Commit graph

184 commits

Author SHA1 Message Date
Ronald Cron d9763466b7 Expand and improve psa-crypto-implementation-structure.md
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2021-02-02 11:49:14 +01:00
Ronald Cron 31520b4b1c Fix psa-crypto-implementation-structure.md
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2021-02-02 11:38:50 +01:00
Ronald Cron 0dbbf1e27f psa: Add architecture document
Add architecture document explaining how this
PR aim to restructure the PSA implementation (only
part of it) and why.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
2021-02-02 11:29:07 +01:00
Ronald Cron ac80be111b
Merge pull request #3878 from gilles-peskine-arm/psa-builtin-keys-via-slot-number-spec
New entry point get_builtin_key for opaque drivers (PSA spec)
2021-01-29 10:43:15 +01:00
Ronald Cron 318515b384
Merge pull request #3984 from gabor-mezei-arm/3268_update_macros_for_ouput_buffer_size_renames
Rename existing support macros for output buffer sizes for PSA Crypto API 1.0.0
2021-01-29 09:31:59 +01:00
Ronald Cron a120146afe
Merge pull request #3962 from gilles-peskine-arm/psa-storage-format-test-strategy
Keystore format stability test strategy
2021-01-25 16:44:23 +01:00
Gilles Peskine 055be83413 Fix typo
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-25 11:36:24 +01:00
gabor-mezei-arm cbcec21684
Rename output buffer size macros
Rename existing support macros for output buffer sizes for PSA Crypto API 1.0.0

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
2021-01-21 13:17:25 +01:00
Gilles Peskine 84ae1eefb4 Minor clarification
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-20 20:20:10 +01:00
Gilles Peskine 3d67365ef7 Add a key_buffer_length output to "get_builtin_key"
While builtin keys will often have a fixed-size context, this is not
necessarily the case, so the "get_builtin_key" entry point needs to
return the size of the actual key context.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-20 20:19:14 +01:00
Gilles Peskine ff457506d3 Remind the reader of what is done about old formats
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-19 14:25:20 +01:00
Gilles Peskine 697ee190b5 Add a section about non-default lifetimes
Alternative locations should be covered. We don't yet support
alternative persistence levels.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-18 23:38:21 +01:00
Gilles Peskine 528144f523 Clarify the methods of key storage testing
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-18 23:36:18 +01:00
Gilles Peskine cf62f10d3f Clarify interoperability non-requirement
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-01-05 11:49:18 +01:00
Gilles Peskine 739e08a68d Keystore format stability test strategy
Initial revision.

Save-compare-load approach: the test case data contains attributes of
the object under test and the expected file content. Create the
object, save it, check that the file has the expected content, load
the file and check that the new object has the expected attributes.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-14 18:51:47 +01:00
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 1fc4c8d11b Let get_builtin_key be called to retrieve the key's attributes
Allow the core to call the "get_builtin_key" entry point to retrieve
the attributes of a built-in key. This is useful to implement
psa_get_key_attributes(), and also when the key data buffer's size
depends on the key type and size.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 18:41:50 +01:00
Gilles Peskine a6454d2820 Minor clarifications
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 17:01:52 +01:00
Gilles Peskine 48d71f2aa4 New entry point get_builtin_key for opaque drivers
Allow opaque drivers to expose keys that were not created through the
PSA API.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2020-12-07 17:01:37 +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