libs/nixio/src/tls-crypto.c

   1 /*
   2  * nixio - Linux I/O library for lua
   3  *
   4  *   Copyright (C) 2009 Steven Barth <steven@midlink.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #include "nixio-tls.h"
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25
  26 static int nixio_crypto_hash__init(lua_State *L, int hmac) {
  27         const char *type = luaL_checkstring(L, 1);
  28         nixio_hash *hash = lua_newuserdata(L, sizeof(nixio_hash));
  29
  30         if (!strcmp(type, "md5")) {
  31                 hash->type = NIXIO_HASH_MD5;
  32                 hash->digest_size = MD5_DIGEST_LENGTH;
  33                 hash->block_size = 64;
  34                 hash->ctx = malloc(sizeof(MD5_CTX));
  35                 if (!hash->ctx) {
  36                         return luaL_error(L, NIXIO_OOM);
  37                 }
  38                 MD5_Init((MD5_CTX*)hash->ctx);
  39                 hash->init = (nixio_hash_initcb)MD5_Init;
  40                 hash->update = (nixio_hash_updatecb)MD5_Update;
  41                 hash->final = (nixio_hash_finalcb)MD5_Final;
  42         } else if (!strcmp(type, "sha1")) {
  43                 hash->type = NIXIO_HASH_SHA1;
  44                 hash->digest_size = SHA_DIGEST_LENGTH;
  45                 hash->block_size = 64;
  46                 hash->ctx = malloc(sizeof(SHA_CTX));
  47                 if (!hash->ctx) {
  48                         return luaL_error(L, NIXIO_OOM);
  49                 }
  50                 SHA1_Init((SHA_CTX*)hash->ctx);
  51                 hash->init = (nixio_hash_initcb)SHA1_Init;
  52                 hash->update = (nixio_hash_updatecb)SHA1_Update;
  53                 hash->final = (nixio_hash_finalcb)SHA1_Final;
  54         } else {
  55                 luaL_argerror(L, 1, "supported values: md5, sha1");
  56         }
  57
  58         luaL_getmetatable(L, NIXIO_CRYPTO_HASH_META);
  59         lua_setmetatable(L, -2);
  60
  61         if (hmac) {
  62                 const char *key = luaL_checklstring(L, 2, &hash->key_size);
  63                 if (hash->key_size > hash->block_size) {
  64                         hash->update(hash->ctx, key, hash->key_size);
  65                         hash->final(hash->digest, hash->ctx);
  66                         hash->init(hash->ctx);
  67                         hash->key_size = hash->digest_size;
  68                         memcpy(hash->key, hash->digest, hash->key_size);
  69                 } else {
  70                         memcpy(hash->key, key, hash->key_size);
  71                 }
  72
  73                 unsigned char pad[NIXIO_CRYPTO_BLOCK_SIZE];
  74                 for (uint i = 0; i < hash->block_size; i++) {
  75                         pad[i] = (i < hash->key_size) ? (0x36 ^ hash->key[i]) : 0x36;
  76                 }
  77                 hash->update(hash->ctx, pad, hash->block_size);
  78                 hash->type |= NIXIO_HMAC_BIT;
  79         }
  80
  81         return 1;
  82 }
  83
  84 static int nixio_crypto_hash(lua_State *L) {
  85         return nixio_crypto_hash__init(L, 0);
  86 }
  87
  88 static int nixio_crypto_hmac(lua_State *L) {
  89         return nixio_crypto_hash__init(L, 1);
  90 }
  91
  92 static int nixio_crypto_hash_update(lua_State *L) {
  93         nixio_hash *hash = luaL_checkudata(L, 1, NIXIO_CRYPTO_HASH_META);
  94         if (hash->type) {
  95                 size_t len;
  96                 const char *chunk = luaL_checklstring(L, 2, &len);
  97                 hash->update(hash->ctx, chunk, len);
  98                 lua_pushvalue(L, 1);
  99                 return 1;
 100         } else {
 101                 return luaL_error(L, "Tried to update finalized hash object.");
 102         }
 103 }
 104
 105 static int nixio_crypto_hash_final(lua_State *L) {
 106         nixio_hash *hash = luaL_checkudata(L, 1, NIXIO_CRYPTO_HASH_META);
 107         if (hash->type & NIXIO_HMAC_BIT) {
 108                 hash->final(hash->digest, hash->ctx);
 109                 hash->init(hash->ctx);
 110
 111                 unsigned char pad[NIXIO_CRYPTO_BLOCK_SIZE];
 112                 for (uint i = 0; i < hash->block_size; i++) {
 113                         pad[i] = (i < hash->key_size) ? (0x5c ^ hash->key[i]) : 0x5c;
 114                 }
 115
 116                 hash->update(hash->ctx, pad, hash->block_size);
 117                 hash->update(hash->ctx, hash->digest, hash->digest_size);
 118         }
 119
 120         if (hash->type) {
 121                 hash->type = NIXIO_HASH_NONE;
 122                 hash->final(hash->digest, hash->ctx);
 123                 free(hash->ctx);
 124         }
 125
 126         char hashdigest[NIXIO_DIGEST_SIZE*2];
 127         for (uint i=0; i < hash->digest_size; i++) {
 128                 hashdigest[2*i]   = nixio__bin2hex[(hash->digest[i] & 0xf0) >> 4];
 129                 hashdigest[2*i+1] = nixio__bin2hex[(hash->digest[i] & 0x0f)];
 130         }
 131
 132         lua_pushlstring(L, hashdigest, hash->digest_size * 2);
 133         memcpy(hashdigest, hash->digest, hash->digest_size);
 134         lua_pushlstring(L, hashdigest, hash->digest_size);
 135
 136         return 2;
 137 }
 138
 139 static int nixio_crypto_hash__gc(lua_State *L) {
 140         nixio_hash *hash = luaL_checkudata(L, 1, NIXIO_CRYPTO_HASH_META);
 141         if (hash->type) {
 142                 hash->final(hash->digest, hash->ctx);
 143                 free(hash->ctx);
 144                 hash->type = NIXIO_HASH_NONE;
 145         }
 146         return 0;
 147 }
 148
 149 static int nixio_crypto_hash__tostring(lua_State *L) {
 150         nixio_hash *hash = luaL_checkudata(L, 1, NIXIO_CRYPTO_HASH_META);
 151         lua_pushfstring(L, "nixio hash object: %p", hash);
 152         return 1;
 153 }
 154
 155
 156 /* module table */
 157 static const luaL_reg R[] = {
 158         {"hash",                nixio_crypto_hash},
 159         {"hmac",                nixio_crypto_hmac},
 160         {NULL,                  NULL}
 161 };
 162
 163 /* hash table */
 164 static const luaL_reg M[] = {
 165         {"update",              nixio_crypto_hash_update},
 166         {"final",               nixio_crypto_hash_final},
 167         {"__gc",                nixio_crypto_hash__gc},
 168         {"__tostring",  nixio_crypto_hash__tostring},
 169         {NULL,                  NULL}
 170 };
 171
 172
 173
 174 void nixio_open_tls_crypto(lua_State *L) {
 175         luaL_newmetatable(L, NIXIO_CRYPTO_HASH_META);
 176         luaL_register(L, NULL, M);
 177         lua_pushvalue(L, -1);
 178         lua_setfield(L, -2, "__index");
 179         lua_pop(L, 1);
 180
 181         lua_newtable(L);
 182     luaL_register(L, NULL, R);
 183
 184         lua_setfield(L, -2, "crypto");
 185 }