// $OpenLDAP$
/*
 * Copyright 2010-2020 The OpenLDAP Foundation, All Rights Reserved.
 * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
 */

#include <fstream>
#include <sstream>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <cstring>
#include "TlsOptions.h"
#include "LDAPException.h"

enum opttype {
    INT=0,
    STRING,
    OTHER
};

typedef struct tls_optmap {
    int optval;
    opttype type;
} tls_optmap_t;

static tls_optmap_t optmap[] = {
    { LDAP_OPT_X_TLS_CACERTFILE, STRING },
    { LDAP_OPT_X_TLS_CACERTDIR, STRING },
    { LDAP_OPT_X_TLS_CERTFILE, STRING },
    { LDAP_OPT_X_TLS_KEYFILE, STRING },
    { LDAP_OPT_X_TLS_REQUIRE_CERT, INT },
    { LDAP_OPT_X_TLS_PROTOCOL_MIN, INT },
    { LDAP_OPT_X_TLS_CIPHER_SUITE, STRING },
    { LDAP_OPT_X_TLS_RANDOM_FILE, STRING },
    { LDAP_OPT_X_TLS_CRLCHECK, INT },
    { LDAP_OPT_X_TLS_DHFILE, STRING },
    { LDAP_OPT_X_TLS_NEWCTX, INT }
};
#if 0 /* not implemented currently */
        static const int TLS_CRLFILE /* GNUtls only */
        static const int TLS_SSL_CTX  /* OpenSSL SSL* */
        static const int TLS_CONNECT_CB
        static const int TLS_CONNECT_ARG
#endif 

static void checkOpt( TlsOptions::tls_option opt, opttype type ) {
    if ( opt < TlsOptions::CACERTFILE || opt >= TlsOptions::LASTOPT ){
        throw( LDAPException( LDAP_PARAM_ERROR, "unknown Option" ) );
    }

    if ( optmap[opt].type != type ){
        throw( LDAPException( LDAP_PARAM_ERROR, "not a string option" ) );
    }
}

TlsOptions::TlsOptions() : m_ld(NULL) {}

TlsOptions::TlsOptions( LDAP* ld ): m_ld(ld) { }

void TlsOptions::setOption( tls_option opt, const std::string& value ) const {
    checkOpt(opt, STRING);
    switch(opt) {
        case TlsOptions::CACERTFILE :
        case TlsOptions::CERTFILE :
        case TlsOptions::KEYFILE :
        {
            // check if the supplied file is actually readable
            std::ifstream ifile(value.c_str());
            if ( !ifile ) {
                throw( LDAPException( LDAP_LOCAL_ERROR, "Unable to open the supplied file for reading" ) );
            }
        }
        break;
        case TlsOptions::CACERTDIR :
        {
            struct stat st;
            std::ostringstream msg;
            bool fail=false;
            int err = stat(value.c_str(),&st);
            if ( err ) {
                msg << strerror(errno);
                fail = true;
            } else {
                if ( !S_ISDIR(st.st_mode) ){
                    msg << "The supplied path is not a directory.";
                    fail = true;
                }
            }
            if ( fail ) {
                std::ostringstream errstr;
                errstr << "Error while setting Certificate Directory (" << value << "): " << msg.str();
                throw( LDAPException( LDAP_LOCAL_ERROR, errstr.str() ) );
            }
        }
        break;
    }
    this->setOption( opt, value.empty() ? NULL : (void*) value.c_str() );
}

void TlsOptions::setOption( tls_option opt, int value ) const {
    checkOpt(opt, INT);
    this->setOption( opt, (void*) &value);
}

void TlsOptions::setOption( tls_option opt, void *value ) const {
    int ret = ldap_set_option( m_ld, optmap[opt].optval, value);
    if ( ret != LDAP_OPT_SUCCESS )
    {
        if ( ret != LDAP_OPT_ERROR ){
            throw( LDAPException( ret ));
        } else {
            throw( LDAPException( LDAP_PARAM_ERROR, "error while setting TLS option" ) );
        }
    }
    this->newCtx();
}

void TlsOptions::getOption( tls_option opt, void* value ) const {
    int ret = ldap_get_option( m_ld, optmap[opt].optval, value);
    if ( ret != LDAP_OPT_SUCCESS )
    {
        if ( ret != LDAP_OPT_ERROR ){
            throw( LDAPException( ret ));
        } else {
            throw( LDAPException( LDAP_PARAM_ERROR, "error while reading TLS option" ) );
        }
    }
}

int TlsOptions::getIntOption( tls_option opt ) const {
    int value;
    checkOpt(opt, INT);
    ldap_get_option( m_ld, optmap[opt].optval, (void*) &value);
    return value;
}

std::string TlsOptions::getStringOption( tls_option opt ) const {
    char *value;
    checkOpt(opt, STRING);
    ldap_get_option( m_ld, optmap[opt].optval, (void*) &value);
    std::string strval;
    if (value)
    {
        strval=std::string(value);
        ldap_memfree(value);
    }
    return strval;
}

void TlsOptions::newCtx() const {
    int val = 0;
    int ret = ldap_set_option( m_ld, LDAP_OPT_X_TLS_NEWCTX, &val);
    if ( ret != LDAP_OPT_SUCCESS )
    {
        if ( ret != LDAP_OPT_ERROR ){
            throw( LDAPException( ret ));
        } else {
            throw( LDAPException( LDAP_LOCAL_ERROR, "error while renewing TLS context" ) );
        }
    }
}
