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mbedtls_psa_register_se_key is unusable with volatile keys #9253

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gilles-peskine-arm opened this issue Jun 13, 2024 · 0 comments
Open

mbedtls_psa_register_se_key is unusable with volatile keys #9253

gilles-peskine-arm opened this issue Jun 13, 2024 · 0 comments
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bug component-psa PSA keystore/dispatch layer (storage, drivers, …) size-xs Estimated task size: extra small (a few hours at most)

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gilles-peskine-arm commented Jun 13, 2024 •
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The function mbedtls_psa_register_se_key creates a PSA key object that is backed by a secure element. If you give it a volatile lifetime, the core chooses a volatile key identifier, which is needed to use the key subsequently. However, the API does not output that key identifier, so the created volatile key just leaks memory. Evidently, when I designed the function, I was only thinking of persistent keys (in beta versions of the PSA crypto API, secure element keys couldn't be volatile).

The goal of this issue is to do a minimal robustness fix in the 2.28 and 3.6 LTS branches: document the limitation and make the function return an error code if it's asked to create a volatile key. We'll make the function usable in 4.0.

(We could add an ext function in 2.28.x and 3.6.x, but so far nobody's complained.)
@gilles-peskine-arm gilles-peskine-arm added bug component-psa PSA keystore/dispatch layer (storage, drivers, …) size-xs Estimated task size: extra small (a few hours at most) labels Jun 13, 2024
@gilles-peskine-arm gilles-peskine-arm self-assigned this Jun 13, 2024
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jun 13, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
5682440 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jun 13, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
619c28a 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jun 13, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
5877124 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jun 13, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
0bd27f2 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jun 21, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
86e56f9 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jul 16, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
7091f0a 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jul 16, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
1dc21ea 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Jul 17, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
d72ad73 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
@gilles-peskine-arm gilles-peskine-arm mentioned this issue Aug 6, 2024
Merged
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gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Aug 7, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
37a4fcc 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Aug 7, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
38e6fa8 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
gilles-peskine-arm added a commit to gilles-peskine-arm/mbedtls that referenced this issue Aug 7, 2024
@gilles-peskine-arm
Prevent mbedtls_psa_register_se_key with volatile keys
b0b1b32 
mbedtls_psa_register_se_key() is not usable with volatile keys, since there
is no way to return the implementation-chosen key identifier which would be
needed to use the key. Document this limitation. Reject an attempt to create
such an unusable key. Fixes Mbed-TLS#9253.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
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bug component-psa PSA keystore/dispatch layer (storage, drivers, …) size-xs Estimated task size: extra small (a few hours at most)
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