When x is the most negative value of a two's complement type,
`(unsigned_type)(-x)` has undefined behavior, whereas `-(unsigned_type)x`
has well-defined behavior and does what was intended.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix undefined behavior (typically harmless in practice) of
mbedtls_mpi_add_mpi(), mbedtls_mpi_add_abs() and mbedtls_mpi_add_int() when
both operands are 0 and the left operand is represented with 0 limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Since they're part of the public API (even if only through a few functions),
they should be documented.
I deliberately skipped documenting how to configure the size of the type.
Right now, MBEDTLS_HAVE_INT32 and MBEDTLS_HAVE_INT64 have no Doxygen
documentation, so it's ambiguous whether they're part of the public API.
Resolving this ambiguity is out of scope of my current work.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The already existing "x509_csr_check()" function is extended in order
to support/test also CSR's extensions. The test is performed by
adding an extended key usage.
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
This patch updates the `mbedtls_mpi_mod_raw_conv_xx()` methods
as follows:
* Renamed for simplicity: conv_fwd -> from_mont_rep, conv_inv -> to_mont_rep.
* Uncoupled the dependency on the legaly bignum interface.
* `mbedtls_mpi` is no longer used for temporary buffer allocation.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
This patch moves `BignumModRawOperation` and `BignumModRawOperationArchSplit`
outside of the scaffolding merge slot.
It also renames `r_sqrt` property to `r2`.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
This patch modifies the BignumModRawOperation class to
provide special access to key members commonly used
in tests.
It binds the module's getters to conversion functions
which enable automatic conversions such as:
* hex to int.
* zero padding hex strings.
* common Montgomery constants such as R, R^2 and R^01
are now be calculated upon access.
class `BignumModRawOperationArchSplit` is also updated to
utilise the new design.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
This patch is adding a basic instantance of `BignumModRawOperation`
and creates an `BignumModRawOperationArchSplit` class, copying
over the implementation of `BignumCoreRawOperationArchSplit`.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
In 'dh_genprime.c', the following condition can be found inside an 'if' statement:
ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0
As the '!=' operator binds closer than the assignment operator ('='), the value assigned to 'ret' will be the boolean result of the comparison (0 or 1) instead of the status code returned by 'mbedtls_mpi_write_file'. This means that the above statement is actually equivalent to:
ret = ( mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0 )
What we want instead is for the the status code to be assigned to 'ret'. If the value assigned is non-zero, it will be 'truthy' and the 'if' branch will be taken.
( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) ) != 0
This PR fixes the issue by explicitly specifying the precedence of operations with parentheses.
Signed-off-by: ihsinme <ihsinme@gmail.com>
A core MPI must have at least 1 limb. We can no longer test with 0 limbs,
and we don't need to anyway, so don't try.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This way static analyzers have a chance of knowing we don't expect the
bignum functions to support empty inputs. As things are, Coverity keeps
complaining about it.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Instead of corrupting the public key part of the message,
corrupt the proof part. A proof is conceptually similar to a signature,
and changing anything in it should make it invalid with
a high probability.
Also, instead of shifting data, perform a bitflip.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
