From 96d29b06a3c9a970589b56627ee30474d2c8cbd7 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Wed, 20 Jan 2021 17:43:44 +0100 Subject: KEYS: trusted: Introduce support for NXP CAAM-based trusted keys MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Signed-off-by: Ahmad Fatoum --- To: Jonathan Corbet To: David Howells To: Jarkko Sakkinen To: James Bottomley To: Mimi Zohar Cc: James Morris Cc: "Serge E. Hallyn" Cc: "Horia Geantă" Cc: Aymen Sghaier Cc: Herbert Xu Cc: "David S. Miller" Cc: Udit Agarwal Cc: Jan Luebbe Cc: David Gstir Cc: Franck LENORMAND Cc: Sumit Garg Cc: keyrings@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org Signed-off-by: Ahmad Fatoum --- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_caam.c | 74 +++++++++++++++++++++++++++++++ security/keys/trusted-keys/trusted_core.c | 6 ++- 3 files changed, 80 insertions(+), 1 deletion(-) create mode 100644 security/keys/trusted-keys/trusted_caam.c (limited to 'security') diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index feb8b6c3cc79..050370690abd 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -12,3 +12,4 @@ trusted-y += trusted_tpm2.o trusted-y += tpm2key.asn1.o trusted-$(CONFIG_TEE) += trusted_tee.o +trusted-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += 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..fc2e3dde9e06 --- /dev/null +++ b/security/keys/trusted-keys/trusted_caam.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#include +#include +#include +#include +#include + +struct caam_blob_priv *blobifier; + +#define KEYMOD "kernel:trusted" + +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 length = p->key_len + CAAM_BLOB_OVERHEAD; + int ret; + + ret = caam_encap_blob(blobifier, KEYMOD, p->key, p->blob, length); + if (ret) + return ret; + + p->blob_len = length; + return 0; +} + +static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob) +{ + int length = p->blob_len; + int ret; + + ret = caam_decap_blob(blobifier, KEYMOD, p->blob, p->key, length); + if (ret) + return ret; + + p->key_len = length - CAAM_BLOB_OVERHEAD; + 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 caam_trusted_key_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 5f92323efedf..e9bfb1bbc014 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 @@ -25,7 +26,7 @@ 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_TCG_TPM) @@ -34,6 +35,9 @@ static const struct trusted_key_source trusted_key_sources[] = { #if defined(CONFIG_TEE) { "tee", &trusted_key_tee_ops }, #endif +#if defined(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) + { "caam", &caam_trusted_key_ops }, +#endif }; DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init); -- cgit v1.2.3