Linux-Sgx Archive on lore.kernel.org
 help / color / Atom feed
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: x86@kernel.org, linux-sgx@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	linux-security-module@vger.kernel.org,
	Jethro Beekman <jethro@fortanix.com>,
	Andy Lutomirski <luto@kernel.org>,
	akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
	asapek@google.com, bp@alien8.de, cedric.xing@intel.com,
	chenalexchen@google.com, conradparker@google.com,
	cyhanish@google.com, dave.hansen@intel.com,
	haitao.huang@intel.com, josh@joshtriplett.org,
	kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com,
	ludloff@google.com, nhorman@redhat.com, npmccallum@redhat.com,
	puiterwijk@redhat.com, rientjes@google.com,
	sean.j.christopherson@intel.com, tglx@linutronix.de,
	yaozhangx@google.com
Subject: [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation
Date: Thu, 18 Jun 2020 01:08:34 +0300
Message-ID: <20200617220844.57423-13-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20200617220844.57423-1-jarkko.sakkinen@linux.intel.com>

Provisioning Certification Enclave (PCE), the root of trust for other
enclaves, generates a signing key from a fused key called Provisioning
Certification Key. PCE can then use this key to certify an attestation key
of a QE, e.g. we get the chain of trust down to the hardware if the Intel
signed PCE is used.

To use the needed keys, ATTRIBUTE.PROVISIONKEY is required but should be
only allowed for those who actually need it so that only the trusted
parties can certify QE's.

Obviously the attestation service should know the public key of the used
PCE and that way detect illegit attestation, but whitelisting the legit
users still adds an additional layer of defence.

Add new device file called /dev/sgx/provision. The sole purpose of this
file is to provide file descriptors that act as privilege tokens to allow
to build enclaves with ATTRIBUTE.PROVISIONKEY set. A new ioctl called
SGX_IOC_ENCLAVE_SET_ATTRIBUTE is used to assign this token to an enclave.

Cc: linux-security-module@vger.kernel.org
Acked-by: Jethro Beekman <jethro@fortanix.com>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/include/uapi/asm/sgx.h  | 11 ++++++++
 arch/x86/kernel/cpu/sgx/driver.c | 14 ++++++++++
 arch/x86/kernel/cpu/sgx/driver.h |  2 ++
 arch/x86/kernel/cpu/sgx/ioctl.c  | 47 ++++++++++++++++++++++++++++++++
 4 files changed, 74 insertions(+)

diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
index 5edb08ab8fd0..57d0d30c79b3 100644
--- a/arch/x86/include/uapi/asm/sgx.h
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -25,6 +25,8 @@ enum sgx_page_flags {
 	_IOWR(SGX_MAGIC, 0x01, struct sgx_enclave_add_pages)
 #define SGX_IOC_ENCLAVE_INIT \
 	_IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init)
+#define SGX_IOC_ENCLAVE_SET_ATTRIBUTE \
+	_IOW(SGX_MAGIC, 0x03, struct sgx_enclave_set_attribute)
 
 /**
  * struct sgx_enclave_create - parameter structure for the
@@ -63,4 +65,13 @@ struct sgx_enclave_init {
 	__u64 sigstruct;
 };
 
+/**
+ * struct sgx_enclave_set_attribute - parameter structure for the
+ *				      %SGX_IOC_ENCLAVE_SET_ATTRIBUTE ioctl
+ * @attribute_fd:	file handle of the attribute file in the securityfs
+ */
+struct sgx_enclave_set_attribute {
+	__u64 attribute_fd;
+};
+
 #endif /* _UAPI_ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index b4aa7b9f8376..d90114cec1c3 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -150,6 +150,13 @@ static struct miscdevice sgx_dev_enclave = {
 	.fops = &sgx_encl_fops,
 };
 
+static struct miscdevice sgx_dev_provision = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "provision",
+	.nodename = "sgx/provision",
+	.fops = &sgx_provision_fops,
+};
+
 int __init sgx_drv_init(void)
 {
 	unsigned int eax, ebx, ecx, edx;
@@ -190,5 +197,12 @@ int __init sgx_drv_init(void)
 		return ret;
 	}
 
+	ret = misc_register(&sgx_dev_provision);
+	if (ret) {
+		pr_err("Creating /dev/sgx/provision failed with %d.\n", ret);
+		misc_deregister(&sgx_dev_enclave);
+		return ret;
+	}
+
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h
index e4063923115b..72747d01c046 100644
--- a/arch/x86/kernel/cpu/sgx/driver.h
+++ b/arch/x86/kernel/cpu/sgx/driver.h
@@ -23,6 +23,8 @@ extern u64 sgx_attributes_reserved_mask;
 extern u64 sgx_xfrm_reserved_mask;
 extern u32 sgx_xsave_size_tbl[64];
 
+extern const struct file_operations sgx_provision_fops;
+
 long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
 
 int sgx_drv_init(void);
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 420d13fc03da..721096f1d5ba 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -669,6 +669,50 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg)
 	return ret;
 }
 
+/**
+ * sgx_ioc_enclave_set_attribute - handler for %SGX_IOC_ENCLAVE_SET_ATTRIBUTE
+ * @filep:	open file to /dev/sgx
+ * @arg:	userspace pointer to a struct sgx_enclave_set_attribute instance
+ *
+ * Mark the enclave as being allowed to access a restricted attribute bit.
+ * The requested attribute is specified via the attribute_fd field in the
+ * provided struct sgx_enclave_set_attribute.  The attribute_fd must be a
+ * handle to an SGX attribute file, e.g. "/dev/sgx/provision".
+ *
+ * Failure to explicitly request access to a restricted attribute will cause
+ * sgx_ioc_enclave_init() to fail.  Currently, the only restricted attribute
+ * is access to the PROVISION_KEY.
+ *
+ * Note, access to the EINITTOKEN_KEY is disallowed entirely.
+ *
+ * Return: 0 on success, -errno otherwise
+ */
+static long sgx_ioc_enclave_set_attribute(struct sgx_encl *encl,
+					  void __user *arg)
+{
+	struct sgx_enclave_set_attribute params;
+	struct file *attribute_file;
+	int ret;
+
+	if (copy_from_user(&params, arg, sizeof(params)))
+		return -EFAULT;
+
+	attribute_file = fget(params.attribute_fd);
+	if (!attribute_file)
+		return -EINVAL;
+
+	if (attribute_file->f_op != &sgx_provision_fops) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	encl->allowed_attributes |= SGX_ATTR_PROVISIONKEY;
+	ret = 0;
+
+out:
+	fput(attribute_file);
+	return ret;
+}
 
 long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 {
@@ -694,6 +738,9 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	case SGX_IOC_ENCLAVE_INIT:
 		ret = sgx_ioc_enclave_init(encl, (void __user *)arg);
 		break;
+	case SGX_IOC_ENCLAVE_SET_ATTRIBUTE:
+		ret = sgx_ioc_enclave_set_attribute(encl, (void __user *)arg);
+		break;
 	default:
 		ret = -ENOIOCTLCMD;
 		break;
-- 
2.25.1


  parent reply index

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-17 22:08 [PATCH v33 00/21] Intel SGX foundations Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 01/21] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-06-22 17:37   ` Borislav Petkov
2020-06-25  1:25     ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 02/21] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-06-24 13:04   ` Borislav Petkov
2020-06-24 14:34     ` Sean Christopherson
2020-06-25  1:28       ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 03/21] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-06-25  8:59   ` Borislav Petkov
2020-06-25 15:34     ` Sean Christopherson
2020-06-25 16:49       ` Borislav Petkov
2020-06-25 20:52     ` Jarkko Sakkinen
2020-06-25 21:11       ` Borislav Petkov
2020-06-26 13:34         ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 04/21] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 05/21] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 06/21] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 07/21] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 08/21] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-06-25 10:14   ` Borislav Petkov
2020-06-25 20:11     ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 09/21] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-06-25 17:06   ` Borislav Petkov
2020-06-25 20:55     ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 10/21] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-06-25 17:14   ` Borislav Petkov
2020-06-25 17:30     ` Matthew Wilcox
2020-06-25 18:06       ` Sean Christopherson
2020-06-25 22:40         ` Jarkko Sakkinen
2020-06-25 22:26     ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 11/21] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-06-25 17:23   ` Borislav Petkov
2020-06-25 18:34     ` Sean Christopherson
2020-06-25 18:45       ` Borislav Petkov
2020-06-26 14:19       ` Jarkko Sakkinen
2020-06-25 20:21     ` Jarkko Sakkinen
2020-06-25 20:25       ` Borislav Petkov
2020-06-26 13:40         ` Jarkko Sakkinen
2020-06-25 18:53   ` Borislav Petkov
2020-06-26 14:17     ` Jarkko Sakkinen
2020-06-26  9:14   ` Borislav Petkov
2020-06-26 14:16     ` Sean Christopherson
2020-06-26 14:20       ` Borislav Petkov
2020-07-03 23:04         ` Jarkko Sakkinen
2020-07-03  3:09     ` Jarkko Sakkinen
2020-06-26 15:34   ` Borislav Petkov
2020-07-04  0:13     ` Jarkko Sakkinen
2020-06-27 17:43   ` Borislav Petkov
2020-06-29 15:27     ` Sean Christopherson
2020-06-29 15:37       ` Borislav Petkov
2020-07-04  1:43       ` Jarkko Sakkinen
2020-07-07  1:38         ` Sean Christopherson
2020-07-07  3:29           ` Jarkko Sakkinen
2020-07-04  1:42     ` Jarkko Sakkinen
2020-07-02  3:59   ` Sean Christopherson
2020-07-04  3:31     ` Jarkko Sakkinen
2020-06-17 22:08 ` Jarkko Sakkinen [this message]
2020-06-29 16:02   ` [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Borislav Petkov
2020-06-29 22:04     ` Sean Christopherson
2020-06-30  8:49       ` Borislav Petkov
2020-06-30 14:20         ` Sean Christopherson
2020-06-30 17:13           ` Andy Lutomirski
2020-07-02 20:47         ` Dr. Greg
2020-07-03  2:43         ` Jarkko Sakkinen
2020-07-03  2:38       ` Jarkko Sakkinen
2020-07-03  2:32     ` Jarkko Sakkinen
2020-07-03  2:55       ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 13/21] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 14/21] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 15/21] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-06-29 17:10   ` Borislav Petkov
2020-06-30  6:00     ` Sean Christopherson
2020-06-30  8:41       ` Borislav Petkov
2020-06-30 14:55         ` Sean Christopherson
2020-06-30 16:48         ` Andy Lutomirski
2020-06-30 17:23           ` Sean Christopherson
2020-07-02 12:52           ` Thomas Gleixner
2020-06-17 22:08 ` [PATCH v33 16/21] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 17/21] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 18/21] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 19/21] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 20/21] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 21/21] x86/sgx: Update MAINTAINERS Jarkko Sakkinen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200617220844.57423-13-jarkko.sakkinen@linux.intel.com \
    --to=jarkko.sakkinen@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=asapek@google.com \
    --cc=bp@alien8.de \
    --cc=cedric.xing@intel.com \
    --cc=chenalexchen@google.com \
    --cc=conradparker@google.com \
    --cc=cyhanish@google.com \
    --cc=dave.hansen@intel.com \
    --cc=haitao.huang@intel.com \
    --cc=jethro@fortanix.com \
    --cc=josh@joshtriplett.org \
    --cc=kai.huang@intel.com \
    --cc=kai.svahn@intel.com \
    --cc=kmoy@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=linux-sgx@vger.kernel.org \
    --cc=ludloff@google.com \
    --cc=luto@kernel.org \
    --cc=nhorman@redhat.com \
    --cc=npmccallum@redhat.com \
    --cc=puiterwijk@redhat.com \
    --cc=rientjes@google.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --cc=yaozhangx@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Sgx Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-sgx/0 linux-sgx/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-sgx linux-sgx/ https://lore.kernel.org/linux-sgx \
		linux-sgx@vger.kernel.org
	public-inbox-index linux-sgx

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-sgx


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git