/* Copyright (C) 2018 Open Information Security Foundation

 *

 * You can copy, redistribute or modify this Program under the terms of

 * the GNU General Public License version 2 as published by the Free

 * Software Foundation.

 *

 * This program 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

 * version 2 along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

//! Kerberos parser wrapper module.

use nom7::IResult;

use nom7::error::{ErrorKind, ParseError};

use nom7::number::streaming::le_u16;

use der_parser6;

use der_parser6::der::parse_der_oid;

use der_parser6::error::BerError;

use kerberos_parser::krb5::{ApReq, PrincipalName, Realm};

use kerberos_parser::krb5_parser::parse_ap_req;

#[derive(Debug)]

pub enum SecBlobError {

    NotSpNego,

    KrbFmtError,

    Ber(BerError),

    NomError(ErrorKind),

}

impl From<BerError> for SecBlobError {

    fn from(error: BerError) -> Self {

        SecBlobError::Ber(error)

    }

}

impl<I> ParseError<I> for SecBlobError {

    fn from_error_kind(_input: I, kind: ErrorKind) -> Self {

        SecBlobError::NomError(kind)

    }

    fn append(_input: I, kind: ErrorKind, _other: Self) -> Self {

        SecBlobError::NomError(kind)

    }

}

#[derive(Debug, PartialEq)]

pub struct Kerberos5Ticket {

    pub realm: Realm,

    pub sname: PrincipalName,

}

fn parse_kerberos5_request_do(blob: &[u8]) -> IResult<&[u8], ApReq<'_>, SecBlobError>

{

    let (_,b) = der_parser6::parse_der(blob).map_err(nom7::Err::convert)?;

    let blob = b.as_slice().or(

        Err(nom7::Err::Error(SecBlobError::KrbFmtError))

    )?;

    let parser = |i| {

        let (i, _base_o) = parse_der_oid(i)?;

        let (i, _tok_id) = le_u16(i)?;

        let (i, ap_req) = parse_ap_req(i)?;

        Ok((i, ap_req))

    };

    parser(blob).map_err(nom7::Err::convert)

}

pub fn parse_kerberos5_request(blob: &[u8]) -> IResult<&[u8], Kerberos5Ticket, SecBlobError> {

    let (rem, req) = parse_kerberos5_request_do(blob)?;

    let t = Kerberos5Ticket {

        realm: req.ticket.realm,

        sname: req.ticket.sname,

    };

    return Ok((rem, t));

}