diff options
| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2022-05-13 16:57:00 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-19 23:05:33 +0200 |
| commit | 20e73ece06b3368a45e29b7671acb283f3de583f (patch) | |
| tree | a904652760afdc79c4c1c3ddd6ab838dd2aa994f /Documentation/security/keys | |
| parent | a01d68b6c666eb967201437b9c95496244cc6ae9 (diff) | |
KEYS: trusted: allow use of kernel RNG for key material
[ Upstream commit fcd7c26901c83681532c6daac599e53d4df11738 ]
The two existing trusted key sources don't make use of the kernel RNG,
but instead let the hardware doing the sealing/unsealing also
generate the random key material. However, both users and future
backends may want to place less trust into the quality of the trust
source's random number generator and instead reuse the kernel entropy
pool, which can be seeded from multiple entropy sources.
Make this possible by adding a new trusted.rng parameter,
that will force use of the kernel RNG. In its absence, it's up
to the trust source to decide, which random numbers to use,
maintaining the existing behavior.
Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Reviewed-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Tested-by: Michael Walle <michael@walle.cc> # on ls1028a (non-E and E)
Tested-by: John Ernberg <john.ernberg@actia.se> # iMX8QXP
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Stable-dep-of: 01bbafc63b65 ("KEYS: trusted: Remove redundant static calls usage")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'Documentation/security/keys')
| -rw-r--r-- | Documentation/security/keys/trusted-encrypted.rst | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index 80d5a5af62a1..99cf34d7c025 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -87,22 +87,26 @@ Key Generation Trusted Keys ------------ -New keys are created from random numbers generated in the trust source. They -are encrypted/decrypted using a child key in the storage key hierarchy. -Encryption and decryption of the child key must be protected by a strong -access control policy within the trust source. +New keys are created from random numbers. They are encrypted/decrypted using +a child key in the storage key hierarchy. Encryption and decryption of the +child key must be protected by a strong access control policy within the +trust source. The random number generator in use differs according to the +selected trust source: - * TPM (hardware device) based RNG + * TPM: hardware device based RNG - Strength of random numbers may vary from one device manufacturer to - another. + Keys are generated within the TPM. Strength of random numbers may vary + from one device manufacturer to another. - * TEE (OP-TEE based on Arm TrustZone) based RNG + * TEE: OP-TEE based on Arm TrustZone based RNG RNG is customizable as per platform needs. It can either be direct output from platform specific hardware RNG or a software based Fortuna CSPRNG which can be seeded via multiple entropy sources. +Users may override this by specifying ``trusted.rng=kernel`` on the kernel +command-line to override the used RNG with the kernel's random number pool. + Encrypted Keys -------------- |