src/lua/quvi/crypto/en_decrypt.c

   1 /* libquvi
   2  * Copyright (C) 2013  Toni Gundogdu <legatvs@gmail.com>
   3  *
   4  * This file is part of libquvi <http://quvi.sourceforge.net/>.
   5  *
   6  * This program is free software: you can redistribute it and/or
   7  * modify it under the terms of the GNU Affero General Public
   8  * License as published by the Free Software Foundation, either
   9  * version 3 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Affero General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Affero General
  17  * Public License along with this program.  If not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * NOTES
  23  *
  24  * The 'key', the 'ciphertext' and the 'plaintext' are all expected to
  25  * be hexadecimal strings when passed from and to a Lua script.
  26  */
  27
  28 #include "config.h"
  29
  30 #include <lauxlib.h>
  31 #include <gcrypt.h>
  32 #include <glib.h>
  33 #include <quvi.h>
  34
  35 #include "_quvi_s.h"
  36 /* -- */
  37 #include "gcrypt/crypto.h"
  38 #include "lua/quvi/crypto/opts.h"
  39 #include "lua/quvi/crypto/err.h"
  40 #include "lua/quvi/opts.h"
  41 #include "lua/getfield.h"
  42 #include "lua/setfield.h"
  43 #include "lua/def.h"
  44
  45 static gint _exec(lua_State *l, const CryptoMode crypto_mode,
  46                   const gchar *push_as)
  47 {
  48   struct l_quvi_object_crypto_opts_s co;
  49   gboolean croak_if_error;
  50   GSList *opts;
  51   crypto_t c;
  52   _quvi_t q;
  53
  54   memset(&co, 0, sizeof(struct l_quvi_object_crypto_opts_s));
  55
  56   /* quvi handle */
  57
  58   q = (_quvi_t) l_get_reg_userdata(l, USERDATA_QUVI_T);
  59   g_assert(q != NULL);
  60
  61   /* function args */
  62
  63   co.text = luaL_checkstring(l, 1);
  64   lua_pop(l, 1);
  65
  66   /* options */
  67
  68   opts = l_quvi_object_opts_new(l, 2);
  69   croak_if_error = l_quvi_object_opts_croak_if_error(opts);
  70   l_quvi_object_crypto_chk_opts(l, opts, &co);
  71
  72   /* encrypt/decrypt (return as a hexstring). */
  73
  74   c = crypto_new(co.algoname, crypto_mode, co.cipher.key,
  75                  co.cipher.mode, co.cipher.flags);
  76   q->status.rc = l_quvi_object_crypto_chk_if_failed(l, c, croak_if_error, q);
  77   {
  78     guchar *s;
  79     gsize n;
  80
  81     s = crypto_hex2bytes(co.text, &n);
  82     if (s != NULL)
  83       {
  84 #ifdef _1
  85         crypto_dump("s", s, n);
  86 #endif
  87         crypto_exec(c, s, n);
  88         g_free(s);
  89
  90         q->status.rc =
  91           l_quvi_object_crypto_chk_if_failed(l, c, croak_if_error, q);
  92       }
  93     else
  94       l_quvi_object_crypto_invalid_hexstr(l, q, croak_if_error);
  95   }
  96
  97   /* Return a table of results. */
  98
  99   lua_newtable(l);
 100   l_setfield_s(l, QO_ERROR_MESSAGE, q->status.errmsg->str, -1);
 101   l_setfield_n(l, QO_QUVI_CODE, q->status.rc);
 102
 103   if (q->status.rc == QUVI_OK)
 104     {
 105       gchar *s = crypto_bytes2hex(c->out.data, c->out.dlen);
 106       l_setfield_s(l, push_as, s, -1);
 107       g_free(s);
 108     }
 109
 110   l_quvi_object_opts_free(opts);
 111   crypto_free(c);
 112
 113   return (1); /* no. of returned values (a table) */
 114 }
 115
 116 gint l_quvi_crypto_encrypt(lua_State *l)
 117 {
 118   return (_exec(l, CRYPTO_MODE_ENCRYPT, QO_CIPHERTEXT));
 119 }
 120
 121 gint l_quvi_crypto_decrypt(lua_State *l)
 122 {
 123   return (_exec(l, CRYPTO_MODE_DECRYPT, QO_PLAINTEXT));
 124 }
 125
 126 /* vim: set ts=2 sw=2 tw=72 expandtab: */