crypt/crypt.h

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// -*- c++ -*-
//
// $Id: crypt.h 3342 2010-09-17 18:32:00Z java $
//
// Copyright (C) 2008-2010  Rafael Ostertag
//
// This file is part of YAPET.
//
// YAPET 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.
//
// YAPET 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 a copy of the GNU General Public License along with
// YAPET.  If not, see <http://www.gnu.org/licenses/>.
//
// Additional permission under GNU GPL version 3 section 7
//
// If you modify this program, or any covered work, by linking or combining it
// with the OpenSSL project's OpenSSL library (or a modified version of that
// library), containing parts covered by the terms of the OpenSSL or SSLeay
// licenses, Rafael Ostertag grants you additional permission to convey the
// resulting work.  Corresponding Source for a non-source form of such a
// combination shall include the source code for the parts of OpenSSL used as
// well as that of the covered work.
//

#ifndef _CRYPT_H
#define _CRYPT_H

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#ifdef HAVE_INTTYPES_H
# include <inttypes.h>
#endif

#include "../intl.h"


#include <openssl/evp.h>

#include "yapetexception.h"
#include "key.h"
#include "bdbuffer.h"
#include "record.h"

namespace YAPET {
    class Crypt {
        private:
            const EVP_CIPHER* cipher;
            uint32_t iv_length;
            uint32_t key_length;
            Key key;

        public:
            Crypt (const Key& k) throw (YAPETException);
            Crypt (const Crypt& c);
            inline ~Crypt() {}

            inline uint32_t getIVLength() const {
                return iv_length;
            }
            inline uint32_t getKeyLength() const {
                return key_length;
            }

            template<class T>
            BDBuffer* encrypt (const Record<T>& data)
            throw (YAPETException, YAPETEncryptionException) {
                if (key.ivec_size() != iv_length)
                    throw YAPETException (_ ("IVec length missmatch") );

                EVP_CIPHER_CTX ctx;
                EVP_CIPHER_CTX_init (&ctx);
                int retval = EVP_EncryptInit_ex (&ctx,
                                                 cipher,
                                                 NULL,
                                                 key,
                                                 key.getIVec() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    throw YAPETEncryptionException (_ ("Error initializing encryption engine") );
                }

                retval = EVP_CIPHER_CTX_set_key_length (&ctx, key.size() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    throw YAPETException (_ ("Error setting the key length") );
                }

                BDBuffer* encdata =
                    new BDBuffer (data.size() + EVP_MAX_BLOCK_LENGTH);
                int outlen;
                retval = EVP_EncryptUpdate (&ctx,
                                            *encdata,
                                            &outlen,
                                            data,
                                            data.size() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    delete encdata;
                    throw YAPETEncryptionException (_ ("Error encrypting data") );
                }

                int tmplen;
                retval = EVP_EncryptFinal_ex (&ctx,
                                              encdata->at (outlen),
                                              &tmplen);

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    delete encdata;
                    throw YAPETEncryptionException (_ ("Error finalizing encryption") );
                }

                encdata->resize (outlen + tmplen);
                EVP_CIPHER_CTX_cleanup (&ctx);
                return encdata;
            }

            template<class T>
            Record<T>* decrypt (const BDBuffer& data)
            throw (YAPETException, YAPETEncryptionException) {
                if ( ( (unsigned int) key.ivec_size() ) != iv_length)
                    throw YAPETException (_ ("IVec length missmatch") );

                EVP_CIPHER_CTX ctx;
                EVP_CIPHER_CTX_init (&ctx);
                int retval = EVP_DecryptInit_ex (&ctx,
                                                 cipher,
                                                 NULL,
                                                 key,
                                                 key.getIVec() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    throw YAPETEncryptionException (_ ("Error initializing encryption engine") );
                }

                retval = EVP_CIPHER_CTX_set_key_length (&ctx, key.size() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    throw YAPETException (_ ("Error setting the key length") );
                }

                BDBuffer* decdata = new BDBuffer (data.size() );
                int outlen;
                retval = EVP_DecryptUpdate (&ctx,
                                            *decdata,
                                            &outlen,
                                            data,
                                            data.size() );

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    delete decdata;
                    throw YAPETEncryptionException (_ ("Error decrypting data") );
                }

                int tmplen;
                retval = EVP_DecryptFinal_ex (&ctx,
                                              decdata->at (outlen),
                                              &tmplen);

                if (retval == 0) {
                    EVP_CIPHER_CTX_cleanup (&ctx);
                    delete decdata;
                    throw YAPETEncryptionException (_ ("Error finalizing decryption") );
                }

                decdata->resize (outlen + tmplen);
                EVP_CIPHER_CTX_cleanup (&ctx);
        Record<T>* r = NULL;
        try {
            r = new Record<T>;
            *r = *decdata;
        } catch (...) {
            if ( r != NULL)
            delete r;
            delete decdata;
            throw;
        }
                delete decdata;
                return r;
            }

            const Crypt& operator= (const Crypt& c);
    };
}

#endif // _CRYPT_H