If the filename parameter for file_read_publickey() was the name of a
directory instead of a file then libssh2 would spin trying to fgetc()
from the FILE * for the opened directory when trying to determine the
length of the encoded public key, since fgetc() can't report errors.
Use fread() instead to correctly detect this error condition along
with many others.
This fixes the problem reported in
http://www.libssh2.org/mail/libssh2-devel-archive-2012-04/0021.shtml
Reported-by: Oleksiy Zagorskyi <zalex_ua@i.ua>
If the function that extracts/computes the public key from a private key
fails the errors it reports were masked by the function calling it. This
patch modifies the key extraction function to return errors using
_libssh_error() function. The error messages are tweaked to contain
reference to the failed operaton in addition to the reason.
* AUTHORS: - add my name
* libgcrypt.c: _libssh2_pub_priv_keyfile(): - return a more verbose
error using
_libssh2_error() func.
* openssl.c: - modify call graph of _libssh2_pub_priv_keyfile() to use
_libssh2_error for error reporting();
* userauth.c: - tweak functions calling _libssh2_pub_priv_keyfile() not
to shadow error messages
Partly reverse 566894494b4972ae12 which was simplifying the code far too
much and ended up overflowing a buffer within the LIBSSH2_SESSION
struct. Back to allocating the buffer properly like it used to do.
Bug: http://www.libssh2.org/mail/libssh2-devel-archive-2011-06/0032.shtml
Reported by: Alfred Gebert
Pass a NULL pointer for the publickey parameter of
libssh2_userauth_publickey_fromfile and
libssh2_userauth_hostbased_fromfile functions. In this case, the
functions recompute the public key from the private key file data.
This is work done by Jean-Louis CHARTON
<Jean-Louis.CHARTON@oikialog.com>, then adapted by Mark Smith and
slightly edited further by me Daniel.
WARNING: this does leave the feature NOT WORKING when libssh2 is built
to use libgcrypt instead of OpenSSL simply due to lack of
implementation.
The man page clearly says it returns 1 for "already authenticated" but
the code said non-zero. I changed the code to use 1 now, as that is also
non-zero but it gets the benefit that it now matches the documentation.
Using 1 instead of non-zero is better for two reasons:
1. We have the opportunity to introduce other return codes in the future for
things like error and what not.
2. We don't expose the internal bitmask variable value.
First I wanted to free the memory in session_free() but then
I had still memory leaks because in my test case the function
userauth_keyboard_interactive() is called twice. It is called
twice perhaps because the server has this authentication
methods available: publickey,gssapi-with-mic,keyboard-interactive
The keyboard-interactive method is successful.
The new function takes two data areas, combines them and sends them as a
single SSH packet. This allows several functions to allocate and copy
less data.
I also found and fixed a mixed up use of the compression function
arguments that I introduced in my rewrite in a recent commit.
The packet length calculated in src/userauth.c's
userauth_hostbased_fromfile() function is too short by 4 bytes;
it forgets to add four bytes for the length of the hostname.
This causes hostbased authentication to fail, since the server
will read junk data.
verified against proftpd's mod_sftp module
This functions get the method length by looking at the first 32
bit of data, and I now made it not accept method lengths that are
longer than the whole data set is, as given in the dedicated
function argument.
This was detected when the function was given bogus public key
data as an ascii string, which caused the first 32bits to create
a HUGE number.
Sending in NULL as the primary pointer is now dealt with by more
public functions. I also narrowed the userauth.c code somewhat to
stay within 80 columns better.
Passing an invalid public key to libssh2_userauth_publickey_fromfile_ex
triggered an assertion. Replaced this with a runtime check that rejects
obviously invalid key data.
To get the blocking vs non-blocking to work as smooth as possible
and behave better internally, we avoid using the external
interfaces when calling functions internally.
Renamed a few internal functions to use _libssh2 prefix when not
being private within a file, and removed the libssh2_ for one
that was private within the file.
This was triggered by a clang-analyzer complaint that turned out
to be valid, and it made me dig deeper and fix some generic non-
blocking problems I disovered in the code.
While cleaning this up, I moved session-specific stuff over to a
new session.h header from the libssh2_priv.h header.
I'll introduce a new internal function set named
_libssh2_store_u32
_libssh2_store_u64
_libssh2_store_str
That can be used all through the library to build binary outgoing
packets. Using these instead of the current approach removes
hundreds of lines from the library while at the same time greatly
enhances readability. I've not yet fully converted everything to
use these functions.
I've converted LOTS of 'unsigned long' to 'size_t' where
data/string lengths are dealt with internally. This is The Right
Thing and it will help us make the transition to our
size_t-polished API later on as well.
I'm removing the PACKET_* error codes. They were originally
introduced as a set of separate error codes from the transport
layer, but having its own set of errors turned out to be very
awkward and they were then converted into a set of #defines that
simply maps them to the global libssh2 error codes instead. Now,
I'l take the next logical step and simply replace the PACKET_*
defines with the actual LIBSSH2_ERROR_* defines. It will increase
readability and decrease confusion.
I also separated packet stuff into its own packet.h header file.
We reserve ^libssh2_ for public symbols and we use _libssh2 as
prefix for internal ones. I fixed the intendation of all these
edits with emacs afterwards, which then changed it slightly more
than just _libssh2_error() expressions but I didn't see any
obvious problems.
when _libssh2_packet_requirev() returns an error when waiting for
SSH_MSG_USERAUTH_SUCCESS or SSH_MSG_USERAUTH_FAILURE, it is an
error and it should be treated as such
libssh2_error() no longer allocates a string and only accepts a const
error string. I also made a lot of functions use the construct of
return libssh2_error(...) instead of having one call to
libssh2_error() and then a separate return call. In several of those
cases I then also changed the former -1 return code to a more
detailed one - something that I think will not change behaviors
anywhere but it's worth keeping an eye open for any such.
To make sure the public API is functional and that the
BLOCK_ADJUST_ERRNO() macro works correctly we MUST make sure to
call libssh2_error() when we return errors.
Mr anonymous in bug #125 pointed out that the userauth_keyboard_interactive()
function does in fact assign the same pointer a second time to a new allocated
buffer without properly freeing the previous one, which caused a memory leak.
To allow the libssh2_session_last_error() function to work as
documented, userauth_password() now better makes sure to call
libssh2_error() everywhere before it returns error.
Pointed out by mr anonymous in bug #128
Neither libssh2_userauth_password_ex() nor
libssh2_userauth_keyboard_interactive_ex() would return a login failure
error if the server responded with a SSH_MSG_USERAUTH_FAILURE, instead
you would see whatever previous error had occurred, typically
LIBSSH2_ERROR_EAGAIN.
This patch changes error code -18 to LIBSSH2_ERROR_AUTHENTICATION_FAILED
and makes LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED an alias for
LIBSSH2_ERROR_AUTHENTICATION_FAILED. In addition, new logic in
userauth_password() properly handles SSH_MSG_USERAUTH_FAILURE and both
this function and userauth_keyboard_interactive() now properly return
LIBSSH2_ERROR_AUTHENTICATION_FAILED.
userauth_publickey_fromfile() reads the key from a
file using file_read_publickey() which returns two
allocated strings, the decoded key and the key
method (such as "ssh-dss"). The latter can be
derived from the former but returning both avoids a
later allocation while doing so.
Older versions of userauth_publickey_fromfile() used
this method string directly but when
userauth_publickey() was factored out of
userauth_publickey_fromfile() it derived the method
from the key itself. This resulted in the method
being allocated twice.
This fix, which maintains the optimisation that
avoids an extra allocation, changes
userauth_publickey() so it doesn't allocate and
derive the method when userauth_pblc_method already
has a value.
Signed-off-by: Alexander Lamaison <awl03@doc.ic.ac.uk>
Commit 70b199f47659a74b8778c528beccf893843e5ecb introduced a parsing
bug in file_read_publickey() which made the algorithm name contain an
extra trailing space character, breaking all publickey authentication.
In case of failure we must make sure that the data we return
doesn't point to a memory area already freed. Reported anonymously
in the bug report #2910103.
I made this change just to easier grep for "return .*EAGAIN" cases
as they should be very rare or done wrongly. Already worked to find
a flaw, marked with "TODO FIXME THIS IS WRONG" in channel.c. I also
fixed a few cases to become more general returns now when we have
more unified return codes internally.
and introduced a transport.h header.
* Fixed the blocking mode to only change behavior not the actual underlying
socket mode so we now always work with non-blocking sockets. This also
introduces a new rule of thumb in libssh2 code: we don't call the
external function calls internally. We use the internal (non-blocking)
ones!
* libssh2_channel_receive_window_adjust2 was added and
libssh2_channel_receive_window_adjust is now deprecated
* Introduced "local" header files with prototypes etc for different parts
instead of cramming everything into libssh2_priv.h. channel.h is the
first.
some tests:
* cut off "_ex" from several internal function names
* corrected some log outputs
* simplified libssh2_channel_read_ex() and made it much faster in the process
* cut out {{{ and }}} comments that were incorrect anyway
* fixed sftp_packet_ask() to return the correct packet by using memcmp() and
not strncmp()
* fixed mkdir()'s wait for packet to use the correct request_id - it
semi-worked previously because strncmp() in sftp_packet_ask() made it
match far too easily.
* took away the polling functionality from sftp_packet_ask() since it wasn't
used
