SecurityKey.cpp

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/*
 * SecurityKey.cpp
 *
 * Copyright (C) 2011 IBR, TU Braunschweig
 *
 * Written-by: Johannes Morgenroth <morgenroth@ibr.cs.tu-bs.de>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "ibrdtn/security/SecurityKey.h"
#include <ibrcommon/ssl/SHA256Stream.h>
#include <ibrcommon/Logger.h>
#include <fstream>
#include <sstream>
#include <iomanip>

#include <openssl/sha.h>
#include <openssl/pem.h>
#include <openssl/err.h>

namespace dtn
{
        namespace security
        {
                SecurityKey::SecurityKey()
                 : type(KEY_UNSPEC), trustlevel(NONE)
                {}

                SecurityKey::~SecurityKey()
                {}

                void SecurityKey::free(RSA* key)
                {
                        RSA_free(key);
                }

                void SecurityKey::free(EVP_PKEY* key)
                {
                        EVP_PKEY_free(key);
                }

                bool SecurityKey::operator==(const SecurityKey &key)
                {
                        return getFingerprint() == key.getFingerprint();
                }

                ibrcommon::File SecurityKey::getMetaFilename() const
                {
                        return ibrcommon::File(file.getPath() + ".txt");
                }

                const std::string SecurityKey::getData() const
                {
                        std::ifstream stream(file.getPath().c_str(), ios::in);
                        std::stringstream ss;

                        ss << stream.rdbuf();

                        stream.close();

                        return ss.str();
                }

                RSA* SecurityKey::getRSA() const
                {
                        switch (type)
                        {
                        case KEY_PRIVATE:
                                return getPrivateRSA();
                        case KEY_PUBLIC:
                                return getPublicRSA();
                        default:
                                return NULL;
                        }
                }

                EVP_PKEY* SecurityKey::getEVP() const
                {
                        EVP_PKEY* ret = EVP_PKEY_new();
                        FILE * pkey_file = fopen(file.getPath().c_str(), "r");

                        switch (type)
                        {
                                case KEY_PRIVATE:
                                {
                                        ret = PEM_read_PrivateKey(pkey_file, &ret, NULL, NULL);
                                        break;
                                }

                                case KEY_PUBLIC:
                                {
                                        ret = PEM_read_PUBKEY(pkey_file, &ret, NULL, NULL);
                                        break;
                                }

                                default:
                                        ret = NULL;
                                        break;
                        }

                        fclose(pkey_file);
                        return ret;
                }

                const std::string SecurityKey::getFingerprint() const
                {
                        switch (type)
                        {
                                case KEY_PRIVATE:
                                {
                                        RSA* rsa = getPrivateRSA();
                                        std::string ret = getFingerprint(rsa);
                                        free(rsa);
                                        return ret;
                                }
                                case KEY_PUBLIC:
                                {
                                        RSA* rsa = getPublicRSA();
                                        std::string ret = getFingerprint(rsa);
                                        free(rsa);
                                        return ret;
                                }
                                default:
                                {
                                        return getFingerprint(file);
                                }
                        }
                }

                RSA* SecurityKey::getPrivateRSA() const
                {
                        RSA *rsa = RSA_new();

                        FILE * rsa_pkey_file = fopen(file.getPath().c_str(), "r");
                        if (!rsa_pkey_file) {
                                IBRCOMMON_LOGGER_ex(critical) << "Failed to open " << file.getPath() << IBRCOMMON_LOGGER_ENDL;
                                throw ibrcommon::Exception("Failed to open " + file.getPath());
                        }
                        if (!PEM_read_RSAPrivateKey(rsa_pkey_file, &rsa, NULL, NULL)) {
                                IBRCOMMON_LOGGER_ex(critical) << "Error loading RSA private key file: " << file.getPath() << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                                throw ibrcommon::Exception("Error loading RSA private key file: " + file.getPath());
                        }
                        fclose(rsa_pkey_file);
                        return rsa;
                }

                RSA* SecurityKey::getPublicRSA() const
                {
                        RSA *rsa = RSA_new();

                        FILE * rsa_pkey_file = fopen(file.getPath().c_str(), "r");
                        if (!rsa_pkey_file) {
                                IBRCOMMON_LOGGER_ex(critical) << "Failed to open " << file.getPath() << IBRCOMMON_LOGGER_ENDL;
                                throw ibrcommon::Exception("Failed to open " + file.getPath());
                        }
                        if (!PEM_read_RSA_PUBKEY(rsa_pkey_file, &rsa, NULL, NULL)) {
                                IBRCOMMON_LOGGER_ex(critical) << "Error loading RSA public key file: " << file.getPath() << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                                throw ibrcommon::Exception("Error loading RSA public key file: " + file.getPath());
                        }
                        fclose(rsa_pkey_file);
                        return rsa;
                }

                std::string SecurityKey::getFingerprint(const ibrcommon::File &file)
                {
                        // create a hash stream
                        ibrcommon::SHA256Stream sha;

                        // open the file
                        ifstream stream(file.getPath().c_str());

                        // hash the contents of the file
                        if (!stream.good()) {
                                sha << stream.rdbuf() << std::flush;
                        }

                        // convert bytes to hex fingerprint
                        std::stringstream fingerprint;
                        while (sha.good())
                        {
                                fingerprint << std::hex << std::setw(2) << std::setfill('0') << (int)sha.get();
                        }

                        return fingerprint.str();
                }

                std::string SecurityKey::getFingerprint(RSA* rsa)
                {
                        unsigned char *p = NULL;
                        int length = i2d_RSA_PUBKEY(rsa, &p);

                        std::string ret = "";
                        if (length > 0)
                        {
                                ret = std::string((const char*)p, length);
                        }
                        else
                        {
                                OPENSSL_free(p);
                                free(rsa);
                                throw(ibrcommon::Exception("Error while parsing rsa key"));
                        }

                        unsigned char hash[SHA256_DIGEST_LENGTH];
                        SHA256(p, length, hash);

                        std::stringstream stream;
                        for(int i = 0; i < SHA256_DIGEST_LENGTH; i++)
                        {
                                stream << std::hex << std::setw(2) << std::setfill('0') << (int)hash[i];
                        }

                        OPENSSL_free(p);
                        return stream.str();
                }
        }
}