| Message ID | f8285eb0135ba30c9d846cf9dd395d1f5f8b1efc.1624364386.git-series.a.fatoum@pengutronix.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | KEYS: trusted: Introduce support for NXP CAAM-based trusted keys | expand |
Hi Ahmad, On Tue, 22 Jun 2021 at 18:08, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote: > > With recent rework, trusted keys are no longer limited to TPM as trust > source. The Kconfig symbol is unchanged however leading to a few issues: > > - TCG_TPM is required, even if only TEE is to be used > - Enabling TCG_TPM, but excluding it from available trusted sources > is not possible > - TEE=m && TRUSTED_KEYS=y will lead to TEE support being silently > dropped, which is not the best user experience > > Remedy these issues by introducing two new Kconfig symbols: > TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate > dependencies. > This should include a fixes tag to the rework commit. > Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> > --- > To: James Bottomley <jejb@linux.ibm.com> > To: Jarkko Sakkinen <jarkko@kernel.org> > To: Mimi Zohar <zohar@linux.ibm.com> > To: David Howells <dhowells@redhat.com> > Cc: James Morris <jmorris@namei.org> > Cc: Eric Biggers <ebiggers@kernel.org> > Cc: "Serge E. Hallyn" <serge@hallyn.com> > Cc: "Horia Geantă" <horia.geanta@nxp.com> > Cc: Aymen Sghaier <aymen.sghaier@nxp.com> > Cc: Udit Agarwal <udit.agarwal@nxp.com> > Cc: Jan Luebbe <j.luebbe@pengutronix.de> > Cc: David Gstir <david@sigma-star.at> > Cc: Richard Weinberger <richard@nod.at> > Cc: Franck LENORMAND <franck.lenormand@nxp.com> > Cc: Sumit Garg <sumit.garg@linaro.org> > Cc: keyrings@vger.kernel.org > Cc: linux-crypto@vger.kernel.org > Cc: linux-integrity@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linux-security-module@vger.kernel.org > --- > security/keys/Kconfig | 14 ++++++------- > security/keys/trusted-keys/Kconfig | 25 ++++++++++++++++++++++++- > security/keys/trusted-keys/Makefile | 8 +++++--- > security/keys/trusted-keys/trusted_core.c | 4 ++-- > 4 files changed, 39 insertions(+), 12 deletions(-) > create mode 100644 security/keys/trusted-keys/Kconfig > > diff --git a/security/keys/Kconfig b/security/keys/Kconfig > index 64b81abd087e..6fdb953b319f 100644 > --- a/security/keys/Kconfig > +++ b/security/keys/Kconfig > @@ -70,23 +70,23 @@ config BIG_KEYS > > config TRUSTED_KEYS > tristate "TRUSTED KEYS" > - depends on KEYS && TCG_TPM > + depends on KEYS > select CRYPTO > select CRYPTO_HMAC > select CRYPTO_SHA1 > select CRYPTO_HASH_INFO Should move these as well to TRUSTED_KEYS_TPM as the core code doesn't mandate their need. > - select ASN1_ENCODER > - select OID_REGISTRY > - select ASN1 > help > This option provides support for creating, sealing, and unsealing > keys in the kernel. Trusted keys are random number symmetric keys, > - generated and RSA-sealed by the TPM. The TPM only unseals the keys, > - if the boot PCRs and other criteria match. Userspace will only ever > - see encrypted blobs. > + generated and sealed by a trust source selected at kernel boot-time. > + Userspace will only ever see encrypted blobs. > > If you are unsure as to whether this is required, answer N. > > +if TRUSTED_KEYS > +source "security/keys/trusted-keys/Kconfig" > +endif > + > config ENCRYPTED_KEYS > tristate "ENCRYPTED KEYS" > depends on KEYS > diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig > new file mode 100644 > index 000000000000..24af4aaceebf > --- /dev/null > +++ b/security/keys/trusted-keys/Kconfig > @@ -0,0 +1,25 @@ > +config TRUSTED_KEYS_TPM > + bool "TPM-based trusted keys" > + depends on TCG_TPM >= TRUSTED_KEYS > + default y > + select ASN1_ENCODER > + select OID_REGISTRY > + select ASN1 > + help > + Enable use of the Trusted Platform Module (TPM) as trusted key > + backend. Trusted keys are are random number symmetric keys, > + which will be generated and RSA-sealed by the TPM. > + The TPM only unseals the keys, if the boot PCRs and other > + criteria match. > + > +config TRUSTED_KEYS_TEE > + bool "TEE-based trusted keys" > + depends on TEE >= TRUSTED_KEYS > + default y > + help > + Enable use of the Trusted Execution Environment (TEE) as trusted > + key backend. > + > +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE > +comment "No trust source selected!" > +endif > diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile > index feb8b6c3cc79..96fc6c377398 100644 > --- a/security/keys/trusted-keys/Makefile > +++ b/security/keys/trusted-keys/Makefile > @@ -5,10 +5,12 @@ > > obj-$(CONFIG_TRUSTED_KEYS) += trusted.o > trusted-y += trusted_core.o > -trusted-y += trusted_tpm1.o > +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o > > $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h > -trusted-y += trusted_tpm2.o > -trusted-y += tpm2key.asn1.o > +trusted-$(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_TEE) += trusted_tee.o This should be dropped. -Sumit > diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c > index d5c891d8d353..8cab69e5d0da 100644 > --- a/security/keys/trusted-keys/trusted_core.c > +++ b/security/keys/trusted-keys/trusted_core.c > @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0); > MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); > > static const struct trusted_key_source trusted_key_sources[] = { > -#if defined(CONFIG_TCG_TPM) > +#if defined(CONFIG_TRUSTED_KEYS_TPM) > { "tpm", &trusted_key_tpm_ops }, > #endif > -#if defined(CONFIG_TEE) > +#if defined(CONFIG_TRUSTED_KEYS_TEE) > { "tee", &trusted_key_tee_ops }, > #endif > }; > -- > git-series 0.9.1
Hello Sumit, On 19.07.21 10:04, Sumit Garg wrote: > Hi Ahmad, > > On Tue, 22 Jun 2021 at 18:08, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote: >> >> With recent rework, trusted keys are no longer limited to TPM as trust >> source. The Kconfig symbol is unchanged however leading to a few issues: >> >> - TCG_TPM is required, even if only TEE is to be used >> - Enabling TCG_TPM, but excluding it from available trusted sources >> is not possible >> - TEE=m && TRUSTED_KEYS=y will lead to TEE support being silently >> dropped, which is not the best user experience >> >> Remedy these issues by introducing two new Kconfig symbols: >> TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate >> dependencies. >> > > This should include a fixes tag to the rework commit. Yes. I wasn't aware of the regression that Andreas (CC'd) recently reported. Knowing, it now indeed warrants a backport. Will add in v2. >> diff --git a/security/keys/Kconfig b/security/keys/Kconfig >> index 64b81abd087e..6fdb953b319f 100644 >> --- a/security/keys/Kconfig >> +++ b/security/keys/Kconfig >> @@ -70,23 +70,23 @@ config BIG_KEYS >> >> config TRUSTED_KEYS >> tristate "TRUSTED KEYS" >> - depends on KEYS && TCG_TPM >> + depends on KEYS > >> select CRYPTO >> select CRYPTO_HMAC >> select CRYPTO_SHA1 >> select CRYPTO_HASH_INFO > > Should move these as well to TRUSTED_KEYS_TPM as the core code doesn't > mandate their need. Ok, will test and change appropriately. > >> - select ASN1_ENCODER >> - select OID_REGISTRY >> - select ASN1 >> $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h >> -trusted-y += trusted_tpm2.o >> -trusted-y += tpm2key.asn1.o >> +trusted-$(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_TEE) += trusted_tee.o > > This should be dropped. Right.. Thanks for the review. I'll isolate this patch for v2. Cheers, Ahmad
diff --git a/security/keys/Kconfig b/security/keys/Kconfig index 64b81abd087e..6fdb953b319f 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -70,23 +70,23 @@ config BIG_KEYS config TRUSTED_KEYS tristate "TRUSTED KEYS" - depends on KEYS && TCG_TPM + depends on KEYS select CRYPTO select CRYPTO_HMAC select CRYPTO_SHA1 select CRYPTO_HASH_INFO - select ASN1_ENCODER - select OID_REGISTRY - select ASN1 help This option provides support for creating, sealing, and unsealing keys in the kernel. Trusted keys are random number symmetric keys, - generated and RSA-sealed by the TPM. The TPM only unseals the keys, - if the boot PCRs and other criteria match. Userspace will only ever - see encrypted blobs. + generated and sealed by a trust source selected at kernel boot-time. + Userspace will only ever see encrypted blobs. If you are unsure as to whether this is required, answer N. +if TRUSTED_KEYS +source "security/keys/trusted-keys/Kconfig" +endif + config ENCRYPTED_KEYS tristate "ENCRYPTED KEYS" depends on KEYS diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig new file mode 100644 index 000000000000..24af4aaceebf --- /dev/null +++ b/security/keys/trusted-keys/Kconfig @@ -0,0 +1,25 @@ +config TRUSTED_KEYS_TPM + bool "TPM-based trusted keys" + depends on TCG_TPM >= TRUSTED_KEYS + default y + select ASN1_ENCODER + select OID_REGISTRY + select ASN1 + help + Enable use of the Trusted Platform Module (TPM) as trusted key + backend. Trusted keys are are random number symmetric keys, + which will be generated and RSA-sealed by the TPM. + The TPM only unseals the keys, if the boot PCRs and other + criteria match. + +config TRUSTED_KEYS_TEE + bool "TEE-based trusted keys" + depends on TEE >= TRUSTED_KEYS + default y + help + Enable use of the Trusted Execution Environment (TEE) as trusted + key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE +comment "No trust source selected!" +endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index feb8b6c3cc79..96fc6c377398 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -5,10 +5,12 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o trusted-y += trusted_core.o -trusted-y += trusted_tpm1.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h -trusted-y += trusted_tpm2.o -trusted-y += tpm2key.asn1.o +trusted-$(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_TEE) += trusted_tee.o diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index d5c891d8d353..8cab69e5d0da 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0); MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); static const struct trusted_key_source trusted_key_sources[] = { -#if defined(CONFIG_TCG_TPM) +#if defined(CONFIG_TRUSTED_KEYS_TPM) { "tpm", &trusted_key_tpm_ops }, #endif -#if defined(CONFIG_TEE) +#if defined(CONFIG_TRUSTED_KEYS_TEE) { "tee", &trusted_key_tee_ops }, #endif };
With recent rework, trusted keys are no longer limited to TPM as trust source. The Kconfig symbol is unchanged however leading to a few issues: - TCG_TPM is required, even if only TEE is to be used - Enabling TCG_TPM, but excluding it from available trusted sources is not possible - TEE=m && TRUSTED_KEYS=y will lead to TEE support being silently dropped, which is not the best user experience Remedy these issues by introducing two new Kconfig symbols: TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate dependencies. Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> --- To: James Bottomley <jejb@linux.ibm.com> To: Jarkko Sakkinen <jarkko@kernel.org> To: Mimi Zohar <zohar@linux.ibm.com> To: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Eric Biggers <ebiggers@kernel.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: "Horia Geantă" <horia.geanta@nxp.com> Cc: Aymen Sghaier <aymen.sghaier@nxp.com> Cc: Udit Agarwal <udit.agarwal@nxp.com> Cc: Jan Luebbe <j.luebbe@pengutronix.de> Cc: David Gstir <david@sigma-star.at> Cc: Richard Weinberger <richard@nod.at> Cc: Franck LENORMAND <franck.lenormand@nxp.com> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: keyrings@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org --- security/keys/Kconfig | 14 ++++++------- security/keys/trusted-keys/Kconfig | 25 ++++++++++++++++++++++++- security/keys/trusted-keys/Makefile | 8 +++++--- security/keys/trusted-keys/trusted_core.c | 4 ++-- 4 files changed, 39 insertions(+), 12 deletions(-) create mode 100644 security/keys/trusted-keys/Kconfig