This patch fixes an issue we encountered with more stringent compiler
warnings. The signature_is_good variable has a possibility of being
used uninitialized. This patch moves the use of the variable to a
place where it cannot be used while uninitialized.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
The SSL context maintains a set of 'out pointers' indicating the
address at which to write the header fields of the next outgoing
record. Some of these addresses have a static offset from the
beginning of the record header, while other offsets can vary
depending on the active record encryption mechanism: For example,
if an explicit IV is in use, there's an offset between the end
of the record header and the beginning of the encrypted data to
allow the explicit IV to be placed in between; also, if the DTLS
Connection ID (CID) feature is in use, the CID is part of the
record header, shifting all subsequent information (length, IV, data)
to the back.
When setting up an SSL context, the out pointers are initialized
according to the identity transform + no CID, and it is important
to keep them up to date whenever the record encryption mechanism
changes, which is done by the helper function ssl_update_out_pointers().
During context deserialization, updating the out pointers according
to the deserialized record transform went missing, leaving the out
pointers the initial state. When attemping to encrypt a record in
this state, this lead to failure if either a CID or an explicit IV
was in use. This wasn't caught in the tests by the bad luck that
they didn't use CID, _and_ used the default ciphersuite based on
ChaChaPoly, which doesn't have an explicit IV. Changing either of
this would have made the existing tests fail.
This commit fixes the bug by adding a call to ssl_update_out_pointers()
to ssl_context_load() implementing context deserialization.
Extending test coverage is left for a separate commit.
According to SP800-90A, the DRBG seeding process should use a nonce
of length `security_strength / 2` bits as part of the DRBG seed. It
further notes that this nonce may be drawn from the same source of
entropy that is used for the first `security_strength` bits of the
DRBG seed. The present HMAC DRBG implementation does that, requesting
`security_strength * 3 / 2` bits of entropy from the configured entropy
source in total to form the initial part of the DRBG seed.
However, some entropy sources may have thresholds in terms of how much
entropy they can provide in a single call to their entropy gathering
function which may be exceeded by the present HMAC DRBG implementation
even if the threshold is not smaller than `security_strength` bits.
Specifically, this is the case for our own entropy module implementation
which only allows requesting at most 32 Bytes of entropy at a time
in configurations disabling SHA-512, and this leads to runtime failure
of HMAC DRBG when used with Mbed Crypto' own entropy callbacks in such
configurations.
This commit fixes this by splitting the seed entropy acquisition into
two calls, one requesting `security_strength` bits first, and another
one requesting `security_strength / 2` bits for the nonce.
Fixes#237.
* origin/development:
Update the crypto submodule
Use multipart PSA key derivation API
platform: Include stdarg.h where needed
Update Mbed Crypto to contain mbed-crypto#152
CMake: Add a subdirectory build regression test
README: Enable builds as a CMake subproject
ChangeLog: Enable builds as a CMake subproject
Remove use of CMAKE_SOURCE_DIR
Update library version to 2.18.0
* origin/pr/2807:
platform: Include stdarg.h where needed
Update Mbed Crypto to contain mbed-crypto#152
CMake: Add a subdirectory build regression test
README: Enable builds as a CMake subproject
ChangeLog: Enable builds as a CMake subproject
Remove use of CMAKE_SOURCE_DIR
Update library version to 2.18.0
Avoid compiler errors when MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER
is set by using the application ID type.
[Error] psa_crypto_slot_management.c@175,9: used type 'psa_key_id_t' (aka 'psa_key_file_id_t') where arithmetic or pointer type is required
Bring Mbed TLS 2.18.0 and 2.18.1 release changes back into the
development branch. We had branched to release 2.18.0 and 2.18.1 in
order to allow those releases to go out without having to block work on
the `development` branch.
Manually resolve conflicts in the Changelog by moving all freshly addded
changes to a new, unreleased version entry.
Reject changes to include/mbedtls/platform.h made in the mbedtls-2.18
branch, as that file is now sourced from Mbed Crypto.
* mbedtls-2.18:
platform: Include stdarg.h where needed
Update Mbed Crypto to contain mbed-crypto#152
CMake: Add a subdirectory build regression test
README: Enable builds as a CMake subproject
ChangeLog: Enable builds as a CMake subproject
Remove use of CMAKE_SOURCE_DIR
Update library version to 2.18.0
* origin/development: (114 commits)
Don't redefine calloc and free
Add changelog entry to record checking
Fix compiler warning
Add debug messages
Remove duplicate entries from ChangeLog
Fix parameter name in doxygen
Add missing guards for mac usage
Improve reability and debugability of large if
Fix a typo in a comment
Fix MSVC warning
Fix compile error in reduced configurations
Avoid duplication of session format header
Implement config-checking header to context s11n
Provide serialisation API only if it's enabled
Fix compiler warning: comparing signed to unsigned
Actually reset the context on save as advertised
Re-use buffer allocated by handshake_init()
Enable serialisation tests in ssl-opt.sh
Change requirements for setting timer callback
Add setting of forced fields when deserializing
...
Breaking into a series of statements makes things easier when stepping through
the code in a debugger.
Previous comments we stating the opposite or what the code tested for (what we
want vs what we're erroring out on) which was confusing.
Also expand a bit on the reasons for these restrictions.
Modelled after the config-checking header from session s11n.
The list of relevant config flags was established by manually checking the
fields serialized in the format, and which config.h flags they depend on.
This probably deserves double-checking by reviewers.
Since the type of cid_len is unsigned but shorter than int, it gets
"promoted" to int (which is also the type of the result), unless we make the
other operand an unsigned int which then forces the expression to unsigned int
as well.
The number of meaning of the flags will be determined later, when handling the
relevant struct members. For now three bytes are reserved as an example, but
this number may change later.
This mainly follows the design document (saving all fields marked "saved" in
the main structure and the transform sub-structure) with two exceptions:
- things related to renegotiation are excluded here (there weren't quite in
the design document as the possibility of allowing renegotiation was still
on the table, which is no longer is) - also, ssl.secure_renegotiation (which
is not guarded by MBEDTLS_SSL_RENEGOTIATION because it's used in initial
handshakes even with renegotiation disabled) is still excluded, as we don't
need it after the handshake.
- things related to Connection ID are added, as they weren't present at the
time the design document was written.
The exact format of the header (value of the bitflag indicating compile-time
options, whether and how to merge it with the serialized session header) will
be determined later.
Enforce restrictions indicated in the documentation.
This allows to make some simplifying assumptions (no need to worry about
saving IVs for CBC in TLS < 1.1, nor about saving handshake data) and
guarantees that all values marked as "forced" in the design document have the
intended values and can be skipped when serialising.
Some of the "forced" values are not checked because their value is a
consequence of other checks (for example, session_negotiated == NULL outside
handshakes). We do however check that session and transform are not NULL (even
if that's also a consequence of the initial handshake being over) as we're
going to dereference them and static analyzers may appreciate the info.
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.
This commit introduces a new SSL error code
`MBEDTLS_ERR_SSL_VERSION_MISMATCH`
which can be used to indicate operation failure due to a
mismatch of version or configuration.
It is put to use in the implementation of `mbedtls_ssl_session_load()`
to signal the attempt to de-serialize a session which has been serialized
in a build of Mbed TLS using a different version or configuration.
This commit makes use of the added space in the session header to
encode the state of those parts of the compile-time configuration
which influence the structure of the serialized session in the
present version of Mbed TLS. Specifically, these are
- the options which influence the presence/omission of fields
from mbedtls_ssl_session (which is currently shallow-copied
into the serialized session)
- the setting of MBEDTLS_X509_CRT_PARSE_C, which determines whether
the serialized session contains a CRT-length + CRT-value pair after
the shallow-copied mbedtls_ssl_session instance.
- the setting of MBEDTLS_SSL_SESSION_TICKETS, which determines whether
the serialized session contains a session ticket.
This commit adds space for two bytes in the header of serizlied
SSL sessions which can be used to determine the structure of the
remaining serialized session in the respective version of Mbed TLS.
Specifically, if parts of the session depend on whether specific
compile-time options are set or not, the setting of these options
can be encoded in the added space.
This commit doesn't yet make use of the fields.
The format of serialized SSL sessions depends on the version and the
configuration of Mbed TLS; attempts to restore sessions established
in different versions and/or configurations lead to undefined behaviour.
This commit adds an 3-byte version header to the serialized session
generated and cleanly fails ticket parsing in case a session from a
non-matching version of Mbed TLS is presented.
This bug was present since cert digest had been introduced, which highlights
the need for testing.
While at it, fix a bug in the comment explaining the format - this was
introduced by me copy-pasting to hastily from current baremetal, that has a
different format (see next PR in the series for the same in development).
We have explicit recommendations to use US spelling for technical writing, so
let's apply this to code as well for uniformity. (My fingers tend to prefer UK
spelling, so this needs to be fixed in many places.)
sed -i 's/\([Ss]eriali\)s/\1z/g' **/*.[ch] **/*.function **/*.data ChangeLog
This uncovered a bug that led to a double-free (in practice, in general could
be free() on any invalid value): initially the session structure is loaded
with `memcpy()` which copies the previous values of pointers peer_cert and
ticket to heap-allocated buffers (or any other value if the input is
attacker-controlled). Now if we exit before we got a chance to replace those
invalid values with valid ones (for example because the input buffer is too
small, or because the second malloc() failed), then the next call to
session_free() is going to call free() on invalid pointers.
This bug is fixed in this commit by always setting the pointers to NULL right
after they've been read from the serialised state, so that the invalid values
can never be used.
(An alternative would be to NULL-ify them when writing, which was rejected
mostly because we need to do it when reading anyway (as the consequences of
free(invalid) are too severe to take any risk), so doing it when writing as
well is redundant and a waste of code size.)
Also, while thinking about what happens in case of errors, it became apparent
to me that it was bad practice to leave the session structure in an
half-initialised state and rely on the caller to call session_free(), so this
commit also ensures we always clear the structure when loading failed.
This allows callers to discover what an appropriate size is. Otherwise they'd
have to either try repeatedly, or allocate an overly large buffer (or some
combination of those).
Adapt documentation an example usage in ssl_client2.
Avoid useless copy with mbedtls_ssl_get_session() before serialising.
Used in ssl_client2 for testing and demonstrating usage, but unfortunately
that means mbedtls_ssl_get_session() is no longer tested, which will be fixed
in the next commit.
On client side, this is required for the main use case where of serialising a
session for later resumption, in case tickets are used.
On server side, this doesn't change much as ticket_len will always be 0.
This unblocks testing the functions by using them in ssl_client2, which will
be done in the next commit.
This finishes making these functions public. Next step is to get them tested,
but there's currently a blocker for that, see next commit (and the commit
after it for tests).
While 'session hash' is currently unique, so suitable to prove that the
intended code path has been taken, it's a generic enough phrase that in the
future we might add other debug messages containing it in completely unrelated
code paths. In order to future-proof the accuracy of the test, let's use a
more specific string.
The previous comment used "TLS" as a shortcut for "TLS 1.0/1.1" which was
confusing. This partially reflected the names of the calc_verify/finished that
go ssl, tls (for 1.0/1.1) tls_shaxxx (for 1.2), but still it's clearer to be
explicit in the comment - and perhaps in the long term the function names
could be clarified instead.
When using this function to deserialize, it's not a problem to have a session
structure as input as we'll have one around anyway (most probably freshly
deserialised).
However for tests it's convenient to be able to build a transform without
having a session structure around.
Also, removing this structure from parameters makes the function signature
more uniform, the only exception left being the ssl param at the end that's
hard to avoid for now.
Configs with no DEBUG_C are used for example in test-ref-configs.pl, which also
runs parts of compat.sh or ssl-opt.sh on them, so the added 'ssl = NULL'
statements will be exercised in those tests at least.
Make it more explicit what's used. Unfortunately, we still need ssl as a
parameter for debugging, and because calc_verify wants it as a parameter (for
all TLS versions except SSL3 it would actually only need handshake, but SSL3
also accesses session_negotiate).
It's also because of calc_verify that we can't make it const yet, but see next
commit.
* origin/development: (51 commits)
Fix possibly-lossy conversion warning from MSVC
Reintroduce length 0 check for records
Don't use memcpy() for 2-byte copy operation
Remove integer parsing macro
Fix alignment in record header parsing routine
Don't disallow 'record from another epoch' log msg in proxy ref test
Make sure 'record from another epoch' is displayed for next epoch
Implement record checking API
Mark ssl_parse_record_header() as `const` in SSL context
Make mbedtls_ssl_in_hdr_len() CID-unaware
Remove duplicate setting of ssl->in_msgtype and ssl->in_msglen
Move update of in_xxx fields in ssl_get_next_record()
Move update of in_xxx fields outside of ssl_prepare_record_content()
Reduce dependency of ssl_prepare_record_content() on in_xxx fields
Move ssl_update_in_pointers() to after record hdr parsing
Mark DTLS replay check as `const` on the SSL context
Move updating the internal rec ptrs to outside of rec hdr parsing
Mark ssl_decrypt_buf() as `const in the input SSL context
Adapt ssl_prepare_record_content() to use SSL record structure
Use record length from record structure when fetching content in TLS
...
* origin/pr/2790: (40 commits)
Fix possibly-lossy conversion warning from MSVC
Reintroduce length 0 check for records
Don't use memcpy() for 2-byte copy operation
Remove integer parsing macro
Fix alignment in record header parsing routine
Don't disallow 'record from another epoch' log msg in proxy ref test
Make sure 'record from another epoch' is displayed for next epoch
Implement record checking API
Mark ssl_parse_record_header() as `const` in SSL context
Make mbedtls_ssl_in_hdr_len() CID-unaware
Remove duplicate setting of ssl->in_msgtype and ssl->in_msglen
Move update of in_xxx fields in ssl_get_next_record()
Move update of in_xxx fields outside of ssl_prepare_record_content()
Reduce dependency of ssl_prepare_record_content() on in_xxx fields
Move ssl_update_in_pointers() to after record hdr parsing
Mark DTLS replay check as `const` on the SSL context
Move updating the internal rec ptrs to outside of rec hdr parsing
Mark ssl_decrypt_buf() as `const in the input SSL context
Adapt ssl_prepare_record_content() to use SSL record structure
Use record length from record structure when fetching content in TLS
...
* origin/pr/2781:
Documentation fixes according to review
Remove unused label in ssl_client2/ssl_server2
Add missing word in documentation of mbedtls_ssl_check_record()
cli/srv ex: Add dbg msg if record checking gives inconsistent result
Fix minor issues in documentation of mbedtls_ssl_check_record()
State that record checking is DTLS only and doesn't check content type
Update version_features.c
Pass dgrams to mbedtls_ssl_check_record in ssl_client2/server2
Add IO wrappers to ssl_server2 as interm's between NET and SSL layer
Add IO wrappers to ssl_client2 as interm's between NET and SSL layer
Introduce configuration option and API for SSL record checking
In psa_import_key, the key bits value was uninitialized before
calling the secure element driver import function. There is a
potential issue if the driver returns PSA_SUCCESS without setting
the key bits. This shouldn't happen, but shouldn't be discounted
either, so we initialize the key bits to an invalid issue.
* development:
Rename local variables
Update submodule
Update Visual studio project file
Move the examples to PSA 1.0
Use psa_raw_key_agreement
Remove calls to psa_allocate_key
Make variable naming consistent
Update psa_create_key to PSA 1.0
Update psa_import_key to PSA 1.0
Update psa_generator_abort to PSA 1.0
Update psa_generator_read to PSA 1.0
Update psa_crypto_generator_t to PSA 1.0
Update psa_key_agreement to PSA 1.0
Update GENERATOR_INIT macro to PSA 1.0
Update KEYPAIR macros to PSA 1.0
* crypto/pr/212: (337 commits)
Make TODO comments consistent
Fix PSA tests
Fix psa_generate_random for >1024 bytes
Add tests to generate more random than MBEDTLS_CTR_DRBG_MAX_REQUEST
Fix double free in psa_generate_key when psa_generate_random fails
Fix copypasta in test data
Avoid a lowercase letter in a macro name
Correct some comments
Fix PSA init/deinit in mbedtls_xxx tests when using PSA
Make psa_calculate_key_bits return psa_key_bits_t
Adjust secure element code to the new ITS interface
More refactoring: consolidate attribute validation
Fix policy validity check on key creation.
Add test function for import with a bad policy
Test key creation with an invalid type (0 and nonzero)
Remove "allocated" flag from key slots
Take advantage of psa_core_key_attributes_t internally #2
Store the key size in the slot in memory
Take advantage of psa_core_key_attributes_t internally: key loading
Switch storage functions over to psa_core_key_attributes_t
...
* development:
Update crypto to a repo with latest crypto
Update Mbed Crypto
tls: Remove duplicate psa_util.h include
Remove unused cryptography test files
Remove crypto C files
Remove files sourced from Mbed Crypto
config: Fix Doxygen link to MBEDTLS_PARAM_FAILED
Use mbedtls-based path for includes
check-names: Consider crypto-sourced header files
Resolve conflicts by performing the following actions:
- Reject changes to ChangeLog, as Mbed Crypto doesn't have one
- Reject changes to tests/compat.sh, as Mbed Crypto doesn't have it
- Reject changes to programs/fuzz/onefile.c, as Mbed Crypto doesn't have
it
- Resolve minor whitespace differences in library/ecdsa.c by taking the
version from Mbed TLS upstream.
* origin/development:
Honor MBEDTLS_CONFIG_FILE in fuzz tests
Test that a shared library build produces a dynamically linked executable
Test that the shared library build with CMake works
Add a test of MBEDTLS_CONFIG_FILE
Exclude DTLS 1.2 only with older OpenSSL
Document the rationale for the armel build
Switch armel build to -Os
Add a build on ARMv5TE in ARM mode
Add changelog entry for ARM assembly fix
bn_mul.h: require at least ARMv6 to enable the ARM DSP code
Adapt ChangeLog
ECP restart: Don't calculate address of sub ctx if ctx is NULL
This commit implements the record checking API
mbedtls_ssl_check_record()
on top of the restructured incoming record stack.
Specifically, it makes use of the fact that the core processing routines
ssl_parse_record_header()
mbedtls_ssl_decrypt_buf()
now operate on instances of the SSL record structure mbedtls_record
instead of the previous mbedtls_ssl_context::in_xxx fields.
