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166 commits

Author SHA1 Message Date
Ronald Cron 8f05aeb2e3
Merge pull request #3882 from gilles-peskine-arm/psa-random-driver-spec
PSA: Specification for random generation and entropy drivers
2020-12-11 14:07:35 +01:00
Gilles Peskine 348eeebb24 Clarify the intent of the KEEPALIVE flag
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-11 10:52:36 +01:00
Manuel Pégourié-Gonnard a27a4e2f18
Merge pull request #3929 from gilles-peskine-arm/psa-driver-remove-old-accel
Remove old proposed accelerator interfaces
2020-12-10 11:31:47 +01:00
Gilles Peskine 24cebf6671 Add a section for transparent drivers
No strategy yet, just state some basic requirements.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-08 15:19:04 +01:00
Gilles Peskine f0e2853d46 Minimal update to mention unified-interface opaque drivers
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-08 15:19:04 +01:00
Gilles Peskine ae7772d0f3 Clarifications around reseed_entropy_size
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:39 +01:00
Gilles Peskine 43100e3fcb Add section on combining get_entropy with add_entropy
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:29 +01:00
Gilles Peskine 32e584c38a Copyediting and minor clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:29 +01:00
Gilles Peskine 3ff79066b1 Note an interrogation about integer value representation
Especially 0 values may need special treatment since they can't be
used as an array size.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:29 +01:00
Gilles Peskine 6a530e8d26 Random driver: make initial_entropy_size mandatory
If a random driver has a built-in entropy source and doesn't need an
external entropy source, make the driver author declare this
explicitly, rather than it being a less secure default.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:22 +01:00
Gilles Peskine ee914f34fa Minor clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:14 +01:00
Gilles Peskine 609394c1cf Open question: can there be multiple RNG instances?
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:48:06 +01:00
Gilles Peskine 8d5092c11f get_random: no output on error
The get_random entry point was allowed to return partial data on both
PSA_SUCCESS and PSA_ERROR_INSUFFICIENT_ENTROPY, but there was no
meaningful difference between the two. Keep it simple: PSA_SUCCESS is
success but can be partial, and PSA_ERROR_INSUFFICIENT_ENTROPY is an
error with no output.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:56 +01:00
Gilles Peskine 1ef6ad48d1 Note that I'm not completly sure about the get_entropy flags
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:45 +01:00
Gilles Peskine 3eb65fbba6 Open question: should add_entropy take an estimated_entropy_bits parameter?
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:45 +01:00
Gilles Peskine b89b4b9025 get_entropy: recommendations on conditioning and entropy estimates
Explicitly recommend that the driver accounts for environmental
conditions that can affect the amount of entropy.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:36 +01:00
Gilles Peskine 05ab2646a3 get_entropy: recommendations on the output_size
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:36 +01:00
Gilles Peskine a14326f054 Make add_entropy optional
A random generation driver does not need to support entropy injection.
This will limit it to platforms where the RNG peripheral is the sole
entropy source and without an RNG seed saved into persistent storage.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:27 +01:00
Gilles Peskine 390c5a2c6f It is not meaningful for reseed_entropy_size to be 0
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:19 +01:00
Gilles Peskine 0e3b7ced4c Don't require a call to add_entropy when 0 bytes are needed
If an RNG peripheral includes an entropy source, it would presumably
declare "initial_entropy_size" and "reseed_entropy_size" to be 0. In
this case, don't require the core to call "add_entropy".

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:47:10 +01:00
Gilles Peskine 5263e1ecdd Transparent drivers can have get_entropy as well
The `get_entropy` entry point can be provided by multiple transparent
drivers, and the core will call all of them. But apart from that,
`get_entropy` doesn't involve an opaque key or a location, so it can
be in a transparent driver.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:46:58 +01:00
Gilles Peskine e80978a260 Specification for random generation and entropy drivers
Transparent drivers may provide a DRBG interface through "add_entropy"
and "get_random" entry points. This interface may also be used with a
non-deterministic generator, for chips that include a TRNG.

Opaque driver may provide a "get_entropy" entry point.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:46:42 +01:00
Gilles Peskine 51977355dc Remove the time stamp
Having a time stamp identifying each revision of the document is
useful, but it's also a pain because it creates a conflict whenever
there are multiple pending changes at the same time. The gain isn't
worth the pain, so I'm removing the time stamp.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 17:01:17 +01:00
Gilles Peskine db6b03b4f2 Remove old-style accelerator and entropy driver interfaces
The driver interfaces described in crypto_accel_driver.h and
crypto_entropy_driver.h are no longer being worked on. We do not
intend to finish the design of these interfaces or to implement them
in Mbed TLS. They have been superseded by the unified driver
interface (docs/proposed/psa-driver-interface.md), which is being
actively worked on both to finalize the specification and to implement
it in Mbed TLS.

The partially implemented dynamic secure element interface is staying
for now.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-30 17:37:14 +01:00
Gilles Peskine e533ff7bb7
Merge pull request #3695 from gilles-peskine-arm/psa-unified-driver-specs-20200918
PSA unified driver specification: key validation and transparent key import
2020-11-30 15:54:45 +01:00
Gilles Peskine f0a9721c18 Use GitHub-compatible table formatting
Also fix a stray `.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-26 10:31:32 +01:00
Gilles Peskine 4228671d0f Copyediting
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-24 13:11:31 +01:00
Gilles Peskine 99e52f6313 Clarifications around key import
Rework the section describing key import, in particular to clarify key
size determination and checking. There is no intended semantic change.

Note an open question around support for implementation-specific
import formats.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-24 13:11:31 +01:00
Gilles Peskine 28b3a946e9 Fix copypasta
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-24 13:08:30 +01:00
Gilles Peskine 662deb38d6
Merge pull request #3547 from ronald-cron-arm/psa-openless
Openless PSA crypto APIs implementation
2020-11-20 18:48:33 +01:00
Gilles Peskine 406a5da4ab
Merge pull request #3697 from gilles-peskine-arm/psa-conditional-inclusion-c-project
PSA C configuration: more concrete information
2020-11-19 13:28:10 +01:00
Gilles Peskine 43818f8614 Copyediting
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-19 11:24:11 +01:00
Gilles Peskine d8c27ccab0 Fix copypasta; minor wording improvements
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-16 21:44:23 +01:00
Gilles Peskine bb483f6af8 Improve explanations around config_psa.h
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-16 14:35:12 +01:00
Gilles Peskine 198024cd02 Note that application code needs PSA_WANT_xxx too
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-16 12:04:40 +01:00
Gilles Peskine 1b1f3fb96d Minor clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-16 12:02:01 +01:00
Gilles Peskine 9e069070de Fix typos
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-16 10:26:01 +01:00
Gilles Peskine 993c249242 Add a section explaining the uses of PSA_WANT_xxx
PSA_WANT_xxx is useful regardless of how the symbols are defined:
explicitly (with MBEDTLS_PSA_CRYPTO_CONFIG) or implicitly (without
MBEDTLS_PSA_CRYPTO_CONFIG).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-13 22:45:13 +01:00
Gilles Peskine b2679984d9 Note that crypto_sizes.h needs config_psa.h as well
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-13 22:37:19 +01:00
Ronald Cron cf56a0a320 psa: Move from key handle to key identifier
Move all the PSA crypto APIs using key handles
to use key identifiers but psa_key_open() and
psa_key_close(). This is done without modifying
any test as key handles and key identifiers are
now the same.

Update the library modules using PSA crypto APIs
to get rid of key handles.

Programs and unit tests are updated to not use
key handles in subsequent commits, not in this
one.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2020-11-10 16:00:41 +01:00
Gilles Peskine 7b5e6b9dcc Typos and clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-11-04 18:30:01 +01:00
Gilles Peskine ce3ec6ffd6 Unify the sections on key creation
Now that transparent drivers have an "import_key" entry point, the key
creation interfaces for transparent drivers and opaque drivers are
very similar. Unify the sections that describe their behavior,
including key validation and key size determination.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-27 18:31:50 +01:00
Gilles Peskine 12760595e7 Replace validate_key by import_key
When importing a transparent key, the key needs to be not only
validated, but also possibly converted, if it is not already in the
canonical representation. So change the validate_key entry point to an
import_key entry point.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-26 18:07:01 +01:00
Torstein Nesse d9246559ca Update changelog entry, format specification, and correct test vectors
Signed-off-by: Torstein Nesse <torstein.nesse@silabs.com>
2020-10-21 11:17:09 +02:00
Gilles Peskine 48584b589f Editorial fixes
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-13 19:07:02 +02:00
Gilles Peskine e4cbb2bb73 Minor clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-12 23:39:18 +02:00
Gilles Peskine 55687646c8 PSA_WANT_xxx needs to be defined in the old-style config mechanism
Without MBEDTLS_PSA_CRYPTO_CONFIG, PSA_WANT_xxx needs to be defined,
for the sake of code that calls the PSA API (TLS code, tests, sample
apps).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-12 23:23:52 +02:00
Torstein Nesse 162a1104be Changes PSA key storage format to include key bits
* Stores bits in psa_persistent_key_storage_format.
* psa_load_persistent_key_into_slot still imports plaintext keys which
  ensures that the bits value gets set.
* Updates key specification to match new implementation.
* Expands persistent store and load tests with to check for bits
  attribute.
* Removes bits storage from psa_se_key_data_storage_t.

Signed-off-by: Torstein Nesse <torstein.nesse@silabs.com>
2020-10-07 10:54:24 +02:00
Gilles Peskine 233f91d5c1 Add bits output to validate_key and import_key
When importing a key, the code that parses the input needs to
determine the key size ("bits" attribute). This is specific to import
since other key creation methods require the caller to supply a size.
Therefore, add an extra output parameter `bits` to the "import_key"
entry point for opaque drivers. Likewise, add a `bits` output
parameter to the "validate_key" entry point for transparent drivers.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-10-02 18:00:00 +02:00
Gilles Peskine 95434380e1 Detailed architecture of symbol definitions and header inclusion
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-09-21 20:08:51 +02:00