This commit modifies a bounds check in `mbedtls_ecp_check_budget()` to
be correct even if the requested number of ECC operations would overflow
the operation counter.
Context:
The macro `MBEDTLS_ECP_BUDGET()` is called before performing a
number of potentially time-consuming ECC operations. If restartable
ECC is enabled, it wraps a call to `mbedtls_ecp_check_budget()`
which in turn checks if the requested number of operations can be
performed without exceeding the maximum number of consecutive ECC
operations.
Issue:
The function `mbedtls_ecp_check_budget()` expects a the number
of requested operations to be given as a value of type `unsigned`,
while some calls of the wrapper macro `MBEDTLS_ECP_BUDGET()` use
expressions of type `size_t`.
This rightfully leads to warnings about implicit truncation
from `size_t` to `unsigned` on some compilers.
Fix:
This commit makes the truncation explicit by adding an explicit cast
to `unsigned` in the expansion of the `MBEDTLS_ECP_BUDGET()` macro.
Justification:
Functionally, the new version is equivalent to the previous code.
The warning about truncation can be discarded because, as can be
inferred from `ecp.h`, the number of requested operations is never
larger than 1000.
Our API makes no guarantee that you can use a context after free()ing it
without re-init()ing it first, so better not give the wrong impression that we
do, while it's not policy and the rest of the code might not allow it.
Rename the PLATFORM HW error, to avoid ABI breakage with Mbed OS.
The value changed as well, as previous value was not in the range of
Mbed TLS low level error codes.
The previous comment in ecp.h that only functions that take a "restart
context" argument can restart was wrong due to ECDH and SSL functions.
Changing that criterion to "document says if can return IN PROGRESS".
This requires updating the documentation of the SSL functions to mention this
explicitly, but it's something we really ought to do anyway, a bit
embarrassing that this wasn't done already - callers need to know what
`MBEDTLS_ERR_SSL_xxx` error codes to special-case. Note that the documentation
of the relevant functions was in a suboptimal state, so it was improved in the
process - it could use some more improvement, but only the changes that helped
cleanly insert the info about the IN_PROGRESS part were done here.
Also, while updating the ecp.h comment, I noticed several functions in the
ECDH module were wrongfully documented as restartable, which is probably a
left-over from the days before `mbedtls_ecdh_enable_restart()` was introduced.
Fixing that as well, to make the criterion used in ecp.h correct.
* development:
ssl-opt.sh: change expected output for large srv packet test with SSLv3
Adapt ChangeLog
Fix bug in SSL ticket implementation removing keys of age < 1s
ssl-opt.sh: Add DTLS session resumption tests
Add ChangeLog entry
Fix typo
Fix hmac_drbg failure in benchmark, with threading
Remove trailing whitespace
Remove trailing whitespace
ssl_server2: add buffer overhead for a termination character
Add missing large and small packet tests for ssl_server2
Added buffer_size and response_size options for ssl-server2. Added appropriate tests.
Solving a conflict in tests/ssl-opt.sh: two set of tests were added at the
same place (just after large packets):
- restartable ECC tests (in this branch)
- server-side large packets (in development)
Resolution was to move the ECC tests after the newly added server large packet
ones.
Exclude ".git" directories anywhere. This avoids spurious errors in git
checkouts that contain branch names that look like a file
check-files.py would check. Fix#1713
Exclude "mbed-os" anywhere and "examples" from the root. Switch to the
new mechanism to exclude "yotta/module". These are directories where
we store third-party files that do not need to match our preferences.
Exclude "cov-int" from the root. Fix#1691
Changes run-test-suites.pl to filter out directories, and select only files
as on OSX, test coverage tests create .dSYM directories which were being
accidentally selected to execute.
