Add a practical way to fill the dynamic key store by artificially limiting
the slice length through a test hook.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
When MBEDTLS_PSA_KEY_STORE_DYNAMIC is enabled, key slots are now organized in
multiple slices. The slices are allocated on demand, which allows the key
store to grow. The size of slices grows exponentially, which allows reaching
a large number of slots with a small (static) number of slices without too
much overhead.
Maintain a linked list of free slots in each slice. This way, allocating a
slot takes O(1) time unless a slice needs to be allocated.
In this commit, slices are only ever freed when deinitializing the key
store. This should be improved in the future to free empty slices.
To avoid growing the persistent key cache without control, the persistent
key cache has a fixed size (reusing MBEDTLS_PSA_KEY_SLOT_COUNT to avoid
creating yet another option).
When MBEDTLS_PSA_KEY_STORE_DYNAMIC is disabled. no semantic change and
minimal changes to the code.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Place some fields of psa_key_slot_t in a union, to prepare for a new field
in free slots that should not require extra memory.
For occupied slots, place only the registered_readers field in the union,
not other fields, to minimize textual changes. All fields could move to the
union except state (also needed in free slots) and attr (which must stay
first to reduce the code size, because it is accessed at many call sites).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix interference between PSA volatile keys and built-in keys
when MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS is enabled and
MBEDTLS_PSA_KEY_SLOT_COUNT is more than 4096. This overlap used to make it
possible that a volatile key would receive the identifier of a built-in key,
and is now caught by a static assertion.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
A bug existed previously where this guarantee was not met,
causing some issues in multi-threaded code.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This means we can hold the mutex around the call to reserve_free_key_slot
in get_and_lock_key_slot, avoiding inefficient rework.
(Changes to get_and_lock_key_slot are not in scope in this PR)
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
There are at least 20 occurences in the current code where
we will need this pattern of code, so I thought it best to
put this in a function
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This function, and mbedtls_psa_crypto_free, are not thread safe as they wipe slots
regardless of state. They are not part of the PSA Crypto API, untrusted applications
cannot call these functions in a crypto service.
In a service intergration, mbedtls_psa_crypto_free on the client cuts the communication
with the crypto service.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Make this a global mutex so that we don't have to init and free it.
Also rename the mutex to follow the convention
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
These error codes are only returned if the program has been tampered with,
so they should be CORRUPTION_DETECTED.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
psa_wipe_key_slot can now be called on a slot in any state, if the slot's state
is PSA_SLOT_FULL or PSA_SLOT_PENDING_DELETION then there must be exactly 1 registered
reader.
Remove the state changing calls that are no longer necessary.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Rename to psa_reserve_free_key_slot, as this function reserves a slot which is
free (not always empty) for filling.
Implement necessary state transitions and state checks.
Rename unlocked_persistent_key_slot to unused_persistent_key_slot.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This inline function is used in every case we want to change the state of a slot,
except for where we do not care about what the state of the slot was before.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Replaces psa_lock_key_slot and psa_unlock_key_slot.
Future commits will remove the calls to locking/unlocking functions,
and add calls to registering/unregistering functions.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Pacify Clang >=15 which complained:
```
include/psa/crypto.h:91:23: error: empty paragraph passed to '\retval' command [-Werror,-Wdocumentation]
* \retval #PSA_SUCCESS
~~~~~~~~~~~~~~~~~~~^
```
This commit performs the following systematic replacement:
```
perl -i -0777 -p -e 's/([\\@])(retval +\S+)\n(?! *\*? *([^\n \\*\/]|\\[cp]\b))/$1$2 ${1}emptydescription\n/g' $(git ls-files '*.[hc]' '*.function' '*.jinja')
```
i.e. add an `\emptydescription` argument to `\retval` commands (or
`@retval`, which we don't normally used) that are followed by a single word,
unless the next line looks like it contains text which would be the
description.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
When creating a persistent key or registering a key
with an invalid key identifier return
PSA_ERROR_INVALID_ARGUMENT instead of
PSA_ERROR_INVALID_HANDLE.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Rename functions to get a key slot:
. to make their naming more consistent
. to emphasize that those functions set a lock on the
key slot they return to protect it from being wiped
out and re-used while some part of the library
is accessing it.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Special handling of volatile key identifiers is not
needed eventually, they can be handled just as
key identifier in the vendor range.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Add key slot access counter to be able to
state if a key slot containing the description
of a permanent key can be reset or reset
and re-used.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Volatile key identifiers in the vendor range are
reserved to volatile keys thus don't allow them
for persistent keys when creating a key.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Define psa_key_handle_t to be equal to
mbedtls_svc_key_id_t. Make the handle of a persistent
key be equal to its key identifier. For volatile keys,
make the key handle equal to the volatile key
identifier of the created volatile key.
The unit tests are modified just to make them compile
not to make them run successfully. They are fixed in
the subsequent commits.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Volatile key identifiers are introduced in
PSA Crypto API v1.0.0. They are returned by the APIs
when importing or generating or deriving a volatile key.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
With key usage based on key identifiers and not
key handles (openless APIs), volatile keys will
also have a key identifier. Thus, isolate key
identifier validation from key persistence
validation to clarify that key identifiers
are not specific to persistent keys.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
With PSA crypto v1.0.0, a volatile key identifier may
contain a owner identifier but no file is associated
to it. Thus rename the type psa_key_file_id_t to
mbedtls_svc_key_id_t to avoid a direct link with a
file when a key identifier involves an owner
identifier.
The new type name is prefixed by mbedtls to highlight
that the type is specific to Mbed TLS implementation
and not defined in the PSA Cryptography API
specification.
The svc in the type name stands for service as this
is the key identifier type from the point of view of
the service providing the Cryptography services.
The service can be completely provided by the present
library or partially in case of a multi-client service.
As a consequence rename as well:
. MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER to
MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER
. PSA_KEY_ID_INIT to MBEDTLS_SVC_KEY_ID_INIT
. PSA_KEY_FILE_GET_KEY_ID to MBEDTLS_SVC_KEY_ID_GET_KEY_ID
. psa_key_file_id_make to mbedtls_svc_key_id_make
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
The purpose of this commit and the following is for
psa_key_id_t to always be as defined by the PSA
Cryptography API specification.
Currently psa_key_id_t departs from its specification
definition when MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER
configuration flag is set. In that configuration, it is set
to be equal to psa_key_file_id_t which in that configuration
encodes an owner identifier along the key identifier.
Type psa_key_file_id_t was meant to be the key identifier type
used throughout the library code. If
MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER is set it
includes both a key and owner identifier, otherwise it is
equal to psa_key_id_t.
It has not been the key identifier type throughout the
library so far because when the PSA Cryptography
specification was developped the library Doxygen
documentation was used to generate the PSA Cryptography API
specification thus the need to use psa_key_id_t and not
psa_key_file_id_t.
As this constraint does not hold anymore, move
to psa_key_file_id_t as the key identifier type throughout
the library code.
By the way, this commit updates the key identifier
initialization in the tests to be compatible with a
composit key identifier. A psa_key_id_make()
inline function is introduced to initialize key
identifiers (composit ot not) at runtime.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
As a result, the copyright of contributors other than Arm is now
acknowledged, and the years of publishing are no longer tracked in the
source files.
Also remove the now-redundant lines declaring that the files are part of
MbedTLS.
This commit was generated using the following script:
# ========================
#!/bin/sh
# Find files
find '(' -path './.git' -o -path './3rdparty' ')' -prune -o -type f -print | xargs sed -bi '
# Replace copyright attribution line
s/Copyright.*Arm.*/Copyright The Mbed TLS Contributors/I
# Remove redundant declaration and the preceding line
$!N
/This file is part of Mbed TLS/Id
P
D
'
# ========================
Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
Also normalize the first line of the copyright headers.
This commit was generated using the following script:
# ========================
#!/bin/sh
# Find scripts
find -path './.git' -prune -o '(' -name '*.c' -o -name '*.cpp' -o -name '*.fmt' -o -name '*.h' ')' -print | xargs sed -i '
# Normalize the first line of the copyright headers (no text on the first line of a block comment)
/^\/\*.*Copyright.*Arm/I {
i\
/*
s/^\// /
}
/Copyright.*Arm/I {
# Print copyright declaration
p
# Read the two lines immediately following the copyright declaration
N
N
# Insert Apache header if it is missing
/SPDX/! i\
* SPDX-License-Identifier: Apache-2.0\
*\
* Licensed under the Apache License, Version 2.0 (the "License"); you may\
* not use this file except in compliance with the License.\
* You may obtain a copy of the License at\
*\
* http://www.apache.org/licenses/LICENSE-2.0\
*\
* Unless required by applicable law or agreed to in writing, software\
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT\
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\
* See the License for the specific language governing permissions and\
* limitations under the License.
# Clear copyright declaration from buffer
D
}
'
# ========================
Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
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).
