* baremetal: (78 commits)
Review corrections 6
Review corrections 5
Minor changes to tinycrypt README
Typos in the tinycrypt README
Addition of copyright statements to tinycrypt files
Add LICENSE and README for tinycrypt
Add SPDX lines to each imported TinyCrypt file
Review corrections 4
Review corrections 3
Review corrections 2
Review corrections
Update signature of BE conversion functions
Use function for 16/24/32-bit BE conversion
x509.c: Minor readability improvement
x509_crt.c: Indicate guarding condition in #else branch
X.509: Don't remove verify callback by default
Fix Doxygen warnings regarding removed verify cb+ctx parameters
ECC restart: Use optional verification mode in bad signature test
Re-implement verify chain if vrfy cbs are disabled
Add zero-cost abstraction layer for CRT verification chain
...
As has been previously done for ciphersuites, this commit introduces
a zero-cost abstraction layer around the type
mbedtls_md_info const *
whose valid values represent implementations of message digest algorithms.
Access to a particular digest implementation can be requested by name or
digest ID through the API mbedtls_md_info_from_xxx(), which either returns
a valid implementation or NULL, representing failure.
This commit replaces such uses of `mbedtls_md_info const *` by an abstract
type `mbedtls_md_handle_t` whose valid values represent digest implementations,
and which has a designated invalid value MBEDTLS_MD_INVALID_HANDLE.
The purpose of this abstraction layer is to pave the way for builds which
support precisely one digest algorithm. In this case, mbedtls_md_handle_t
can be implemented as a two-valued type, with one value representing the
invalid handle, and the unique valid value representing the unique enabled
digest.
The failure of mbedtls_md was not checked in one place. This could have led
to an incorrect computation if a hardware accelerator failed. In most cases
this would have led to the key exchange failing, so the impact would have been
a hard-to-diagnose error reported in the wrong place. If the two sides of the
key exchange failed in the same way with an output from mbedtls_md that was
independent of the input, this could have led to an apparently successful key
exchange with a predictable key, thus a glitching md accelerator could have
caused a security vulnerability.
This commit allows users to provide alternative implementations of the
ECJPAKE interface through the configuration option MBEDTLS_ECJPAKE_ALT.
When set, the user must add `ecjpake_alt.h` declaring the same
interface as `ecjpake.h`, as well as add some compilation unit which
implements the functionality. This is in line with the preexisting
support for alternative implementations of other modules.
Two causes:
- the buffer is too short (missing 4 bytes for encoding id_len)
- the test was wrong
Would only happen when MBEDTLS_ECP_MAX_BITS == the bitsize of the curve
actually used (does not happen in the default config).
Could not be triggered remotely.
I'm not sure this is necessary, because it is only multiplied by xm2 which is
already random and secret, but OTOH, xm2 is related to a public value, so
let's add blinding with a random value that's only use for blinding, just to
be extra sure.
- reference handshake tests that we get the right values (not much now, but
much more later when we get to deriving the PMS)
- random handshake in addition tests our generate/write functions against our
read functions, that are tested by the reference handshake, and will be
further tested in the test suite later against invalid inputs
