The purpose of random.c file is to contain the helper
functions to generate random numbers that have been
in helpers.function so far.
The purpose of random.h is to contain the interface
exposed by random.c thus helper function prototypes.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
The purpose of helpers.c file is to contain the helper
functions that have been in helpers.function so far and
that are not related to the mechanism of unit test
execution and not related to random number generation
(will be moved in a dedicated file).
The purpose of helpers.h is to contain the interface
exposed by helpers.c thus helper function prototypes.
Make the changes in the build systems (make and cmake)
to build helpers.c and link it to test executables
along with mbedtls library.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Fix for coverity bugs 349041, 349052
Allocated pointers could potentially be leaked in the case of errors.
Signed-off-by: Paul Elliott <paul.elliott@arm.com>
Strict platforms cannot be expected to accept C99 code as valid
when earlier standards versions are selected.
This helps the programs build on Solaris-like platforms (e.g.
illumos).
Fixes#3420
Signed-off-by: nia <nia@netbsd.org>
This is basically the same as reading from /dev/urandom on supported
systems, only it has a limit of 256 bytes per call, and does not require
an open file descriptor (so it can be used in chroots, when resource
limits are in place, or are otherwise exhausted).
It's functionally equivalent to the comparable function getentropy(),
but has been around for longer. It's actually used to implement
getentropy in FreeBSD's libc. Discussions about adding getrandom or
getentropy to NetBSD are still ongoing.
It's present in all supported versions of FreeBSD and NetBSD.
It's not present in DragonFly or OpenBSD.
Documentation: https://netbsd.gw.com/cgi-bin/man-cgi?sysctl+7
Comparable code in OpenSSL:
ddec332f32/crypto/rand/rand_unix.c (L208)
Signed-off-by: nia <nia@netbsd.org>
By convention, in the project, functions that have a
check or similar in the name return 0 if the check
succeeds, non-zero otherwise. Align with this for
mbedtls_ssl_chk_buf_ptr().
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Just adding an empty file. The purpose of this header
file is to contain the definition of generic macros
used for the purpose of testing.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
In preparation of moving the content of helpers.function
to its own compilation unit, remove/add static qualifiers
where appropriate.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Create an include folder dedicated to include files for
tests. With the upcoming work on tests for PSA crypto
drivers the number of includes specific to tests is going
to increase significantly thus create a dedicated folder.
Don't put the include files in the include folder but in
include/test folder. This way test headers can be included
using a test/* path pattern as mbedtls and psa headers
are included using an mbedtls/* and psa/* path pattern.
This makes explicit the scope of the test headers.
Move the existing includes for tests into include/test and
update the code and build systems (make and cmake)
accordingly.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Add the min/max version negotiation tests from ssl-opt.sh as unit
tests for the sake of utility and easier running of tests during
development
Signed-off-by: Paul Elliott <paul.elliott@arm.com>
Instead, we insert a comment containing GDB_BREAK_HERE in the line we
want to break at, and let the gdb script search for it.
Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
The function mbedtls_mpi_sub_abs first checked that A >= B and then
performed the subtraction, relying on the fact that A >= B to
guarantee that the carry propagation would stop, and not taking
advantage of the fact that the carry when subtracting two numbers can
only be 0 or 1. This made the carry propagation code a little hard to
follow.
Write an ad hoc loop for the carry propagation, checking the size of
the result. This makes termination obvious.
The initial check that A >= B is no longer needed, since the function
now checks that the carry propagation terminates, which is equivalent.
This is a slight performance gain.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
There was some confusion during review about when A->p[n] could be
nonzero. In fact, there is no need to set A->p[n]: only the
intermediate result d might need to extend to n+1 limbs, not the final
result A. So never access A->p[n]. Rework the explanation of the
calculation in a way that should be easier to follow.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The function mpi_sub_hlp had confusing semantics: although it took a
size parameter, it accessed the limb array d beyond this size, to
propagate the carry. This made the function difficult to understand
and analyze, with a potential buffer overflow if misused (not enough
room to propagate the carry).
Change the function so that it only performs the subtraction within
the specified number of limbs, and returns the carry.
Move the carry propagation out of mpi_sub_hlp and into its caller
mbedtls_mpi_sub_abs. This makes the code of subtraction very slightly
less neat, but not significantly different.
In the one other place where mpi_sub_hlp is used, namely mpi_montmul,
this is a net win because the carry is potentially sensitive data and
the function carefully arranges to not have to propagate it.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mpi_sub_hlp performs a subtraction A - B, but took parameters in the
order (B, A). Swap the parameters so that they match the usual
mathematical syntax.
This has the additional benefit of putting the output parameter (A)
first, which is the normal convention in this module.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
While pure sh doesn't have a concept of local variables, we can partially
emulate them by unsetting variables before we exit the function, and use the
convention of giving them lowercase names to distinguish from global
variables.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Since dd prints everything on stderr, both normal status update and actual
errors when they occur, redirecting that to /dev/null is a trade-off that's
acceptable in quiet mode (typically used on a developer's machine and the
developer will re-run in non-quiet mode if anything fails without sufficient
detail in the output), but not that much in non-quiet mode.
For example, if our dd invocation fails because the disk in full on a CI
machine, we want the error to be reported at the time we invoke dd, and not
later when a seemingly unrelated test fails due to an incorrect seedfile.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Let code analyzers know that this is deliberate. For example MSVC
warns about the conversion if it's implicit.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Similarly to the recently-added tests for dependencies on CTR_DRBG:
constrained environments will probably want only one DRBG module, and we
should make sure that tests pass in such a configuration.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
In mpi_montmul, an auxiliary function for modular
exponentiation (mbedtls_mpi_mod_exp) that performs Montgomery
multiplication, the last step is a conditional subtraction to force
the result into the correct range. The current implementation uses a
branch and therefore may leak information about secret data to an
adversary who can observe what branch is taken through a side channel.
Avoid this potential leak by always doing the same subtraction and
doing a contant-trace conditional assignment to set the result.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Separate out a version of mpi_safe_cond_assign that works on
equal-sized limb arrays, without worrying about allocation sizes or
signs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This reverts commit 2cc69fffcf.
A check was added in mpi_montmul because clang-analyzer warned about a
possibly null pointer. However this was a false positive. Recent
versions of clang-analyzer no longer emit a warning (3.6 does, 6
doesn't).
Incidentally, the size check was wrong: mpi_montmul needs
T->n >= 2 * (N->n + 1), not just T->n >= N->n + 1.
Given that this is an internal function which is only used from one
public function and in a tightly controlled way, remove both the null
check (which is of low value to begin with) and the size check (which
would be slightly more valuable, but was wrong anyway). This allows
the function not to need to return an error, which makes the source
code a little easier to read and makes the object code a little
smaller.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
