Merge tag 'keys-trusted-next-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

Pull trusted keys updates from Jarkko Sakkinen:
 "This contains a new key type for the Data Co-Processor (DCP), which is
  an IP core built into many NXP SoCs such as i.mx6ull"

* tag 'keys-trusted-next-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  docs: trusted-encrypted: add DCP as new trust source
  docs: document DCP-backed trusted keys kernel params
  MAINTAINERS: add entry for DCP-based trusted keys
  KEYS: trusted: Introduce NXP DCP-backed trusted keys
  KEYS: trusted: improve scalability of trust source config
  crypto: mxs-dcp: Add support for hardware-bound keys

2 files changed, 66 insertions, 0 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5dd8b6b08dee..7d22e8a89a58 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6765,6 +6765,7 @@
 			- "tpm"
 			- "tee"
 			- "caam"
+			- "dcp"
 			If not specified then it defaults to iterating through
 			the trust source list starting with TPM and assigns the
 			first trust source as a backend which is initialized
@@ -6780,6 +6781,18 @@
 			If not specified, "default" is used. In this case,
 			the RNG's choice is left to each individual trust source.
 
+	trusted.dcp_use_otp_key
+			This is intended to be used in combination with
+			trusted.source=dcp and will select the DCP OTP key
+			instead of the DCP UNIQUE key blob encryption.
+
+	trusted.dcp_skip_zk_test
+			This is intended to be used in combination with
+			trusted.source=dcp and will disable the check if the
+			blob key is all zeros. This is helpful for situations where
+			having this key zero'ed is acceptable. E.g. in testing
+			scenarios.
+
 	tsc=		Disable clocksource stability checks for TSC.
 			Format: <string>
 			[x86] reliable: mark tsc clocksource as reliable, this
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
index e989b9802f92..f4d7e162d5e4 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