pdns/digests.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23
  24 #include <stdexcept>
  25 #include <string>
  26
  27 #include <openssl/evp.h>
  28
  29 inline std::string pdns_hash(const EVP_MD * md, const std::string& input)
  30 {
  31 #if OPENSSL_VERSION_NUMBER < 0x1010000fL
  32   auto mdctx = std::unique_ptr<EVP_MD_CTX, void(*)(EVP_MD_CTX*)>(EVP_MD_CTX_create(), EVP_MD_CTX_destroy);
  33 #else
  34   auto mdctx = std::unique_ptr<EVP_MD_CTX, void(*)(EVP_MD_CTX*)>(EVP_MD_CTX_new(), EVP_MD_CTX_free);
  35 #endif
  36   if (!mdctx) {
  37     throw std::runtime_error(std::string(EVP_MD_name(md)) + " context initialization failed");
  38   }
  39
  40   if (EVP_DigestInit_ex(mdctx.get(), md, nullptr) != 1) {
  41     throw std::runtime_error(std::string(EVP_MD_name(md)) + " EVP initialization failed");
  42   }
  43
  44   if (EVP_DigestUpdate(mdctx.get(), input.data(), input.size()) != 1) {
  45     throw std::runtime_error(std::string(EVP_MD_name(md)) + " EVP update failed");
  46   }
  47
  48   unsigned int written;
  49   std::string result;
  50   result.resize(EVP_MD_size(md));
  51
  52   if (EVP_DigestFinal_ex(mdctx.get(), const_cast<unsigned char *>(reinterpret_cast<const unsigned char*>(result.c_str())), &written) != 1) {
  53     throw std::runtime_error(std::string(EVP_MD_name(md)) + " EVP final failed");
  54   }
  55
  56   if (written != result.size()) {
  57     throw std::runtime_error(std::string(EVP_MD_name(md)) + " EVP final wrote " + std::to_string(written) + ", expected " + std::to_string(result.size()));
  58   }
  59
  60   return result;
  61 }
  62
  63 inline std::string pdns_md5sum(const std::string& input)
  64 {
  65   const auto md = EVP_md5();
  66   if (md == nullptr) {
  67     throw std::runtime_error("The MD5 digest is not available via the OpenSSL EVP interface");
  68   }
  69
  70   return pdns_hash(md, input);
  71 }
  72
  73 inline std::string pdns_sha1sum(const std::string& input)
  74 {
  75   const auto md = EVP_sha1();
  76   if (md == nullptr) {
  77     throw std::runtime_error("The SHA1 digest is not available via the OpenSSL EVP interface");
  78   }
  79
  80   return pdns_hash(md, input);
  81 }