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maya |
3227 |
/* |
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doda |
6841 |
* Copyright (c) 1998-2001, Robert O'Callahan |
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nmaya |
9048 |
* (C) 2004- TeraTerm Project |
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doda |
6841 |
* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. The name of the author may not be used to endorse or promote products |
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* derived from this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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maya |
3227 |
|
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/* |
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This code is copyright (C) 1998-1999 Robert O'Callahan. |
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See LICENSE.TXT for the license. |
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*/ |
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#include "ttxssh.h" |
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#include "util.h" |
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#include "pkt.h" |
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#define READAMOUNT CHAN_SES_WINDOW_DEFAULT |
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void PKT_init(PTInstVar pvar) |
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{ |
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buf_create(&pvar->pkt_state.buf, &pvar->pkt_state.buflen); |
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pvar->pkt_state.datastart = 0; |
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pvar->pkt_state.datalen = 0; |
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pvar->pkt_state.seen_server_ID = FALSE; |
| 47 |
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pvar->pkt_state.seen_newline = FALSE; |
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pvar->pkt_state.predecrypted_packet = FALSE; |
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} |
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/* Read some data, leave no more than up_to_amount bytes in the buffer, |
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return the number of bytes read or -1 on error or blocking. */ |
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static int recv_data(PTInstVar pvar, unsigned long up_to_amount) |
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{ |
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int amount_read; |
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| 57 |
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/* Shuffle data to the start of the buffer */ |
| 58 |
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if (pvar->pkt_state.datastart != 0) { |
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memmove(pvar->pkt_state.buf, |
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pvar->pkt_state.buf + pvar->pkt_state.datastart, |
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pvar->pkt_state.datalen); |
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pvar->pkt_state.datastart = 0; |
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} |
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doda |
6966 |
buf_ensure_size(&pvar->pkt_state.buf, &pvar->pkt_state.buflen, up_to_amount); |
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maya |
3227 |
|
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_ASSERT(pvar->pkt_state.buf != NULL); |
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amount_read = (pvar->Precv) (pvar->socket, |
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doda |
6966 |
pvar->pkt_state.buf + pvar->pkt_state.datalen, |
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maya |
3227 |
up_to_amount - pvar->pkt_state.datalen, |
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0); |
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if (amount_read > 0) { |
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/* Update seen_newline if necessary */ |
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doda |
6966 |
if (!pvar->pkt_state.seen_server_ID && !pvar->pkt_state.seen_newline) { |
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maya |
3227 |
int i; |
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for (i = 0; i < amount_read; i++) { |
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doda |
6966 |
if (pvar->pkt_state.buf[pvar->pkt_state.datalen + i] == '\n') { |
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maya |
3227 |
pvar->pkt_state.seen_newline = 1; |
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} |
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} |
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} |
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pvar->pkt_state.datalen += amount_read; |
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} |
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return amount_read; |
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} |
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// ���s�R�[�h���o�������������� |
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static int recv_line_data(PTInstVar pvar) |
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{ |
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int amount_read; |
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char buf[256]; |
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size_t up_to_amount = sizeof(buf); |
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int i; |
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/* Shuffle data to the start of the buffer */ |
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if (pvar->pkt_state.datastart != 0) { |
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memmove(pvar->pkt_state.buf, |
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pvar->pkt_state.buf + pvar->pkt_state.datastart, |
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pvar->pkt_state.datalen); |
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pvar->pkt_state.datastart = 0; |
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} |
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doda |
6966 |
buf_ensure_size(&pvar->pkt_state.buf, &pvar->pkt_state.buflen, up_to_amount); |
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maya |
3227 |
|
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for (i = 0 ; i < (int)up_to_amount ; i++) { |
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doda |
6966 |
amount_read = (pvar->Precv) (pvar->socket, &buf[i], 1, 0); |
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maya |
3227 |
if (amount_read != 1) { |
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return 0; // error |
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zmatsuo |
10618 |
} |
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maya |
3227 |
|
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pvar->pkt_state.datalen += amount_read; |
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if (buf[i] == '\n') { // 0x0a |
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buf[i+1] = 0; |
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break; |
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} |
| 121 |
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} |
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amount_read = i + 1; // ���������T�C�Y�iLF�������j |
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memcpy(pvar->pkt_state.buf, buf, amount_read); |
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pvar->pkt_state.seen_newline = 1; |
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| 127 |
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return amount_read; |
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} |
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/* This function does two things: |
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-- reads data from the sshd and feeds the SSH protocol packets to ssh.c |
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-- copies any available decrypted session data into the application buffer |
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*/ |
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doda |
6801 |
int PKT_recv(PTInstVar pvar, char *buf, int buflen) |
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maya |
3227 |
{ |
| 136 |
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int amount_in_buf = 0; |
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BOOL connection_closed = FALSE; |
| 138 |
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while (SSH_is_any_payload(pvar) ? buflen > 0 : !connection_closed) { |
| 140 |
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if (SSH_is_any_payload(pvar)) { |
| 141 |
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/* ssh.c has some session data for us to give to Tera Term. */ |
| 142 |
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int grabbed = SSH_extract_payload(pvar, buf, buflen); |
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amount_in_buf += grabbed; |
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buf += grabbed; |
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buflen -= grabbed; |
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doda |
6968 |
} |
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else if (!pvar->pkt_state.seen_server_ID && (pvar->pkt_state.seen_newline || pvar->pkt_state.datalen >= 255)) { |
| 149 |
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/* |
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* We're looking for the initial ID string and either we've seen the |
| 151 |
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* terminating newline, or we've exceeded the limit at which we should see a newline. |
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*/ |
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maya |
3227 |
unsigned int i; |
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doda |
6966 |
for (i = 0; pvar->pkt_state.buf[i] != '\n' && i < pvar->pkt_state.datalen; i++) { |
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maya |
3227 |
} |
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if (pvar->pkt_state.buf[i] == '\n') { |
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i++; |
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} |
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// SSH�T�[�o���o�[�W�����`�F�b�N���s�� |
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if (SSH_handle_server_ID(pvar, pvar->pkt_state.buf, i)) { |
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pvar->pkt_state.seen_server_ID = 1; |
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doda |
6966 |
if (SSHv2(pvar)) { |
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maya |
3227 |
// send Key Exchange Init |
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SSH2_send_kexinit(pvar); |
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} |
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maya |
4549 |
} else { |
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// reset flag to re-read server ID (2008.1.24 yutaka) |
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pvar->pkt_state.seen_newline = 0; |
| 172 |
maya |
3227 |
} |
| 173 |
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pvar->pkt_state.datastart += i; |
| 175 |
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pvar->pkt_state.datalen -= i; |
| 176 |
doda |
6968 |
} |
| 177 |
doda |
6982 |
else if (pvar->pkt_state.seen_server_ID && pvar->pkt_state.datalen >= SSH_get_min_packet_size(pvar)) { |
| 178 |
doda |
6966 |
char *data = pvar->pkt_state.buf + pvar->pkt_state.datastart; |
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nmaya |
9255 |
uint32 padding_size = 0; |
| 180 |
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uint32 pktsize = 0; |
| 181 |
maya |
3227 |
uint32 total_packet_size; |
| 182 |
doda |
6969 |
struct Mac *mac = &pvar->ssh2_keys[MODE_IN].mac; |
| 183 |
doda |
6985 |
struct Enc *enc = &pvar->ssh2_keys[MODE_IN].enc; |
| 184 |
nmaya |
9255 |
int authlen = 0, aadlen = 0; |
| 185 |
maya |
3227 |
|
| 186 |
nmaya |
9255 |
if (SSHv2(pvar)) { |
| 187 |
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/* |
| 188 |
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* pktsize |
| 189 |
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* uint32 packet_length |
| 190 |
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* �� |
| 191 |
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* byte padding_length |
| 192 |
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* byte[n1] payload; n1 = packet_length - padding_length - 1 |
| 193 |
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* byte[n2] random padding; n2 = padding_length |
| 194 |
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* �����������v�� |
| 195 |
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* byte[m] mac (Message Authentication Code - MAC); m = mac_length |
| 196 |
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* �����������������B |
| 197 |
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* cf. RFC 4253 6. Binary Packet Protocol |
| 198 |
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*/ |
| 199 |
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| 200 |
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if (enc && enc->auth_len > 0) { |
| 201 |
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authlen = enc->auth_len; |
| 202 |
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} |
| 203 |
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|
| 204 |
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/* |
| 205 |
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* | | lead 4 bytes are encrypted | aadlen | |
| 206 |
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* Encryption type |
| 207 |
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* enc->auth_len > 0 | AEAD | AES-GCM ... no | 4 | (2) |
| 208 |
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* | | chacha20-poly1305 ... yes | 4 | (1) (2) |
| 209 |
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* enc->auth_len == 0 | not AEAD | depends on MAC type | <- | |
| 210 |
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* MAC type |
| 211 |
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* mac->etm == true | EtM | no | 4 | |
| 212 |
|
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* mac->etm == false | E&M | yes | 0 | |
| 213 |
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* (1) lead 4 bytes are encrypted separately from main part. |
| 214 |
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* (2) implicit MAC type of AEAD is EtM |
| 215 |
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*/ |
| 216 |
|
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/* |
| 217 |
|
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* aadlen: Additional Authenticated Data Length |
| 218 |
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* MAC �������������f�[�^�����������������������A"MAC �������������f�[�^������"���T�C�Y |
| 219 |
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* ���������� packet_length ���Auint32 (4�o�C�g) |
| 220 |
zmatsuo |
10618 |
* |
| 221 |
nmaya |
9255 |
* - ������ MAC ���� (E&M) �����p�P�b�g������������������������������ aadlen �� 0 �������B |
| 222 |
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* - EtM ������ MAC �� AEAD �� AES-GCM �����A�p�P�b�g�������������������������� |
| 223 |
|
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* aadlen �� 4 �������B |
| 224 |
|
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* - AEAD �� chacha20-poly1305 �����p�P�b�g�����������������������AMAC �������������f�[�^ |
| 225 |
|
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* ������������������������ aadlen �� 4 �������B |
| 226 |
zmatsuo |
10618 |
* |
| 227 |
nmaya |
9255 |
*/ |
| 228 |
|
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if ((mac && mac->etm) || authlen > 0) { |
| 229 |
|
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aadlen = 4; |
| 230 |
|
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} |
| 231 |
|
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|
| 232 |
|
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if (authlen > 0 && |
| 233 |
|
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pvar->cc[MODE_IN]->cipher->id == SSH2_CIPHER_CHACHAPOLY) { |
| 234 |
|
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/* |
| 235 |
|
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* AEAD �� chacha20-poly1305 �����p�P�b�g�����������������������������B |
| 236 |
|
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* ���������������������������Adata �������������������������B |
| 237 |
|
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*/ |
| 238 |
|
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chachapoly_get_length(pvar->cc[MODE_IN]->cp_ctx, &pktsize, |
| 239 |
|
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pvar->ssh_state.receiver_sequence_number, |
| 240 |
|
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data, pvar->pkt_state.datalen); |
| 241 |
|
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} |
| 242 |
|
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else if (authlen == 0 && |
| 243 |
|
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aadlen == 0 && |
| 244 |
|
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!pvar->pkt_state.predecrypted_packet && aadlen == 0) { |
| 245 |
|
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/* |
| 246 |
|
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* AEAD ������ E&M (aadlen �� 0) �������A�����������������p�P�b�g���� |
| 247 |
|
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* �m���K�v���L�������A������ 1 �u���b�N�������O�����������B |
| 248 |
|
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*/ |
| 249 |
|
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SSH_predecrypt_packet(pvar, data); |
| 250 |
|
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pvar->pkt_state.predecrypted_packet = TRUE; |
| 251 |
|
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|
| 252 |
|
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pktsize = get_uint32_MSBfirst(data); |
| 253 |
|
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} |
| 254 |
|
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else { |
| 255 |
|
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/* |
| 256 |
|
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* EtM ������ MAC ���AAEAD �� AES-GCM ���������������������������B |
| 257 |
|
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*/ |
| 258 |
|
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pktsize = get_uint32_MSBfirst(data); |
| 259 |
|
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} |
| 260 |
doda |
6985 |
} |
| 261 |
|
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else { |
| 262 |
nmaya |
9255 |
pktsize = get_uint32_MSBfirst(data); |
| 263 |
doda |
6985 |
} |
| 264 |
doda |
6969 |
|
| 265 |
maya |
3227 |
if (SSHv1(pvar)) { |
| 266 |
doda |
6983 |
// SSH1 �����p�P�b�g�����l���� padding �����������������������B |
| 267 |
|
|
// ���� padding ���������������p�P�b�g���������������A�p�P�b�g�����l�����v�Z�����B |
| 268 |
nmaya |
9255 |
padding_size = 8 - (pktsize % 8); |
| 269 |
maya |
3227 |
|
| 270 |
nmaya |
9255 |
// ���~�������� pktsize �� padding_size ���l�������������������O���������������B |
| 271 |
|
|
pktsize += padding_size; |
| 272 |
maya |
3227 |
} |
| 273 |
|
|
|
| 274 |
nmaya |
9255 |
// �p�P�b�g(TCP�y�C���[�h)���S�����T�C�Y���A |
| 275 |
|
|
// 4�i�p�P�b�g�����T�C�Y�j+�p�P�b�g���i+MAC���T�C�Y�j�������B |
| 276 |
|
|
total_packet_size = 4 + pktsize + SSH_get_authdata_size(pvar, MODE_IN); |
| 277 |
maya |
3227 |
|
| 278 |
|
|
if (total_packet_size <= pvar->pkt_state.datalen) { |
| 279 |
doda |
6972 |
// ���M�����f�[�^���\���L���������p�P�b�g�����������s�� |
| 280 |
doda |
6968 |
if (SSHv1(pvar)) { |
| 281 |
doda |
6983 |
// SSH1 �� EtM ������ (�������� MAC �������� CRC ���g��) |
| 282 |
nmaya |
9255 |
SSH1_handle_packet(pvar, data, pktsize, padding_size); |
| 283 |
doda |
6968 |
} |
| 284 |
|
|
else { |
| 285 |
doda |
6983 |
// SSH2 �����������_���� padding ���������������������������������������A |
| 286 |
|
|
// padding �����n�������A�K�v���������������������������B |
| 287 |
nmaya |
9255 |
SSH2_handle_packet(pvar, data, pktsize, aadlen, authlen); |
| 288 |
doda |
6968 |
} |
| 289 |
doda |
6972 |
|
| 290 |
maya |
3227 |
pvar->pkt_state.predecrypted_packet = FALSE; |
| 291 |
|
|
pvar->pkt_state.datastart += total_packet_size; |
| 292 |
|
|
pvar->pkt_state.datalen -= total_packet_size; |
| 293 |
|
|
|
| 294 |
doda |
6983 |
} |
| 295 |
|
|
else if (total_packet_size > PACKET_MAX_SIZE) { |
| 296 |
doda |
6972 |
// �p�P�b�g�������������������������I�������B |
| 297 |
|
|
// �����������������v�����������s���p�P�b�g���������������������������B |
| 298 |
maya |
3227 |
UTIL_get_lang_msg("MSG_PKT_OVERSIZED_ERROR", pvar, |
| 299 |
maya |
4549 |
"Oversized packet received from server; connection will close."); |
| 300 |
zmatsuo |
10618 |
notify_fatal_error(pvar, pvar->UIMsg, TRUE); |
| 301 |
doda |
6983 |
} |
| 302 |
|
|
else { |
| 303 |
doda |
6966 |
int amount_read = recv_data(pvar, max(total_packet_size, READAMOUNT)); |
| 304 |
maya |
3227 |
|
| 305 |
|
|
if (amount_read == SOCKET_ERROR) { |
| 306 |
|
|
if (amount_in_buf == 0) { |
| 307 |
|
|
return SOCKET_ERROR; |
| 308 |
|
|
} else { |
| 309 |
|
|
return amount_in_buf; |
| 310 |
|
|
} |
| 311 |
|
|
} else { |
| 312 |
|
|
if (amount_read == 0) { |
| 313 |
|
|
connection_closed = TRUE; |
| 314 |
|
|
} |
| 315 |
|
|
} |
| 316 |
|
|
} |
| 317 |
|
|
} else { |
| 318 |
doda |
6966 |
// �p�P�b�g�����M |
| 319 |
maya |
3227 |
int amount_read; |
| 320 |
|
|
|
| 321 |
zmatsuo |
10959 |
// SCP�t�@�C�����M�������������~���������Arecv()���������B |
| 322 |
zmatsuo |
10960 |
if (pvar->recv.suspended) { |
| 323 |
zmatsuo |
10959 |
// �������������M�����f�[�^�T�C�Y��Tera Term���������B |
| 324 |
|
|
return amount_in_buf; |
| 325 |
|
|
|
| 326 |
|
|
} |
| 327 |
|
|
|
| 328 |
doda |
6966 |
amount_read = recv_data(pvar, READAMOUNT); |
| 329 |
maya |
3227 |
|
| 330 |
|
|
if (amount_read == SOCKET_ERROR) { |
| 331 |
|
|
if (amount_in_buf == 0) { |
| 332 |
|
|
return SOCKET_ERROR; |
| 333 |
|
|
} else { |
| 334 |
|
|
return amount_in_buf; |
| 335 |
|
|
} |
| 336 |
|
|
} else if (amount_read == 0) { |
| 337 |
|
|
connection_closed = TRUE; |
| 338 |
|
|
} |
| 339 |
|
|
} |
| 340 |
|
|
|
| 341 |
|
|
if (pvar->fatal_error) { |
| 342 |
|
|
return amount_in_buf; |
| 343 |
|
|
} |
| 344 |
|
|
} |
| 345 |
|
|
|
| 346 |
|
|
if (SSH_is_any_payload(pvar)) { |
| 347 |
doda |
6966 |
PostMessage(pvar->NotificationWindow, WM_USER_COMMNOTIFY, pvar->socket, MAKELPARAM(FD_READ, 0)); |
| 348 |
maya |
3227 |
} |
| 349 |
|
|
|
| 350 |
|
|
return amount_in_buf; |
| 351 |
|
|
} |
| 352 |
|
|
|
| 353 |
|
|
void PKT_end(PTInstVar pvar) |
| 354 |
|
|
{ |
| 355 |
|
|
buf_destroy(&pvar->pkt_state.buf, &pvar->pkt_state.buflen); |
| 356 |
|
|
} |