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 sftp_write function shouldn't assume that the buffer pointer will be
the same in subsequent calls, even if it assumes that the data already
passed in before haven't changed.
The sftp structs are now moved to sftp.h (which I forgot to add before)
sftp_write was rewritten to split up outgoing data into multiple packets
and deal with the acks in a more asynchronous manner. This is meant to
help overcome latency and round-trip problems with the SFTP protocol.
Neither _libssh2_channel_write nor sftp_write now have the 32500 size
limit anymore and instead the channel writing function now has its own
logic to send data in multiple calls until everything is sent.
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.
We now allow libssh2_session_flag() to enable compression with a new
flag and I added documentation for the previous LIBSSH2_FLAG_SIGPIPE
flag which I wasn't really aware of!
As a zero return code from channel_read() is not an error we must make
sure that the SCP functions deal with that properly. channel_read()
always returns 0 if the channel is EOFed already so we check for EOF
after 0-reads to be able to return error properly.
In the transport functions we avoid a strcmp() now and just check a
boolean instead.
The compress/decompress function's return code is now acknowledged and
used as actual return code in case of failures.
The function libssh2_session_startup() is now considered deprecated due
to the portability issue with the socket argument.
libssh2_session_handshake() is the name of the replacement.
When a call to _libssh2_transport_write() succeeds, we must return from
_libssh2_channel_write() to allow the caller to provide the next chunk
of data.
We cannot move on to send the next piece of data that may already have
been provided in this same function call, as we risk getting EAGAIN for
that and we can't return information both about sent data as well as
EAGAIN. So, by returning short now, the caller will call this function
again with new data to send.
Replaced -1/SOCKET_NONE errors with appropriate error defines instead.
Made the verbose trace output during banner receiving less annoying for
non-blocking sessions.
In an attempt to make the trace output less cluttered for non-blocking
sessions the error function now avoids calling the debug function if the
error is the EAGAIN and the session is non-blocking.
LIBSSH2_SOCKET_NONE (-1) should no longer be used as error code as it is
(too) generic and we should instead use specific and dedicated error
codes to better describe the error.
The well known and used ssh server Dropbear has a maximum SSH packet
length at 32768 by default. Since the libssh2 design current have a
fixed one-to-one mapping from channel_write() to the packet size created
by transport_write() the previous limit of 32768 in the channel layer
caused the transport layer to create larger packets than 32768 at times
which Dropbear rejected forcibly (by closing the connection).
The long term fix is of course to remove the hard relation between the
outgoing SSH packet size and what the input length argument is in the
transport_write() function call.
When parsing the SCP protocol and verifying that the data looks like a
valid file name, byte values over 126 must not be consider illegal since
UTF-8 file names will use such codes.
Reported by: Uli Zappe
Bug: http://www.libssh2.org/mail/libssh2-devel-archive-2010-08/0112.shtml
Since libssh2 often sets LIBSSH2_ERROR_EAGAIN internally before
_libssh2_wait_socket is called, we can decrease some amount of
confusion in user programs by resetting the error code in this function
to reduce the risk of EAGAIN being stored as error when a blocking
function returns.
As reported on the mailing list, the code path using poll() should
multiple seconds with 1000 to get milliseconds, not divide!
Reported by: Jan Van Boghout
As was pointed out in bug #182, we must not return failure from
_libssh2_channel_free() when _libssh2_channel_close() returns an error
that isn't EAGAIN. It can effectively cause the function to never go
through, like it did now in the case where the socket was actually
closed but socket_state still said LIBSSH2_SOCKET_CONNECTED.
I consider this fix the right thing as it now also survives other
errors, even if making sure socket_state isn't lying is also a good
idea.
Fixed a compiler warning I introduced previously when checking input
arguments more. I also added a check for the other pointer to avoid NULL
pointer dereferences.
Make use of the EVP interface for the AES-funktion. Using this method
supports the use of different ENGINES in OpenSSL for the AES function
(and the direct call to the AES_encrypt should not be used according to
openssl.org)
There was a buffer overflow waiting to happen when a debug message was
longer than 1536 bytes.
Thanks to Daniel who spotted that there was a problem with the message
length passed to a trace handler also after commit
0f0652a3093111fc7dac0205fdcf8d02bf16e89f.
In KEXINIT messages, the client and server agree on, among other
things, whether to use compression. This method agreement occurs
in src/kex.c's kex_agree_methods() function. However, if
compression is enabled (either client->server, server->client, or
both), then the compression layer is initialized in
kex_agree_methods() -- before NEWKEYS has been received.
Instead, the initialization of the compression layer should
happen after NEWKEYS has been received. This looks to occur
insrc/kex.c's diffie_hellman_sha1(), which even has the comment:
/* The first key exchange has been performed,
switch to active crypt/comp/mac mode */
There, after NEWKEYS is received, the cipher and mac algorithms
are initialized, and that is where the compression should be
initialized as well.
The current implementation fails if server->client compression is
enabled because most server implementations follow OpenSSH's
lead, where compression is initialized after NEWKEYS. Since the
server initializes compression after NEWKEYS, but libssh2
initializes compression after KEXINIT (i.e. before NEWKEYS), they
are out of sync.
Reported in bug report #180
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
