[v8,4/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4deed1908a75..9afb7046ce97 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5958,6 +5958,7 @@ 
 			sources:
 			- "tpm"
 			- "tee"
+			- "caam"
 			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
diff --git a/include/keys/trusted_caam.h b/include/keys/trusted_caam.h
new file mode 100644
index 000000000000..73fe2f32f65e
--- /dev/null
+++ b/include/keys/trusted_caam.h
@@ -0,0 +1,11 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
+ */
+
+#ifndef __CAAM_TRUSTED_KEY_H
+#define __CAAM_TRUSTED_KEY_H
+
+extern struct trusted_key_ops trusted_key_caam_ops;
+
+#endif
diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig
index fc4abd581abb..dbfdd8536468 100644
--- a/security/keys/trusted-keys/Kconfig
+++ b/security/keys/trusted-keys/Kconfig
@@ -24,6 +24,15 @@  config TRUSTED_KEYS_TEE
 	  Enable use of the Trusted Execution Environment (TEE) as trusted
 	  key backend.
 
-if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE
+config TRUSTED_KEYS_CAAM
+	bool "CAAM-based trusted keys"
+	depends on CRYPTO_DEV_FSL_CAAM_JR >= TRUSTED_KEYS
+	select CRYPTO_DEV_FSL_CAAM_BLOB_GEN
+	default y
+	help
+	  Enable use of NXP's Cryptographic Accelerator and Assurance Module
+	  (CAAM) as trusted key backend.
+
+if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE && !TRUSTED_KEYS_CAAM
 comment "No trust source selected!"
 endif
diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
index 2e2371eae4d5..735aa0bc08ef 100644
--- a/security/keys/trusted-keys/Makefile
+++ b/security/keys/trusted-keys/Makefile
@@ -12,3 +12,5 @@  trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o
 trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o
 
 trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o
diff --git a/security/keys/trusted-keys/trusted_caam.c b/security/keys/trusted-keys/trusted_caam.c
new file mode 100644
index 000000000000..46cb2484ec36
--- /dev/null
+++ b/security/keys/trusted-keys/trusted_caam.c
@@ -0,0 +1,82 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
+ */
+
+#include <keys/trusted_caam.h>
+#include <keys/trusted-type.h>
+#include <linux/build_bug.h>
+#include <linux/key-type.h>
+#include <soc/fsl/caam-blob.h>
+
+static struct caam_blob_priv *blobifier;
+
+#define KEYMOD "SECURE_KEY"
+
+static_assert(MAX_KEY_SIZE + CAAM_BLOB_OVERHEAD <= CAAM_BLOB_MAX_LEN);
+static_assert(MAX_BLOB_SIZE <= CAAM_BLOB_MAX_LEN);
+
+static int trusted_caam_seal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct caam_blob_info info = {
+		.input  = p->key,  .input_len   = p->key_len,
+		.output = p->blob, .output_len  = MAX_BLOB_SIZE,
+		.key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1,
+	};
+
+	ret = caam_encap_blob(blobifier, &info);
+	if (ret)
+		return ret;
+
+	p->blob_len = info.output_len;
+	return 0;
+}
+
+static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct caam_blob_info info = {
+		.input   = p->blob,  .input_len  = p->blob_len,
+		.output  = p->key,   .output_len = MAX_KEY_SIZE,
+		.key_mod = KEYMOD,  .key_mod_len = sizeof(KEYMOD) - 1,
+	};
+
+	ret = caam_decap_blob(blobifier, &info);
+	if (ret)
+		return ret;
+
+	p->key_len = info.output_len;
+	return 0;
+}
+
+static int trusted_caam_init(void)
+{
+	int ret;
+
+	blobifier = caam_blob_gen_init();
+	if (IS_ERR(blobifier)) {
+		pr_err("Job Ring Device allocation for transform failed\n");
+		return PTR_ERR(blobifier);
+	}
+
+	ret = register_key_type(&key_type_trusted);
+	if (ret)
+		caam_blob_gen_exit(blobifier);
+
+	return ret;
+}
+
+static void trusted_caam_exit(void)
+{
+	unregister_key_type(&key_type_trusted);
+	caam_blob_gen_exit(blobifier);
+}
+
+struct trusted_key_ops trusted_key_caam_ops = {
+	.migratable = 0, /* non-migratable */
+	.init = trusted_caam_init,
+	.seal = trusted_caam_seal,
+	.unseal = trusted_caam_unseal,
+	.exit = trusted_caam_exit,
+};
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);