Look for changes that remove X509/SSL functionality.
```
git diff 'HEAD^{/^Merge}~1' HEAD --diff-filter=M -- . ':!library/error.c' ':!library/version_features.c' ':!programs/test/query_config.c' ':!visualc' ':!*.pdf' ':!*.der' | grep -E "^-.*MBEDTLS_(ERR_)?(PKCS11|X509|NET|SSL)_"
```
All of these removals are in `config.h` or `check_config.h`. Selectively revert the differences in these two files.
```
git diff 'HEAD^{/^Merge}~1' 'HEAD^{/^Merge}' include/mbedtls/config.h include/mbedtls/check_config.h | git apply -p1 -R
```
* `include/mbedtls/check_config.h`:
* ARIA for GCM: don't remove it.
* `MBEDTLS_PSA_CRYPTO_SE_C`: don't remove it.
* `MBEDTLS_SHA512_NO_SHA384`: don't remove it.
* `MBEDTLS_SSL_DTLS_CONNECTION_ID`: restore it.
* `include/mbedtls/config.h`:
* warning about `MBEDTLS_ECDSA_SIGN_ALT`: don't remove it.
* `MBEDTLS_CTR_DRBG_USE_128_BIT_KEY` full paragraph: don't remove it.
* `MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER`: don't remove it.
* `MBEDTLS_SHA512_SMALLER`…: don't remove it.
* `MBEDTLS_SSL_RECORD_CHECKING`: restore it.
* `MBEDTLS_SSL_CONTEXT_SERIALIZATION`: restore it.
* `MBEDTLS_USE_PSA_CRYPTO` note: don't restore the tls version.
* `MBEDTLS_USE_PSA_CRYPTO` warning: restore the tls version.
* `MBEDTLS_CMAC_C`: restore it to being disabled by default. It's a minor API change in Mbed TLS because it changes the layout of `mbedtls_cipher_context_t`.
* `MBEDTLS_CTR_DRBG_C`: don't restore the older version of the description from tls.
* `MBEDTLS_GCM_C`: don't restore the older description from tls.
* `MBEDTLS_PSA_CRYPTO_C`: don't restore `crypto/`.
* `MBEDTLS_PSA_CRYPTO_SE_C`: don't remove it.
* `MBEDTLS_PSA_CRYPTO_STORAGE_C`: don't restore `crypto/`. Don't disable it by default.
* `MBEDTLS_PSA_ITS_FILE_C`: don't restore, like for ``MBEDTLS_PSA_CRYPTO_STORAGE_C``.
* `MBEDTLS_CTR_DRBG_USE_128_BIT_KEY` single line: don't restore it since there is now a full paragraph in the proper section above.
* `MBEDTLS_SSL_CID_IN_LEN_MAX`…: restore it.
* `MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES`: restore the version without a space to format the line like the others.
Merge `unremove-non-crypto` into `mbedtls/development`. The branch
`unremove-non-crypto` was obtained by starting from `mbed-crypto/development`,
then reverting many commits that removed X.509 and TLS functionality when Mbed
Crypto forked from Mbed TLS (the “unremoval”), then make a few tweaks to
facilitate the merge.
The unremoval step restored old versions of some tls files. If a file doesn't
exist in mbed-crypto, check out the mbedtls version, regardless of what
happened during the unremoval of tls files in the crypto tree. Also
unconditionally take the mbedtls version of a few files where the
modifications are completely project-specific and are not relevant in
mbed-crypto:
* `.github/issue_template.md`: completely different. We may want to reconcile
them independently as a follow-up.
* `.travis.yml`: would only be reverted to an earlier tls version.
* `README.md`: completely different. We may want to reconcile them
independently as a follow-up.
* `doxygen/input/doc_mainpage.h`: the changes in crypto were minimal and not
relevant except as a stopgap as mbed-crypto did not have its own product
versioning in the Doxygen documentation.
* `tests/.jenkins/Jenkinsfile`: completely different.
* `tests/data_files/Makefile`: there were no changes in mbed-crypto,
but the unremoval step restored an old version.
Shell script for everything to do after the merge apart from the conflict
resolution:
```
tls_files=($(comm -23 <(git ls-tree -r --name-only HEAD) <(git ls-tree -r --name-only $(git merge-base upstream-crypto/development MERGE_HEAD))))
tls_files+=($tls_files .github/issue_template.md .travis.yml README.md doxygen/input/doc_mainpage.h tests/.jenkins/Jenkinsfile tests/data_files/Makefile)
git checkout --theirs HEAD -- $tls_files
git add -- $tls_files
```
Resolve the remaining conflicts:
* `library/CMakeLists.txt`:
* Keep the TLS definition of `src_crypto`
* `USE_SHARED_MBEDTLS_LIBRARY`: keep all three libraries, with both
`include` and `crypto/include` in `target_include_directories`, all with
version `2.21.0`.
* `programs/Makefile`:
* Reconcile the APPS lists (add/add from a differently-formatted common
ancestor): insert the `psa/*` from crypto into the tls list.
* Keep the `fuzz` target defined only in tls version.
* Keep the recipe (only in tls version) cleaning `ssl_pthread_server`
stuff for the `clean` target.
* `scripts/config.py`:
* `include_in_full`: add/add conflict. Keep both.
* `tests/scripts/all.sh`:
* `component_test_no_use_psa_crypto_full_cmake_asan`: partially old
version in crypto. Take the tls version.
* `component_test_malloc_0_null` and more: take
`component_test_malloc_0_null` from crypto (with `config.py` rather than
`config.pl`, and with `$ASAN_FLAGS` rather than an explicit list), but
add the call to `ssl-opt.sh` from tls. Take the other components from
crypto.
With this commit, building and running the unit tests with both `make ` and
`cmake` work in the default configuration on Linux. Other platforms, build
systems and configurations are likely not to work, and there is some
regression in test coverage.
There is some loss of functionality because the unremoval step restored older
versions of tls content. This commit contains the latest tls version of
tls-only files, but some changes from the tls side in files that existed on
both sides have regressed. Most problematic changes are hunks that remove some
tls-specific feature and contain either a C preprocessor symbol identifying a
tls-specific module or option, or the name of a tls-specific file. Hunks
that remove a tls-specific preprocessor symbol can be identified with the
regular expression `^-.*MBEDTLS_(ERR_)?(PKCS11|X509|NET|SSL)_`.
Subsequent commits will revert a few parts of the patch from this merge commit
in order to restore the tls functionality that it removes, ensure that the
test coverage includes what was covered in either branch, and fix test
failures.
This reverts commit 9afb2e9921.
Conflicts:
* include/CMakeLists.txt
* "Make config.h available" comment: there has been a change
adjacent to where it was removed. Just re-add what was removed.
* tests/CMakeLists.txt:
* compat.sh: there has been a change immediately before where it was
removed. Just re-add what was removed.
This reverts commit 1c66e48670.
Conflicts:
* include/mbedtls/check_config.h:
* MBEDTLS_SSL_PROTO_SSL3: there has been an addition (of
MBEDTLS_SHA512_NO_SHA384) at the place where it was removed. Re-add it
after (alphabetical order).
* MBEDTLS_ENABLE_WEAK_CIPHERSUITES: there has been an addition (of
MBEDTLS_CTR_DRBG_USE_128_BIT_KEY) at the place where it was removed.
Re-add it after (alphabetical order).
* MBEDTLS_SSL_ALL_ALERT_MESSAGES: there has been an addition (of
MBEDTLS_SHA512_SMALLER) at the place where it was removed. Re-add it
after (alphabetical order).
* include/mbedtls/config.h:
* MBEDTLS_ENABLE_WEAK_CIPHERSUITES: there has been an addition (of
MBEDTLS_CTR_DRBG_USE_128_BIT_KEY) at the place where it was removed.
Re-add it after (alphabetical order).
* MBEDTLS_SSL_ALL_ALERT_MESSAGES: there has been an addition (of
MBEDTLS_SHA512_SMALLER) at the place where it was removed. Re-add it
after (alphabetical order).
* library/version_features.c: re-generate by running
scripts/generate_features.pl.
* programs/test/query_config.c: re-generate by running
scripts/generate_query_config.pl.
* scripts/config.pl: this file has been replaced by config.py. Port
the reversed changes to config.py:
* Revert removing three symbols from the list of symbols to
exclude from full.
* Revert removing one symbol (MBEDTLS_NET_C) from the list of symbols
to exclude from baremetal.
* scripts/footprint.sh:
* Re-add the line to unset MBEDTLS_NET_C, but with config.py instead of
config.pl.
* tests/scripts/all.sh:
* component_test_no_platform: re-add the line to unset MBEDTLS_NET_C, but
with config.py instead of config.pl.
* component_build_arm_none_eabi_gcc,
component_build_arm_none_eabi_gcc_no_udbl_division,
component_build_arm_none_eabi_gcc_no_64bit_multiplication,
component_build_armcc: these components now use the baremetal
configuration, so they do not need to turn off MBEDTLS_NET_C explicitly.
This reverts commit bb1f701212.
* include/mbedtls/check_config.h:
* MBEDTLS_X509_RSASSA_PSS_SUPPORT: there has been an addition (of
MBEDTLS_SHA512_NO_SHA384) at the place where it was removed.
Re-add it before MBEDTLS_SHA512_NO_SHA384 to keep it grouped
with MBEDTLS_RSA_C.
Conflicts:
* scripts/config.pl: this file has been replaced by config.py. Port
the reversed changes to config.py:
* Revert removing three symbols from the list of symbols to
exclude from full.
Add a description of MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY to the
documentation, as suggested by hanno-arm.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
Add a conditional buffer resizing feature. Introduce tests exercising
it in various setups (serialization, renegotiation, mfl manipulations).
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
This patch changes the compatibility API defined in crypto_compat.h
to static inline functions as the previous macro definitions were
causing issues for the C pre-processor when included in projects
which need to redefine the PSA function names. Making it static
inline function solves this problem neatly and also modern compilers
do a good job at inlining the function which makes the need for making
it a macro redundant.
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
* iotssl-2652-deprecate-pkcs11:
Group PKCS11_C entries in check_config.h
Clarify that what we're dropping is pkcs11-helper support
Fix typo in doxy docs for ssl_pkcs11_sign()
Add missing docs to PKCS#11 public funcs
Wrap PKCS1 module with DEPRECATED_REMOVED
Fix deprecated docs for PKCS1
Deprecate MBEDTLS_PKCS11_C functions
Add ChangeLog entry for MBEDTLS_PKCS11_C deprecation
Deprecate MBEDTLS_PKCS11_C feature
Files deleted by us: keep them deleted.
```
git rm $(git status -s | sed -n 's/^DU //p')
```
Individual files with conflicts:
* `README.md`: keep the crypto version.
* `doxygen/input/doc_mainpage.h`: keep the crypto version (with an obsolete Mbed Crypto version number).
* `include/mbedtls/error.h`:
* `ERROR`: similar additions made through parallel commits, with only whitespace differences. Align with the tls version.
* `library/CMakeLists.txt`: keep the crypto version.
* `library/Makefile`: keep the crypto version.
* `scripts/generate_errors.pl`: keep the crypto version (the relevant changes were made through parallel commits).
* `tests/scripts/check-test-cases.py`:
* `Results`: keep the crypto version, which has both the new argument to the constructor (added in crypto only) and the class docstring (added through parallel commits).
* `tests/suites/helpers.function`:
* `ARRAY_LENGTH`, `ASSERT_ALLOC`: additions in the same location. Keep both, in indifferent order.
* `tests/suites/target_test.function`:
* `receive_uint32`: keep the crypto version which has an additional bug fix. The tls changes made in tls are irrelevant after this bug fix.
* `visualc/VS2010/mbedTLS.vcxproj`: run `scripts/generate_visualc_files.pl`.
Review of non-conflicting changes:
* `all.sh`: 1 change.
* zlib test components: don't add them.
* `include/CMakeLists.txt`: 1 change.
* `target_include_directories`: doesn't work as is (different target name). Don't take the change.
* All other non-conflicting changes: take them.
Adapt to the change of encoding of elliptic curve key types in PSA
crypto. Before, an EC key type encoded the TLS curve identifier. Now
the EC key type only includes an ad hoc curve family identifier, and
determining the exact curve requires both the key type and size. This
commit moves from the old encoding and old definitions from
crypto/include/mbedtls/psa_util.h to the new encoding and definitions
from the immediately preceding crypto submodule update.
Change the encoding of key types, EC curve families and DH group
families to make the low-order bit a parity bit (with even parity).
This ensures that distinct key type values always have a Hamming
distance of at least 2, which makes it easier for implementations to
resist single bit flips.
All key types now have an encoding on 32 bits where the bottom 16 bits
are zero. Change to using 16 bits only.
Keep 32 bits for key types in storage, but move the significant
half-word from the top to the bottom.
Likewise, change EC curve and DH group families from 32 bits out of
which the top 8 and bottom 16 bits are zero, to 8 bits only.
Reorder psa_core_key_attributes_t to avoid padding.
Remove the values of curve encodings that are based on the TLS registry
and include the curve size, keeping only the new encoding that merely
encodes a curve family in 8 bits.
Keep the old constant names as aliases for the new values and
deprecate the old names.
Define constants for ECC curve families and DH group families. These
constants have 0x0000 in the lower 16 bits of the key type.
Support these constants in the implementation and in the PSA metadata
tests.
Switch the slot management and secure element driver HAL tests to the
new curve encodings. This requires SE driver code to become slightly
more clever when figuring out the bit-size of an imported EC key since
it now needs to take the data size into account.
Switch some documentation to the new encodings.
Remove the macro PSA_ECC_CURVE_BITS which can no longer be implemented.
Change the representation of psa_ecc_curve_t and psa_dh_group_t from
the IETF 16-bit encoding to a custom 24-bit encoding where the upper 8
bits represent a curve family and the lower 16 bits are the key size
in bits. Families are based on naming and mathematical similarity,
with sufficiently precise families that no two curves in a family have
the same bit size (for example SECP-R1 and SECP-R2 are two different
families).
As a consequence, the lower 16 bits of a key type value are always
either the key size or 0.
Don't assume that the PSA encoding of elliptic curves is identical to
the TLS encoding. This is currently true but about to change.
The new implementation only works when MBEDTLS_ECP_C is defined. This
is ok because the function is only used with MBEDTLS_ECP_C defined.
Internally, use the corresponding function from psa_crypto.c instead.
Externally, this function is not used in Mbed TLS and is documented as
"may change at any time".
Key types are now encoded through a category in the upper 4 bits (bits
28-31) and a type-within-category in the next 11 bits (bits 17-27),
with bit 16 unused and bits 0-15 only used for the EC curve or DH
group.
For symmetric keys, bits 20-22 encode the block size (0x0=stream,
0x3=8B, 0x4=16B).
Change the numerical encoding of values for symmetric key types to
have 0000 as the lower 16 bits. Now the lower 16 bits are only used
for key types that have a subtype (EC curve or DH group).
Whether a parameter should be const is an implementation detail of the
function, so don't declare a parameter of psa_hash_compare as
const. (This only applies to parameters themselves, not to objects
that pointer parameters points to.)
Before the initial seeding, reseed_counter used to always be 0. Now, the
value depends on whether or not the user has explicitly set the amount
of data to get from the nonce (via e.g.
mbedtls_ctr_drbg_set_nonce_len()). Add comments to clarify the possible
values reseed_counter can have before the initial seeding.
One of the error codes was already reserved, this commit just makes it
explicit. The other one is a new error code for initializing return
values in the library: `MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED` should
not be returned by the library. If it is returned, then it is surely a
bug in the library or somebody is tampering with the device.
One of the error codes was already reserved, this commit just makes it
explicit. The other one is a new error code for initializing return
values in the library: `MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED` should
not be returned by the library. If it is returned, then it is surely a
bug in the library or somebody is tampering with the device.
Rename some macros and functions related to signature which are
changing as part of the addition of psa_sign_message and
psa_verify_message.
perl -i -pe '%t = (
PSA_KEY_USAGE_SIGN => PSA_KEY_USAGE_SIGN_HASH,
PSA_KEY_USAGE_VERIFY => PSA_KEY_USAGE_VERIFY_HASH,
PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE => PSA_SIGNATURE_MAX_SIZE,
PSA_ASYMMETRIC_SIGN_OUTPUT_SIZE => PSA_SIGN_OUTPUT_SIZE,
psa_asymmetric_sign => psa_sign_hash,
psa_asymmetric_verify => psa_verify_hash,
); s/\b(@{[join("|", keys %t)]})\b/$t{$1}/ge' $(git ls-files . ':!:**/crypto_compat.h')
Move backward compatibility aliases to a separate header. Reserve
crypto_extra.h for implementation-specific extensions that we intend
to keep supporting.
This is better documentation for users. New users should simply ignore
backward compatibility aliases, and old users can look at
crypto_compat.h to see what is deprecated without bothering about new
features appearing in crypto_extra.h.
This facilitates maintenance because scripts such as
generate_psa_constants that want to ignore backward compability
aliases can simply exclude crypto_compat.h from their parsing.
First deal with deleted files.
* Files deleted by us: keep them deleted.
* Files deleted by them, whether modified by us or not: keep our version.
```
git rm $(git status -s | sed -n 's/^DU //p')
git reset -- $(git status -s | sed -n 's/^D //p')
git checkout -- $(git status -s | sed -n 's/^ D //p')
git add -- $(git status -s | sed -n 's/^UD //p')
```
Individual files with conflicts:
* `3rdparty/everest/library/Hacl_Curve25519_joined.c`: spurious conflict because git mistakenly identified this file as a rename. Keep our version.
* `README.md`: conflict due to their change in a paragraph that doesn't exist in our version. Keep our version of this paragraph.
* `docs/architecture/Makefile`: near-identical additions. Adapt the definition of `all_markdown` and include the clean target.
* `doxygen/input/docs_mainpage.h`: conflict in the version number. Keep our version number.
* `include/mbedtls/config.h`: two delete/modify conflicts. Keep the removed chunks out.
* `library/CMakeLists.txt`: discard all their changes as they are not relevant.
* `library/Makefile`:
* Discard the added chunk about the crypto submodule starting with `INCLUDING_FROM_MBEDTLS:=1`.
* delete/modify: keep the removed chunk out.
* library build: This is almost delete/modify. Their changes are mostly not applicable. Do keep the `libmbedcrypto.$(DLEXT): | libmbedcrypto.a` order dependency.
* `.c.o`: `-o` was added on both sides but in a different place. Change to their place.
* `library/error.c`: to be regenerated.
* `library/version_features.c`: to be regenerated.
* `programs/Makefile`: Most of the changes are not relevant. The one relevant change is in the `clean` target for Windows; adapt it by removing `/S` from our version.
* `programs/test/query_config.c`: to be regenerated.
* `scripts/config.py`: added in parallel on both sides. Keep our version.
* `scripts/footprint.sh`: parallel changes. Keep our version.
* `scripts/generate_visualc_files.pl`: one delete/modify conflict. Keep the removed chunks out.
* `tests/Makefile`: discard all of their changes.
* `tests/scripts/all.sh`:
* `pre_initialize_variables` add `append_outcome`: add it.
* `pre_initialize_variables` add `ASAN_CFLAGS`: already there, keep our version.
* `pre_parse_command_line` add `--no-append-outcome`: add it.
* `pre_parse_command_line` add `--outcome-file`: add it.
* `pre_print_configuration`: add `MBEDTLS_TEST_OUTCOME_FILE`.
* Several changes in SSL-specific components: keep our version without them.
* Several changes where `config.pl` was changed to `config.py` and there was an adjacent difference: keep our version.
* Changes regarding the inclusion of `MBEDTLS_MEMORY_xxx`: ignore them here, they will be normalized in a subsequent commit.
* `component_test_full_cmake_gcc_asan`: add it without the TLS tests.
* `component_test_no_use_psa_crypto_full_cmake_asan`: keep the fixed `msg`, discard other changes.
* `component_test_memory_buffer_allocator_backtrace`, `component_test_memory_buffer_allocator`: add them without the TLS tests.
* `component_test_m32_everest`: added in parallel on both sides. Keep our version.
* `tests/scripts/check-names.sh`, `tests/scripts/list-enum-consts.pl`, `tests/scripts/list-identifiers.sh`, ``tests/scripts/list-macros.sh`: discard all of their changes.
* `tests/scripts/test-ref-configs.pl`: the change in the conflict is not relevant, so keep our version there.
* `visualc/VS2010/*.vcxproj`: to be regenerated.
Regenerate files:
```
scripts/generate_visualc_files.pl
git add visualc/VS2010/*.vcxproj
scripts/generate_errors.pl
git add library/error.c
scripts/generate_features.pl
git add library/version_features.c
scripts/generate_query_config.pl
git add programs/test/query_config.c
```
Rejected changes in non-conflicting files:
* `CMakeLists.txt`: discard their addition which has already been side-ported.
* `doxygen/mbedtls.doxyfile`: keep the version number change. Discard the changes related to `../crypto` paths.
Keep the following changes after examination:
* `.travis.yml`: all of their changes are relevant.
* `include/mbedtls/error.h`: do keep their changes. Even though Crypto doesn't use TLS errors, it must not encroach on TLS's allocated numbers.
* `tests/scripts/check-test-cases.py`: keep the code dealing with `ssl-opt.sh`. It works correctly when the file is not present.
git grep -Fl /config.pl | xargs sed -i -e 's!/config\.pl!/config.py!g'
Also:
* Change one comment in include/mbedtls/check_config.h.
* Change PERL to PYTHON in CMakeLists.txt.
The initial value for the max calculation needs to be 0. The fallback
needs to come last. With the old code, the value was never smaller
than the fallback.
For RSA_ALT, use MPI_MAX_SIZE. Only use this if RSA_ALT is enabled.
For PSA, check PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE, and separately check
the special case of ECDSA where PSA and mbedtls have different
representations for the signature.
PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE was taking the maximum ECDSA key
size as the ECDSA signature size. Fix it to use the actual maximum
size of an ECDSA signature.
The original definition of MBEDTLS_PK_SIGNATURE_MAX_SIZE only took RSA
into account. An ECDSA signature may be larger than the maximum
possible RSA signature size, depending on build options; for example
this is the case with config-suite-b.h.
The signature of mbedtls_mpi_cmp_mpi_ct() meant to support using it in
place of mbedtls_mpi_cmp_mpi(). This meant full comparison functionality
and a signed result.
To make the function more universal and friendly to constant time
coding, we change the result type to unsigned. Theoretically, we could
encode the comparison result in an unsigned value, but it would be less
intuitive.
Therefore we won't be able to represent the result as unsigned anymore
and the functionality will be constrained to checking if the first
operand is less than the second. This is sufficient to support the
current use case and to check any relationship between MPIs.
The only drawback is that we need to call the function twice when
checking for equality, but this can be optimised later if an when it is
needed.
You can't reuse a CTR_DRBG context without free()ing it and
re-init()ing it. This generally happened to work, but was never
guaranteed. It could have failed with alternative implementations of
the AES module because mbedtls_ctr_drbg_seed() calls
mbedtls_aes_init() on a context which is already initialized if
mbedtls_ctr_drbg_seed() hasn't been called before, plausibly causing a
memory leak. Since the addition of mbedtls_ctr_drbg_set_nonce_len(),
the second call to mbedtls_ctr_drbg_seed() uses a nonsensical value as
the entropy nonce length.
Calling free() and seed() with no intervening init fails when
MBEDTLS_THREADING_C is enabled and all-bits-zero is not a valid mutex
representation.
The default entropy nonce length is either zero or nonzero depending
on the desired security strength and the entropy length.
The implementation calculates the actual entropy nonce length from the
actual entropy length, and therefore it doesn't need a constant that
indicates the default entropy nonce length. A portable application may
be interested in this constant, however. And our test code could
definitely use it.
Define a constant MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN and use it in
test code. Previously, test_suite_ctr_drbg had knowledge about the
default entropy nonce length built in and test_suite_psa_crypto_init
failed. Now both use MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN.
This change means that the test ctr_drbg_entropy_usage no longer
validates that the default entropy nonce length is sensible. So add a
new test that checks that the default entropy length and the default
entropy nonce length are sufficient to ensure the expected security
strength.
Change the default entropy nonce length to be nonzero in some cases.
Specifically, the default nonce length is now set in such a way that
the entropy input during the initial seeding always contains enough
entropy to achieve the maximum possible security strength per
NIST SP 800-90A given the key size and entropy length.
If MBEDTLS_CTR_DRBG_ENTROPY_LEN is kept to its default value,
mbedtls_ctr_drbg_seed() now grabs extra entropy for a nonce if
MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is disabled and either
MBEDTLS_ENTROPY_FORCE_SHA256 is enabled or MBEDTLS_SHA512_C is
disabled. If MBEDTLS_CTR_DRBG_USE_128_BIT_KEY is enabled, or if
the entropy module uses SHA-512, then the default value of
MBEDTLS_CTR_DRBG_ENTROPY_LEN does not require a second call to the
entropy function to achieve the maximum security strength.
This choice of default nonce size guarantees NIST compliance with the
maximum security strength while keeping backward compatibility and
performance high: in configurations that do not require grabbing more
entropy, the code will not grab more entropy than before.
Add a new function mbedtls_ctr_drbg_set_nonce_len() which configures
the DRBG instance to call f_entropy a second time during the initial
seeding to grab a nonce.
The default nonce length is 0, so there is no behavior change unless
the user calls the new function.
mbedtls_ctr_drbg_seed() always set the entropy length to the default,
so a call to mbedtls_ctr_drbg_set_entropy_len() before seed() had no
effect. Change this to the more intuitive behavior that
set_entropy_len() sets the entropy length and seed() respects that and
only uses the default entropy length if there was no call to
set_entropy_len().
This removes the need for the test-only function
mbedtls_ctr_drbg_seed_entropy_len(). Just call
mbedtls_ctr_drbg_set_entropy_len() followed by
mbedtls_ctr_drbg_seed(), it works now.
mbedtls_hmac_drbg_seed() always set the entropy length to the default,
so a call to mbedtls_hmac_drbg_set_entropy_len() before seed() had no
effect. Change this to the more intuitive behavior that
set_entropy_len() sets the entropy length and seed() respects that and
only uses the default entropy length if there was no call to
set_entropy_len().
Document that passing 0 to a close/destroy function does nothing and
returns PSA_SUCCESS.
Although this was not written explicitly, the specification strongly
suggested that this would return PSA_ERROR_INVALID_HANDLE. While
returning INVALID_HANDLE makes sense, it was awkward for a very common
programming style where applications can store 0 in a handle variable
to indicate that the handle has been closed or has never been open:
applications had to either check if (handle != 0) before calling
psa_close_key(handle) or psa_destroy_key(handle), or ignore errors
from the close/destroy function. Now applications following this style
can just call psa_close_key(handle) or psa_destroy_key(handle).
The documentation of HMAC_DRBG erroneously claimed that
mbedtls_hmac_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_hmac_drbg_seed() forces
the entropy length to its chosen value. Fix the documentation.
The documentation of CTR_DRBG erroneously claimed that
mbedtls_ctr_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_ctr_drbg_seed() forces
the initial seeding to grab MBEDTLS_CTR_DRBG_ENTROPY_LEN bytes of
entropy. Fix the documentation and rewrite the discussion of the
entropy length and the security strength accordingly.
