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/*
* Copyright (c) 2013 Lukasz Marek <lukasz.m.luki@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <fcntl.h>
#define LIBSSH_STATIC
#include <libssh/sftp.h>
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "libavutil/attributes.h"
#include "avformat.h"
#include "internal.h"
#include "url.h"
typedef struct {
const AVClass *class;
ssh_session session;
sftp_session sftp;
sftp_file file;
int64_t filesize;
int rw_timeout;
int trunc;
char *priv_key;
} LIBSSHContext;
static av_cold int libssh_create_ssh_session(LIBSSHContext *libssh, const char* hostname, unsigned int port)
{
static const int verbosity = SSH_LOG_NOLOG;
if (!(libssh->session = ssh_new())) {
av_log(libssh, AV_LOG_ERROR, "SSH session creation failed: %s\n", ssh_get_error(libssh->session));
return AVERROR(ENOMEM);
}
ssh_options_set(libssh->session, SSH_OPTIONS_HOST, hostname);
ssh_options_set(libssh->session, SSH_OPTIONS_PORT, &port);
ssh_options_set(libssh->session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
if (libssh->rw_timeout > 0) {
long timeout = libssh->rw_timeout * 1000;
ssh_options_set(libssh->session, SSH_OPTIONS_TIMEOUT_USEC, &timeout);
}
if (ssh_options_parse_config(libssh->session, NULL) < 0) {
av_log(libssh, AV_LOG_WARNING, "Could not parse the config file.\n");
}
if (ssh_connect(libssh->session) != SSH_OK) {
av_log(libssh, AV_LOG_ERROR, "Connection failed: %s\n", ssh_get_error(libssh->session));
return AVERROR(EIO);
}
return 0;
}
static av_cold int libssh_authentication(LIBSSHContext *libssh, const char *user, const char *password)
{
int authorized = 0;
int auth_methods;
if (user)
ssh_options_set(libssh->session, SSH_OPTIONS_USER, user);
if (ssh_userauth_none(libssh->session, NULL) == SSH_AUTH_SUCCESS)
return 0;
auth_methods = ssh_userauth_list(libssh->session, NULL);
if (auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
if (libssh->priv_key) {
ssh_string pub_key;
ssh_private_key priv_key;
int type;
if (!ssh_try_publickey_from_file(libssh->session, libssh->priv_key, &pub_key, &type)) {
priv_key = privatekey_from_file(libssh->session, libssh->priv_key, type, password);
if (ssh_userauth_pubkey(libssh->session, NULL, pub_key, priv_key) == SSH_AUTH_SUCCESS) {
av_log(libssh, AV_LOG_DEBUG, "Authentication successful with selected private key.\n");
authorized = 1;
}
} else {
av_log(libssh, AV_LOG_DEBUG, "Invalid key is provided.\n");
return AVERROR(EACCES);
}
} else if (ssh_userauth_autopubkey(libssh->session, password) == SSH_AUTH_SUCCESS) {
av_log(libssh, AV_LOG_DEBUG, "Authentication successful with auto selected key.\n");
authorized = 1;
}
}
if (!authorized && (auth_methods & SSH_AUTH_METHOD_PASSWORD)) {
if (ssh_userauth_password(libssh->session, NULL, password) == SSH_AUTH_SUCCESS) {
av_log(libssh, AV_LOG_DEBUG, "Authentication successful with password.\n");
authorized = 1;
}
}
if (!authorized) {
av_log(libssh, AV_LOG_ERROR, "Authentication failed.\n");
return AVERROR(EACCES);
}
return 0;
}
static av_cold int libssh_create_sftp_session(LIBSSHContext *libssh)
{
if (!(libssh->sftp = sftp_new(libssh->session))) {
av_log(libssh, AV_LOG_ERROR, "SFTP session creation failed: %s\n", ssh_get_error(libssh->session));
return AVERROR(ENOMEM);
}
if (sftp_init(libssh->sftp) != SSH_OK) {
av_log(libssh, AV_LOG_ERROR, "Error initializing sftp session: %s\n", ssh_get_error(libssh->session));
return AVERROR(EIO);
}
return 0;
}
static av_cold int libssh_open_file(LIBSSHContext *libssh, int flags, const char *file)
{
int access;
if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
access = O_CREAT | O_RDWR;
if (libssh->trunc)
access |= O_TRUNC;
} else if (flags & AVIO_FLAG_WRITE) {
access = O_CREAT | O_WRONLY;
if (libssh->trunc)
access |= O_TRUNC;
} else
access = O_RDONLY;
/* 0666 = -rw-rw-rw- = read+write for everyone, minus umask */
if (!(libssh->file = sftp_open(libssh->sftp, file, access, 0666))) {
av_log(libssh, AV_LOG_ERROR, "Error opening sftp file: %s\n", ssh_get_error(libssh->session));
return AVERROR(EIO);
}
return 0;
}
static av_cold void libssh_stat_file(LIBSSHContext *libssh)
{
sftp_attributes stat;
if (!(stat = sftp_fstat(libssh->file))) {
av_log(libssh, AV_LOG_WARNING, "Cannot stat remote file.\n");
libssh->filesize = -1;
} else {
libssh->filesize = stat->size;
sftp_attributes_free(stat);
}
}
static av_cold int libssh_close(URLContext *h)
{
LIBSSHContext *libssh = h->priv_data;
if (libssh->file) {
sftp_close(libssh->file);
libssh->file = NULL;
}
if (libssh->sftp) {
sftp_free(libssh->sftp);
libssh->sftp = NULL;
}
if (libssh->session) {
ssh_disconnect(libssh->session);
ssh_free(libssh->session);
libssh->session = NULL;
}
return 0;
}
static av_cold int libssh_open(URLContext *h, const char *url, int flags)
{
LIBSSHContext *libssh = h->priv_data;
char proto[10], path[MAX_URL_SIZE], hostname[1024], credencials[1024];
int port, ret;
const char *user = NULL, *pass = NULL;
char *end = NULL;
av_url_split(proto, sizeof(proto),
credencials, sizeof(credencials),
hostname, sizeof(hostname),
&port,
path, sizeof(path),
url);
// a port of 0 will use a port from ~/.ssh/config or the default value 22
if (port < 0 || port > 65535)
port = 0;
if ((ret = libssh_create_ssh_session(libssh, hostname, port)) < 0)
goto fail;
user = av_strtok(credencials, ":", &end);
pass = av_strtok(end, ":", &end);
if ((ret = libssh_authentication(libssh, user, pass)) < 0)
goto fail;
if ((ret = libssh_create_sftp_session(libssh)) < 0)
goto fail;
if ((ret = libssh_open_file(libssh, flags, path)) < 0)
goto fail;
libssh_stat_file(libssh);
return 0;
fail:
libssh_close(h);
return ret;
}
static int64_t libssh_seek(URLContext *h, int64_t pos, int whence)
{
LIBSSHContext *libssh = h->priv_data;
int64_t newpos;
if (libssh->filesize == -1 && (whence == AVSEEK_SIZE || whence == SEEK_END)) {
av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
return AVERROR(EIO);
}
switch(whence) {
case AVSEEK_SIZE:
return libssh->filesize;
case SEEK_SET:
newpos = pos;
break;
case SEEK_CUR:
newpos = sftp_tell64(libssh->file) + pos;
break;
case SEEK_END:
newpos = libssh->filesize + pos;
break;
default:
return AVERROR(EINVAL);
}
if (newpos < 0) {
av_log(h, AV_LOG_ERROR, "Seeking to nagative position.\n");
return AVERROR(EINVAL);
}
if (sftp_seek64(libssh->file, newpos)) {
av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
return AVERROR(EIO);
}
return newpos;
}
static int libssh_read(URLContext *h, unsigned char *buf, int size)
{
LIBSSHContext *libssh = h->priv_data;
int bytes_read;
if ((bytes_read = sftp_read(libssh->file, buf, size)) < 0) {
av_log(libssh, AV_LOG_ERROR, "Read error.\n");
return AVERROR(EIO);
}
return bytes_read;
}
static int libssh_write(URLContext *h, const unsigned char *buf, int size)
{
LIBSSHContext *libssh = h->priv_data;
int bytes_written;
if ((bytes_written = sftp_write(libssh->file, buf, size)) < 0) {
av_log(libssh, AV_LOG_ERROR, "Write error.\n");
return AVERROR(EIO);
}
return bytes_written;
}
#define OFFSET(x) offsetof(LIBSSHContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
{"truncate", "Truncate existing files on write", OFFSET(trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
{"private_key", "set path to private key", OFFSET(priv_key), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D|E },
{NULL}
};
static const AVClass libssh_context_class = {
.class_name = "libssh",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
URLProtocol ff_libssh_protocol = {
.name = "sftp",
.url_open = libssh_open,
.url_read = libssh_read,
.url_write = libssh_write,
.url_seek = libssh_seek,
.url_close = libssh_close,
.priv_data_size = sizeof(LIBSSHContext),
.priv_data_class = &libssh_context_class,
.flags = URL_PROTOCOL_FLAG_NETWORK,
};
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