On 32b architecture when processing the SFTP packets, the value
0x7ffffffc in the payload_len will overflow to negative integer values,
causing these checks to pass and possibly reading behind the buffer
bounds later.
This affects only SFTP server implementations running on 32b
architecture.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Since sftp_init() returns 0 on success, < 0 on error with ssh error set. This
change sets the appropriate ssh error when the SSH_FXP_VERSION packet cannot be
unpacked and sftp_init() return with -1.
Signed-off-by: Ajit Singh <ajeetsinghchahar2@gmail.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
In the sftp_init() call, the limits are stored in the sftp_sesssion.
If the limits@openssh.com extension is supported the limits are retrieved
from the server, else libssh uses the default limits.
The sftp library functions that require the limits can access them using
the sftp session.
The library user can call sftp_limits() to get a copy of the limits
stored in the sftp session. Since the limits were already retrieved
from the server during sftp_init(), this sftp_limits() call requires
no communication with the server.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Currently the sftp api code is limited to sftp.c, sftpserver.c
In future it can be required to add new sftp related APIs which
are present in their own separate source files instead of adding
their code to the already large sftp.c file.
Those new hypothetical or existing (in sftpserver.c) sftp API
functions present in the source files other than sftp.c will
need to call certain functions present in sftp.c which are not
provided in the public api as they are for internal use (by other
sftp related functions) only. Some of these sftp.c functions have
external linkage, some of them don't and cannot be currently accessed
outside sftp.c
This commit :
1. Moves such functions along with the functions they depend on
from sftp.c to a new file sftp_common.c, to seperate them out
from other sftp api functions.
2. Makes necessary changes to make required functions visible
outside sftp_common.c
3. Uses the header file sftp_priv.h for necessary declarations
(and not sftp.h) since these functions are not to be provided
in the public sftp api.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Sahana Prasad <sahana@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
The curl does not do any (or enough) chunking when writing large files using the
sftp_write() function which causes some servers to choke [1]. The simplest
solution is to limit the SFTP packet size according the SFTP specification
recommendation which is 32768 B and not write more.
This means the function will not write the whole amount of data it was asked to
write and the calling applications are required to handle the return values
correctly.
More complicated solution would be to send several SFTP packet from the single
sftp_write() function by iterating over the all data passed.
The next improvement in the long term should be respecting the value reported by
the server in the limits@openssh.com extension, which specifies the maximum
packet size and reads/writes explicitly (if supported).
[1] https://github.com/curl/curl/pull/11804
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
... to better describe the function, which is only replying to the client with
our version and extensions.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Changes done in sftp_rename such that it will use
posix-rename@openssh.com extension if supported
and send a SSH_FXP_EXTENDED request. If the
extension is not supported a normal SSH_FXP_RENAME
request will be sent.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
sftp_hardlink() has been introduced which when called
sends a SSH_FXP_EXTENDED request to server for creating
a hardlink.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
uint32_t should be formated by PRI?32
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Change-Id: I811cfd764010f9e8bb599b370155ac065ee1905c
Loglevel INFO is the default openssh configuration setting which does not print
redundant information. On a system using openssh with loglevels set by the
terms of openssh will cause unwanted log lines in the output.
recategorized based on - SSH_LOG_DEBUG are informational debug logs (no error)
Signed-off-by: Norbert Pocs <npocs@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
to avoid allocate 16KB buffer from stack and one memory copy
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Change-Id: Ib71cb5834b7810bf9791e13c58571e2b9fa5bca1
All subsecond timestamps are only in the packets if both the
SUBSECOND_TIMES flag and the timestamp flag, e.g. ATTR_ACCESSTIME
are set.
SUBSECOND_TIMES are not very common across server implementations
(e.g. openssh does not include it, nor does libssh's sftpserver
implementation), but this interpretation of the SFTP protocol draft
is used by WinSCP and lftp.
Fixes T219.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
