From e9c5048c2de1913d0bcd589bc1487810c2e24bc1 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 13 May 2022 16:57:03 +0200 Subject: 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 Reviewed-by: Pankaj Gupta Reviewed-by: Jarkko Sakkinen Tested-by: Tim Harvey Tested-by: Matthias Schiffer Tested-by: Pankaj Gupta Tested-by: Michael Walle # on ls1028a (non-E and E) Tested-by: John Ernberg # iMX8QXP Signed-off-by: Ahmad Fatoum Signed-off-by: Jarkko Sakkinen --- security/keys/trusted-keys/Kconfig | 11 ++++- security/keys/trusted-keys/Makefile | 2 + security/keys/trusted-keys/trusted_caam.c | 80 +++++++++++++++++++++++++++++++ security/keys/trusted-keys/trusted_core.c | 6 ++- 4 files changed, 97 insertions(+), 2 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_caam.c (limited to 'security/keys') 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..e3415c520c0a --- /dev/null +++ b/security/keys/trusted-keys/trusted_caam.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#include +#include +#include +#include +#include + +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)) + 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 #include #include +#include #include #include #include @@ -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); -- cgit v1.2.3