ttssh2/ttxssh/hosts.c

/*
Copyright (c) 1998-2001, Robert O'Callahan
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list
of conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.

The name of Robert O'Callahan may not be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*
This code is copyright (C) 1998-1999 Robert O'Callahan.
See LICENSE.TXT for the license.
*/

#include "ttxssh.h"
#include "util.h"
#include "resource.h"
#include "matcher.h"
#include "ssh.h"
#include "key.h"
#include "hosts.h"

#include <openssl/bn.h>
#include <openssl/evp.h>
#include <openssl/rsa.h>
#include <openssl/dsa.h>

#include <fcntl.h>
#include <io.h>
#include <errno.h>
#include <sys/stat.h>
#include <direct.h>
#include <memory.h>

#include <windns.h>

static HFONT DlgHostsAddFont;
static HFONT DlgHostsReplaceFont;

// BASE64�\���������i��������'='�����������������j
static char base64[] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";


// �z�X�g�L�[�������� (2006.3.21 yutaka)
static void init_hostkey(Key *key)
{
        key->type = KEY_UNSPEC;

        // SSH1
        key->bits = 0;
        if (key->exp != NULL) {
                free(key->exp);
                key->exp = NULL;
        }
        if (key->mod != NULL) {
                free(key->mod);
                key->mod = NULL;
        }

        // SSH2
        if (key->dsa != NULL) {
                DSA_free(key->dsa);
                key->dsa = NULL;
        }
        if (key->rsa != NULL) {
                RSA_free(key->rsa);
                key->rsa = NULL;
        }
        if (key->ecdsa != NULL) {
                EC_KEY_free(key->ecdsa);
                key->ecdsa = NULL;
        }
}


static char FAR *FAR * parse_multi_path(char FAR * buf)
{
        int i;
        int ch;
        int num_paths = 1;
        char FAR *FAR * result;
        int last_path_index;

        for (i = 0; (ch = buf[i]) != 0; i++) {
                if (ch == ';') {
                        num_paths++;
                }
        }

        result =
                (char FAR * FAR *) malloc(sizeof(char FAR *) * (num_paths + 1));

        last_path_index = 0;
        num_paths = 0;
        for (i = 0; (ch = buf[i]) != 0; i++) {
                if (ch == ';') {
                        buf[i] = 0;
                        result[num_paths] = _strdup(buf + last_path_index);
                        num_paths++;
                        buf[i] = ch;
                        last_path_index = i + 1;
                }
        }
        if (i > last_path_index) {
                result[num_paths] = _strdup(buf + last_path_index);
                num_paths++;
        }
        result[num_paths] = NULL;
        return result;
}

void HOSTS_init(PTInstVar pvar)
{
        pvar->hosts_state.prefetched_hostname = NULL;
        init_hostkey(&pvar->hosts_state.hostkey);
        pvar->hosts_state.hosts_dialog = NULL;
        pvar->hosts_state.file_names = NULL;
}

void HOSTS_open(PTInstVar pvar)
{
        pvar->hosts_state.file_names =
                parse_multi_path(pvar->session_settings.KnownHostsFiles);
}

//
// known_hosts�t�@�C�������e�������� pvar->hosts_state.file_data ����������
//
static int begin_read_file(PTInstVar pvar, char FAR * name,
                           int suppress_errors)
{
        int fd;
        int length;
        int amount_read;
        char buf[2048];

        get_teraterm_dir_relative_name(buf, sizeof(buf), name);
        fd = _open(buf, _O_RDONLY | _O_SEQUENTIAL | _O_BINARY);
        if (fd == -1) {
                if (!suppress_errors) {
                        if (errno == ENOENT) {
                                UTIL_get_lang_msg("MSG_HOSTS_READ_ENOENT_ERROR", pvar,
                                                  "An error occurred while trying to read a known_hosts file.\n"
                                                  "The specified filename does not exist.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        } else {
                                UTIL_get_lang_msg("MSG_HOSTS_READ_ERROR", pvar,
                                                  "An error occurred while trying to read a known_hosts file.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        }
                }
                return 0;
        }

        length = (int) _lseek(fd, 0, SEEK_END);
        _lseek(fd, 0, SEEK_SET);

        if (length >= 0 && length < 0x7FFFFFFF) {
                pvar->hosts_state.file_data = malloc(length + 1);
                if (pvar->hosts_state.file_data == NULL) {
                        if (!suppress_errors) {
                                UTIL_get_lang_msg("MSG_HOSTS_ALLOC_ERROR", pvar,
                                                  "Memory ran out while trying to allocate space to read a known_hosts file.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        }
                        _close(fd);
                        return 0;
                }
        } else {
                if (!suppress_errors) {
                        UTIL_get_lang_msg("MSG_HOSTS_READ_ERROR", pvar,
                                          "An error occurred while trying to read a known_hosts file.");
                        notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                }
                _close(fd);
                return 0;
        }

        amount_read = _read(fd, pvar->hosts_state.file_data, length);
        pvar->hosts_state.file_data[length] = 0;

        _close(fd);

        if (amount_read != length) {
                if (!suppress_errors) {
                        UTIL_get_lang_msg("MSG_HOSTS_READ_ERROR", pvar,
                                          "An error occurred while trying to read a known_hosts file.");
                        notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                }
                free(pvar->hosts_state.file_data);
                pvar->hosts_state.file_data = NULL;
                return 0;
        } else {
                return 1;
        }
}

static int end_read_file(PTInstVar pvar, int suppress_errors)
{
        free(pvar->hosts_state.file_data);
        pvar->hosts_state.file_data = NULL;
        return 1;
}

static int begin_read_host_files(PTInstVar pvar, int suppress_errors)
{
        pvar->hosts_state.file_num = 0;
        pvar->hosts_state.file_data = NULL;
        return 1;
}

// MIME64�����������X�L�b�v����
static int eat_base64(char FAR * data)
{
        int index = 0;
        int ch;

        for (;;) {
                ch = data[index];
                if (ch == '=' || strchr(base64, ch)) {
                        // BASE64���\�������������������� index ���i����
                        index++;
                } else {
                        break;
                }
        }

        return index;
}

static int eat_spaces(char FAR * data)
{
        int index = 0;
        int ch;

        while ((ch = data[index]) == ' ' || ch == '\t') {
                index++;
        }
        return index;
}

static int eat_digits(char FAR * data)
{
        int index = 0;
        int ch;

        while ((ch = data[index]) >= '0' && ch <= '9') {
                index++;
        }
        return index;
}

static int eat_to_end_of_line(char FAR * data)
{
        int index = 0;
        int ch;

        while ((ch = data[index]) != '\n' && ch != '\r' && ch != 0) {
                index++;
        }

        while ((ch = data[index]) == '\n' || ch == '\r') {
                index++;
        }

        return index;
}

static int eat_to_end_of_pattern(char FAR * data)
{
        int index = 0;
        int ch;

        while (ch = data[index], is_pattern_char(ch)) {
                index++;
        }

        return index;
}

// 
// BASE64�f�R�[�h�������s���B(rfc1521)
// src�o�b�t�@�� null-terminate ���������K�v�����B
//
static int uudecode(unsigned char *src, int srclen, unsigned char *target, int targsize)
{
        char pad = '=';
        int tarindex, state, ch;
        char *pos;

        state = 0;
        tarindex = 0;

        while ((ch = *src++) != '\0') {
                if (isspace(ch))        /* Skip whitespace anywhere. */
                        continue;

                if (ch == pad)
                        break;

                pos = strchr(base64, ch);
                if (pos == 0)           /* A non-base64 character. */
                        return (-1);

                switch (state) {
                case 0:
                        if (target) {
                                if (tarindex >= targsize)
                                        return (-1);
                                target[tarindex] = (pos - base64) << 2;
                        }
                        state = 1;
                        break;
                case 1:
                        if (target) {
                                if (tarindex + 1 >= targsize)
                                        return (-1);
                                target[tarindex]   |=  (pos - base64) >> 4;
                                target[tarindex+1]  = ((pos - base64) & 0x0f) << 4 ;
                        }
                        tarindex++;
                        state = 2;
                        break;
                case 2:
                        if (target) {
                                if (tarindex + 1 >= targsize)
                                        return (-1);
                                target[tarindex]   |=  (pos - base64) >> 2;
                                target[tarindex+1]  = ((pos - base64) & 0x03) << 6;
                        }
                        tarindex++;
                        state = 3;
                        break;
                case 3:
                        if (target) {
                                if (tarindex >= targsize)
                                        return (-1);
                                target[tarindex] |= (pos - base64);
                        }
                        tarindex++;
                        state = 0;
                        break;
                }
        }

        /*
         * We are done decoding Base-64 chars.  Let's see if we ended
         * on a byte boundary, and/or with erroneous trailing characters.
         */

        if (ch == pad) {                /* We got a pad char. */
                ch = *src++;            /* Skip it, get next. */
                switch (state) {
                case 0:         /* Invalid = in first position */
                case 1:         /* Invalid = in second position */
                        return (-1);

                case 2:         /* Valid, means one byte of info */
                        /* Skip any number of spaces. */
                        for (; ch != '\0'; ch = *src++)
                                if (!isspace(ch))
                                        break;
                        /* Make sure there is another trailing = sign. */
                        if (ch != pad)
                                return (-1);
                        ch = *src++;            /* Skip the = */
                        /* Fall through to "single trailing =" case. */
                        /* FALLTHROUGH */

                case 3:         /* Valid, means two bytes of info */
                        /*
                         * We know this char is an =.  Is there anything but
                         * whitespace after it?
                         */
                        for (; ch != '\0'; ch = *src++)
                                if (!isspace(ch))
                                        return (-1);

                        /*
                         * Now make sure for cases 2 and 3 that the "extra"
                         * bits that slopped past the last full byte were
                         * zeros.  If we don't check them, they become a
                         * subliminal channel.
                         */
                        if (target && target[tarindex] != 0)
                                return (-1);
                }
        } else {
                /*
                 * We ended by seeing the end of the string.  Make sure we
                 * have no partial bytes lying around.
                 */
                if (state != 0)
                        return (-1);
        }

        return (tarindex);
}


// SSH2���� BASE64 �`�����i�[����������
static Key *parse_uudecode(char *data)
{
        int count;
        unsigned char *blob = NULL;
        int len, n;
        Key *key = NULL;
        char ch;

        // BASE64���������T�C�Y������
        count = eat_base64(data);
        len = 2 * count;
        blob = malloc(len);
        if (blob == NULL)
                goto error;

        // BASE64�f�R�[�h
        ch = data[count];
        data[count] = '\0';  // ���������s�R�[�h������������������������������������
        n = uudecode(data, count, blob, len);
        data[count] = ch;
        if (n < 0) {
                goto error;
        }

        key = key_from_blob(blob, n);
        if (key == NULL)
                goto error;

error:
        if (blob != NULL)
                free(blob);

        return (key);
}


static char FAR *parse_bignum(char FAR * data)
{
        uint32 digits = 0;
        BIGNUM *num = BN_new();
        BIGNUM *billion = BN_new();
        BIGNUM *digits_num = BN_new();
        BN_CTX *ctx = BN_CTX_new();
        char FAR *result;
        int ch;
        int leftover_digits = 1;

        BN_CTX_init(ctx);
        BN_set_word(num, 0);
        BN_set_word(billion, 1000000000L);

        while ((ch = *data) >= '0' && ch <= '9') {
                if (leftover_digits == 1000000000L) {
                        BN_set_word(digits_num, digits);
                        BN_mul(num, num, billion, ctx);
                        BN_add(num, num, digits_num);
                        leftover_digits = 1;
                        digits = 0;
                }

                digits = digits * 10 + ch - '0';
                leftover_digits *= 10;
                data++;
        }

        BN_set_word(digits_num, digits);
        BN_set_word(billion, leftover_digits);
        BN_mul(num, num, billion, ctx);
        BN_add(num, num, digits_num);

        result = (char FAR *) malloc(2 + BN_num_bytes(num));
        set_ushort16_MSBfirst(result, BN_num_bits(num));
        BN_bn2bin(num, result + 2);

        BN_CTX_free(ctx);
        BN_free(digits_num);
        BN_free(num);
        BN_free(billion);

        return result;
}

//
// known_hosts�t�@�C�������e���������A�w�������z�X�g�����J�����T���B
//
static int check_host_key(PTInstVar pvar, char FAR * hostname,
                          unsigned short tcpport, char FAR * data)
{
        int index = eat_spaces(data);
        int matched = 0;
        int keybits = 0;

        if (data[index] == '#') {
                return index + eat_to_end_of_line(data + index);
        }

        /* if we find an empty line, then it won't have any patterns matching the hostname
           and so we skip it */
        index--;
        do {
                int negated;
                int bracketed;
                char *end_bracket;
                int host_matched = 0;
                unsigned short keyfile_port = 22;

                index++;
                negated = data[index] == '!';

                if (negated) {
                        index++;
                        bracketed = data[index] == '[';
                        if (bracketed) {
                                end_bracket = strstr(data + index + 1, "]:");
                                if (end_bracket != NULL) {
                                        *end_bracket = ' ';
                                        index++;
                                }
                        }
                        host_matched = match_pattern(data + index, hostname);
                        if (bracketed && end_bracket != NULL) {
                                *end_bracket = ']';
                                keyfile_port = atoi(end_bracket + 2);
                        }
                        if (host_matched && keyfile_port == tcpport) {
                                return index + eat_to_end_of_line(data + index);
                        }
                } else {
                        bracketed = data[index] == '[';
                        if (bracketed) {
                                end_bracket = strstr(data + index + 1, "]:");
                                if (end_bracket != NULL) {
                                        *end_bracket = ' ';
                                        index++;
                                }
                        }
                        host_matched = match_pattern(data + index, hostname);
                        if (bracketed && end_bracket != NULL) {
                                *end_bracket = ']';
                                keyfile_port = atoi(end_bracket + 2);
                        }
                        if (host_matched && keyfile_port == tcpport) {
                                matched = 1;
                        }
                }

                index += eat_to_end_of_pattern(data + index);
        } while (data[index] == ',');

        if (!matched) {
                return index + eat_to_end_of_line(data + index);
        } else {
                // ���������������t�H�[�}�b�g��������
                // �����A���������v�����G���g�����������������������B
                /*
                [SSH1]
                192.168.1.2 1024 35 13032....

                [SSH2]
                192.168.1.2 ssh-rsa AAAAB3NzaC1....
                192.168.1.2 ssh-dss AAAAB3NzaC1....
                192.168.1.2 rsa AAAAB3NzaC1....
                192.168.1.2 dsa AAAAB3NzaC1....
                192.168.1.2 rsa1 AAAAB3NzaC1....
                 */
                int rsa1_key_bits;

                index += eat_spaces(data + index);

                rsa1_key_bits = atoi(data + index);
                if (rsa1_key_bits > 0) { // RSA1������
                        if (!SSHv1(pvar)) { // SSH2��������������������
                                return index + eat_to_end_of_line(data + index);
                        }

                        pvar->hosts_state.hostkey.type = KEY_RSA1;

                        pvar->hosts_state.hostkey.bits = rsa1_key_bits;
                        index += eat_digits(data + index);
                        index += eat_spaces(data + index);

                        pvar->hosts_state.hostkey.exp = parse_bignum(data + index);
                        index += eat_digits(data + index);
                        index += eat_spaces(data + index);

                        pvar->hosts_state.hostkey.mod = parse_bignum(data + index);

                        /*
                        if (pvar->hosts_state.key_bits < 0
                                || pvar->hosts_state.key_exp == NULL
                                || pvar->hosts_state.key_mod == NULL) {
                                pvar->hosts_state.key_bits = 0;
                                free(pvar->hosts_state.key_exp);
                                free(pvar->hosts_state.key_mod);
                        }*/

                } else {
                        char *cp, *p;
                        Key *key;

                        if (!SSHv2(pvar)) { // SSH1��������������������
                                return index + eat_to_end_of_line(data + index);
                        }

                        cp = data + index;
                        p = strchr(cp, ' ');
                        if (p == NULL) {
                                return index + eat_to_end_of_line(data + index);
                        }
                        index += (p - cp);  // setup index
                        *p = '\0';
                        pvar->hosts_state.hostkey.type = get_keytype_from_name(cp);
                        *p = ' ';

                        index += eat_spaces(data + index);  // update index

                        // uudecode
                        key = parse_uudecode(data + index);
                        if (key == NULL) {
                                return index + eat_to_end_of_line(data + index);
                        }

                        // setup
                        pvar->hosts_state.hostkey.type = key->type;
                        pvar->hosts_state.hostkey.dsa = key->dsa;
                        pvar->hosts_state.hostkey.rsa = key->rsa;
                        pvar->hosts_state.hostkey.ecdsa = key->ecdsa;

                        index += eat_base64(data + index);
                        index += eat_spaces(data + index);

                        // Key�\�������g���������� (2008.3.2 yutaka)
                        free(key);
                }

                return index + eat_to_end_of_line(data + index);
        }
}

//
// known_hosts�t�@�C�������z�X�g�������v�����s������
//
static int read_host_key(PTInstVar pvar,
                         char FAR * hostname, unsigned short tcpport,
                         int suppress_errors, int return_always)
{
        int i;
        int while_flg;

        for (i = 0; hostname[i] != 0; i++) {
                int ch = hostname[i];

                if (!is_pattern_char(ch) || ch == '*' || ch == '?') {
                        if (!suppress_errors) {
                                UTIL_get_lang_msg("MSG_HOSTS_HOSTNAME_INVALID_ERROR", pvar,
                                                  "The host name contains an invalid character.\n"
                                                  "This session will be terminated.");
                                notify_fatal_error(pvar, pvar->ts->UIMsg);
                        }
                        return 0;
                }
        }

        if (i == 0) {
                if (!suppress_errors) {
                        UTIL_get_lang_msg("MSG_HOSTS_HOSTNAME_EMPTY_ERROR", pvar,
                                          "The host name should not be empty.\n"
                                          "This session will be terminated.");
                        notify_fatal_error(pvar, pvar->ts->UIMsg);
                }
                return 0;
        }

        // hostkey type is KEY_UNSPEC.
        init_hostkey(&pvar->hosts_state.hostkey);

        do {
                if (pvar->hosts_state.file_data == NULL
                 || pvar->hosts_state.file_data[pvar->hosts_state.file_data_index] == 0) {
                        char FAR *filename;
                        int keep_going = 1;

                        if (pvar->hosts_state.file_data != NULL) {
                                end_read_file(pvar, suppress_errors);
                        }

                        do {
                                filename =
                                        pvar->hosts_state.file_names[pvar->hosts_state.file_num];

                                if (filename == NULL) {
                                        return 1;
                                } else {
                                        pvar->hosts_state.file_num++;

                                        if (filename[0] != 0) {
                                                if (begin_read_file(pvar, filename, suppress_errors)) {
                                                        pvar->hosts_state.file_data_index = 0;
                                                        keep_going = 0;
                                                }
                                        }
                                }
                        } while (keep_going);
                }

                pvar->hosts_state.file_data_index +=
                        check_host_key(pvar, hostname, tcpport,
                                       pvar->hosts_state.file_data +
                                       pvar->hosts_state.file_data_index);

                if (!return_always) {
                        // �L�����L�[��������������
                        while_flg = (pvar->hosts_state.hostkey.type == KEY_UNSPEC);
                }
                else {
                        while_flg = 0;
                }
        } while (while_flg);

        return 1;
}

static void finish_read_host_files(PTInstVar pvar, int suppress_errors)
{
        if (pvar->hosts_state.file_data != NULL) {
                end_read_file(pvar, suppress_errors);
        }
}

// �T�[�o�����������O���Aknown_hosts�t�@�C�������z�X�g���J�������������������B
void HOSTS_prefetch_host_key(PTInstVar pvar, char FAR * hostname, unsigned short tcpport)
{
        if (!begin_read_host_files(pvar, 1)) {
                return;
        }

        if (!read_host_key(pvar, hostname, tcpport, 1, 0)) {
                return;
        }

        free(pvar->hosts_state.prefetched_hostname);
        pvar->hosts_state.prefetched_hostname = _strdup(hostname);

        finish_read_host_files(pvar, 1);
}

static BOOL equal_mp_ints(unsigned char FAR * num1,
                          unsigned char FAR * num2)
{
        if (num1 == NULL || num2 == NULL) {
                return FALSE;
        } else {
                uint32 bytes = (get_ushort16_MSBfirst(num1) + 7) / 8;

                if (bytes != (get_ushort16_MSBfirst(num2) + 7) / 8) {
                        return FALSE;           /* different byte lengths */
                } else {
                        return memcmp(num1 + 2, num2 + 2, bytes) == 0;
                }
        }
}

// ���J����������������������
//   -1 ... �����^������
//    0 ... ����������
//    1 ... ������
static int match_key(PTInstVar pvar, Key *key)
{
        int bits;
        unsigned char FAR * exp;
        unsigned char FAR * mod;
        const EC_GROUP *group;
        const EC_POINT *pa, *pb;

        if (pvar->hosts_state.hostkey.type != key->type) {
                return -1;
        }

        switch (key->type) {
        case KEY_RSA1: // SSH1 host public key
                bits = key->bits;
                exp = key->exp;
                mod = key->mod;

                /* just check for equal exponent and modulus */
                return equal_mp_ints(exp, pvar->hosts_state.hostkey.exp)
                    && equal_mp_ints(mod, pvar->hosts_state.hostkey.mod);
                /*
                return equal_mp_ints(exp, pvar->hosts_state.key_exp)
                        && equal_mp_ints(mod, pvar->hosts_state.key_mod);
                        */

        case KEY_RSA: // SSH2 RSA host public key
                return key->rsa != NULL && pvar->hosts_state.hostkey.rsa != NULL &&
                       BN_cmp(key->rsa->e, pvar->hosts_state.hostkey.rsa->e) == 0 && 
                       BN_cmp(key->rsa->n, pvar->hosts_state.hostkey.rsa->n) == 0;

        case KEY_DSA: // SSH2 DSA host public key
                return key->dsa != NULL && pvar->hosts_state.hostkey.dsa && 
                       BN_cmp(key->dsa->p, pvar->hosts_state.hostkey.dsa->p) == 0 && 
                       BN_cmp(key->dsa->q, pvar->hosts_state.hostkey.dsa->q) == 0 &&
                       BN_cmp(key->dsa->g, pvar->hosts_state.hostkey.dsa->g) == 0 &&
                       BN_cmp(key->dsa->pub_key, pvar->hosts_state.hostkey.dsa->pub_key) == 0;

        case KEY_ECDSA256:
        case KEY_ECDSA384:
        case KEY_ECDSA521:
                if (key->ecdsa == NULL || pvar->hosts_state.hostkey.ecdsa == NULL) {
                        return FALSE;
                }
                group = EC_KEY_get0_group(key->ecdsa);
                pa = EC_KEY_get0_public_key(key->ecdsa),
                pb = EC_KEY_get0_public_key(pvar->hosts_state.hostkey.ecdsa);
                return EC_POINT_cmp(group, pa, pb, NULL) == 0;

        default:
                return FALSE;
        }

}

static void init_hosts_dlg(PTInstVar pvar, HWND dlg)
{
        char buf[1024];
        char buf2[2048];
        int i, j;
        int ch;
        char *fp = NULL;

        // static text�� # �������z�X�g�����u������
        GetDlgItemText(dlg, IDC_HOSTWARNING, buf, sizeof(buf));
        for (i = 0; (ch = buf[i]) != 0 && ch != '#'; i++) {
                buf2[i] = ch;
        }
        strncpy_s(buf2 + i, sizeof(buf2) - i,
                  pvar->hosts_state.prefetched_hostname, _TRUNCATE);
        j = i + strlen(buf2 + i);
        for (; buf[i] == '#'; i++) {
        }
        strncpy_s(buf2 + j, sizeof(buf2) - j, buf + i, _TRUNCATE);

        SetDlgItemText(dlg, IDC_HOSTWARNING, buf2);

        // fingerprint����������
        fp = key_fingerprint(&pvar->hosts_state.hostkey, SSH_FP_HEX);
        SendMessage(GetDlgItem(dlg, IDC_FINGER_PRINT), WM_SETTEXT, 0, (LPARAM)fp);
        free(fp);

        // �r�W���A����fingerprint���\������
        fp = key_fingerprint(&pvar->hosts_state.hostkey, SSH_FP_RANDOMART);
        SendMessage(GetDlgItem(dlg, IDC_FP_RANDOMART), WM_SETTEXT, 0, (LPARAM)fp);
        SendMessage(GetDlgItem(dlg, IDC_FP_RANDOMART), WM_SETFONT, (WPARAM)GetStockObject(ANSI_FIXED_FONT), TRUE);
        free(fp);
}

static int print_mp_int(char FAR * buf, unsigned char FAR * mp)
{
        int i = 0, j, k;
        BIGNUM *num = BN_new();
        int ch;

        BN_bin2bn(mp + 2, (get_ushort16_MSBfirst(mp) + 7) / 8, num);

        do {
                buf[i] = (char) ((BN_div_word(num, 10)) + '0');
                i++;
        } while (!BN_is_zero(num));

        /* we need to reverse the digits */
        for (j = 0, k = i - 1; j < k; j++, k--) {
                ch = buf[j];
                buf[j] = buf[k];
                buf[k] = ch;
        }

        buf[i] = 0;
        return i;
}

//
// known_hosts �t�@�C�������������G���g�������������B
//
static char FAR *format_host_key(PTInstVar pvar)
{
        int host_len = strlen(pvar->hosts_state.prefetched_hostname);
        char *result = NULL;
        int index;
        ssh_keytype type = pvar->hosts_state.hostkey.type;

        switch (type) {
        case KEY_RSA1:
        {
                int result_len = host_len + 50 + 8 +
                                 get_ushort16_MSBfirst(pvar->hosts_state.hostkey.exp) / 3 +
                                 get_ushort16_MSBfirst(pvar->hosts_state.hostkey.mod) / 3;
                result = (char FAR *) malloc(result_len);

                if (pvar->ssh_state.tcpport == 22) {
                        strncpy_s(result, result_len, pvar->hosts_state.prefetched_hostname, _TRUNCATE);
                        index = host_len;
                }
                else {
                        _snprintf_s(result, result_len, _TRUNCATE, "[%s]:%d",
                                    pvar->hosts_state.prefetched_hostname,
                                    pvar->ssh_state.tcpport);
                        index = strlen(result);
                }

                _snprintf_s(result + index, result_len - host_len, _TRUNCATE,
                            " %d ", pvar->hosts_state.hostkey.bits);
                index += strlen(result + index);
                index += print_mp_int(result + index, pvar->hosts_state.hostkey.exp);
                result[index] = ' ';
                index++;
                index += print_mp_int(result + index, pvar->hosts_state.hostkey.mod);
                strncpy_s(result + index, result_len - index, " \r\n", _TRUNCATE);

                break;
        }

        case KEY_RSA:
        case KEY_DSA:
        case KEY_ECDSA256:
        case KEY_ECDSA384:
        case KEY_ECDSA521:
        {
                Key *key = &pvar->hosts_state.hostkey;
                char *blob = NULL;
                int blen, uulen, msize;
                char *uu = NULL;
                int n;

                key_to_blob(key, &blob, &blen);
                uulen = 2 * blen;
                uu = malloc(uulen);
                if (uu == NULL) {
                        goto error;
                }
                n = uuencode(blob, blen, uu, uulen);
                if (n > 0) {
                        msize = host_len + 50 + uulen;
                        result = malloc(msize);
                        if (result == NULL) {
                                goto error;
                        }

                        // setup
                        if (pvar->ssh_state.tcpport == 22) {
                                _snprintf_s(result, msize, _TRUNCATE, "%s %s %s\r\n",
                                            pvar->hosts_state.prefetched_hostname, 
                                            get_sshname_from_key(key),
                                            uu);
                        } else {
                                _snprintf_s(result, msize, _TRUNCATE, "[%s]:%d %s %s\r\n",
                                            pvar->hosts_state.prefetched_hostname,
                                            pvar->ssh_state.tcpport,
                                            get_sshname_from_key(key),
                                            uu);
                        }
                }
error:
                if (blob != NULL)
                        free(blob);
                if (uu != NULL)
                        free(uu);

                break;
        }

        default:
                return NULL;

        }

        return result;
}

static void add_host_key(PTInstVar pvar)
{
        char FAR *name = NULL;

        if ( pvar->hosts_state.file_names != NULL)
                name = pvar->hosts_state.file_names[0];

        if (name == NULL || name[0] == 0) {
                UTIL_get_lang_msg("MSG_HOSTS_FILE_UNSPECIFY_ERROR", pvar,
                                  "The host and its key cannot be added, because no known-hosts file has been specified.\n"
                                  "Restart Tera Term and specify a read/write known-hosts file in the TTSSH Setup dialog box.");
                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
        } else {
                char FAR *keydata = format_host_key(pvar);
                int length = strlen(keydata);
                int fd;
                int amount_written;
                int close_result;
                char buf[FILENAME_MAX];

                get_teraterm_dir_relative_name(buf, sizeof(buf), name);
                fd = _open(buf,
                          _O_APPEND | _O_CREAT | _O_WRONLY | _O_SEQUENTIAL | _O_BINARY,
                          _S_IREAD | _S_IWRITE);
                if (fd == -1) {
                        if (errno == EACCES) {
                                UTIL_get_lang_msg("MSG_HOSTS_WRITE_EACCES_ERROR", pvar,
                                                  "An error occurred while trying to write the host key.\n"
                                                  "You do not have permission to write to the known-hosts file.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        } else {
                                UTIL_get_lang_msg("MSG_HOSTS_WRITE_ERROR", pvar,
                                                  "An error occurred while trying to write the host key.\n"
                                                  "The host key could not be written.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        }
                        return;
                }

                amount_written = _write(fd, keydata, length);
                free(keydata);
                close_result = _close(fd);

                if (amount_written != length || close_result == -1) {
                        UTIL_get_lang_msg("MSG_HOSTS_WRITE_ERROR", pvar,
                                          "An error occurred while trying to write the host key.\n"
                                          "The host key could not be written.");
                        notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                }
        }
}

static char FAR *copy_mp_int(char FAR * num)
{
        int len = (get_ushort16_MSBfirst(num) + 7) / 8 + 2;
        char FAR *result = (char FAR *) malloc(len);

        if (result != NULL) {
                memcpy(result, num, len);
        }

        return result;
}

//
// �����z�X�g�����e���������L�[����������
// add_host_key ����������������
//
static void delete_different_key(PTInstVar pvar)
{
        char FAR *name = pvar->hosts_state.file_names[0];

        if (name == NULL || name[0] == 0) {
                UTIL_get_lang_msg("MSG_HOSTS_FILE_UNSPECIFY_ERROR", pvar,
                                  "The host and its key cannot be added, because no known-hosts file has been specified.\n"
                                  "Restart Tera Term and specify a read/write known-hosts file in the TTSSH Setup dialog box.");
                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
        }
        else {
                Key key; // ���������z�X�g���L�[
                int length;
                char filename[MAX_PATH];
                char tmp[L_tmpnam];
                int fd;
                int amount_written = 0;
                int close_result;
                int data_index = 0;
                char buf[FILENAME_MAX];

                // �������������t�@�C�����J��
                _getcwd(filename, sizeof(filename));
                tmpnam_s(tmp,sizeof(tmp));
                strcat_s(filename, sizeof(filename), tmp);
                fd = _open(filename,
                          _O_CREAT | _O_WRONLY | _O_SEQUENTIAL | _O_BINARY | _O_TRUNC,
                          _S_IREAD | _S_IWRITE);

                if (fd == -1) {
                        if (errno == EACCES) {
                                UTIL_get_lang_msg("MSG_HOSTS_WRITE_EACCES_ERROR", pvar,
                                                  "An error occurred while trying to write the host key.\n"
                                                  "You do not have permission to write to the known-hosts file.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        } else {
                                UTIL_get_lang_msg("MSG_HOSTS_WRITE_ERROR", pvar,
                                                  "An error occurred while trying to write the host key.\n"
                                                  "The host key could not be written.");
                                notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        }
                        return;
                }

                // ���������T�[�o���L�[����������
                switch (pvar->hosts_state.hostkey.type) {
                case KEY_RSA1: // SSH1
                        key.type = KEY_RSA1;
                        key.bits = pvar->hosts_state.hostkey.bits;
                        key.exp = copy_mp_int(pvar->hosts_state.hostkey.exp);
                        key.mod = copy_mp_int(pvar->hosts_state.hostkey.mod);
                        break;
                case KEY_RSA: // SSH2 RSA
                        key.type = KEY_RSA;
                        key.rsa = duplicate_RSA(pvar->hosts_state.hostkey.rsa);
                        break;
                case KEY_DSA: // SSH2 DSA
                        key.type = KEY_DSA;
                        key.dsa = duplicate_DSA(pvar->hosts_state.hostkey.dsa);
                        break;
                case KEY_ECDSA256:
                case KEY_ECDSA384:
                case KEY_ECDSA521:
                        key.type = pvar->hosts_state.hostkey.type;
                        key.ecdsa = EC_KEY_dup(pvar->hosts_state.hostkey.ecdsa);
                        break;
                }

                // �t�@�C��������������
                begin_read_host_files(pvar, 0);
                do {
                        int host_index = 0;
                        int matched = 0;
                        int keybits = 0;
                        char FAR *data;
                        int do_write = 0;
                        length = amount_written = 0;

                        if (!read_host_key(pvar, pvar->ssh_state.hostname, pvar->ssh_state.tcpport, 0, 1)) {
                                break;
                        }

                        if (data_index == pvar->hosts_state.file_data_index) {
                                // index ���i������ == ��������������
                                break;
                        }

                        data = pvar->hosts_state.file_data + data_index;
                        host_index = eat_spaces(data);

                        if (data[host_index] == '#') {
                                do_write = 1;
                        }
                        else {
                                // �z�X�g������
                                host_index--;
                                do {
                                        int negated;
                                        int bracketed;
                                        char *end_bracket;
                                        int host_matched = 0;
                                        unsigned short keyfile_port = 22;

                                        host_index++;
                                        negated = data[host_index] == '!';

                                        if (negated) {
                                                host_index++;
                                                bracketed = data[host_index] == '[';
                                                if (bracketed) {
                                                        end_bracket = strstr(data + host_index + 1, "]:");
                                                        if (end_bracket != NULL) {
                                                                *end_bracket = ' ';
                                                                host_index++;
                                                        }
                                                }
                                                host_matched = match_pattern(data + host_index, pvar->ssh_state.hostname);
                                                if (bracketed && end_bracket != NULL) {
                                                        *end_bracket = ']';
                                                        keyfile_port = atoi(end_bracket + 2);
                                                }
                                                if (host_matched && keyfile_port == pvar->ssh_state.tcpport) {
                                                        matched = 0;
                                                        // �����o�[�W�����`�F�b�N�������� host_index ���i��������������
                                                        host_index--;
                                                        do {
                                                                host_index++;
                                                                host_index += eat_to_end_of_pattern(data + host_index);
                                                        } while (data[host_index] == ',');
                                                        break;
                                                }
                                        }
                                        else {
                                                bracketed = data[host_index] == '[';
                                                if (bracketed) {
                                                        end_bracket = strstr(data + host_index + 1, "]:");
                                                        if (end_bracket != NULL) {
                                                                *end_bracket = ' ';
                                                                host_index++;
                                                        }
                                                }
                                                host_matched = match_pattern(data + host_index, pvar->ssh_state.hostname);
                                                if (bracketed && end_bracket != NULL) {
                                                        *end_bracket = ']';
                                                        keyfile_port = atoi(end_bracket + 2);
                                                }
                                                if (host_matched && keyfile_port == pvar->ssh_state.tcpport) {
                                                        matched = 1;
                                                }
                                        }
                                        host_index += eat_to_end_of_pattern(data + host_index);
                                } while (data[host_index] == ',');

                                // �z�X�g������������
                                if (!matched) {
                                        do_write = 1;
                                }
                                // �z�X�g��������
                                else {
                                        // �����`�������� or ���v�����L�[
                                        if (match_key(pvar, &key) != 0) {
                                                do_write = 1;
                                        }
                                        // �����`�������������v�������L�[���X�L�b�v������
                                }
                        }

                        // ������������
                        if (do_write) {
                                length = pvar->hosts_state.file_data_index - data_index;
                                amount_written =
                                        _write(fd, pvar->hosts_state.file_data + data_index,
                                               length);

                                if (amount_written != length) {
                                        goto error1;
                                }
                        }
                        data_index = pvar->hosts_state.file_data_index;
                } while (1); // ������������

error1:
                close_result = _close(fd);
                if (amount_written != length || close_result == -1) {
                        UTIL_get_lang_msg("MSG_HOSTS_WRITE_ERROR", pvar,
                                          "An error occurred while trying to write the host key.\n"
                                          "The host key could not be written.");
                        notify_nonfatal_error(pvar, pvar->ts->UIMsg);
                        goto error2;
                }

                // �������������t�@�C���������l�[��
                get_teraterm_dir_relative_name(buf, sizeof(buf), name);
                _unlink(buf);
                rename(filename, buf);

error2:
                _unlink(filename);

                finish_read_host_files(pvar, 0);
        }
}

//
// Unknown host���z�X�g���J���� known_hosts �t�@�C����������������������
// ���[�U���m�F�������B
// TODO: finger print���\�����s���B
// (2006.3.25 yutaka)
//
static BOOL CALLBACK hosts_add_dlg_proc(HWND dlg, UINT msg, WPARAM wParam,
                                        LPARAM lParam)
{
        PTInstVar pvar;
        LOGFONT logfont;
        HFONT font;
        char uimsg[MAX_UIMSG];

        switch (msg) {
        case WM_INITDIALOG:
                pvar = (PTInstVar) lParam;
                pvar->hosts_state.hosts_dialog = dlg;
                SetWindowLong(dlg, DWL_USER, lParam);

                // �����E�u���������� init_hosts_dlg �����������������A�����O���Z�b�g�����K�v������
                GetWindowText(dlg, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_UNKNONWHOST_TITLE", pvar, uimsg);
                SetWindowText(dlg, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_UNKNOWNHOST_WARNING", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING2, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_UNKNOWNHOST_WARNING2", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING2, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTFINGERPRINT, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_UNKNOWNHOST_FINGERPRINT", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTFINGERPRINT, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_UNKNOWNHOST_ADD", pvar, uimsg);
                SetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_CONTINUE, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_CONTINUE", pvar, uimsg);
                SetDlgItemText(dlg, IDC_CONTINUE, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDCANCEL, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_DISCONNECT", pvar, uimsg);
                SetDlgItemText(dlg, IDCANCEL, pvar->ts->UIMsg);

                init_hosts_dlg(pvar, dlg);

                font = (HFONT)SendMessage(dlg, WM_GETFONT, 0, 0);
                GetObject(font, sizeof(LOGFONT), &logfont);
                if (UTIL_get_lang_font("DLG_TAHOMA_FONT", dlg, &logfont, &DlgHostsAddFont, pvar)) {
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING2, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTFINGERPRINT, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_FINGER_PRINT, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_ADDTOKNOWNHOSTS, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_CONTINUE, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDCANCEL, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                }
                else {
                        DlgHostsAddFont = NULL;
                }

                // add host check box���`�F�b�N���f�t�H���g������������ 
                SendMessage(GetDlgItem(dlg, IDC_ADDTOKNOWNHOSTS), BM_SETCHECK, BST_CHECKED, 0);

                return TRUE;                    /* because we do not set the focus */

        case WM_COMMAND:
                pvar = (PTInstVar) GetWindowLong(dlg, DWL_USER);

                switch (LOWORD(wParam)) {
                case IDC_CONTINUE:
                        if (IsDlgButtonChecked(dlg, IDC_ADDTOKNOWNHOSTS)) {
                                add_host_key(pvar);
                        }

                        if (SSHv1(pvar)) {
                                SSH_notify_host_OK(pvar);
                        } else { // SSH2
                                // SSH2���������� SSH_notify_host_OK() �������B
                        }

                        pvar->hosts_state.hosts_dialog = NULL;

                        EndDialog(dlg, 1);

                        if (DlgHostsAddFont != NULL) {
                                DeleteObject(DlgHostsAddFont);
                        }

                        return TRUE;

                case IDCANCEL:                  /* kill the connection */
                        pvar->hosts_state.hosts_dialog = NULL;
                        notify_closed_connection(pvar);
                        EndDialog(dlg, 0);

                        if (DlgHostsAddFont != NULL) {
                                DeleteObject(DlgHostsAddFont);
                        }

                        return TRUE;

                default:
                        return FALSE;
                }

        default:
                return FALSE;
        }
}

//
// �u�����������m�F�_�C�A���O������
//
static BOOL CALLBACK hosts_replace_dlg_proc(HWND dlg, UINT msg, WPARAM wParam,
                                            LPARAM lParam)
{
        PTInstVar pvar;
        LOGFONT logfont;
        HFONT font;
        char uimsg[MAX_UIMSG];

        switch (msg) {
        case WM_INITDIALOG:
                pvar = (PTInstVar) lParam;
                pvar->hosts_state.hosts_dialog = dlg;
                SetWindowLong(dlg, DWL_USER, lParam);

                // �����E�u���������� init_hosts_dlg �����������������A�����O���Z�b�g�����K�v������
                GetWindowText(dlg, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTKEY_TITLE", pvar, uimsg);
                SetWindowText(dlg, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTKEY_WARNING", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING2, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTKEY_WARNING2", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING2, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTFINGERPRINT, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTKEY_FINGERPRINT", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTFINGERPRINT, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTKEY_REPLACE", pvar, uimsg);
                SetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_CONTINUE, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_CONTINUE", pvar, uimsg);
                SetDlgItemText(dlg, IDC_CONTINUE, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDCANCEL, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_DISCONNECT", pvar, uimsg);
                SetDlgItemText(dlg, IDCANCEL, pvar->ts->UIMsg);

                init_hosts_dlg(pvar, dlg);

                font = (HFONT)SendMessage(dlg, WM_GETFONT, 0, 0);
                GetObject(font, sizeof(LOGFONT), &logfont);
                if (UTIL_get_lang_font("DLG_TAHOMA_FONT", dlg, &logfont, &DlgHostsReplaceFont, pvar)) {
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING2, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTFINGERPRINT, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_ADDTOKNOWNHOSTS, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_CONTINUE, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDCANCEL, WM_SETFONT, (WPARAM)DlgHostsReplaceFont, MAKELPARAM(TRUE,0));
                }
                else {
                        DlgHostsReplaceFont = NULL;
                }

                // �f�t�H���g���`�F�b�N����������
                return TRUE;                    /* because we do not set the focus */

        case WM_COMMAND:
                pvar = (PTInstVar) GetWindowLong(dlg, DWL_USER);

                switch (LOWORD(wParam)) {
                case IDC_CONTINUE:
                        if (IsDlgButtonChecked(dlg, IDC_ADDTOKNOWNHOSTS)) {
                                add_host_key(pvar);
                                delete_different_key(pvar);
                        }

                        if (SSHv1(pvar)) {
                                SSH_notify_host_OK(pvar);
                        } else { // SSH2
                                // SSH2���������� SSH_notify_host_OK() �������B
                        }

                        pvar->hosts_state.hosts_dialog = NULL;

                        EndDialog(dlg, 1);

                        if (DlgHostsReplaceFont != NULL) {
                                DeleteObject(DlgHostsReplaceFont);
                        }

                        return TRUE;

                case IDCANCEL:                  /* kill the connection */
                        pvar->hosts_state.hosts_dialog = NULL;
                        notify_closed_connection(pvar);
                        EndDialog(dlg, 0);

                        if (DlgHostsReplaceFont != NULL) {
                                DeleteObject(DlgHostsReplaceFont);
                        }

                        return TRUE;

                default:
                        return FALSE;
                }

        default:
                return FALSE;
        }
}

//
// �����z�X�g�����`�����������������m�F�_�C�A���O������
//
static BOOL CALLBACK hosts_add2_dlg_proc(HWND dlg, UINT msg, WPARAM wParam,
                                         LPARAM lParam)
{
        PTInstVar pvar;
        LOGFONT logfont;
        HFONT font;
        char uimsg[MAX_UIMSG];

        switch (msg) {
        case WM_INITDIALOG:
                pvar = (PTInstVar) lParam;
                pvar->hosts_state.hosts_dialog = dlg;
                SetWindowLong(dlg, DWL_USER, lParam);

                // �����E�u���������� init_hosts_dlg �����������������A�����O���Z�b�g�����K�v������
                GetWindowText(dlg, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTTYPEKEY_TITLE", pvar, uimsg);
                SetWindowText(dlg, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTTYPEKEY_WARNING", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTWARNING2, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTTYPEKEY_WARNING2", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTWARNING2, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_HOSTFINGERPRINT, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTTYPEKEY_FINGERPRINT", pvar, uimsg);
                SetDlgItemText(dlg, IDC_HOSTFINGERPRINT, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("DLG_DIFFERENTTYPEKEY_ADD", pvar, uimsg);
                SetDlgItemText(dlg, IDC_ADDTOKNOWNHOSTS, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDC_CONTINUE, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_CONTINUE", pvar, uimsg);
                SetDlgItemText(dlg, IDC_CONTINUE, pvar->ts->UIMsg);
                GetDlgItemText(dlg, IDCANCEL, uimsg, sizeof(uimsg));
                UTIL_get_lang_msg("BTN_DISCONNECT", pvar, uimsg);
                SetDlgItemText(dlg, IDCANCEL, pvar->ts->UIMsg);

                init_hosts_dlg(pvar, dlg);

                font = (HFONT)SendMessage(dlg, WM_GETFONT, 0, 0);
                GetObject(font, sizeof(LOGFONT), &logfont);
                if (UTIL_get_lang_font("DLG_TAHOMA_FONT", dlg, &logfont, &DlgHostsAddFont, pvar)) {
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTWARNING2, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_HOSTFINGERPRINT, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_FINGER_PRINT, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_ADDTOKNOWNHOSTS, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDC_CONTINUE, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                        SendDlgItemMessage(dlg, IDCANCEL, WM_SETFONT, (WPARAM)DlgHostsAddFont, MAKELPARAM(TRUE,0));
                }
                else {
                        DlgHostsAddFont = NULL;
                }

                // add host check box ���f�t�H���g�� off ������
                // SendMessage(GetDlgItem(dlg, IDC_ADDTOKNOWNHOSTS), BM_SETCHECK, BST_CHECKED, 0);

                return TRUE;                    /* because we do not set the focus */

        case WM_COMMAND:
                pvar = (PTInstVar) GetWindowLong(dlg, DWL_USER);

                switch (LOWORD(wParam)) {
                case IDC_CONTINUE:
                        if (IsDlgButtonChecked(dlg, IDC_ADDTOKNOWNHOSTS)) {
                                add_host_key(pvar);
                        }

                        if (SSHv1(pvar)) {
                                SSH_notify_host_OK(pvar);
                        } else { // SSH2
                                // SSH2���������� SSH_notify_host_OK() �������B
                        }

                        pvar->hosts_state.hosts_dialog = NULL;

                        EndDialog(dlg, 1);

                        if (DlgHostsAddFont != NULL) {
                                DeleteObject(DlgHostsAddFont);
                        }

                        return TRUE;

                case IDCANCEL:                  /* kill the connection */
                        pvar->hosts_state.hosts_dialog = NULL;
                        notify_closed_connection(pvar);
                        EndDialog(dlg, 0);

                        if (DlgHostsAddFont != NULL) {
                                DeleteObject(DlgHostsAddFont);
                        }

                        return TRUE;

                default:
                        return FALSE;
                }

        default:
                return FALSE;
        }
}

void HOSTS_do_unknown_host_dialog(HWND wnd, PTInstVar pvar)
{
        if (pvar->hosts_state.hosts_dialog == NULL) {
                HWND cur_active = GetActiveWindow();

                DialogBoxParam(hInst, MAKEINTRESOURCE(IDD_SSHUNKNOWNHOST),
                               cur_active != NULL ? cur_active : wnd,
                               hosts_add_dlg_proc, (LPARAM) pvar);
        }
}

void HOSTS_do_different_key_dialog(HWND wnd, PTInstVar pvar)
{
        if (pvar->hosts_state.hosts_dialog == NULL) {
                HWND cur_active = GetActiveWindow();

                DialogBoxParam(hInst, MAKEINTRESOURCE(IDD_SSHDIFFERENTKEY),
                               cur_active != NULL ? cur_active : wnd,
                               hosts_replace_dlg_proc, (LPARAM) pvar);
        }
}

void HOSTS_do_different_type_key_dialog(HWND wnd, PTInstVar pvar)
{
        if (pvar->hosts_state.hosts_dialog == NULL) {
                HWND cur_active = GetActiveWindow();

                DialogBoxParam(hInst, MAKEINTRESOURCE(IDD_SSHDIFFERENTTYPEKEY),
                               cur_active != NULL ? cur_active : wnd,
                               hosts_add2_dlg_proc, (LPARAM) pvar);
        }
}

int is_numeric_hostname(const char *hostname)
{
        struct addrinfo hints, *ai;

        if (hostname == NULL) {
                return -1;
        }

        memset(&hints, 0, sizeof(hints));
        hints.ai_socktype = SOCK_DGRAM;
        hints.ai_flags = AI_NUMERICHOST;

        if (getaddrinfo(hostname, NULL, &hints, &ai) == 0) {
                freeaddrinfo(ai);
                return 1;
        }

        return 0;
}

#define DNS_TYPE_SSHFP  44
typedef struct {
        BYTE Algorithm;
        BYTE DigestType;
        BYTE Digest[1];
} DNS_SSHFP_DATA, *PDNS_SSHFP_DATA;
enum verifydns_result {
        DNS_VERIFY_NONE,
        DNS_VERIFY_MATCH,
        DNS_VERIFY_MISMATCH,
        DNS_VERIFY_DIFFERENTTYPE,
        DNS_VERIFY_AUTH_MATCH,
        DNS_VERIFY_AUTH_MISMATCH,
        DNS_VERIFY_AUTH_DIFFERENTTYPE
};

int verify_hostkey_dns(char FAR *hostname, Key *key)
{
        DNS_STATUS status;
        PDNS_RECORD rec, p;
        PDNS_SSHFP_DATA t;
        int hostkey_alg, hostkey_dtype, hostkey_dlen;
        BYTE *hostkey_digest;
        int found = DNS_VERIFY_NONE;

        switch (key->type) {
        case KEY_RSA:
                hostkey_alg = SSHFP_KEY_RSA;
                hostkey_dtype = SSHFP_HASH_SHA1;
                break;
        case KEY_DSA:
                hostkey_alg = SSHFP_KEY_DSA;
                hostkey_dtype = SSHFP_HASH_SHA1;
                break;
        case KEY_ECDSA256:
        case KEY_ECDSA384:
        case KEY_ECDSA521:
                hostkey_alg = SSHFP_KEY_ECDSA;
                hostkey_dtype = SSHFP_HASH_SHA256;
                break;
        default: // Un-supported algorithm
                hostkey_alg = SSHFP_KEY_RESERVED;
                hostkey_dtype = SSHFP_HASH_RESERVED;
        }

        if (hostkey_alg) {
                hostkey_digest = key_fingerprint_raw(key, hostkey_dtype, &hostkey_dlen);
        }
        else {
                hostkey_digest = NULL;
        }

        status = DnsQuery(hostname, DNS_TYPE_SSHFP, DNS_QUERY_STANDARD, NULL, &rec, NULL);

        if (status == 0) {
                for (p=rec; p!=NULL; p=p->pNext) {
                        if (p->wType == DNS_TYPE_SSHFP) {
                                t = (PDNS_SSHFP_DATA)&(p->Data.Null);
                                if (t->Algorithm == hostkey_alg && t->DigestType == hostkey_dtype) {
                                        if (hostkey_dlen == p->wDataLength-2 && memcmp(hostkey_digest, t->Digest, hostkey_dlen) == 0) {
                                                found = DNS_VERIFY_MATCH;
                                                break;
                                        }
                                        else {
                                                found = DNS_VERIFY_MISMATCH;
                                                break;
                                        }
                                }
                                else {
                                        found = DNS_VERIFY_DIFFERENTTYPE;
                                }
                        }
                }
        }

        free(hostkey_digest);
        DnsRecordListFree(rec, DnsFreeRecordList);
        return found;
}

//
// �T�[�o�����������������z�X�g���J�������������`�F�b�N����
//
// SSH2���������� (2006.3.24 yutaka)
//
BOOL HOSTS_check_host_key(PTInstVar pvar, char FAR * hostname, unsigned short tcpport, Key *key)
{
        int found_different_key = 0, found_different_type_key = 0, dns_sshfp_check = 0;

        // ������ known_hosts �t�@�C�������z�X�g���J�����������������������A���������r�����B
        if (pvar->hosts_state.prefetched_hostname != NULL
         && _stricmp(pvar->hosts_state.prefetched_hostname, hostname) == 0
         && match_key(pvar, key) == 1) {

                if (SSHv1(pvar)) {
                        SSH_notify_host_OK(pvar);
                } else {
                        // SSH2���������� SSH_notify_host_OK() �������B
                }
                return TRUE;
        }

        // �������������������������A�������_���t�@�C��������������
        if (begin_read_host_files(pvar, 0)) {
                do {
                        if (!read_host_key(pvar, hostname, tcpport, 0, 0)) {
                                break;
                        }

                        if (pvar->hosts_state.hostkey.type != KEY_UNSPEC) {
                                int match = match_key(pvar, key);
                                if (match == 1) {
                                        finish_read_host_files(pvar, 0);
                                        // ���������G���g�����Q�������A���v�����L�[�������������������B
                                        // SSH2���������������������������B(2006.3.29 yutaka)
                                        if (SSHv1(pvar)) {
                                                SSH_notify_host_OK(pvar);
                                        } else {
                                                // SSH2���������� SSH_notify_host_OK() �������B
                                        }
                                        return TRUE;
                                }
                                else if (match == 0) {
                                        // �L�[�� known_hosts ���������������A�L�[�����e���������B
                                        found_different_key = 1;
                                }
                                else {
                                        // �L�[���`������������
                                        found_different_type_key = 1;
                                }
                        }
                } while (pvar->hosts_state.hostkey.type != KEY_UNSPEC);  // �L�[�����������������������[�v����

                finish_read_host_files(pvar, 0);
        }

        // known_hosts �������������L�[���������t�@�C�������������������A�������������������B
        pvar->hosts_state.hostkey.type = key->type;
        switch (key->type) {
        case KEY_RSA1: // SSH1
                pvar->hosts_state.hostkey.bits = key->bits;
                pvar->hosts_state.hostkey.exp = copy_mp_int(key->exp);
                pvar->hosts_state.hostkey.mod = copy_mp_int(key->mod);
                break;
        case KEY_RSA: // SSH2 RSA
                pvar->hosts_state.hostkey.rsa = duplicate_RSA(key->rsa);
                break;
        case KEY_DSA: // SSH2 DSA
                pvar->hosts_state.hostkey.dsa = duplicate_DSA(key->dsa);
                break;
        case KEY_ECDSA256: // SSH2 ECDSA
        case KEY_ECDSA384:
        case KEY_ECDSA521:
                pvar->hosts_state.hostkey.ecdsa = EC_KEY_dup(key->ecdsa);
                break;
        }
        free(pvar->hosts_state.prefetched_hostname);
        pvar->hosts_state.prefetched_hostname = _strdup(hostname);

        // "/nosecuritywarning"���w�����������������A�_�C�A���O���\���������� return success �����B
        if (pvar->nocheck_known_hosts == TRUE) {
                return TRUE;
        }

        if (pvar->settings.VerifyHostKeyDNS && !is_numeric_hostname(hostname)) {
                dns_sshfp_check = verify_hostkey_dns(hostname, key);
        }

        // known_hosts�_�C�A���O�������I���\�������A�������_�����������[�U���m�F
        // �������K�v�����������A�����R�[�������X�����B
        // ����������known_hosts���m�F�����������A�T�[�o�����[�U���������������������������������B
        // (2007.10.1 yutaka)
        if (found_different_key) {
                HOSTS_do_different_key_dialog(pvar->NotificationWindow, pvar);
        }
        else if (found_different_type_key) {
                HOSTS_do_different_type_key_dialog(pvar->NotificationWindow, pvar);
        }
        else {
                HOSTS_do_unknown_host_dialog(pvar->NotificationWindow, pvar);
        }

        return TRUE;
}

void HOSTS_notify_disconnecting(PTInstVar pvar)
{
        if (pvar->hosts_state.hosts_dialog != NULL) {
                PostMessage(pvar->hosts_state.hosts_dialog, WM_COMMAND, IDCANCEL, 0);
                /* the main window might not go away if it's not enabled. (see vtwin.cpp) */
                EnableWindow(pvar->NotificationWindow, TRUE);
        }
}

void HOSTS_end(PTInstVar pvar)
{
        int i;

        free(pvar->hosts_state.prefetched_hostname);
        init_hostkey(&pvar->hosts_state.hostkey);

        if (pvar->hosts_state.file_names != NULL) {
                for (i = 0; pvar->hosts_state.file_names[i] != NULL; i++) {
                        free(pvar->hosts_state.file_names[i]);
                }
                free(pvar->hosts_state.file_names);
        }
}