Tested-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
Testing Details with iMX8 platform:
- Using command "keyctl", successfully able to create/load key from the @s keyring.
- Able to use the key with DM-Crypt utility.
- Across power cycle, Validated the decrypted content with correct key; as well as the incorrect key.
Regards
Pankaj
> -----Original Message-----
> From: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> Sent: Wednesday, March 2, 2022 10:08 AM
> To: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>; Jonathan Corbet
> <corbet@xxxxxxx>; David Howells <dhowells@xxxxxxxxxx>; Jarkko Sakkinen
> <jarkko@xxxxxxxxxx>; James Bottomley <jejb@xxxxxxxxxxxxx>; Mimi Zohar
> <zohar@xxxxxxxxxxxxx>
> Cc: kernel@xxxxxxxxxxxxxx; David Gstir <david@xxxxxxxxxxxxx>;
> tharvey@xxxxxxxxxxxxx; Matthias Schiffer <matthias.schiffer@xxxxx-
> group.com>; James Morris <jmorris@xxxxxxxxx>; Serge E. Hallyn
> <serge@xxxxxxxxxx>; Horia Geanta <horia.geanta@xxxxxxx>; Aymen
> Sghaier <aymen.sghaier@xxxxxxx>; Herbert Xu
> <herbert@xxxxxxxxxxxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Eric Biggers <ebiggers@xxxxxxxxxx>; Jan Luebbe <j.luebbe@xxxxxxxxxxxxxx>;
> Richard Weinberger <richard@xxxxxx>; Franck Lenormand
> <franck.lenormand@xxxxxxx>; Sumit Garg <sumit.garg@xxxxxxxxxx>;
> keyrings@xxxxxxxxxxxxxxx; linux-crypto@xxxxxxxxxxxxxxx; linux-
> doc@xxxxxxxxxxxxxxx; linux-integrity@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-security-module@xxxxxxxxxxxxxxx
> Subject: RE: [EXT] [PATCH v5 5/5] KEYS: trusted: Introduce support for NXP
> CAAM-based trusted keys
>
> Caution: EXT Email
>
> Reviewed-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
>
> > -----Original Message-----
> > From: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> > Sent: Wednesday, February 23, 2022 1:28 AM
> > To: Jonathan Corbet <corbet@xxxxxxx>; David Howells
> > <dhowells@xxxxxxxxxx>; Jarkko Sakkinen <jarkko@xxxxxxxxxx>; James
> > Bottomley <jejb@xxxxxxxxxxxxx>; Mimi Zohar <zohar@xxxxxxxxxxxxx>
> > Cc: kernel@xxxxxxxxxxxxxx; David Gstir <david@xxxxxxxxxxxxx>;
> > tharvey@xxxxxxxxxxxxx; Matthias Schiffer <matthias.schiffer@xxxxx-
> > group.com>; Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>; James Morris
> > <jmorris@xxxxxxxxx>; Serge E. Hallyn <serge@xxxxxxxxxx>; Horia Geanta
> > <horia.geanta@xxxxxxx>; Aymen Sghaier <aymen.sghaier@xxxxxxx>;
> Herbert
> > Xu <herbert@xxxxxxxxxxxxxxxxxxx>; David S. Miller
> > <davem@xxxxxxxxxxxxx>; Eric Biggers <ebiggers@xxxxxxxxxx>; Jan Luebbe
> > <j.luebbe@xxxxxxxxxxxxxx>; Richard Weinberger <richard@xxxxxx>;
> Franck
> > Lenormand <franck.lenormand@xxxxxxx>; Sumit Garg
> > <sumit.garg@xxxxxxxxxx>; Pankaj Gupta <pankaj.gupta@xxxxxxx>;
> > keyrings@xxxxxxxxxxxxxxx; linux-crypto@xxxxxxxxxxxxxxx; linux-
> > doc@xxxxxxxxxxxxxxx; linux-integrity@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; linux-security-module@xxxxxxxxxxxxxxx
> > Subject: [EXT] [PATCH v5 5/5] KEYS: trusted: Introduce support for NXP
> > CAAM-based trusted keys
> >
> > Caution: EXT Email
> >
> > 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@xxxxxxxxxxxxx>
> > Tested-By: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> > Tested-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> > Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> > ---
> > To: Jonathan Corbet <corbet@xxxxxxx>
> > To: David Howells <dhowells@xxxxxxxxxx>
> > To: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > To: James Bottomley <jejb@xxxxxxxxxxxxx>
> > To: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> > Cc: James Morris <jmorris@xxxxxxxxx>
> > Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
> > Cc: "Horia Geantă" <horia.geanta@xxxxxxx>
> > Cc: Aymen Sghaier <aymen.sghaier@xxxxxxx>
> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
> > Cc: Jan Luebbe <j.luebbe@xxxxxxxxxxxxxx>
> > Cc: David Gstir <david@xxxxxxxxxxxxx>
> > Cc: Richard Weinberger <richard@xxxxxx>
> > Cc: Franck LENORMAND <franck.lenormand@xxxxxxx>
> > Cc: Sumit Garg <sumit.garg@xxxxxxxxxx>
> > Cc: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> > Cc: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> > Cc: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> > Cc: keyrings@xxxxxxxxxxxxxxx
> > Cc: linux-crypto@xxxxxxxxxxxxxxx
> > Cc: linux-doc@xxxxxxxxxxxxxxx
> > Cc: linux-integrity@xxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: linux-security-module@xxxxxxxxxxxxxxx
> > ---
> > .../admin-guide/kernel-parameters.txt | 1 +
> > .../security/keys/trusted-encrypted.rst | 40 +++++++++-
> > MAINTAINERS | 9 +++
> > include/keys/trusted_caam.h | 11 +++
> > security/keys/trusted-keys/Kconfig | 11 ++-
> > security/keys/trusted-keys/Makefile | 2 +
> > security/keys/trusted-keys/trusted_caam.c | 74
> +++++++++++++++++++
> > security/keys/trusted-keys/trusted_core.c | 6 +-
> > 8 files changed, 151 insertions(+), 3 deletions(-) create mode
> > 100644 include/keys/trusted_caam.h create mode 100644
> > security/keys/trusted- keys/trusted_caam.c
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt
> > b/Documentation/admin-guide/kernel-parameters.txt
> > index 844c883ca9d8..9e7ef4c6585d 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -5875,6 +5875,7 @@
> > 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/Documentation/security/keys/trusted-encrypted.rst
> > b/Documentation/security/keys/trusted-encrypted.rst
> > index 99cf34d7c025..ed60c48cb692 100644
> > --- a/Documentation/security/keys/trusted-encrypted.rst
> > +++ b/Documentation/security/keys/trusted-encrypted.rst
> > @@ -35,6 +35,13 @@ safe.
> > Rooted to Hardware Unique Key (HUK) which is generally burnt
> > in on- chip
> > fuses and is accessible to TEE only.
> >
> > + (3) CAAM (Cryptographic Acceleration and Assurance Module: IP on
> > + NXP SoCs)
> > +
> > + When High Assurance Boot (HAB) is enabled and the CAAM is in
> secure
> > + mode, trust is rooted to the OTPMK, a never-disclosed 256-bit key
> > + randomly generated and fused into each SoC at manufacturing time.
> > + Otherwise, a common fixed test key is used instead.
> > +
> > * Execution isolation
> >
> > (1) TPM
> > @@ -46,6 +53,10 @@ safe.
> > Customizable set of operations running in isolated execution
> > environment verified via Secure/Trusted boot process.
> >
> > + (3) CAAM
> > +
> > + Fixed set of operations running in isolated execution environment.
> > +
> > * Optional binding to platform integrity state
> >
> > (1) TPM
> > @@ -63,6 +74,11 @@ safe.
> > Relies on Secure/Trusted boot process for platform integrity. It can
> > be extended with TEE based measured boot process.
> >
> > + (3) CAAM
> > +
> > + Relies on the High Assurance Boot (HAB) mechanism of NXP SoCs
> > + for platform integrity.
> > +
> > * Interfaces and APIs
> >
> > (1) TPM
> > @@ -74,10 +90,13 @@ safe.
> > TEEs have well-documented, standardized client interface and APIs.
> For
> > more details refer to ``Documentation/staging/tee.rst``.
> >
> > + (3) CAAM
> > +
> > + Interface is specific to silicon vendor.
> >
> > * Threat model
> >
> > - The strength and appropriateness of a particular TPM or TEE for a given
> > + The strength and appropriateness of a particular trust source
> > + for a given
> > purpose must be assessed when using them to protect
> > security-relevant data.
> >
> >
> > @@ -104,6 +123,12 @@ selected trust source:
> > from platform specific hardware RNG or a software based Fortuna
> > CSPRNG
> > which can be seeded via multiple entropy sources.
> >
> > + * CAAM: Kernel RNG
> > +
> > + The normal kernel random number generator is used. To seed it from
> the
> > + CAAM HWRNG, enable CRYPTO_DEV_FSL_CAAM_RNG_API and
> ensure
> > the device
> > + is probed.
> > +
> > 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.
> >
> > @@ -192,6 +217,19 @@ Usage::
> > specific to TEE device implementation. The key length for new keys
> > is always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits).
> >
> > +Trusted Keys usage: CAAM
> > +------------------------
> > +
> > +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 CAAM device implementation. The key length for
> > +new keys is always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024
> bits).
> > +
> > Encrypted Keys usage
> > --------------------
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index
> > f670002134e0..6eca4476bb76 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -10655,6 +10655,15 @@ S: Supported
> > F: include/keys/trusted_tee.h
> > F: security/keys/trusted-keys/trusted_tee.c
> >
> > +KEYS-TRUSTED-CAAM
> > +M: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> > +R: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> > +L: linux-integrity@xxxxxxxxxxxxxxx
> > +L: keyrings@xxxxxxxxxxxxxxx
> > +S: Maintained
> > +F: include/keys/trusted_caam.h
> > +F: security/keys/trusted-keys/trusted_caam.c
> > +
> > KEYS/KEYRINGS
> > M: David Howells <dhowells@xxxxxxxxxx>
> > M: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > diff --git a/include/keys/trusted_caam.h b/include/keys/trusted_caam.h
> > new file mode 100644 index 000000000000..2fba0996b0b0
> > --- /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@xxxxxxxxxxxxxx> */
> > +
> > +#ifndef __CAAM_TRUSTED_KEY_H
> > +#define __CAAM_TRUSTED_KEY_H
> > +
> > +extern struct trusted_key_ops caam_trusted_key_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..066f08d6eb2c
> > --- /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
> > +<kernel@xxxxxxxxxxxxxx> */
> > +
> > +#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 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 9235fb7d0ec9..640434cd437a 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", &caam_trusted_key_ops }, #endif
> > };
> >
> > DEFINE_STATIC_CALL_NULL(trusted_key_init,
> > *trusted_key_sources[0].ops->init);
> > --
> > 2.30.2
