release/src/router/tinc/src/gcrypt/digest.c

   1 /*
   2     digest.c -- Digest handling
   3     Copyright (C) 2007-2012 Guus Sliepen <guus@tinc-vpn.org>
   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; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License along
  16     with this program; if not, write to the Free Software Foundation, Inc.,
  17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "system.h"
  21
  22 #include "digest.h"
  23 #include "logger.h"
  24
  25 static struct {
  26         const char *name;
  27         int algo;
  28         int nid;
  29 } digesttable[] = {
  30         {"none", GCRY_MD_NONE, 0},
  31         {"sha1", GCRY_MD_SHA1, 64},
  32         {"sha256", GCRY_MD_SHA256, 672},
  33         {"sha384", GCRY_MD_SHA384, 673},
  34         {"sha512", GCRY_MD_SHA512, 674},
  35 };
  36
  37 static bool nametodigest(const char *name, int *algo) {
  38         int i;
  39
  40         for(i = 0; i < sizeof digesttable / sizeof *digesttable; i++) {
  41                 if(digesttable[i].name && !strcasecmp(name, digesttable[i].name)) {
  42                         *algo = digesttable[i].algo;
  43                         return true;
  44                 }
  45         }
  46
  47         return false;
  48 }
  49
  50 static bool nidtodigest(int nid, int *algo) {
  51         int i;
  52
  53         for(i = 0; i < sizeof digesttable / sizeof *digesttable; i++) {
  54                 if(nid == digesttable[i].nid) {
  55                         *algo = digesttable[i].algo;
  56                         return true;
  57                 }
  58         }
  59
  60         return false;
  61 }
  62
  63 static bool digesttonid(int algo, int *nid) {
  64         int i;
  65
  66         for(i = 0; i < sizeof digesttable / sizeof *digesttable; i++) {
  67                 if(algo == digesttable[i].algo) {
  68                         *nid = digesttable[i].nid;
  69                         return true;
  70                 }
  71         }
  72
  73         return false;
  74 }
  75
  76 static bool digest_open(digest_t *digest, int algo, int maclength) {
  77         if(!digesttonid(algo, &digest->nid)) {
  78                 logger(DEBUG_ALWAYS, LOG_DEBUG, "Digest %d has no corresponding nid!", algo);
  79                 return false;
  80         }
  81
  82         unsigned int len = gcry_md_get_algo_dlen(algo);
  83
  84         if(maclength > len || maclength < 0)
  85                 digest->maclength = len;
  86         else
  87                 digest->maclength = maclength;
  88
  89         digest->algo = algo;
  90         digest->hmac = NULL;
  91
  92         return true;
  93 }
  94
  95 bool digest_open_by_name(digest_t *digest, const char *name, int maclength) {
  96         int algo;
  97
  98         if(!nametodigest(name, &algo)) {
  99                 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest name '%s'!", name);
 100                 return false;
 101         }
 102
 103         return digest_open(digest, algo, maclength);
 104 }
 105
 106 bool digest_open_by_nid(digest_t *digest, int nid, int maclength) {
 107         int algo;
 108
 109         if(!nidtodigest(nid, &algo)) {
 110                 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest ID %d!", nid);
 111                 return false;
 112         }
 113
 114         return digest_open(digest, algo, maclength);
 115 }
 116
 117 bool digest_open_sha1(digest_t *digest, int maclength) {
 118         return digest_open(digest, GCRY_MD_SHA1, maclength);
 119 }
 120
 121 void digest_close(digest_t *digest) {
 122         if(digest->hmac)
 123                 gcry_md_close(digest->hmac);
 124         digest->hmac = NULL;
 125 }
 126
 127 bool digest_set_key(digest_t *digest, const void *key, size_t len) {
 128         if(!digest->hmac)
 129                 gcry_md_open(&digest->hmac, digest->algo, GCRY_MD_FLAG_HMAC);
 130         if(!digest->hmac)
 131                 return false;
 132
 133         return !gcry_md_setkey(digest->hmac, key, len);
 134 }
 135
 136 bool digest_create(digest_t *digest, const void *indata, size_t inlen, void *outdata) {
 137         unsigned int len = gcry_md_get_algo_dlen(digest->algo);
 138
 139         if(digest->hmac) {
 140                 char *tmpdata;
 141                 gcry_md_reset(digest->hmac);
 142                 gcry_md_write(digest->hmac, indata, inlen);
 143                 tmpdata = gcry_md_read(digest->hmac, digest->algo);
 144                 if(!tmpdata)
 145                         return false;
 146                 memcpy(outdata, tmpdata, digest->maclength);
 147         } else {
 148                 char tmpdata[len];
 149                 gcry_md_hash_buffer(digest->algo, tmpdata, indata, inlen);
 150                 memcpy(outdata, tmpdata, digest->maclength);
 151         }
 152
 153         return true;
 154 }
 155
 156 bool digest_verify(digest_t *digest, const void *indata, size_t inlen, const void *cmpdata) {
 157         unsigned int len = digest->maclength;
 158         char outdata[len];
 159
 160         return digest_create(digest, indata, inlen, outdata) && !memcmp(cmpdata, outdata, len);
 161 }
 162
 163 int digest_get_nid(const digest_t *digest) {
 164         return digest->nid;
 165 }
 166
 167 size_t digest_length(const digest_t *digest) {
 168         return digest->maclength;
 169 }
 170
 171 bool digest_active(const digest_t *digest) {
 172         return digest->algo != GCRY_MD_NONE;
 173 }