
  48
  49   // If no users, then everybody is allowed to do everything
  50   if (numusers == 0) return 1;
  51   if (strcmp(username,GUEST_USER) == 0) return 0;
  52   dperm = (char *) malloc(strlen(perm)+3);
  53   strcpy(dperm+1,perm);
  54   dperm[0] = ':';
  55   dperm[strlen(perm)+1]=':';
  56   dperm[strlen(perm)+2]=0;
  57   // Now dperm = ":perm:"
  58   for (i=0; i < numusers; i++) {
  59      if (strcmp(userdb[i]->username,username)==0) // Found the user
  60      {
  61         if (userdb[i]->perms == NULL) return 0; // No permission
  62         tmp = strstr(userdb[i]->perms,dperm); // Search for permission
  63         free (dperm); // Release memory
  64         if (tmp == NULL) return 0; else return 1;
  65      }
  66   }
  67   // User not found return 0
  68   free (dperm);
  69   return 0;
  70 }
  71
  72 // Initialise the list of of user passwords permissions from file
  73 void init_passwords(const char *filename)
  74 {
  75   int i;
  76   char line[MAX_LINE], *p,*user,*pwdhash,*perms;
  77   FILE *f;
  78
  79   for (i=0; i < MAX_USERS; i++) userdb[i] = NULL;
  80   numusers = 0;
  81
  82   if ( !filename ) return; // No filename specified
  83
  84   f = fopen(filename,"r");
  85   if ( !f ) return; // File does not exist
  86
  87   // Process each line
  88   while ( fgets(line, sizeof line, f) ) {
  89     // Replace EOLN with \0
  90     p = strchr(line, '\r');
  91     if ( p ) *p = '\0';
  92     p = strchr(line, '\n');
  93     if ( p ) *p = '\0';
  94
  95     // If comment line or empty ignore line
  96     p = line;
  97     while (*p==' ') p++; // skip initial spaces
  98     if ( (*p == '#') || (*p == '\0')) continue; // Skip comment lines
  99
 100     user = p; // This is where username starts
 101     p = strchr(user,':');
 102     if (p == NULL) continue; // Malformed line skip
 103     *p = '\0';
 104     pwdhash = p+1;
 105     if (*pwdhash == 0) continue; // Malformed line (no password specified)
 106     p = strchr(pwdhash,':');
 107     if (p == NULL) { // No perms specified
 108        perms = NULL;
 109     } else {
 110        *p = '\0';
 111        perms = p+1;
 112        if (*perms == 0) perms = NULL;
 113     }
 114     // At this point we have user,pwdhash and perms setup
 115     userdb[numusers] = (p_pwdentry)malloc(sizeof(pwdentry));
 116     strcpy(userdb[numusers]->username,user);
 117     strcpy(userdb[numusers]->pwdhash,pwdhash);
 118     if (perms == NULL)
 119       userdb[numusers]->perms = NULL;
 120     else {
 121       userdb[numusers]->perms = (char *)malloc(strlen(perms)+3);
 122       (userdb[numusers]->perms)[0] = ':';
 123       strcpy(userdb[numusers]->perms + 1,perms);
 124       (userdb[numusers]->perms)[strlen(perms)+1] = ':';
 125       (userdb[numusers]->perms)[strlen(perms)+2] = 0;
 126       // Now perms field points to ":perms:"
 127     }
 128     numusers++;
 129   }
 130   fclose(f);
 131 }
 132
 133 void close_passwords()
 134 {
 135   int i;
 136
 137   for (i=0; i < numusers; i++)
 138     if (userdb[i] != NULL) free(userdb[i]);
 139   numusers = 0;
 140 }