This way we will get errors as return code else we don't know if the
function failed (SSH_ERROR) or the exit_status is -1 which would
correspond to SSH_ERROR.
Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
This is what we get in the packet and is defined in RFC4254.
Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Legacy code in 'ssh_set_callbacks' will fallback to
'ssh_legacy_log_callback' (if the current log cb is
NULL) setting the user data to the current session.
However, if any other session is created afterwards,
it won't update the user data with the new session,
potentially leading to a use-after-free.
Fixes#238.
Signed-off-by: Diego Roux <diegoroux04@protonmail.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
When opening a PTY on the server, try to use the current TTY's settings
(i.e. based on STDIN). If that fails or STDIN isn't a TTY, use default
modes that avoid any character translation.
Don't rely on stdin to be a TTY (breaks CI). Instead, open a PTY and
temporarily use that as "fake" stdin.
Signed-off-by: Daniel Evers (daniel.evers@utimaco.com)
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Added the new function `ssh_channel_request_pty_size_modes` which allows
to pass additional encoded SSH terminal modes (see opcodes in RFC 4245).
Signed-off-by: Daniel Evers (daniel.evers@utimaco.com)
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Malicious code can be injected using the username with metacharacters,
therefore the username must be validated before using it with any %u.
Signed-off-by: Norbert Pocs <norbertpocs0@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>
The closing brace of the @addtogroup command was too low, causing some logging
functions to be added to the threads group.
Signed-off-by: James Wrigley <james@puiterwijk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Norbert Pocs <norbertpocs0@gmail.com>
The hostname can be a domain name or an ip address. The colon has to be
allowed because of IPv6 even it is prohibited in domain names.
Signed-off-by: Norbert Pocs <norbertpocs0@gmail.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
This also adds an fallback to OpenSSH file format in non-OpenSSL backends and
OpenSSH-compatible private key export for writing OpenSSH private keys.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This involves reading the certificates from configuration files through options
and handling them similarly as the OpenSSH does when doing the auto pubkey
authentication, also in combination with agent or identities only.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Sahana Prasad <sahana@redhat.com>
The existing sftp async read api has two problems :
1. sftp_async_read() assumes that the value of the third
parameter count is same as the number of bytes requested
to read in the corresponding call to sftp_async_read_begin().
But the documentation of sftp_async_read() allows the value of
count parameter to be more than that requested length. If value
of count parameter is more than that requested length then
sftp_async_read() updates the file->offset incorrectly which
leads to further read/writes occuring from incorrect offsets.
The problem here is that sftp_async_read() doesn't know about
the number of bytes requested to read specified in the call to
sftp_async_read_begin(), and it wrongly assumes the value
of its count parameter (which is actually the size of the buffer
to store the read data) to be the same as the number of bytes
requested to read.
2. sftp_async_read_begin() returns an uint32_t type value type
casted to int as a request identifier, whereas sftp_async_read()
expects an uint32_t type value as a request identifier. Due to this
the user has to typecast the identifier returned by sftp_async_read_begin()
from int to uint32_t and then pass it to sftp_async_read(). This
type casting is cumbersome for the user and hence the approach is
not user-friendly.
This commit solves the above two problems by introducing a new
sftp aio api.
The sftp_aio_begin_*() functions in the api send an i/o request to
the sftp server and provide the caller a dynamically allocated
structure storing information about the sent request. Information
like number of bytes requested for i/o, id of sent request etc is
stored in the structure.
That structure should be provided to the sftp_aio_wait_*() functions
in the api which wait for the response corresponding to the request whose
info is stored in the provided structure.
The libssh user is supposed to handle that structure through an
opaque type sftp_aio.
Since the structure stores the number of bytes requested for i/o,
sftp_aio_wait_*() knows about the number of bytes requested for i/o
(specified in the call to sftp_aio_begin_*()) and hence updates the
file->offset correctly solving problem #1 present in the existing
async api.
Since the structure provided by sftp_aio_begin_*() (containing the
request id) is supplied to sftp_aio_wait_*(), no casting of id's
needs to be done by the user solving problem #2 of the existing
async api.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Sahana Prasad <sahana@redhat.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>
The intention is that this releases memory allocated by the crypto
library, for functions like bignum_bn2hex() and bignum_bn2dec().
Consequently, ssh_gcry_bn2dec and ssh_mbedcry_bn2num should use
gcry_malloc() and mbedtls_calloc() respectively to allocate
memory since it will/should be released by ssh_crypto_free() so
that the internal APIs are consistent between crypto libraries.
Signed-off-by: Simon Josefsson <simon@josefsson.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
A call to write() may perform a short write on a local file.
To avoid short writes, ssh_writen() can be used.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Norbert Pocs <npocs@redhat.com>
A call to read() may peform a short read from a local file even when
sufficient data is present in the file. ssh_readn() can be used
instead of read() to avoid such short reads.
Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Norbert Pocs <npocs@redhat.com>
This aligns it with libgcrypt/OpenSSL backends which uses char*.
It also aligns mbedcrypto's bignum_bn2hex() to use an unsigned
cast just like OpenSSL backend.
Signed-off-by: Simon Josefsson <simon@josefsson.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
