From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilias Apalodimas Date: Mon, 25 Jan 2021 10:38:37 +0200 Subject: [PATCH v3 11/11] tpm: Allow disabling platform hierarchy with TPM2 In-Reply-To: <20210123102600.v3.11.I151cb828b53c98409ab85c3ea82c774fc6cb88f7@changeid> References: <20210123172607.2879600-1-sjg@chromium.org> <20210123102600.v3.11.I151cb828b53c98409ab85c3ea82c774fc6cb88f7@changeid> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Sat, Jan 23, 2021 at 10:26:07AM -0700, Simon Glass wrote: > With TPM2 we don't actually lock the TPM once verified boot is finished. > Instead we disable the platform hierarchy which serves the same purpose. > Add an implementation of this so we can safely boot into the kernel. > > Signed-off-by: Simon Glass > --- > > (no changes since v2) > > Changes in v2: > - Add definition of TPM2_RC_NV_DEFINED return code > > include/tpm-v2.h | 13 +++++++++++++ > lib/tpm-v2.c | 35 +++++++++++++++++++++++++++++++++++ > 2 files changed, 48 insertions(+) > > diff --git a/include/tpm-v2.h b/include/tpm-v2.h > index 1ca1e7e2011..e18c8b1ccca 100644 > --- a/include/tpm-v2.h > +++ b/include/tpm-v2.h > @@ -235,6 +235,7 @@ enum tpm2_handles { > enum tpm2_command_codes { > TPM2_CC_STARTUP = 0x0144, > TPM2_CC_SELF_TEST = 0x0143, > + TPM2_CC_HIER_CONTROL = 0x0121, > TPM2_CC_CLEAR = 0x0126, > TPM2_CC_CLEARCONTROL = 0x0127, > TPM2_CC_HIERCHANGEAUTH = 0x0129, > @@ -272,6 +273,7 @@ enum tpm2_return_codes { > TPM2_RC_COMMAND_CODE = TPM2_RC_VER1 + 0x0043, > TPM2_RC_AUTHSIZE = TPM2_RC_VER1 + 0x0044, > TPM2_RC_AUTH_CONTEXT = TPM2_RC_VER1 + 0x0045, > + TPM2_RC_NV_DEFINED = TPM2_RC_VER1 + 0x004c, > TPM2_RC_NEEDS_TEST = TPM2_RC_VER1 + 0x0053, > TPM2_RC_WARN = 0x0900, > TPM2_RC_TESTING = TPM2_RC_WARN + 0x000A, > @@ -582,4 +584,15 @@ u32 tpm2_get_random(struct udevice *dev, void *data, u32 count); > */ > u32 tpm2_write_lock(struct udevice *dev, u32 index); > > +/** > + * Disable access to any platform data > + * > + * This can be called to close off access to the firmware data in the data, > + * before calling the kernel. > + * > + * @dev TPM device > + * @return code of the operation > + */ > +u32 tpm2_disable_platform_hierarchy(struct udevice *dev); > + > #endif /* __TPM_V2_H */ > diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c > index 35f3917aeb5..1b32661979d 100644 > --- a/lib/tpm-v2.c > +++ b/lib/tpm-v2.c > @@ -625,3 +625,38 @@ u32 tpm2_write_lock(struct udevice *dev, u32 index) > > return tpm_sendrecv_command(dev, command_v2, NULL, NULL); > } > + > +u32 tpm2_disable_platform_hierarchy(struct udevice *dev) > +{ > + struct tpm_chip_priv *priv = dev_get_uclass_priv(dev); > + u8 command_v2[COMMAND_BUFFER_SIZE] = { > + /* header 10 bytes */ > + tpm_u16(TPM2_ST_SESSIONS), /* TAG */ > + tpm_u32(10 + 4 + 13 + 5), /* Length */ > + tpm_u32(TPM2_CC_HIER_CONTROL), /* Command code */ > + > + /* 4 bytes */ > + tpm_u32(TPM2_RH_PLATFORM), /* Primary platform seed */ > + > + /* session header 9 bytes */ > + tpm_u32(9), /* Header size */ > + tpm_u32(TPM2_RS_PW), /* Password authorisation */ > + tpm_u16(0), /* nonce_size */ > + 0, /* session_attrs */ > + tpm_u16(0), /* auth_size */ > + > + /* payload 5 bytes */ > + tpm_u32(TPM2_RH_PLATFORM), /* Hierarchy to disable */ > + 0, /* 0=disable */ > + }; > + int ret; > + > + ret = tpm_sendrecv_command(dev, command_v2, NULL, NULL); > + log_info("ret=%s, %x\n", dev->name, ret); > + if (ret) > + return ret; > + > + priv->plat_hier_disabled = true; > + > + return 0; > +} > -- > 2.30.0.280.ga3ce27912f-goog > Acked-by: Ilias Apalodimas