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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:17:46 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:17:46 +0000 |
commit | 7f3a4257159dea8e7ef66d1a539dc6df708b8ed3 (patch) | |
tree | bcc69b5f4609f348fac49e2f59e210b29eaea783 /Documentation/security/keys | |
parent | Adding upstream version 6.9.12. (diff) | |
download | linux-7f3a4257159dea8e7ef66d1a539dc6df708b8ed3.tar.xz linux-7f3a4257159dea8e7ef66d1a539dc6df708b8ed3.zip |
Adding upstream version 6.10.3.upstream/6.10.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/security/keys')
-rw-r--r-- | Documentation/security/keys/trusted-encrypted.rst | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index e989b9802f..f4d7e162d5 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -42,6 +42,14 @@ safe. randomly generated and fused into each SoC at manufacturing time. Otherwise, a common fixed test key is used instead. + (4) DCP (Data Co-Processor: crypto accelerator of various i.MX SoCs) + + Rooted to a one-time programmable key (OTP) that is generally burnt + in the on-chip fuses and is accessible to the DCP encryption engine only. + DCP provides two keys that can be used as root of trust: the OTP key + and the UNIQUE key. Default is to use the UNIQUE key, but selecting + the OTP key can be done via a module parameter (dcp_use_otp_key). + * Execution isolation (1) TPM @@ -57,6 +65,12 @@ safe. Fixed set of operations running in isolated execution environment. + (4) DCP + + Fixed set of cryptographic operations running in isolated execution + environment. Only basic blob key encryption is executed there. + The actual key sealing/unsealing is done on main processor/kernel space. + * Optional binding to platform integrity state (1) TPM @@ -79,6 +93,11 @@ safe. Relies on the High Assurance Boot (HAB) mechanism of NXP SoCs for platform integrity. + (4) DCP + + Relies on Secure/Trusted boot process (called HAB by vendor) for + platform integrity. + * Interfaces and APIs (1) TPM @@ -94,6 +113,11 @@ safe. Interface is specific to silicon vendor. + (4) DCP + + Vendor-specific API that is implemented as part of the DCP crypto driver in + ``drivers/crypto/mxs-dcp.c``. + * Threat model The strength and appropriateness of a particular trust source for a given @@ -129,6 +153,13 @@ selected trust source: CAAM HWRNG, enable CRYPTO_DEV_FSL_CAAM_RNG_API and ensure the device is probed. + * DCP (Data Co-Processor: crypto accelerator of various i.MX SoCs) + + The DCP hardware device itself does not provide a dedicated RNG interface, + so the kernel default RNG is used. SoCs with DCP like the i.MX6ULL do have + a dedicated hardware RNG that is independent from DCP which can be enabled + to back the kernel RNG. + 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. @@ -231,6 +262,19 @@ Usage:: CAAM-specific format. The key length for new keys is always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). +Trusted Keys usage: DCP +----------------------- + +Usage:: + + keyctl add trusted name "new keylen" ring + keyctl add trusted name "load hex_blob" ring + keyctl print keyid + +"keyctl print" returns an ASCII hex copy of the sealed key, which is in format +specific to this DCP key-blob implementation. The key length for new keys is +always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). + Encrypted Keys usage -------------------- @@ -426,3 +470,12 @@ string length. privkey is the binary representation of TPM2B_PUBLIC excluding the initial TPM2B header which can be reconstructed from the ASN.1 octed string length. + +DCP Blob Format +--------------- + +.. kernel-doc:: security/keys/trusted-keys/trusted_dcp.c + :doc: dcp blob format + +.. kernel-doc:: security/keys/trusted-keys/trusted_dcp.c + :identifiers: struct dcp_blob_fmt |