Files : kex.c, misc.c, misc.h
Notes :
Fixed possible out of bounds memory access when reading malformed data in diffie_hellman_sha1() and diffie_hellman_sha256().
Added _libssh2_copy_string() to misc.c to return an allocated and filled char buffer from a string_buf offset. Removed no longer needed s var in kmdhgGPshakex_state_t.
OpenSSH Key and ED25519 support #39
Added _libssh2_explicit_zero() to explicitly zero sensitive data in memory #120
* ED25519 Key file support - Requires OpenSSL 1.1.1 or later
* OpenSSH Key format reading support - Supports RSA/DSA/ECDSA/ED25519 types
* New string buffer reading functions - These add build-in bounds checking and convenance methods. Used for OpenSSL PEM file reading.
* Added new tests for OpenSSH formatted Keys
Use checksrc.pl from the curl project, with (for now)
suppressed long line warnings and indentation set to
4 spaces. Fixes are whitespace for the most part.
Warning count went down from 2704 to 12.
Also fix codespell typos, two non-ANSI C89 comments
and a stray tab in include/libssh2.h.
Ref: https://github.com/libssh2/libssh2/pull/235
This commit lands full ECDSA key support when using the OpenSSL
backend. Which includes:
New KEX methods:
ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521
Can now read OpenSSL formatted ECDSA key files.
Now supports known host keys of type ecdsa-sha2-nistp256.
New curve types:
NID_X9_62_prime256v1, NID_secp384r1, NID_secp521r1
Default host key preferred ordering is now nistp256, nistp384,
nistp521, rsa, dss.
Ref: https://github.com/libssh2/libssh2/issues/41
Closes https://github.com/libssh2/libssh2/pull/206
Since they use our own PEM parser which did not support encrypted
PEM files, trying to use such files on these backends failed.
Fix that by augmenting the PEM parser to support encrypted PEM files.
* os400: minimum supported OS version is now V6R1.
Do not log compiler informational messages.
* Implement crypto backend specific Diffie-Hellman computation.
This feature is now needed on os400 because the QC3 library does not
implement bn_mod_exp() natively. Up to now, this function was emulated using
an RSA encryption, but commits ca5222ea819cc5ed797860070b4c6c1aeeb28420 and
7934c9ce2a029c43e3642a492d3b9e494d1542be (CVE-2016-0787) broke the emulation
because QC3 only supports RSA exponents up to 512 bits.
Happily, QC3 supports a native API for Diffie-Hellman computation, with
opaque random value: this commit implements the use of this API and, as a
side effect, enables support of this feature for any other crypto backend that
would use it.
A "generic" Diffie-Hellman computation internal API supports crypto backends
not implementing their own: this generic API uses the same functions as before.
* Fix typos in docs/HACKING.CRYPTO.
Some structure fields holding callback addresses have the same name as the
underlying system function (connect, send, recv). Set parentheses around
their reference to suppress a possible macro substitution.
Use a macro for connect() on OS/400 to resolve a const/nonconst parameter
problem.
Before this patch "_libssh2_error" required the error message to be a
static string.
This patch adds a new function "_libssh2_error_flags" accepting an
additional "flags" argument and specifically the flag
"LIBSSH2_ERR_FLAG_DUP" indicating that the passed string must be
duplicated into the heap.
Then, the method "_libssh2_error" has been rewritten to use that new
function under the hood.
Signed-off-by: Salvador Fandino <sfandino@yahoo.com>
Signed-off-by: Salvador Fandiño <sfandino@yahoo.com>
A common novice programmer error (at least among those using the
wrapping Perl module Net::SSH2), is to try to reuse channels.
This patchs detects that incorrect usage and fails with a
LIBSSH2_ERROR_BAD_USE error instead of hanging.
Signed-off-by: Salvador Fandino <sfandino-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
Until now, the window size (channel->remote.window_size) was being
updated just after receiving the packet from the transport layer.
That behaviour is wrong because the channel queue may grow uncontrolled
when data arrives from the network faster that the upper layer consumes
it.
This patch adds a new counter, read_avail, which keeps a count of the
bytes available from the packet queue for reading. Also, now the window
size is adjusted when the data is actually read by an upper layer.
That way, if the upper layer stops reading data, the window will
eventually fill and the remote host will stop sending data. When the
upper layers reads enough data, a window adjust packet is delivered and
the transfer resumes.
The read_avail counter is used to detect the situation when the remote
server tries to send data surpassing the window size. In that case, the
extra data is discarded.
Signed-off-by: Salvador <sfandino@yahoo.com>
Add a "use_in_auth" flag to the LIBSSH2_COMP_METHOD struct and a
separate "zlib@openssh.com" method, along with checking session->state
for LIBSSH2_STATE_AUTHENTICATED. Appears to work on the OpenSSH servers
I've tried against, and it should work as before with normal zlib
compression.
Usually a format macro should hold the whole format, otherwise
it should be named a prefix. Also fixed usage of this macro in
scp.c for a signed var where it was used as prefix for unsigned.
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
Added crypto.h that is the unified header to include when using crypto
functionality. It should be the only header that needs to adapt to the
underlying crypto library in use. It provides the set of prototypes that
are library agnostic.
The attempts made to have _libssh2_channel_write() accept larger pieces
of data and split up the data by itself into 32700 byte chunks and pass
them on to channel_write() in a loop as a way to do faster operations on
larger data blocks was a failed attempt.
The reason why it is difficult:
The API only allows EAGAIN or a length to be returned. When looping over
multiple blocks to get sent, one block can get sent and the next might
not. And yet: when transport_send() has returned EAGAIN we must not call
it again with new data until it has returned OK on the existing data it
is still working on. This makes it a mess and we do get a much easier
job by simply returning the bytes or EAGAIN at once, as in the EAGAIN
case we can assume that we will be called with the same arguments again
and transport_send() will be happy.
Unfortunately, I think we take a small performance hit by not being able
to do this.
Starting now, we unconditionally use the internal replacement functions
for send() and recv() - creatively named _libssh2_recv() and
_libssh2_send().
On errors, these functions return the negative 'errno' value instead of
the traditional -1. This design allows systems that have no "natural"
errno support to not have to invent it. It also means that no code
outside of these two transfer functions should use the errno variable.
When SCP send or recv fails, it gets a special message from the server
with a warning or error message included. We have no current API to
expose that message but the foundation is there. Removed unnecessary use
of session struct fields.
I added size checks in several places. I fixed the code flow to be easier
to read in some places.
I removed unnecessary zeroing of structs. I removed unused struct fields.
We don't like magic numbers in the code. Now the acceptable failure
codes sent in the SSH_MSG_CHANNEL_OPEN_FAILURE message are added as
defined values in the private header file.
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.
