This commit introduces a server-side static helper function
`ssl_srv_check_client_no_crt_notification()`, which checks if
the message we received during the incoming certificate state
notifies the server of the lack of certificate on the client.
For SSLv3, such a notification comes as a specific alert,
while for all other TLS versions, it comes as a `Certificate`
handshake message with an empty CRT list.
So far, we've used the `peer_cert` pointer to detect whether
we're parsing the first CRT, but that will soon be removed
if `MBEDTLS_SSL_KEEP_PEER_CERTIFICATE` is unset.
This commit introduces a helper function `ssl_clear_peer_cert()`
which frees all data related to the peer's certificate from an
`mbedtls_ssl_session` structure. Currently, this is the peer's
certificate itself, while eventually, it'll be its digest only.
After mitigating the 'triple handshake attack' by checking that
the peer's end-CRT didn't change during renegotation, the current
code avoids re-parsing the CRT by moving the CRT-pointer from the
old session to the new one. While efficient, this will no longer
work once only the hash of the peer's CRT is stored beyond the
handshake.
This commit removes the code-path moving the old CRT, and instead
frees the entire peer CRT chain from the initial handshake as soon
as the 'triple handshake attack' protection has completed.
Multiple tests in ssl-opt.sh grep for debug output that's omitted
if MBEDTLS_X509_REMOVE_INFO is defined. This commit modifies ssl-opt.sh
to skip those tests in this case.
Introduce MBEDTLS_X509_INFO to indicate the availability of the
mbedtls_x509_*_info() function and closely related APIs. When this is
not defined, also omit name and description from
mbedtls_oid_descriptor_t, and omit OID arrays, macros, and types that
are entirely unused. This saves several KB of code space.
Change-Id: I056312613379890e0d70e1d08c34171287c0aa17
In a reduced configuration without PEM, PKCS5 or PKCS12, armc5 found that ret
was set but not used. Fixing that lead to a new warning about the variable not
being used at all. Now the variable is only declared when it's needed.
Only effective together with --rom, makes two changes:
- abort in case of build warnings
- skip writing statistics
The goal is to make sure we build cleanly in the configuration used for
measuring code size, with all the compilers we use, both because we care about
that configuration and those compilers, and because any warnings would cast a
shadow on the code size measurements.
Currently the build fails with armc5 due to a pre-existing warning in PK, this
will be fixed in the next commit.
The next commit will also add an all.sh component to make sure we have no
regression in the future. (Which is the motivation for --check skipping
statistics: an all.sh component should probably not leave files around.)
While at it, fix two things:
1. The call to gcc --version was redundant with the echo line below
2. WARNING_CFLAGS shouldn't be overriden with armclang, as it would remove the
-Wall -Wextra and any directory-specific warning (such as
-Wdeclaration-after-statement in library). It's meant to be overriden only
with compilers that don't accept the default value (namely armc5 here).
Some TLS-only code paths were not protected by an #ifdef and while some
compiler are happy to just silently remove them, armc5 complains:
Warning: #111-D: statement is unreachable
Let's make armc5 happy.
This is enabled by default as we generally enable things by default unless
there's a reason not to (experimental, deprecated, security risk).
We need a compile-time option because, even though the functions themselves
can be easily garbage-collected by the linker, implementing them will require
saving 64 bytes of Client/ServerHello.random values after the handshake, that
would otherwise not be needed, and people who don't need this feature
shouldn't have to pay the price of increased RAM usage.
