blob: 915f17c165809026c86e3b9a886bb29db10338d7 [file] [log] [blame]
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
* Copyright (c) 2017-2019, Regents of the University of California.
*
* This file is part of ndncert, a certificate management system based on NDN.
*
* ndncert is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Foundation, either
* version 3 of the License, or (at your option) any later version.
*
* ndncert is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received copies of the GNU General Public License along with
* ndncert, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndncert authors and contributors.
*/
#include "crypto-helper.hpp"
#include "../logging.hpp"
#include <openssl/pem.h>
#include <openssl/rand.h>
#include <openssl/err.h>
#include <ndn-cxx/security/transform/block-cipher.hpp>
#include <ndn-cxx/security/transform/base64-decode.hpp>
#include <ndn-cxx/security/transform/base64-encode.hpp>
#include <ndn-cxx/security/transform/buffer-source.hpp>
#include <ndn-cxx/security/transform/step-source.hpp>
#include <ndn-cxx/security/transform/stream-sink.hpp>
#include <ndn-cxx/util/random.hpp>
#include <ndn-cxx/encoding/buffer-stream.hpp>
#include <ndn-cxx/security/transform/hmac-filter.hpp>
namespace ndn {
namespace ndncert {
const size_t HASH_SIZE = 32;
_LOG_INIT(crypto-support);
ECDHState::ECDHState()
{
OpenSSL_add_all_algorithms();
context = std::make_unique<ECDH_CTX>();
context->EC_NID = NID_X9_62_prime256v1;
// Create the context for parameter generation
if (nullptr == (context->ctx_params = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, nullptr))) {
handleErrors("Could not create context contexts.");
return;
}
// Initialise the parameter generation
if (EVP_PKEY_paramgen_init(context->ctx_params) != 1) {
handleErrors("Could not initialize parameter generation.");
return;
}
// We're going to use the ANSI X9.62 Prime 256v1 curve
if (1 != EVP_PKEY_CTX_set_ec_paramgen_curve_nid(context->ctx_params, context->EC_NID)) {
handleErrors("Likely unknown elliptical curve ID specified.");
return;
}
// Create the parameter object params
if (!EVP_PKEY_paramgen(context->ctx_params, &context->params)) {
// the generated key is written to context->params
handleErrors("Could not create parameter object parameters.");
return;
}
// Create the context for the key generation
if (nullptr == (context->ctx_keygen = EVP_PKEY_CTX_new(context->params, nullptr))) {
//The EVP_PKEY_CTX_new() function allocates public key algorithm context using
//the algorithm specified in pkey and ENGINE e (in this case nullptr).
handleErrors("Could not create the context for the key generation");
return;
}
// initializes a public key algorithm context
if (1 != EVP_PKEY_keygen_init(context->ctx_keygen)){
handleErrors("Could not init context for key generation.");
return;
}
if (1 != EVP_PKEY_keygen(context->ctx_keygen, &context->privkey)) {
//performs a key generation operation, the generated key is written to context->privkey.
handleErrors("Could not generate DHE keys in final step");
return;
}
}
ECDHState::~ECDHState()
{
// Contexts
if(context->ctx_params != nullptr){
EVP_PKEY_CTX_free(context->ctx_params);
}
if(context->ctx_keygen != nullptr){
EVP_PKEY_CTX_free(context->ctx_keygen);
}
// Keys
if(context->privkey != nullptr){
EVP_PKEY_free(context->privkey);
}
if(context->peerkey != nullptr){
EVP_PKEY_free(context->peerkey);
}
if(context->params != nullptr){
EVP_PKEY_free(context->params);
}
}
uint8_t*
ECDHState::getRawSelfPubKey()
{
auto privECKey = EVP_PKEY_get1_EC_KEY(context->privkey);
if (privECKey == nullptr) {
handleErrors("Could not get referenced key when calling EVP_PKEY_get1_EC_KEY().");
return nullptr;
}
auto ecPoint = EC_KEY_get0_public_key(privECKey);
const EC_GROUP* group = EC_KEY_get0_group(privECKey);
context->publicKeyLen = EC_POINT_point2oct(group, ecPoint, POINT_CONVERSION_COMPRESSED,
context->publicKey, 256, nullptr);
EC_KEY_free(privECKey);
if (context->publicKeyLen == 0) {
handleErrors("Could not convert EC_POINTS to octet string when calling EC_POINT_point2oct.");
return nullptr;
}
return context->publicKey;
}
std::string
ECDHState::getBase64PubKey()
{
if (context->publicKeyLen == 0) {
this->getRawSelfPubKey();
}
std::stringstream os;
security::transform::bufferSource(context->publicKey, context->publicKeyLen)
>> security::transform::base64Encode() >> security::transform::streamSink(os);
return os.str();
}
uint8_t*
ECDHState::deriveSecret(const uint8_t* peerkey, int peerKeySize)
{
auto privECKey = EVP_PKEY_get1_EC_KEY(context->privkey);
if (privECKey == nullptr) {
handleErrors("Could not get referenced key when calling EVP_PKEY_get1_EC_KEY().");
return nullptr;
}
auto group = EC_KEY_get0_group(privECKey);
auto peerPoint = EC_POINT_new(group);
EC_POINT_oct2point(group, peerPoint, peerkey, peerKeySize, nullptr);
if (0 == (context->sharedSecretLen = ECDH_compute_key(context->sharedSecret, 256,
peerPoint, privECKey, nullptr))) {
EC_POINT_free(peerPoint);
EC_KEY_free(privECKey);
handleErrors("Cannot generate ECDH secret with ECDH_compute_key");
}
EC_POINT_free(peerPoint);
EC_KEY_free(privECKey);
return context->sharedSecret;
}
uint8_t*
ECDHState::deriveSecret(const std::string& peerKeyStr)
{
namespace t = ndn::security::transform;
OBufferStream os;
security::transform::bufferSource(peerKeyStr)
>> security::transform::base64Decode()
>> security::transform::streamSink(os);
ConstBufferPtr result = os.buf();
return this->deriveSecret(result->data(), result->size());
}
int ndn_compute_hmac_sha256 (const uint8_t *data, const unsigned data_length,
const uint8_t *key, const unsigned key_length,
uint8_t *prk) {
OBufferStream os;
security::transform::bufferSource(data, data_length) >>
security::transform::hmacFilter(
DigestAlgorithm::SHA256, key, key_length) >>
security::transform::streamSink(os);
auto result = os.buf();
memcpy(prk, result->data(), HASH_SIZE);
return 0;
}
//removed dependency of OpenSSL@1.1
int
hkdf(const uint8_t* secret, int secretLen, const uint8_t* salt,
int saltLen, uint8_t* okm, int okm_len,
const uint8_t* info, int info_len)
{
// hkdf generate prk
uint8_t prk[HASH_SIZE];
ndn_compute_hmac_sha256(salt, saltLen, secret, secretLen, prk);
// hkdf expand
uint8_t prev[HASH_SIZE] = {0};
int done_len = 0, dig_len = HASH_SIZE, n = okm_len / dig_len;
if (okm_len % dig_len) n++;
if (n > 255 || okm == nullptr) return 0;
for (int i = 1; i <= n; i++) {
size_t copy_len;
const uint8_t ctr = i;
OBufferStream os;
security::transform::StepSource source;
source >> security::transform::hmacFilter(DigestAlgorithm::SHA256, prk, dig_len)
>> security::transform::streamSink(os);
if (i > 1) {
source.write(prev, dig_len);
}
source.write(info, info_len);
source.write(&ctr, 1);
source.end();
auto result = os.buf();
memcpy(prev, result->data(), dig_len);
copy_len = (done_len + dig_len > okm_len) ?
okm_len - done_len :
dig_len;
memcpy(okm + done_len, prev, copy_len);
done_len += copy_len;
}
return done_len;
}
void
handleErrors(const std::string& errorInfo)
{
_LOG_DEBUG("Error in CRYPTO SUPPORT " << errorInfo);
BOOST_THROW_EXCEPTION(CryptoError("Error in CRYPTO SUPPORT: " + errorInfo));
}
} // namespace ndncert
} // namespace ndn