| Message ID | 20200209212609.7928-14-jarkko.sakkinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Intel SGX foundations | expand |
This patch and 22/22 contain the following email header: Content-Type: text/plain; charset=a git am doesn't like this. -- Jethro Beekman | Fortanix On 2020-02-09 22:26, Jarkko Sakkinen wrote: > In order to provide a mechanism for devilering provisoning rights: > > 1. Add a new device file /dev/sgx/provision that works as a token for > allowing an enclave to have the provisioning privileges. > 2. Add a new ioctl called SGX_IOC_ENCLAVE_SET_ATTRIBUTE that accepts the > following data structure: > > struct sgx_enclave_set_attribute { > __u64 addr; > __u64 attribute_fd; > }; > > A daemon could sit on top of /dev/sgx/provision and send a file > descriptor of this file to a process that needs to be able to provision > enclaves. > > The way this API is used is straight-forward. Lets assume that dev_fd is > a handle to /dev/sgx/enclave and prov_fd is a handle to > /dev/sgx/provision. You would allow SGX_IOC_ENCLAVE_CREATE to > initialize an enclave with the PROVISIONKEY attribute by > > params.addr = <enclave address>; > params.token_fd = prov_fd; > > ioctl(dev_fd, SGX_IOC_ENCLAVE_SET_ATTRIBUTE, ¶ms); > > Cc: linux-security-module@vger.kernel.org > 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 83513cdfd1c0..262001df3ae4 100644 > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > @@ -663,6 +663,50 @@ 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(¶ms, 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) > { > @@ -686,6 +730,9 @@ 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; >
On Thu, Feb 13, 2020 at 11:49:18AM +0100, Jethro Beekman wrote: > This patch and 22/22 contain the following email header: > > Content-Type: text/plain; charset=a > > git am doesn't like this. > > -- > Jethro Beekman | Fortanix Hmm... I just used git format-patch and git send-email. Have no idea why this happened. /Jarkko
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 83513cdfd1c0..262001df3ae4 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -663,6 +663,50 @@ 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(¶ms, 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) { @@ -686,6 +730,9 @@ 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;
In order to provide a mechanism for devilering provisoning rights: 1. Add a new device file /dev/sgx/provision that works as a token for allowing an enclave to have the provisioning privileges. 2. Add a new ioctl called SGX_IOC_ENCLAVE_SET_ATTRIBUTE that accepts the following data structure: struct sgx_enclave_set_attribute { __u64 addr; __u64 attribute_fd; }; A daemon could sit on top of /dev/sgx/provision and send a file descriptor of this file to a process that needs to be able to provision enclaves. The way this API is used is straight-forward. Lets assume that dev_fd is a handle to /dev/sgx/enclave and prov_fd is a handle to /dev/sgx/provision. You would allow SGX_IOC_ENCLAVE_CREATE to initialize an enclave with the PROVISIONKEY attribute by params.addr = <enclave address>; params.token_fd = prov_fd; ioctl(dev_fd, SGX_IOC_ENCLAVE_SET_ATTRIBUTE, ¶ms); Cc: linux-security-module@vger.kernel.org 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(+)