PKCS#1 v1.5 signatures are not defined for use with TLS 1.3 (they can
only appear in certificates, we now send a signature_algorithms_cert
extension to indicate support for them). So for RSA certificates, we
must support RSA-PSS signatures.
There are two sets of schemes, that are differentiated by the type of
RSA key used for the signature, one is for classic RSA keys (rsaEncryption
OID), which can also be used with PKCS#1 when using TLS 1.2, the other
is for RSA-PSS keys (RSASSA-PSS OID), which are not yet commonly
used (and can't be generated by our pki tool). According to the RFC,
PSS must also be supported for TLS 1.2 if the schemes are included in
the signature_algorithms extension (e.g. OpenSSL does not use PKCS#1 v1.5
anymore if PSS is proposed).
This changes how these schemes are stored and enumerated (they are not
treated as combination of hash algo and key type anymore).
Legacy schemes (MD5/SHA-1) are removed.
With the previous code, there was an issue when replying to TLS 1.3
post-handshake messages. In this case, SUCCESS is eventually returned
from build(), however, no actual data has been received so in_done is 0.
This was interpreted as EOF, plain_eof was set to TRUE and no further data
was read from the socket afterwards.
Returning SUCCESS from build() if the exchange is initiated by
write_(), as is the case with the finished reply, never was a problem
because there the return value of 0 is not interpreted as EOF.
If data is processed that eventually includes a TLS close notify, build()
will fail after a close notify has been sent in turn. However, propagating
that error immediately when reading prevented ever returning the data
already processed before the close notify was received.
Note that this breaks connecting to many TLS 1.3 servers until we support
HelloRetryRequest as we now send a key_share for ECP_256 while still
proposing other groups, so many servers request to use CURVE_25519.
These DH groups don't use the point format prefix (RFC 8422 deprecated
any other format anyway). Since they are enumerated now, they can also
be used by servers for TLS 1.2.
There is no point proposing legacy (or future) cipher suites depending on
the proposed TLS versions. It was actually possible to negotiate and use
cipher suites only defined for TLS 1.2 with earlier TLS versions.
The code is a minimal handshake with the HelloRetryRequest message
implementation missing.
Can be tested with an OpenSSL server running TLS 1.3. The server must
be at least version 1.1.1 (September 2018).
Co-authored-by: ryru <pascal.knecht@hsr.ch>
TLS 1.3 uses HMAC-based Extract-and-Expand Key Derivation Function (HKDF)
as defined in RFC 5869 to compute traffic secrets.
Co-authored-by: bytinbit <meline.sieber@hsr.ch>
The key material, in particular the nonce/IV, is derived differently and
the IV is also generated in a different way. Additionally, the actual
content type is encrypted and there may be optional padding to mask the
actual size of the encrypted data.
If we pass a pointer to NULL, the memory allocated by OpenSSL has to be
freed with OPENSSL_free(). Otherwise, this can lead to random
crashes/freezes for Windows builds as seen on AppVeyor. To not
complicate things for callers of this macro, we allocate our own memory,
which we already do for other i2d_* calls.
If no valid key is configured (e.g. because it's inadvertently uninitialized),
we should not just reuse the previous key.
The `key_set` flag is not necessary anymore because a non-NULL key is set
during initialization since 6b347d5232 ("openssl: Ensure underlying hash
algorithm is available during HMAC init").
If the peer deletes the CHILD_SA, we recreate it due to the close
action. However, if we create a new TUN device, we do so with a new
VpnService.Builder object and on that the DNS servers were never applied.
The latter happened only on the fly in the attribute handler when an
IKE_SA was established. Now we do this explicitly when creating the TUN
device, like the virtual IPs and routes. While we could avoid the
recreation of the TUN device if the CHILD_SA is recreated, there is the
theoretical possibility that the remote traffic selectors change. This
way we also avoid adding stuff to the builder in different places.
Fixes#3637.
This is not an error (as reflected by the returned status code) so we
should not print to stderr as output there might still be considered an
error (or at least an audit-worthy event) by some scripts.
In some cases, the algorithms that have been compiled into a plugin have
to be disabled at runtime. Based on the array returned by the get_features()
function the optionally provided function can strip algorithms or even
callbacks or registrations from a plugin, giving us a handy and powerful way
for runtime feature configuration aside from the plugin list.
Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
This adds helper functions to determine the first or last directory separator
in a string and to check if a given character is a separator.
Paths starting with a separator are now also considered absolute on
Windows as these are rooted at the current drive.
Note that it's fine to use DIRECTORY_SEPARATOR when combining strings as
Windows API calls accept both forward and backward slashes as separators.
Co-authored-by: Michał Skalski <mskalski@enigma.com.pl>
References #3684.
Apparently, we should use OPENSSL_free() to release memory allocated by
OpenSSL. While it generally maps to free() that's apparently not the
case on Windows, where the ECP test vectors caused `ACCESS_VIOLATION
exception` crashes (not always the same vector).
Fixes: 74e02ff5e6 ("openssl: Mainly use EVP interface for ECDH")
Tobias Brunner