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671 commits

Author SHA1 Message Date
Gilles Peskine 961914df12
Merge pull request #3382 from stevew817/feature/volatile-keys-in-SE
Support volatile keys in external SE
2020-06-26 20:27:11 +02:00
Steven Cooreman 8c1e759e1d Documentation and new function signature update
Inline with review comments.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
2020-06-17 14:52:05 +02:00
Steven Cooreman 81fe7c311a Split 'validate persistent key parameters' into independent validation
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
2020-06-17 13:53:18 +02:00
Bence Szépkúti 869746577a Add Apache-2.0 headers to all source files
Also normalize the first line of the copyright headers.

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Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
2020-06-16 17:38:44 +02:00
Steven Cooreman bbeaf18eac Do not persist transactions on volatile external keys
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
2020-06-08 18:29:44 +02:00
Steven Cooreman c59de6ab7e Refactor lifetime checking to reflect split in location and persistence
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
2020-06-08 18:28:25 +02:00
Darryl Green 2f0eb51aae psa: Define mbedtls_ecc_group_to_psa() inline
On dual world platforms, we want to run the PK module (pk.c) on the NS
side so TLS can use PSA APIs via the PK interface. PK currently has a
hard dependency on mbedtls_ecc_group_to_psa() which is declared in
crypto_extra.h, but only defined in psa_crypto.c, which is only built
for the S side.

Without this change, dual world platforms get error messages like the
following.

    [Error] @0,0: L6218E: Undefined symbol mbedtls_ecc_group_to_psa (referred from BUILD/LPC55S69_NS/ARM/mbed-os/features/mbedtls/mbed-crypto/src/pk.o)

Make mbedtls_ecc_group_to_psa() inline within crypto_extra.h so that it
is available to both NS and S world code.

Fixes #3300

Signed-off-by: Darryl Green <darryl.green@arm.com>
Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>
2020-05-05 12:41:48 +01:00
Jaeden Amero 1bde9cdf71 psa: Clear bits in mbedtls_ecc_group_to_psa()
Clear bits in mbedtls_ecc_group_to_psa() to avoid static analyzers and
possibly compilers from warning that bits may be used uninitialized in
certain code paths.

For example, if mbedtls_ecc_group_to_psa() were to be inlined in
crypto_extra.h, the following compiler warning is likely.

    In file included from ../include/psa/crypto.h:3774:0,
                     from ../include/mbedtls/pk.h:49,
                     from pk.c:29:
    pk.c: In function 'mbedtls_pk_wrap_as_opaque':
    ../include/psa/crypto_struct.h:460:33: error: 'bits' may be used uninitialized in this function [-Werror=maybe-uninitialized]
             attributes->core.bits = (psa_key_bits_t) bits;
                                     ^~~~~~~~~~~~~~~~~~~~~
    pk.c:608:12: note: 'bits' was declared here
         size_t bits;
                ^~~~

Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>
2020-05-05 12:41:41 +01:00
Janos Follath b7000d4b2f
Merge pull request #345 from gilles-peskine-arm/psa_mac_verify_finish-status
Fix possible error code mangling in psa_mac_verify_finish
2020-02-03 13:55:11 +00:00
Gilles Peskine 3e819b7d69 psa_key_agreement_ecdh: zeroize output on failure
If psa_key_agreement_ecdh fails, there may be output that leaks
sensitive information in the output buffer. Zeroize it.

If this is due to an underlying failure in the ECDH implementation, it
is currently not an issue since both the traditional Mbed TLS/Crypto
implementation and Everest only write to the output buffer once every
intermediate step has succeeded, but zeroizing is more robust. If this
is because the recently added key size check fails, a leak could be a
serious issue.
2020-01-31 10:24:21 +01:00
Gilles Peskine f65ed6f254 Change key types to a 16-bit encoding
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.
2020-01-31 10:24:21 +01:00
Gilles Peskine b87b719467 Remove old values of curve encodings
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.
2020-01-31 10:24:21 +01:00
Gilles Peskine 228abc5773 Define EC curve family constants
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.
2020-01-31 10:15:32 +01:00
Gilles Peskine 025fccdc32 Change the encoding of EC curves and DH groups to include the size
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.
2020-01-31 10:15:32 +01:00
Gilles Peskine 5055b239bf Expose mbedtls/psa curve identifier conversions from psa_crypto.c 2020-01-31 10:15:32 +01:00
Gilles Peskine 4295e8b9c5 Rework PSA curve to mbedlts group id conversion
Don't rely on the bit size encoded in the PSA curve identifier, in
preparation for removing that.

For some inputs, the error code on EC key creation changes from
PSA_ERROR_INVALID_ARGUMENT to PSA_ERROR_NOT_SUPPORTED or vice versa.
There will be further such changes in subsequent commits.
2020-01-31 10:15:32 +01:00
Gilles Peskine c7ef5b3f45 Rework mbedlts group id to PSA curve conversion
Don't rely on the PSA curve identifier determining the key size, in
preparation for removing that.
2020-01-31 10:15:32 +01:00
Gilles Peskine 84b8fc8213 Use psa_hash_compute in psa_hmac_setup_internal 2020-01-30 12:27:14 +01:00
Gilles Peskine 0a749c8fa3 Implement and test psa_hash_compute, psa_hash_compare 2020-01-30 12:27:12 +01:00
Manuel Pégourié-Gonnard b7f7092f57 Remove preprocessor directive for consistency
Other cases in this switch statement aren't guarded either.
2020-01-24 10:59:08 +01:00
Gilles Peskine 28cd41676e Fix possible error code mangling in psa_mac_verify_finish
If psa_mac_finish_internal fails (which can only happen due to bad
parameters or hardware problem), the error code was converted to
PSA_ERROR_INVALID_SIGNATURE if the uninitialized stack variable
actual_mac happened to contain the expected MAC. This is a minor bug
but it may be possible to leverage it as part of a longer attack path
in some scenarios.

Reported externally. Found by static analysis.
2020-01-20 16:31:06 +01:00
Manuel Pégourié-Gonnard 792b16d83b Make more code paths conditional in psa_crypto.c 2020-01-07 10:13:18 +01:00
Manuel Pégourié-Gonnard d602084cde Implement NO_SHA384 in MD layer and PSA 2020-01-06 11:40:23 +01:00
Jaeden Amero 795c6bab62
Merge pull request #323 from yanesca/iotcrypt-942-initialise-return-values
Initialise return values to an error
2019-12-19 10:24:22 +00:00
Gilles Peskine 4cd3277656 Factor common code of psa_import_ec_{public,private}_key 2019-12-12 09:00:27 +01:00
Janos Follath 24eed8d2d2 Initialise return values to an error
Initialising the return values to and error is best practice and makes
the library more robust.
2019-12-03 16:07:18 +00:00
Janos Follath a13b905d8d Map the new Mbed TLS error value in PSA 2019-12-03 16:03:11 +00:00
Gilles Peskine 89d8c5c447 Rename some signature-related identifiers
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')
2019-11-26 18:20:59 +01:00
Gilles Peskine cb0101ff33
Merge pull request #298 from gilles-peskine-arm/config-symmetric-only
Test a build without any asymmetric cryptography
2019-11-12 19:37:13 +01:00
Gilles Peskine 150d577780
Merge pull request #292 from gilles-peskine-arm/psa-destroy_0
Make psa_close_key(0) and psa_destroy_key(0) succeed
2019-10-14 11:21:54 +02:00
Gilles Peskine b16841ee69 Fixed -Wunused warnings when building without asymmetric crypto 2019-10-11 18:21:08 +02:00
Gilles Peskine 1841cf43ee Make psa_close_key(0) and psa_destroy_key(0) succeed 2019-10-08 15:57:27 +02:00
Gilles Peskine d9348f218e SE driver: call the p_init method during psa_crypto_init() 2019-10-01 15:22:29 +02:00
Gilles Peskine 3efcebbc5e SE support: Use a transaction when registering a key
When registering a key in a secure element, go through the transaction
mechanism. This makes the code simpler, at the expense of a few extra
storage operations. Given that registering a key is typically very
rare over the lifetime of a device, this is an acceptable loss.

Drivers must now have a p_validate_slot_number method, otherwise
registering a key is not possible. This reduces the risk that due to a
mistake during the integration of a device, an application might claim
a slot in a way that is not supported by the driver.
2019-10-01 14:18:35 +02:00
Gilles Peskine 178c9aa966 Key derivation: forbid output_key without input_key
If none of the inputs to a key derivation is a
PSA_KEY_DERIVATION_INPUT_SECRET passed with
psa_key_derivation_input_key(), forbid
psa_key_derivation_output_key(). It usually doesn't make sense to
derive a key object if the secret isn't itself a proper key.
2019-09-24 18:39:03 +02:00
Gilles Peskine b8965193a0 Use the constant PSA_KEY_TYPE_NONE rather than 0
No behavior change, just a readability improvement.
2019-09-24 18:39:03 +02:00
Gilles Peskine 46d7faf195 Don't jump past a variable declaration
This is valid C99 (since the variable in question is not a VLA and is
not used) but not accepted by IAR 8.20.
2019-09-24 18:39:03 +02:00
Gilles Peskine 593773d9f2 Consistently abort key derivation operations on input error 2019-09-24 18:39:03 +02:00
Gilles Peskine 224b0d656a Key derivation: allow both keys and direct inputs
Allow a direct input as the SECRET input step in a key derivation, in
addition to allowing DERIVE keys. This makes it easier for
applications to run a key derivation where the "secret" input is
obtained from somewhere else. This makes it possible for the "secret"
input to be empty (keys cannot be empty), which some protocols do (for
example the IV derivation in EAP-TLS).

Conversely, allow a RAW_DATA key as the INFO/LABEL/SALT/SEED input to a key
derivation, in addition to allowing direct inputs. This doesn't
improve security, but removes a step when a personalization parameter
is stored in the key store, and allows this personalization parameter
to remain opaque.

Add test cases that explore step/key-type-and-keyhood combinations.
2019-09-24 18:39:03 +02:00
Gilles Peskine a291413a1e
Merge pull request #257 from gilles-peskine-arm/psa-remove_zero_length_keys
Forbid zero-length keys
2019-09-19 13:07:41 +02:00
Gilles Peskine 89cc74f447 Fix signature size checks in psa_asymmetric_verify for RSA
The signature must have exactly the same length as the key, it can't
be longer. Fix #258

If the signature doesn't have the correct size, that's an invalid
signature, not a problem with an output buffer size. Fix the error code.

Add test cases.
2019-09-13 11:39:11 +02:00
Gilles Peskine 4019f0e914 Immediately reject 0-size signature buffer when signing
In psa_asymmetric_sign, immediately reject an empty signature buffer.
This can never be right.

Add test cases (one RSA and one ECDSA).

Change the SE HAL mock tests not to use an empty signature buffer.
2019-09-12 22:05:59 +02:00
Gilles Peskine f916894ef3 Remove special handling for zero-length keys
Zero-length keys are rejected at creation time, so we don't need any
special handling internally.

When exporting a key, we do need to take care of the case where the
output buffer is empty, but this is easy: an empty output buffer is
never valid.
2019-09-12 19:21:37 +02:00
Gilles Peskine 0f84d6245b Reject keys of size 0
Implement the prohibition on keys of size 0.
2019-09-12 19:03:13 +02:00
Ron Eldor 296eca6e76 Fix a buffer overflow in hmac_setup_internal
At the end of `psa_hmac_setup_internal()`, the ipad is cleared.
However, the size that was given to clear was `key_len` which is larger
than the size of `ipad`.
2019-09-10 15:21:37 +03:00
Darryl Green 5e843fa133 Use safer deterministic function in psa_ecdsa_sign 2019-09-05 14:06:34 +01:00
Jaeden Amero 21db2a94a4
Merge pull request #229 from k-stachowiak/IOTCRYPT-791-remove-legacy-psa-key-derivation
Remove legacy psa key derivation
2019-08-29 11:31:23 +01:00
Darryl Green 0892d0fbbf Initialize key bits to max size + 1 in psa_import_key
In psa_import_key, the key bits value was uninitialized before
calling the secure element driver import function. There is a
potential issue if the driver returns PSA_SUCCESS without setting
the key bits. This shouldn't happen, but shouldn't be discounted
either, so we initialize the key bits to an invalid issue.
2019-08-21 16:56:16 +01:00
Darryl Green 572a16e694 Merge branch 'psa-api-1.0-beta' into api-to-development 2019-08-21 10:31:12 +01:00
k-stachowiak 012dcc4b87 Remove PSA_PRE_1_0_KEY_DERIVATION and the corresponding code 2019-08-13 18:42:40 +02:00
k-stachowiak 0b74cf85ea Remove psa_key_derivation() and associated static functions 2019-08-13 18:42:27 +02:00
Gilles Peskine c9d7f94a65 Add issue numbers for some missing parts of secure element support 2019-08-13 16:17:16 +02:00
Gilles Peskine 4b7f340fbf Clean up status code handling inside psa_destroy_key
Adopt a simple method for tracking whether there was a failure: each
fallible operation sets overall_status, unless overall_status is
already non-successful. Thus in case of multiple failures, the
function always reports whatever failed first. This may not always be
the right thing, but it's simple.

This revealed a bug whereby if the only failure was the call to
psa_destroy_se_key(), i.e. if the driver reported a failure or if the
driver lacked support for destroying keys, psa_destroy_key() would
ignore that failure.

For a key in a secure element, if creating a transaction file fails,
don't touch storage, but close the key in memory. This may not be
right, but it's no wronger than it was before. Tracked in
https://github.com/ARMmbed/mbed-crypto/issues/215
2019-08-13 15:58:36 +02:00
Gilles Peskine 9ce31c466d Note about destroying a key with other open handles
https://github.com/ARMmbed/mbed-crypto/issues/214
2019-08-13 15:14:20 +02:00
Gilles Peskine caec27821f SE keys: make psa_destroy_key remove the key from storage 2019-08-13 15:11:49 +02:00
Gilles Peskine 3f7cd62ff5 Document better what wiping a key slot does not do
When a key slot is wiped, a copy of the key material may remain in
operations. This is undesirable, but does not violate the safety of
the code. Tracked in https://github.com/ARMmbed/mbed-crypto/issues/86
2019-08-13 15:01:08 +02:00
Janos Follath 1d57a20cbe Make TODO comments consistent 2019-08-13 12:15:34 +01:00
Gilles Peskine edc6424d77 SE driver support: Implement sign and verify hooks 2019-08-09 16:43:35 +02:00
Gilles Peskine 11792086cc SE keys: implement and smoke-test p_generate 2019-08-09 16:43:35 +02:00
Gilles Peskine f3801fff77 Update import_key and generate_key SE methods to the current API
The methods to import and generate a key in a secure element drivers
were written for an earlier version of the application-side interface.
Now that there is a psa_key_attributes_t structure that combines all
key metadata including its lifetime (location), type, size, policy and
extra type-specific data (domain parameters), pass that to drivers
instead of separate arguments for each piece of metadata. This makes
the interface less cluttered.

Update parameter names and descriptions to follow general conventions.

Document the public-key output on key generation more precisely.
Explain that it is optional in a driver, and when a driver would
implement it. Declare that it is optional in the core, too (which
means that a crypto core might not support drivers for secure elements
that do need this feature).

Update the implementation and the tests accordingly.
2019-08-09 16:43:35 +02:00
Gilles Peskine a5f8749812 SE key registration: call p_validate_slot_number
When registering a key in a secure element, if the driver has a
p_validate_slot_number method, call it.
2019-08-09 15:05:32 +02:00
Gilles Peskine d772958ffc New function mbedtls_psa_register_se_key
Register an existing key in a secure element.

Minimal implementation that doesn't call any driver method and just
lets the application declare whatever it wants.
2019-08-09 15:05:21 +02:00
Gilles Peskine e88c2c1338 Pass the key creation method to drivers
Pass the key creation method (import/generate/derive/copy) to the
driver methods to allocate or validate a slot number. This allows
drivers to enforce policies such as "this key slot can only be used
for keys generated inside the secure element".
2019-08-09 14:59:31 +02:00
Gilles Peskine df17914e01 psa_start_key_creation: take the method as a parameter
Let psa_start_key_creation know what type of key creation this is. This
will be used at least for key registration in a secure element, which
is a peculiar kind of creation since it uses existing key material.
2019-08-09 14:54:03 +02:00
Janos Follath 8aa7e9bc56 Merge branch 'psa-api-1.0-beta' into merge-psa-api-branch-into-development 2019-08-08 14:40:23 +01:00
Gilles Peskine 46d9439a5e Support slot_number attribute when creating a key
Allow the application to choose the slot number in a secure element,
rather than always letting the driver choose.

With this commit, any application may request any slot. In an
implementation with isolation, it's up to the service to filter key
creation requests and apply policies to limit which applications can
request which slot.
2019-08-08 11:02:30 +02:00
Gilles Peskine edbed5670a Rename psa_internal_allocate_key_slot to psa_get_empty_key_slot
This function no longer modifies anything, so it doesn't actually
allocate the slot. Now, it just returns the empty key slot, and it's
up to the caller to cause the slot to be in use (or not).
2019-08-08 10:58:09 +02:00
Gilles Peskine 094dac1d12 Fix copypasta 2019-08-08 10:58:09 +02:00
Gilles Peskine 013f5474cf Fix erasure of external flags
This didn't break anything now, but would have broken things once we
start to add internal flags.
2019-08-08 10:58:09 +02:00
Gilles Peskine 5a68056755 Rename internal macro to pass check-names.sh
check-names.sh rejects MBEDTLS_XXX identifiers that are not defined in
a public header.
2019-08-08 10:58:09 +02:00
Gilles Peskine c8000c005a Add slot_number attribute
Add a slot_number field to psa_key_attributes_t and getter/setter
functions. Since slot numbers can have the value 0, indicate the
presence of the field via a separate flag.

In psa_get_key_attributes(), report the slot number if the key is in a
secure element.

When creating a key, for now, applications cannot choose a slot
number. A subsequent commit will add this capability in the secure
element HAL.
2019-08-08 10:58:09 +02:00
Gilles Peskine 91e8c33f48 Add infrastructure for key attribute flags
Add infrastructure for internal, external and dual-use flags, with a
compile-time check (if static_assert is available) to ensure that the
same numerical value doesn't get declared for two different purposes
in crypto_struct.h (external or dual-use) and
psa_crypto_core.h (internal).
2019-08-08 10:58:09 +02:00
Gilles Peskine 0c77b0e2f9
Merge pull request #198 from gilles-peskine-arm/psa-api-1.0-beta-merge_development_20190801
Merge mbed-crypto/development into psa-api-1.0-beta
2019-08-08 10:24:53 +02:00
Gilles Peskine f181eca350 Fix psa_generate_random for >1024 bytes
mbedtls_ctr_drbg_random can only return up to
MBEDTLS_CTR_DRBG_MAX_REQUEST (normally 1024) bytes at a time. So if
more than that is requested, call mbedtls_ctr_drbg_random in a loop.
2019-08-07 13:49:00 +02:00
Gilles Peskine a6b2f60b4c Fix double free in psa_generate_key when psa_generate_random fails
When psa_generate_random fails, psa_generate_key_internal frees the
key buffer but a the pointer to the now-freed buffer in the slot. Then
psa_generate_key calls psa_fail_key_creation which sees the pointer
and calls free() again.

This bug was introduced by ff5f0e7221
"Implement atomic-creation psa_{generate,generator_import}_key" which
changed how psa_generate_key() cleans up on errors. I went through the
code and could not find a similar bug in cleanup on an error during
key creation.

Fix #207
2019-08-07 13:43:09 +02:00
Gilles Peskine 1b9505c451 Correct some comments 2019-08-07 10:59:45 +02:00
Vikas Katariya 21599b6622 Return right error code.
Issue : 126
https://github.com/ARMmbed/mbed-crypto/issues/126

PSA_ERROR_BUFFER_TOO_SMALL error returned when we check for output_size.
2019-08-02 13:01:58 +01:00
Gilles Peskine 8908c5e81c Make psa_calculate_key_bits return psa_key_bits_t
This is cleaner and solves a complaint from MSVC about truncation from
size_t to psa_key_bits_t.
2019-07-31 18:55:00 +02:00
Gilles Peskine 72c8c5b352 Merge remote-tracking branch 'upstream-crypto/development' into psa-api-1.0-beta-merge_development_20190801
Conflict resolution:
* `scripts/config.pl`:
  Take the exclusion of `MBEDTLS_PSA_CRYPTO_SE_C` from the API branch.
  Take the removal of `MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C` (obsolete) from
  the development branch.
* `tests/scripts/all.sh`:
  Multiple instances of factoring a sequence of `config.pl` calls into
  a mere `config.pl baremetal` in the development branch, and a change in
  the composition of `baremetal` in the API branch. In each case, take the
  version from development.
* `tests/suites/test_suite_psa_crypto_slot_management.function`:
  A function became non-static in development and disappeared in the API
  branch. Keep the version from the API branch. Functions need to be
  non-static if they're defined but unused in some configurations,
  which is not the case for any function in this file at the moment.
* `tests/suites/test_suite_psa_crypto.function`:
  Consecutive changes in the two branches, reconciled.
2019-07-31 17:47:49 +02:00
Gilles Peskine 1b8594a218 More refactoring: consolidate attribute validation
Consolidate attribute validation at the beginning of key creation into
a single function. Improve comments.
2019-07-31 17:21:46 +02:00
Gilles Peskine 3825e14e65 Fix policy validity check on key creation.
Add a non-regression test.
2019-07-31 16:54:38 +02:00
Gilles Peskine 41e50d26ea Remove "allocated" flag from key slots
The flag to mark key slots as allocated was introduced to mark slots
that are claimed and in use, but do not have key material yet, at a
time when creating a key used several API functions: allocate a slot,
then progressively set its metadata, and finally create the key
material. Now that all of these steps are combined into a single
API function call, the notion of allocated-but-not-filled slot is no
longer relevant. So remove the corresponding flag.

A slot is occupied iff there is a key in it. (For a key in a secure
element, the key material is not present, but the slot contains the
key metadata.) This key must have a type which is nonzero, so use this
as an indicator that a slot is in use.
2019-07-31 16:54:38 +02:00
Gilles Peskine 76aa09c9a9 Take advantage of psa_core_key_attributes_t internally #2
Key creation and psa_get_key_attributes
2019-07-31 16:54:37 +02:00
Gilles Peskine b46bef2f76 Store the key size in the slot in memory
There is now a field for the key size in the key slot in memory. Use
it.

This makes psa_get_key_attributes() marginally faster at the expense
of memory that is available anyway in the current memory layout (16
bits for the size, 16 bits for flags). That's not the goal, though:
the goal is to simplify the code, in particular to make it more
uniform between transparent keys (whose size can be recomputed) and
keys in secure elements (whose size cannot be recomputed).

For keys in a secure element, the bit size is now saved by serializing
the type psa_key_bits_t (which is an alias for uint16_t) rather than
size_t.
2019-07-31 14:16:50 +02:00
Gilles Peskine 4ed0e6f11a Switch storage functions over to psa_core_key_attributes_t 2019-07-31 14:15:27 +02:00
Gilles Peskine 8e3387029d Use psa_core_key_attributes_t in key slots in memory
Change the type of key slots in memory to use
psa_core_key_attributes_t rather than separate fields. The goal is to
simplify some parts of the code. This commit only does the mechanical
replacement, not the substitution.

The bit-field `allocate` is now a flag `PSA_KEY_SLOT_FLAG_ALLOCATED`
in the `flags` field.

Write accessor functions for flags.

Key slots now contain a bit size field which is currently unused.
Subsequent commits will make use of it.
2019-07-31 14:15:27 +02:00
Gilles Peskine 68cc433b5b Store key sizes in 16 bits in attributes
This is larger than the maximum key size introduced in the previous
commit, by design.

Make some room for flags (not used yet).
2019-07-30 21:08:38 +02:00
Gilles Peskine c744d99386 Limit keys to 65528 bits
65528 bits is more than any reasonable key until we start supporting
post-quantum cryptography.

This limit is chosen to allow bit-sizes to be stored in 16 bits, with
65535 left to indicate an invalid value. It's a whole number of bytes,
which facilitates some calculations, in particular allowing a key of
exactly PSA_CRYPTO_MAX_STORAGE_SIZE to be created but not one bit
more.

As a resource usage limit, this is arguably too large, but that's out
of scope of the current commit.

Test that key import, generation and derivation reject overly large
sizes.
2019-07-30 20:58:33 +02:00
Gilles Peskine 7e0cff90b9 Move attribute fields to a substructure
Move the "core attributes" to a substructure of psa_key_attribute_t.
The motivation is to be able to use the new structure
psa_core_key_attributes_t internally.
2019-07-30 20:58:27 +02:00
Gilles Peskine e60d1d08a4 SE keys: save the bit size in storage
For a key in a secure element, save the bit size alongside the slot
number.

This is a quick-and-dirty implementation where the storage format
depends on sizeof(size_t), which is fragile. This should be replaced
by a more robust implementation before going into production.
2019-07-29 18:11:09 +02:00
Gilles Peskine 1801740a7c SE driver: report the bit size on key import
Add a parameter to the key import method of a secure element driver to
make it report the key size in bits. This is necessary (otherwise the
core has no idea what the bit-size is), and making import report it is
easier than adding a separate method (for other key creation methods,
this information is an input, not an output).
2019-07-29 18:07:09 +02:00
Gilles Peskine dc5bfe9784 SE keys: implement and test psa_get_key_attributes 2019-07-29 18:07:03 +02:00
Gilles Peskine 424f89453b SE keys: store the bit size internally (partial implementation)
This commit blindingly copies the size from the attributes. This is
not correct for copy and import.
2019-07-29 17:06:06 +02:00
Gilles Peskine adb1c52149
Merge pull request #157 from gilles-peskine-arm/psa-se_driver-create_key
Secure element key creation foundation
2019-07-26 14:39:55 +02:00
Gilles Peskine 66be51c35d If starting a transaction fails, wipe the transaction data
Nothing has been saved to disk yet, but there is stale data in
psa_crypto_transaction. This stale data should not be reused, but do
wipe it to reduce the risk of it mattering somehow in the future.
2019-07-26 13:23:51 +02:00
Gilles Peskine f9bb29ec26 Add boilerplate to recover a transaction during init 2019-07-25 17:52:59 +02:00
Gilles Peskine 4aea1036c6 Bug fix: don't start a transaction for non-SE keys 2019-07-25 17:38:34 +02:00
Gilles Peskine 2e0f388d2a Don't explicitly dereference function pointers
Be stylistically consistent.
2019-07-25 11:42:19 +02:00
Gilles Peskine 60450a4812 Improve comments 2019-07-25 11:32:45 +02:00
Gilles Peskine 725f22a545 Bug fix: save the driver's persistent data in destroy_key 2019-07-25 11:32:27 +02:00
Gilles Peskine adad813d7b psa_key_slot_is_external exists. Use it. 2019-07-25 11:32:27 +02:00
Gilles Peskine f77a6acf83 Fix indentation 2019-07-25 10:51:03 +02:00
Gilles Peskine 4b73422318 Transaction support: be more future-proof
If there's ever a non-SE-related transaction, make sure it gets
handled during init.
2019-07-24 15:56:31 +02:00
Gilles Peskine f4ee662868 SE keys: error out in key creation function that lack support 2019-07-24 13:44:30 +02:00
Gilles Peskine 28f8f3068f SE keys: ensure that functions that lack support properly error out
Introduce a new function psa_get_transparent_key which returns
NOT_SUPPORTED if the key is in a secure element. Use this function in
functions that don't support keys in a secure element.

After this commit, all functions that access a key slot directly via
psa_get_key_slot or psa_get_key_from_slot rather than via
psa_get_transparent_key have at least enough support for secure
elements not to crash or otherwise cause undefined behavior. Lesser
bad behavior such as wrong results or resource leakage is still
possible in error cases.
2019-07-24 13:30:31 +02:00
Gilles Peskine 1df83d4f5b SE keys: implement persistent storage
For a key in a secure element, persist the key slot.

This is implemented in the nominal case. Failures may not be handled
properly.
2019-07-23 16:13:14 +02:00
Gilles Peskine bfd322ff34 Use a key attribute structure in the internal storage interface
Pass information via a key attribute structure rather than as separate
parameters to psa_crypto_storage functions. This makes it easier to
maintain the code when the metadata of a key evolves.

This has negligible impact on code size (+4B with "gcc -Os" on x86_64).
2019-07-23 13:31:54 +02:00
Gilles Peskine fc76265385 Do secure element key creation and destruction in a transaction
Key creation and key destruction for a key in a secure element both
require updating three pieces of data: the key data in the secure
element, the key metadata in internal storage, and the SE driver's
persistent data. Perform these actions in a transaction so that
recovery is possible if the action is interrupted midway.
2019-07-22 19:46:22 +02:00
Gilles Peskine c11c4dcf95 Favor stdint.h types in internal types
Use uint8_t for PSA buffers. Keep unsigned char for generic libc
buffers and for mbedtls buffers.
2019-07-15 11:17:53 +02:00
Gilles Peskine 7228da25f9 Favor stdint.h types in implementation-specific API 2019-07-15 11:16:18 +02:00
Andrew Thoelke 163639b830 Apply same changes to implementation source code 2019-07-15 11:14:56 +02:00
Gilles Peskine 5d309672af SE keys: support import and export 2019-07-12 23:47:28 +02:00
Gilles Peskine 354f7671f4 SE keys: support destroy
When destroying a key in a secure element, call the driver's destroy
method and update the driver's persistent data in storage.
2019-07-12 23:46:38 +02:00
Gilles Peskine cbaff467ef SE keys: allocate a slot before creating the key 2019-07-12 23:46:04 +02:00
Gilles Peskine 73167e128f SE keys: store the slot number in the memory slot 2019-07-12 23:44:37 +02:00
Gilles Peskine 8abe6a2d5c Driver table entries are now mutable
Since driver table entries contain the driver context, which is
mutable, they can't be const anymore.
2019-07-12 23:42:20 +02:00
Gilles Peskine 011e4284a1 Look up the SE driver when creating a key
When creating a key with a lifetime that places it in a secure
element, retrieve the appropriate driver table entry.

This commit doesn't yet achieve behavior: so far the code only
retrieves the driver, it doesn't call the driver.
2019-07-12 11:47:50 +02:00
Adrian L. Shaw 2282cfa660 Remove GMAC algorithm (for now)
It can't be implemented with the current version of the API
2019-07-11 15:51:45 +01:00
Jaeden Amero c19dcebbdd
Merge pull request #154 from yanesca/iotcrypt-789-update-tls-prf-to-multipart
Update TLS 1.2 PRF to multipart API
2019-07-04 11:53:04 +01:00
Janos Follath d6dce9f4f3 Fix zero-length seed or label in TLS 1.2 PRF
The psa_tls12_prf_set_seed() and psa_tls12_prf_set_label() functions did
not work on platforms where malloc(0) returns NULL.

It does not affect the TLS use case but these PRFs are used in other
protocols as well and might not be used the same way. For example EAP
uses the TLS PRF with an empty secret. (This would not trigger the bug,
but is a strong indication that it is not safe to assume that certain
inputs to this function are not zero length.)

The conditional block includes the memcpy() call as well to avoid
passing a NULL pointer as a parameter resulting in undefined behaviour.

The current tests are already using zero length label and seed, there is
no need to add new test for this bug.
2019-07-04 09:11:38 +01:00
Janos Follath 0c1ed84258 Improve style 2019-06-28 15:10:06 +01:00
Gilles Peskine a8ade16ffd Gate secure element support by a separate config option
Secure element support has its own source file, and in addition
requires many hooks in other files. This is a nontrivial amount of
code, so make it optional (but default on).
2019-06-26 20:01:35 +02:00
Janos Follath 40e1393816 Optimize TLS PRF PSK key calculation 2019-06-26 13:23:10 +01:00
Janos Follath 76c3984477 Clarify TLS PRF algorithm description 2019-06-26 12:50:36 +01:00
Janos Follath 30090bc2cf Fix error code
PSA_ERROR_BAD_STATE means that the function was called on a context in a
bad state.

This error is something that can't happen while only using the PSA API and
therefore a PSA_ERROR_CORRUPTION_DETECTED is a more appropriate error
code.
2019-06-26 09:15:08 +01:00
Janos Follath 5fe19734d5 Make key derivation initialisation consistent
The macro initialiser might leave bytes in the union unspecified.
Zeroising it in setup makes sure that the behaviour is the same
independently of the initialisation method used.
2019-06-26 09:15:08 +01:00
Janos Follath ea29bfb148 Add tls12_prf key derivation to the new API
The TLS 1.2 pseudorandom function does a lot of distinct HMAC operations
with the same key. To save the battery and CPU cycles spent on
calculating the paddings and hashing the inner padding, we keep the
hash context in the status right after the inner padding having been
hashed and clone it as needed.
2019-06-26 09:15:08 +01:00
Janos Follath 844eb0e5fa Add tls12_prf_read for the new API
Technically we could have reused the old one for the new API, but then
we had to set an extra field during setup. The new version works when
all the fields that haven't been set explicitely are zero-initialised.
2019-06-26 09:15:08 +01:00
Janos Follath 7742feea53 Add stub for new tls12_prf_generate_next_block 2019-06-26 09:15:08 +01:00
Janos Follath 6c6c8fceaa Improve style 2019-06-26 09:15:08 +01:00
Janos Follath 6660f0eb98 Add TLS 1.2 PSK master secret generation 2019-06-26 09:15:08 +01:00
Janos Follath 51f4a0f9ac Style: enforce 80 column limit 2019-06-26 09:15:08 +01:00
Janos Follath c56215163f Simplify psa_key_derivation_input_bytes
The specific key derivation input functions support a subset of the
input options and need to check it anyway. Checking it at the top level
is redundant, it brings a very little value and comes with a cost in
code size and maintainability.
2019-06-26 09:15:08 +01:00
Janos Follath adbec81cc4 Remove the deprecated PSA_ALG_SELECT_RAW option
This change affects the psa_key_derivation_s structure. With the buffer
removed from the union, it is empty if MBEDTLS_MD_C is not defined.

We can avoid undefined behaviour by adding a new dummy field that is
always present or make the whole union conditional on MBEDTLS_MD_C.

In this latter case the initialiser macro has to depend on MBEDTLS_MD_C
as well. Furthermore the first structure would be either
psa_hkdf_key_derivation_t or psa_tls12_prf_key_derivation_t both of
which are very deep and would make the initialisation macro difficult
to maintain, therefore we go with the first option.
2019-06-26 09:15:08 +01:00
Janos Follath 63028dd906 Add label input for psa_tls12_prf_input 2019-06-26 09:15:08 +01:00
Janos Follath 8155054e28 Add key import for psa_tls12_prf_input 2019-06-26 09:15:08 +01:00
Janos Follath f08e2654ed Add seed input for psa_tls12_prf_input 2019-06-26 09:15:08 +01:00
Janos Follath ef83f5e98e Move raw key derivation input to a new function 2019-06-26 09:15:08 +01:00
Janos Follath b80a94e2ea Rename psa_key_derivation_input_raw
The function dispatches between all the available methods and
does not just handle the raw key derivation case like the name suggests.
2019-06-26 09:15:08 +01:00
Janos Follath b03233e196 Add stubs for psa_tls12_prf_input 2019-06-26 09:15:08 +01:00
Janos Follath 6a1d262803 Adapt psa_key_derivation_abort to the new context 2019-06-26 09:15:08 +01:00
Janos Follath 999f648437 Add new psa_tls12_prf_key_derivation_t
As part of adapting TLS 1.2 key derivation to the PSA 1.0 API we need to
change the context structure.
2019-06-26 09:15:08 +01:00
Janos Follath 083036af64 Safely erase key material upon abort
Some key derivation operation contexts (like
psa_tls12_prf_key_derivation_t) directly contain buffers with parts of
the derived key. Erase them safely as part of the abort.
2019-06-26 09:15:58 +01:00
Janos Follath 71a4c9125b Add flag for removing deprecated API
Add the compile time option PSA_PRE_1_0_KEY_DERIVATION. If this is not
turned on, then the function `psa_key_derivation()` is removed.

Most of the tests regarding key derivation haven't been adapted to the
new API yet and some of them have only been adapted partially. When this
new option is turned off, the tests using the old API and test cases
using the old API of partially adapted tests are skipped.

The sole purpose of this option is to make the transition to the new API
smoother. Once the transition is complete it can and should be removed
along with the old API and its implementation.
2019-06-26 09:15:08 +01:00
Gilles Peskine 8f2a6dcc25 Support PSA_KEY_DERIVATION_INPUT_SEED 2019-06-25 12:02:31 +01:00
Gilles Peskine d089021128 Unregister drivers on library deinitialization 2019-06-24 19:55:48 +02:00
Jaeden Amero 7654161dbf psa: Add NV seed as an entropy source when needed
When MBEDTLS_PSA_INJECT_ENTROPY is used, we now require also defining
MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES. When
MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES is defined, we do not add entropy
sources by default. This includes the NV seed entropy source, which the
PSA entropy injection API is built upon.

The PSA entropy injection feature depends on using NV seed as an entropy
source. Add NV seed as an entropy source for PSA entropy injection.

Fixes e3dbdd8d90 ("Gate entropy injection through a dedicated configuration option")
2019-06-05 11:09:38 +01:00
Gilles Peskine 267c65666a Simplify key slot allocation
Now that psa_allocate_key() is no longer a public function, expose
psa_internal_allocate_key_slot() instead, which provides a pointer to
the slot to its caller.
2019-06-05 11:34:54 +02:00
Gilles Peskine f46f81ceb5 Remove obsolete key creation functions
Remove the key creation functions from before the attribute-based API,
i.e. the key creation functions that worked by allocating a slot, then
setting metadata through the handle and finally creating key material.
2019-06-05 11:34:54 +02:00
Gilles Peskine f25c9ec02e Minor documentation improvements 2019-05-27 14:08:27 +02:00