KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core
built into many newer i.MX and QorIQ SoCs by NXP.

The CAAM does crypto acceleration, hardware number generation and
has a blob mechanism for encapsulation/decapsulation of sensitive material.

This blob mechanism depends on a device specific random 256-bit One Time
Programmable Master Key that is fused in each SoC at manufacturing
time. This key is unreadable and can only be used by the CAAM for AES
encryption/decryption of user data.

This makes it a suitable backend (source) for kernel trusted keys.

Previous commits generalized trusted keys to support multiple backends
and added an API to access the CAAM blob mechanism. Based on these,
provide the necessary glue to use the CAAM for trusted keys.

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: Tim Harvey <tharvey@gateworks.com>
Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
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>

1 files changed, 5 insertions, 1 deletions

diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index 9235fb7d0ec9..c6fc50d67214 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -9,6 +9,7 @@
 #include <keys/user-type.h>
 #include <keys/trusted-type.h>
 #include <keys/trusted_tee.h>
+#include <keys/trusted_caam.h>
 #include <keys/trusted_tpm.h>
 #include <linux/capability.h>
 #include <linux/err.h>
@@ -29,7 +30,7 @@ MODULE_PARM_DESC(rng, "Select trusted key RNG");
 
 static char *trusted_key_source;
 module_param_named(source, trusted_key_source, charp, 0);
-MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
+MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee or caam)");
 
 static const struct trusted_key_source trusted_key_sources[] = {
 #if defined(CONFIG_TRUSTED_KEYS_TPM)
@@ -38,6 +39,9 @@ static const struct trusted_key_source trusted_key_sources[] = {
 #if defined(CONFIG_TRUSTED_KEYS_TEE)
 	{ "tee", &trusted_key_tee_ops },
 #endif
+#if defined(CONFIG_TRUSTED_KEYS_CAAM)
+	{ "caam", &trusted_key_caam_ops },
+#endif
 };
 
 DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);