/*

  callbacks.cpp - callback targets for internal use:

  Copyright (C) 2003,2004 Klarälvdalens Datakonsult AB

  2016 Bundesamt für Sicherheit in der Informationstechnik

  Software engineering by Intevation GmbH

  This file is part of GPGME++.

  GPGME++ is free software; you can redistribute it and/or

  modify it under the terms of the GNU Library General Public

  License as published by the Free Software Foundation; either

  version 2 of the License, or (at your option) any later version.

  GPGME++ 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 Library General Public License for more details.

  You should have received a copy of the GNU Library General Public License

  along with GPGME++; see the file COPYING.LIB.  If not, write to the

  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

  Boston, MA 02110-1301, USA.

*/

#ifdef HAVE_CONFIG_H

 #include "config.h"

#endif

#include "callbacks.h"

#include "util.h"

#include <interfaces/progressprovider.h>

#include <interfaces/passphraseprovider.h>

#include <interfaces/dataprovider.h>

#include <error.h>

#include <gpgme.h>

#include <gpg-error.h>

#include <cassert>

#include <cerrno>

#include <cstring>

#include <unistd.h>

#include <stdlib.h>

static inline gpgme_error_t make_err_from_syserror()

{

    return gpgme_error_from_syserror();

}

using GpgME::ProgressProvider;

using GpgME::PassphraseProvider;

using GpgME::DataProvider;

void progress_callback(void *opaque, const char *what,

                       int type, int current, int total)

{

    ProgressProvider *provider = static_cast<ProgressProvider *>(opaque);

    if (provider) {

        provider->showProgress(what, type, current, total);

    }

}

/* To avoid that a compiler optimizes certain memset calls away, these

   macros may be used instead. */

#define wipememory2(_ptr,_set,_len) do { \

        volatile char *_vptr=(volatile char *)(_ptr); \

        size_t _vlen=(_len); \

        while(_vlen) { *_vptr=(_set); _vptr++; _vlen--; } \

    } while(0)

#define wipememory(_ptr,_len) wipememory2(_ptr,0,_len)

gpgme_error_t passphrase_callback(void *opaque, const char *uid_hint, const char *desc,

                                  int prev_was_bad, int fd)

{

    PassphraseProvider *provider = static_cast<PassphraseProvider *>(opaque);

    bool canceled = false;

    gpgme_error_t err = GPG_ERR_NO_ERROR;

    char *passphrase = provider ? provider->getPassphrase(uid_hint, desc, prev_was_bad, canceled) : nullptr ;

    if (canceled) {

        err = make_error(GPG_ERR_CANCELED);

    } else {

        if (passphrase && *passphrase) {

            size_t passphrase_length = std::strlen(passphrase);

            size_t written = 0;

            do {

                ssize_t now_written = gpgme_io_write(fd, passphrase + written, passphrase_length - written);

                if (now_written < 0) {

                    err = make_err_from_syserror();

                    break;

                }

                written += now_written;

            } while (written < passphrase_length);

        }

    }

    if (passphrase && *passphrase) {

        wipememory(passphrase, std::strlen(passphrase));

    }

    free(passphrase);

    gpgme_io_write(fd, "\n", 1);

    return err;

}

static gpgme_ssize_t

data_read_callback(void *opaque, void *buf, size_t buflen)

{

    DataProvider *provider = static_cast<DataProvider *>(opaque);

    if (!provider) {

        gpgme_err_set_errno(gpgme_err_code_to_errno(GPG_ERR_EINVAL));

        return -1;

    }

    return (gpgme_ssize_t)provider->read(buf, buflen);

}

static gpgme_ssize_t

data_write_callback(void *opaque, const void *buf, size_t buflen)

{

    DataProvider *provider = static_cast<DataProvider *>(opaque);

    if (!provider) {

        gpgme_err_set_errno(gpgme_err_code_to_errno(GPG_ERR_EINVAL));

        return -1;

    }

    return (gpgme_ssize_t)provider->write(buf, buflen);

}

static gpgme_off_t

data_seek_callback(void *opaque, gpgme_off_t offset, int whence)

{

    DataProvider *provider = static_cast<DataProvider *>(opaque);

    if (!provider) {

        gpgme_err_set_errno(gpgme_err_code_to_errno(GPG_ERR_EINVAL));

        return -1;

    }

    if (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END) {

        gpgme_err_set_errno(gpgme_err_code_to_errno(GPG_ERR_EINVAL));

        return -1;

    }

    return provider->seek((off_t)offset, whence);

}

static void data_release_callback(void *opaque)

{

    DataProvider *provider = static_cast<DataProvider *>(opaque);

    if (provider) {

        provider->release();

    }

}

const gpgme_data_cbs GpgME::data_provider_callbacks = {

    &data_read_callback,

    &data_write_callback,

    &data_seek_callback,

    &data_release_callback

};