auth.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19
  20 #define _GNU_SOURCE
  21 #define _XOPEN_SOURCE   700
  22 #include "uhttpd.h"
  23
  24 static LIST_HEAD(auth_realms);
  25
  26 void uh_auth_add(const char *path, const char *user, const char *pass)
  27 {
  28         struct auth_realm *new = NULL;
  29         struct passwd *pwd;
  30         const char *new_pass = NULL;
  31         char *dest_path, *dest_user, *dest_pass;
  32
  33 #ifdef HAVE_SHADOW
  34         struct spwd *spwd;
  35 #endif
  36
  37         /* given password refers to a passwd entry */
  38         if ((strlen(pass) > 3) && !strncmp(pass, "$p$", 3)) {
  39 #ifdef HAVE_SHADOW
  40                 /* try to resolve shadow entry */
  41                 spwd = getspnam(&pass[3]);
  42                 if (spwd)
  43                         new_pass = spwd->sp_pwdp;
  44 #endif
  45                 if (!new_pass) {
  46                         pwd = getpwnam(&pass[3]);
  47                         if (pwd && pwd->pw_passwd && pwd->pw_passwd[0] &&
  48                             pwd->pw_passwd[0] != '!')
  49                                 new_pass = pwd->pw_passwd;
  50                 }
  51         } else {
  52                 new_pass = pass;
  53         }
  54
  55         if (!new_pass || !new_pass[0])
  56                 return;
  57
  58         new = calloc_a(sizeof(*new),
  59                 &dest_path, strlen(path) + 1,
  60                 &dest_user, strlen(user) + 1,
  61                 &dest_pass, strlen(new_pass) + 1);
  62
  63         if (!new)
  64                 return;
  65
  66         new->path = strcpy(dest_path, path);
  67         new->user = strcpy(dest_user, user);
  68         new->pass = strcpy(dest_pass, new_pass);
  69         list_add(&new->list, &auth_realms);
  70 }
  71
  72 bool uh_auth_check(struct client *cl, struct path_info *pi)
  73 {
  74         struct http_request *req = &cl->request;
  75         struct auth_realm *realm;
  76         bool user_match = false;
  77         char *user = NULL;
  78         char *pass = NULL;
  79         int plen;
  80
  81         if (pi->auth && !strncasecmp(pi->auth, "Basic ", 6)) {
  82                 const char *auth = pi->auth + 6;
  83
  84                 uh_b64decode(uh_buf, sizeof(uh_buf), auth, strlen(auth));
  85                 pass = strchr(uh_buf, ':');
  86                 if (pass) {
  87                         user = uh_buf;
  88                         *pass++ = 0;
  89                 }
  90         }
  91
  92         req->realm = NULL;
  93         plen = strlen(pi->name);
  94         list_for_each_entry(realm, &auth_realms, list) {
  95                 int rlen = strlen(realm->path);
  96
  97                 if (plen < rlen)
  98                         continue;
  99
 100                 if (strncasecmp(pi->name, realm->path, rlen) != 0)
 101                         continue;
 102
 103                 req->realm = realm;
 104                 if (!user)
 105                         break;
 106
 107                 if (strcmp(user, realm->user) != 0)
 108                         continue;
 109
 110                 user_match = true;
 111                 break;
 112         }
 113
 114         if (!req->realm)
 115                 return true;
 116
 117         if (user_match && !strcmp(crypt(pass, realm->pass), realm->pass))
 118                 return true;
 119
 120         uh_http_header(cl, 401, "Authorization Required");
 121         ustream_printf(cl->us,
 122                                   "WWW-Authenticate: Basic realm=\"%s\"\r\n"
 123                                   "Content-Type: text/plain\r\n\r\n",
 124                                   conf.realm);
 125         uh_chunk_printf(cl, "Authorization Required\n");
 126         uh_request_done(cl);
 127
 128         return false;
 129 }