New openssl API, libmbedtls, libgcrypt use size_t for
HMAC len pameter.
New helper functions were added in libcrypto.c to avoid
code duplication. (the header pki.h is needed for this
reason)
Signed-off-by: Norbert Pocs <npocs@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Generally, when the extension negotiation is enabled and client supports
SHA2 algorithms for RSA, they are supposed to be prioritized against the
old SHA1. If it is not (ssh-rsa is listed in front of rsa-sha2-* hostkey
algorithms during negotiation), the server wrongly tries to provide the
new typo of signature, ignoring the negotiated algirithm
This commit propagates the digest algorithm from negotiation to the actual
signature functions, which were previously responsible for decision
about the hash algorithm based just on the negotiated extensions.
Fixes T191
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Cleanup the KDF function to use only one function per crypto backend.
Improve the KDF function to properly handle requested lenght and to
avoid unnecessarily reallocating buffers.
In OpenSSL use the new EVP_KDF API if available.
Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This adds a flag to the type structures to track if we use a
Encrypt-then-MAC cipher instead of Encrypt-and-MAC. EtM is a more secure
hashing mechanism.
Signed-off-by: Dirkjan Bussink <d.bussink@gmail.com>
Reviewed-by: Jon Simons <jon@jonsimons.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
This is not supported by OpenSSH and not recommended to be implemented
either.
Signed-off-by: Dirkjan Bussink <d.bussink@gmail.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
And remove most of the direct access to the structure throughout the code
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Daiki Ueno <dueno@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
The commit also propares the internals throughout the code base
for the inclusion of a new AEAD cipher, because previously, the
source code counted only with chacha20-poly1305 cipher, which
is very specific in many cases.
The SSH_HMAC_AEAD_GCM mac algorithm is not actually used, but the name
needed to be defined so we can match in the algorithms selection per
OpenSSH specification (MACs are ignored in case GCM is select as a cipher [1]).
If the provided OpenSSL does not provide EVP_aes_128_gcm() function,
the AES-GCM ciphers will not be compiled in.
[1] https://cvsweb.openbsd.org/src/usr.bin/ssh/PROTOCOL.chacha20poly1305?annotate=HEAD
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This changes the private API by adding one more argument to function
pki_signature_from_blob()
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Summary:
This patch adds support for mbedTLS as a crypto backend for libssh.
mbedTLS is an SSL/TLS library that has been designed to mainly be used
in embedded systems. It is loosely coupled and has a low memory
footprint. mbedTLS also provides a cryptography library (libmbedcrypto)
that can be used without the TLS modules.
The patch is unfortunately quite big, since several new files had to
be added.
DSA is disabled at compile time, since mbedTLS doesn't support DSA
Patch review and feedback would be appreciated, and if any issues or
suggestions appear, I'm willing to work on them.
Signed-off-by: Juraj Vijtiuk <juraj.vijtiuk@sartura.hr>
Test Plan:
* The patch has been tested with a Debug and MinSizeRel build, with
libssh unit tests, client tests and the pkd tests.
* All the tests have been run with valgrind's memcheck, drd and helgrind
tools.
* The examples/samplessh client works when built with the patch.
Reviewers: asn, aris
Subscribers: simonsj
Differential Revision: https://bugs.libssh.org/D1
When accepting a new connection, a forking server based on libssh forks
and the child process handles the request. The RAND_bytes() function of
openssl doesn't reset its state after the fork, but simply adds the
current process id (getpid) to the PRNG state, which is not guaranteed
to be unique.
This can cause several children to end up with same PRNG state which is
a security issue.
