libssh2

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/* Copyright (C) Xaver Loppenstedt <xaver@loppenstedt.de>
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms,
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 * with or without modification, are permitted provided
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 * that the following conditions are met:
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 *
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 *   Redistributions of source code must retain the above
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 *   copyright notice, this list of conditions and the
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 *   following disclaimer.
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 *
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 *   Redistributions in binary form must reproduce the above
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 *   copyright notice, this list of conditions and the following
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 *   disclaimer in the documentation and/or other materials
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 *   provided with the distribution.
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 *
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 *   Neither the name of the copyright holder nor the names
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 *   of any other contributors may be used to endorse or
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 *   promote products derived from this software without
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 *   specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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 * OF SUCH DAMAGE.
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 *
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 * SPDX-License-Identifier: BSD-3-Clause
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 */
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#include "libssh2_priv.h"
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#include "userauth_kbd_packet.h"
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int userauth_keyboard_interactive_decode_info_request(LIBSSH2_SESSION *session)
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{
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    unsigned char *language_tag;
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    size_t language_tag_len;
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    unsigned int i;
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    unsigned char packet_type;
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    uint32_t tmp_u32;
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    struct string_buf decoded;
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    decoded.data = session->userauth_kybd_data;
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    decoded.dataptr = session->userauth_kybd_data;
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    decoded.len = session->userauth_kybd_data_len;
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    if(session->userauth_kybd_data_len < 17) {
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        _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
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                       "userauth keyboard data buffer too small "
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                       "to get length");
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        return -1;
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    }
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    /* byte      SSH_MSG_USERAUTH_INFO_REQUEST */
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    _libssh2_get_byte(&decoded, &packet_type);
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    /* string    name (ISO-10646 UTF-8) */
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    if(_libssh2_copy_string(session, &decoded,
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                            &session->userauth_kybd_auth_name,
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                            &session->userauth_kybd_auth_name_len) == -1) {
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        _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                       "Unable to decode "
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                       "keyboard-interactive 'name' "
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                       "request field");
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        return -1;
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    }
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    /* string    instruction (ISO-10646 UTF-8) */
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    if(_libssh2_copy_string(session, &decoded,
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                            &session->userauth_kybd_auth_instruction,
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                            &session->userauth_kybd_auth_instruction_len)
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       == -1) {
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        _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                       "Unable to decode "
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                       "keyboard-interactive 'instruction' "
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                       "request field");
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        return -1;
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    }
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    /* string    language tag (as defined in [RFC-3066]) */
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    if(_libssh2_get_string(&decoded, &language_tag,
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                           &language_tag_len) == -1) {
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        _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                       "Unable to decode "
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                       "keyboard-interactive 'language tag' "
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                       "request field");
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        return -1;
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    }
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    /* int       num-prompts */
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    if(_libssh2_get_u32(&decoded, &tmp_u32) == -1 ||
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       (session->userauth_kybd_num_prompts = tmp_u32) != tmp_u32) {
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        _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
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                       "Unable to decode "
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                       "keyboard-interactive number of keyboard prompts");
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        return -1;
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    }
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    if(session->userauth_kybd_num_prompts > 100) {
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        _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY,
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                       "Too many replies for "
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                       "keyboard-interactive prompts");
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        return -1;
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    }
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    if(session->userauth_kybd_num_prompts == 0) {
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        return 0;
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    }
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    session->userauth_kybd_prompts =
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        LIBSSH2_CALLOC(session,
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                       sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) *
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                       session->userauth_kybd_num_prompts);
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    if(!session->userauth_kybd_prompts) {
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        _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                       "Unable to allocate memory for "
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                       "keyboard-interactive prompts array");
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        return -1;
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    }
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    session->userauth_kybd_responses =
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        LIBSSH2_CALLOC(session,
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                       sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) *
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                       session->userauth_kybd_num_prompts);
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    if(!session->userauth_kybd_responses) {
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        _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                       "Unable to allocate memory for "
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                       "keyboard-interactive responses array");
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        return -1;
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    }
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    for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
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        /* string    prompt[1] (ISO-10646 UTF-8) */
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        if(_libssh2_copy_string(session, &decoded,
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                                &session->userauth_kybd_prompts[i].text,
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                                &session->userauth_kybd_prompts[i].length)
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           == -1) {
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            _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
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                           "Unable to decode "
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                           "keyboard-interactive prompt message");
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            return -1;
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        }
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        /* boolean   echo[1] */
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        if(_libssh2_get_boolean(&decoded,
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                                &session->userauth_kybd_prompts[i].echo)
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           == -1) {
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            _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
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                           "Unable to decode "
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                           "user auth keyboard prompt echo");
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            return -1;
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        }
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    }
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    return 0;
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}
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