/**
 * \file ssl_ticket.h
 *
 * \brief Internal functions shared by the SSL modules
 *
 *  Copyright (C) 2015, ARM Limited, All Rights Reserved
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  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 along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef MBEDTLS_SSL_INTERNAL_H
#define MBEDTLS_SSL_INTERNAL_H

#include "ssl.h"

#ifdef __cplusplus
extern "C" {
#endif

int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl );
int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl );
void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl );

int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl );

void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl );
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl );

int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl );
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want );

int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl );
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );

int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );

int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl );

int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl );

void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
                            const mbedtls_ssl_ciphersuite_t *ciphersuite_info );

#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex );
#endif

#if defined(MBEDTLS_PK_C)
unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk );
mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig );
#endif

mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash );

#if defined(MBEDTLS_SSL_SET_CURVES)
int mbedtls_ssl_curve_is_acceptable( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id );
#endif

#if defined(MBEDTLS_X509_CRT_PARSE_C)
static inline mbedtls_pk_context *mbedtls_ssl_own_key( mbedtls_ssl_context *ssl )
{
    mbedtls_ssl_key_cert *key_cert;

    if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
        key_cert = ssl->handshake->key_cert;
    else
        key_cert = ssl->conf->key_cert;

    return( key_cert == NULL ? NULL : key_cert->key );
}

static inline mbedtls_x509_crt *mbedtls_ssl_own_cert( mbedtls_ssl_context *ssl )
{
    mbedtls_ssl_key_cert *key_cert;

    if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
        key_cert = ssl->handshake->key_cert;
    else
        key_cert = ssl->conf->key_cert;

    return( key_cert == NULL ? NULL : key_cert->cert );
}

/*
 * Check usage of a certificate wrt extensions:
 * keyUsage, extendedKeyUsage (later), and nSCertType (later).
 *
 * Warning: cert_endpoint is the endpoint of the cert (ie, of our peer when we
 * check a cert we received from them)!
 *
 * Return 0 if everything is OK, -1 if not.
 */
int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
                          const mbedtls_ssl_ciphersuite_t *ciphersuite,
                          int cert_endpoint,
                          uint32_t *flags );
#endif /* MBEDTLS_X509_CRT_PARSE_C */

void mbedtls_ssl_write_version( int major, int minor, int transport,
                        unsigned char ver[2] );
void mbedtls_ssl_read_version( int *major, int *minor, int transport,
                       const unsigned char ver[2] );

static inline size_t mbedtls_ssl_hdr_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
        return( 13 );
#else
    ((void) ssl);
#endif
    return( 5 );
}

static inline size_t mbedtls_ssl_hs_hdr_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
        return( 12 );
#else
    ((void) ssl);
#endif
    return( 4 );
}

#if defined(MBEDTLS_SSL_PROTO_DTLS)
void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl );
void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl );
int mbedtls_ssl_resend( mbedtls_ssl_context *ssl );
#endif

/* Visible for testing purposes only */
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context *ssl );
void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl );
#endif

/* constant-time buffer comparison */
static inline int mbedtls_ssl_safer_memcmp( const void *a, const void *b, size_t n )
{
    size_t i;
    const unsigned char *A = (const unsigned char *) a;
    const unsigned char *B = (const unsigned char *) b;
    unsigned char diff = 0;

    for( i = 0; i < n; i++ )
        diff |= A[i] ^ B[i];

    return( diff );
}

#ifdef __cplusplus
}
#endif

#endif /* ssl_internal.h */