* [PATCH v5 0/2] powerpc: Enabling IMA arch specific secure boot policies @ 2019-08-19 12:35 ` Nayna Jain 0 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Michael Ellerman, Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther, Nayna Jain IMA subsystem supports custom, built-in, arch-specific policies to define the files to be measured and appraised. These policies are honored based on the priority where arch-specific policies is the highest and custom is the lowest. OpenPOWER systems rely on IMA for signature verification of the kernel. This patchset adds support for powerpc specific arch policies that are defined based on system's OS secureboot state. The OS secureboot state of the system is determined via device-tree entry. Changelog: v5: * secureboot state is now read via device tree entry rather than OPAL secure variables * ima arch policies are updated to use policy based template for measurement rules v4: * Fixed the build issue as reported by Satheesh Rajendran. v3: * OPAL APIs in Patch 1 are updated to provide generic interface based on key/keylen. This patchset updates kernel OPAL APIs to be compatible with generic interface. * Patch 2 is cleaned up to use new OPAL APIs. * Since OPAL can support different types of backend which can vary in the variable interpretation, the Patch 2 is updated to add a check for the backend version * OPAL API now expects consumer to first check the supported backend version before calling other secvar OPAL APIs. This check is now added in patch 2. * IMA policies in Patch 3 is updated to specify appended signature and per policy template. * The patches now are free of any EFIisms. v2: * Removed Patch 1: powerpc/include: Override unneeded early ioremap functions * Updated Subject line and patch description of the Patch 1 of this series * Removed dependency of OPAL_SECVAR on EFI, CPU_BIG_ENDIAN and UCS2_STRING * Changed OPAL APIs from static to non-static. Added opal-secvar.h for the same * Removed EFI hooks from opal_secvar.c * Removed opal_secvar_get_next(), opal_secvar_enqueue() and opal_query_variable_info() function * get_powerpc_sb_mode() in secboot.c now directly calls OPAL Runtime API rather than via EFI hooks. * Fixed log messages in get_powerpc_sb_mode() function. * Added dependency for PPC_SECURE_BOOT on configs PPC64 and OPAL_SECVAR * Replaced obj-$(CONFIG_IMA) with obj-$(CONFIG_PPC_SECURE_BOOT) in arch/powerpc/kernel/Makefile Nayna Jain (2): powerpc: detect the secure boot mode of the system powerpc: Add support to initialize ima policy rules arch/powerpc/Kconfig | 13 ++++++ arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ arch/powerpc/kernel/Makefile | 2 + arch/powerpc/kernel/ima_arch.c | 50 +++++++++++++++++++++ arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ include/linux/ima.h | 3 +- 6 files changed, 165 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/include/asm/secboot.h create mode 100644 arch/powerpc/kernel/ima_arch.c create mode 100644 arch/powerpc/kernel/secboot.c -- 2.20.1 ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v5 0/2] powerpc: Enabling IMA arch specific secure boot policies @ 2019-08-19 12:35 ` Nayna Jain 0 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Nayna Jain, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson IMA subsystem supports custom, built-in, arch-specific policies to define the files to be measured and appraised. These policies are honored based on the priority where arch-specific policies is the highest and custom is the lowest. OpenPOWER systems rely on IMA for signature verification of the kernel. This patchset adds support for powerpc specific arch policies that are defined based on system's OS secureboot state. The OS secureboot state of the system is determined via device-tree entry. Changelog: v5: * secureboot state is now read via device tree entry rather than OPAL secure variables * ima arch policies are updated to use policy based template for measurement rules v4: * Fixed the build issue as reported by Satheesh Rajendran. v3: * OPAL APIs in Patch 1 are updated to provide generic interface based on key/keylen. This patchset updates kernel OPAL APIs to be compatible with generic interface. * Patch 2 is cleaned up to use new OPAL APIs. * Since OPAL can support different types of backend which can vary in the variable interpretation, the Patch 2 is updated to add a check for the backend version * OPAL API now expects consumer to first check the supported backend version before calling other secvar OPAL APIs. This check is now added in patch 2. * IMA policies in Patch 3 is updated to specify appended signature and per policy template. * The patches now are free of any EFIisms. v2: * Removed Patch 1: powerpc/include: Override unneeded early ioremap functions * Updated Subject line and patch description of the Patch 1 of this series * Removed dependency of OPAL_SECVAR on EFI, CPU_BIG_ENDIAN and UCS2_STRING * Changed OPAL APIs from static to non-static. Added opal-secvar.h for the same * Removed EFI hooks from opal_secvar.c * Removed opal_secvar_get_next(), opal_secvar_enqueue() and opal_query_variable_info() function * get_powerpc_sb_mode() in secboot.c now directly calls OPAL Runtime API rather than via EFI hooks. * Fixed log messages in get_powerpc_sb_mode() function. * Added dependency for PPC_SECURE_BOOT on configs PPC64 and OPAL_SECVAR * Replaced obj-$(CONFIG_IMA) with obj-$(CONFIG_PPC_SECURE_BOOT) in arch/powerpc/kernel/Makefile Nayna Jain (2): powerpc: detect the secure boot mode of the system powerpc: Add support to initialize ima policy rules arch/powerpc/Kconfig | 13 ++++++ arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ arch/powerpc/kernel/Makefile | 2 + arch/powerpc/kernel/ima_arch.c | 50 +++++++++++++++++++++ arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ include/linux/ima.h | 3 +- 6 files changed, 165 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/include/asm/secboot.h create mode 100644 arch/powerpc/kernel/ima_arch.c create mode 100644 arch/powerpc/kernel/secboot.c -- 2.20.1 ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v5 1/2] powerpc: detect the secure boot mode of the system 2019-08-19 12:35 ` Nayna Jain @ 2019-08-19 12:35 ` Nayna Jain -1 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Michael Ellerman, Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther, Nayna Jain Secure boot on POWER defines different IMA policies based on the secure boot state of the system. This patch defines a function to detect the secure boot state of the system. The PPC_SECURE_BOOT config represents the base enablement of secureboot on POWER. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> --- arch/powerpc/Kconfig | 11 +++++ arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ arch/powerpc/kernel/Makefile | 2 + arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ 4 files changed, 111 insertions(+) create mode 100644 arch/powerpc/include/asm/secboot.h create mode 100644 arch/powerpc/kernel/secboot.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 77f6ebf97113..c902a39124dc 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -912,6 +912,17 @@ config PPC_MEM_KEYS If unsure, say y. +config PPC_SECURE_BOOT + prompt "Enable PowerPC Secure Boot" + bool + default n + depends on PPC64 + help + Linux on POWER with firmware secure boot enabled needs to define + security policies to extend secure boot to the OS.This config + allows user to enable OS Secure Boot on PowerPC systems that + have firmware secure boot support. + endmenu config ISA_DMA_API diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h new file mode 100644 index 000000000000..e726261bb00b --- /dev/null +++ b/arch/powerpc/include/asm/secboot.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PowerPC secure boot definitions + * + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + */ +#ifndef POWERPC_SECBOOT_H +#define POWERPC_SECBOOT_H + +#ifdef CONFIG_PPC_SECURE_BOOT +extern struct device_node *is_powerpc_secvar_supported(void); +extern bool get_powerpc_secureboot(void); +#else +static inline struct device_node *is_powerpc_secvar_supported(void) +{ + return NULL; +} + +static inline bool get_powerpc_secureboot(void) +{ + return false; +} + +#endif +#endif diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ea0c69236789..d310ebb4e526 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -157,6 +157,8 @@ endif obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o + # Disable GCOV, KCOV & sanitizers in odd or sensitive code GCOV_PROFILE_prom_init.o := n KCOV_INSTRUMENT_prom_init.o := n diff --git a/arch/powerpc/kernel/secboot.c b/arch/powerpc/kernel/secboot.c new file mode 100644 index 000000000000..5ea0d52d64ef --- /dev/null +++ b/arch/powerpc/kernel/secboot.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + * secboot.c + * - util function to get powerpc secboot state + */ +#include <linux/types.h> +#include <linux/of.h> +#include <asm/secboot.h> + +struct device_node *is_powerpc_secvar_supported(void) +{ + struct device_node *np; + int status; + + np = of_find_node_by_name(NULL, "ibm,secureboot"); + if (!np) { + pr_info("secureboot node is not found\n"); + return NULL; + } + + status = of_device_is_compatible(np, "ibm,secureboot-v3"); + if (!status) { + pr_info("Secure variables are not supported by this firmware\n"); + return NULL; + } + + return np; +} + +bool get_powerpc_secureboot(void) +{ + struct device_node *np; + struct device_node *secvar_np; + const u64 *psecboot; + u64 secboot = 0; + + np = is_powerpc_secvar_supported(); + if (!np) + goto disabled; + + /* Fail-safe for any failure related to secvar */ + secvar_np = of_get_child_by_name(np, "secvar"); + if (!secvar_np) { + pr_err("Expected secure variables support, fail-safe\n"); + goto enabled; + } + + if (!of_device_is_available(secvar_np)) { + pr_err("Secure variables support is in error state, fail-safe\n"); + goto enabled; + } + + psecboot = of_get_property(secvar_np, "secure-mode", NULL); + if (!psecboot) + goto enabled; + + secboot = be64_to_cpup((__be64 *)psecboot); + if (!(secboot & (~0x0))) + goto disabled; + +enabled: + pr_info("secureboot mode enabled\n"); + return true; + +disabled: + pr_info("secureboot mode disabled\n"); + return false; +} -- 2.20.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v5 1/2] powerpc: detect the secure boot mode of the system @ 2019-08-19 12:35 ` Nayna Jain 0 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Nayna Jain, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson Secure boot on POWER defines different IMA policies based on the secure boot state of the system. This patch defines a function to detect the secure boot state of the system. The PPC_SECURE_BOOT config represents the base enablement of secureboot on POWER. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> --- arch/powerpc/Kconfig | 11 +++++ arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ arch/powerpc/kernel/Makefile | 2 + arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ 4 files changed, 111 insertions(+) create mode 100644 arch/powerpc/include/asm/secboot.h create mode 100644 arch/powerpc/kernel/secboot.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 77f6ebf97113..c902a39124dc 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -912,6 +912,17 @@ config PPC_MEM_KEYS If unsure, say y. +config PPC_SECURE_BOOT + prompt "Enable PowerPC Secure Boot" + bool + default n + depends on PPC64 + help + Linux on POWER with firmware secure boot enabled needs to define + security policies to extend secure boot to the OS.This config + allows user to enable OS Secure Boot on PowerPC systems that + have firmware secure boot support. + endmenu config ISA_DMA_API diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h new file mode 100644 index 000000000000..e726261bb00b --- /dev/null +++ b/arch/powerpc/include/asm/secboot.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PowerPC secure boot definitions + * + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + */ +#ifndef POWERPC_SECBOOT_H +#define POWERPC_SECBOOT_H + +#ifdef CONFIG_PPC_SECURE_BOOT +extern struct device_node *is_powerpc_secvar_supported(void); +extern bool get_powerpc_secureboot(void); +#else +static inline struct device_node *is_powerpc_secvar_supported(void) +{ + return NULL; +} + +static inline bool get_powerpc_secureboot(void) +{ + return false; +} + +#endif +#endif diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ea0c69236789..d310ebb4e526 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -157,6 +157,8 @@ endif obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o + # Disable GCOV, KCOV & sanitizers in odd or sensitive code GCOV_PROFILE_prom_init.o := n KCOV_INSTRUMENT_prom_init.o := n diff --git a/arch/powerpc/kernel/secboot.c b/arch/powerpc/kernel/secboot.c new file mode 100644 index 000000000000..5ea0d52d64ef --- /dev/null +++ b/arch/powerpc/kernel/secboot.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + * secboot.c + * - util function to get powerpc secboot state + */ +#include <linux/types.h> +#include <linux/of.h> +#include <asm/secboot.h> + +struct device_node *is_powerpc_secvar_supported(void) +{ + struct device_node *np; + int status; + + np = of_find_node_by_name(NULL, "ibm,secureboot"); + if (!np) { + pr_info("secureboot node is not found\n"); + return NULL; + } + + status = of_device_is_compatible(np, "ibm,secureboot-v3"); + if (!status) { + pr_info("Secure variables are not supported by this firmware\n"); + return NULL; + } + + return np; +} + +bool get_powerpc_secureboot(void) +{ + struct device_node *np; + struct device_node *secvar_np; + const u64 *psecboot; + u64 secboot = 0; + + np = is_powerpc_secvar_supported(); + if (!np) + goto disabled; + + /* Fail-safe for any failure related to secvar */ + secvar_np = of_get_child_by_name(np, "secvar"); + if (!secvar_np) { + pr_err("Expected secure variables support, fail-safe\n"); + goto enabled; + } + + if (!of_device_is_available(secvar_np)) { + pr_err("Secure variables support is in error state, fail-safe\n"); + goto enabled; + } + + psecboot = of_get_property(secvar_np, "secure-mode", NULL); + if (!psecboot) + goto enabled; + + secboot = be64_to_cpup((__be64 *)psecboot); + if (!(secboot & (~0x0))) + goto disabled; + +enabled: + pr_info("secureboot mode enabled\n"); + return true; + +disabled: + pr_info("secureboot mode disabled\n"); + return false; +} -- 2.20.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v5 1/2] powerpc: detect the secure boot mode of the system 2019-08-19 12:35 ` Nayna Jain @ 2019-09-02 11:52 ` Michael Ellerman -1 siblings, 0 replies; 13+ messages in thread From: Michael Ellerman @ 2019-09-02 11:52 UTC (permalink / raw) To: Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther, Nayna Jain Hi Nayna, Sorry I've taken so long to get to this series, there's just too many patches that need reviewing :/ Nayna Jain <nayna@linux.ibm.com> writes: > Secure boot on POWER defines different IMA policies based on the secure > boot state of the system. The terminology throughout is a bit vague, we have POWER, PowerPC, Linux on POWER etc. What this patch is talking about is a particular implemention of secure boot on some OpenPOWER machines running bare metal - am I right? So saying "Secure boot on POWER defines different IMA policies" is a bit broad I think. Really we've just decided that a way to implement secure boot is to use IMA policies. > This patch defines a function to detect the secure boot state of the > system. > > The PPC_SECURE_BOOT config represents the base enablement of secureboot > on POWER. > > Signed-off-by: Nayna Jain <nayna@linux.ibm.com> > --- > arch/powerpc/Kconfig | 11 +++++ > arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ > arch/powerpc/kernel/Makefile | 2 + > arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ > 4 files changed, 111 insertions(+) > create mode 100644 arch/powerpc/include/asm/secboot.h > create mode 100644 arch/powerpc/kernel/secboot.c > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 77f6ebf97113..c902a39124dc 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -912,6 +912,17 @@ config PPC_MEM_KEYS > > If unsure, say y. > > +config PPC_SECURE_BOOT > + prompt "Enable PowerPC Secure Boot" How about "Enable secure boot support" > + bool > + default n The default is 'n', so you don't need that default line. > + depends on PPC64 Should it just depend on POWERNV for now? AFAIK there's nothing in here that's necessarily going to be shared with the guest secure boot code is there? > + help > + Linux on POWER with firmware secure boot enabled needs to define > + security policies to extend secure boot to the OS.This config > + allows user to enable OS Secure Boot on PowerPC systems that > + have firmware secure boot support. Again POWER vs PowerPC. I think something like: "Enable support for secure boot on some systems that have firmware support for it. If in doubt say N." > diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h secure_boot.h would be fine. > new file mode 100644 > index 000000000000..e726261bb00b > --- /dev/null > +++ b/arch/powerpc/include/asm/secboot.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * PowerPC secure boot definitions > + * > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> I prefer to not have email addresses in copyright headers, as they just bit rot. Your email is in the git log. > + * > + */ > +#ifndef POWERPC_SECBOOT_H > +#define POWERPC_SECBOOT_H We usually do _ASM_POWERPC_SECBOOT_H (or _ASM_POWERPC_SECURE_BOOT_H). > +#ifdef CONFIG_PPC_SECURE_BOOT > +extern struct device_node *is_powerpc_secvar_supported(void); > +extern bool get_powerpc_secureboot(void); You don't need 'extern' for functions in headers. > +#else > +static inline struct device_node *is_powerpc_secvar_supported(void) > +{ > + return NULL; > +} > + > +static inline bool get_powerpc_secureboot(void) > +{ > + return false; > +} > + > +#endif > +#endif > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile > index ea0c69236789..d310ebb4e526 100644 > --- a/arch/powerpc/kernel/Makefile > +++ b/arch/powerpc/kernel/Makefile > @@ -157,6 +157,8 @@ endif > obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o > obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o > > +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o > + > # Disable GCOV, KCOV & sanitizers in odd or sensitive code > GCOV_PROFILE_prom_init.o := n > KCOV_INSTRUMENT_prom_init.o := n > diff --git a/arch/powerpc/kernel/secboot.c b/arch/powerpc/kernel/secboot.c > new file mode 100644 > index 000000000000..5ea0d52d64ef > --- /dev/null > +++ b/arch/powerpc/kernel/secboot.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> > + * > + * secboot.c > + * - util function to get powerpc secboot state That's not really necessary. > + */ > +#include <linux/types.h> > +#include <linux/of.h> > +#include <asm/secboot.h> > + > +struct device_node *is_powerpc_secvar_supported(void) This is a pretty weird signature. The "is_" implies it will return a bool, but then it actually returns a device node *. > +{ > + struct device_node *np; > + int status; > + > + np = of_find_node_by_name(NULL, "ibm,secureboot"); > + if (!np) { > + pr_info("secureboot node is not found\n"); > + return NULL; > + } There's no good reason to search by name. You should just search by compatible. eg. of_find_compatible_node() > + status = of_device_is_compatible(np, "ibm,secureboot-v3"); > + if (!status) { > + pr_info("Secure variables are not supported by this firmware\n"); > + return NULL; > + } > + > + return np; > +} > + > +bool get_powerpc_secureboot(void) > +{ > + struct device_node *np; > + struct device_node *secvar_np; > + const u64 *psecboot; > + u64 secboot = 0; > + > + np = is_powerpc_secvar_supported(); > + if (!np) > + goto disabled; > + > + /* Fail-safe for any failure related to secvar */ > + secvar_np = of_get_child_by_name(np, "secvar"); Finding a child by name is not ideal, it encodes the structure of the tree in the API. It's better to just search by compatible. eg. of_find_compatible_node("ibm,secvar-v1") You should also define what that means, ie. write a little snippet of doc to define what the expected properties are and their meaning and so on. > + if (!secvar_np) { > + pr_err("Expected secure variables support, fail-safe\n"); I'm a bit confused by this. This is the exact opposite of what I understand fail-safe to mean. We shouldn't tell the user the system is securely booted unless we're 100% sure it is. Right? > + goto enabled; > + } > + > + if (!of_device_is_available(secvar_np)) { > + pr_err("Secure variables support is in error state, fail-safe\n"); > + goto enabled; > + } It seems a little weird to use the status property to indicate ok/error and then also have a "secure-mode" property. Wouldn't just "secure-mode" be sufficient with several states to represent what we need? > + psecboot = of_get_property(secvar_np, "secure-mode", NULL); > + if (!psecboot) > + goto enabled; Please use of_read_property_u64() or similar. > + secboot = be64_to_cpup((__be64 *)psecboot); > + if (!(secboot & (~0x0))) I'm not sure what that's trying to do. > + goto disabled; > + > +enabled: > + pr_info("secureboot mode enabled\n"); > + return true; > + > +disabled: > + pr_info("secureboot mode disabled\n"); > + return false; > +} cheers ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 1/2] powerpc: detect the secure boot mode of the system @ 2019-09-02 11:52 ` Michael Ellerman 0 siblings, 0 replies; 13+ messages in thread From: Michael Ellerman @ 2019-09-02 11:52 UTC (permalink / raw) To: Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Nayna Jain, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson Hi Nayna, Sorry I've taken so long to get to this series, there's just too many patches that need reviewing :/ Nayna Jain <nayna@linux.ibm.com> writes: > Secure boot on POWER defines different IMA policies based on the secure > boot state of the system. The terminology throughout is a bit vague, we have POWER, PowerPC, Linux on POWER etc. What this patch is talking about is a particular implemention of secure boot on some OpenPOWER machines running bare metal - am I right? So saying "Secure boot on POWER defines different IMA policies" is a bit broad I think. Really we've just decided that a way to implement secure boot is to use IMA policies. > This patch defines a function to detect the secure boot state of the > system. > > The PPC_SECURE_BOOT config represents the base enablement of secureboot > on POWER. > > Signed-off-by: Nayna Jain <nayna@linux.ibm.com> > --- > arch/powerpc/Kconfig | 11 +++++ > arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ > arch/powerpc/kernel/Makefile | 2 + > arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ > 4 files changed, 111 insertions(+) > create mode 100644 arch/powerpc/include/asm/secboot.h > create mode 100644 arch/powerpc/kernel/secboot.c > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 77f6ebf97113..c902a39124dc 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -912,6 +912,17 @@ config PPC_MEM_KEYS > > If unsure, say y. > > +config PPC_SECURE_BOOT > + prompt "Enable PowerPC Secure Boot" How about "Enable secure boot support" > + bool > + default n The default is 'n', so you don't need that default line. > + depends on PPC64 Should it just depend on POWERNV for now? AFAIK there's nothing in here that's necessarily going to be shared with the guest secure boot code is there? > + help > + Linux on POWER with firmware secure boot enabled needs to define > + security policies to extend secure boot to the OS.This config > + allows user to enable OS Secure Boot on PowerPC systems that > + have firmware secure boot support. Again POWER vs PowerPC. I think something like: "Enable support for secure boot on some systems that have firmware support for it. If in doubt say N." > diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h secure_boot.h would be fine. > new file mode 100644 > index 000000000000..e726261bb00b > --- /dev/null > +++ b/arch/powerpc/include/asm/secboot.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * PowerPC secure boot definitions > + * > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> I prefer to not have email addresses in copyright headers, as they just bit rot. Your email is in the git log. > + * > + */ > +#ifndef POWERPC_SECBOOT_H > +#define POWERPC_SECBOOT_H We usually do _ASM_POWERPC_SECBOOT_H (or _ASM_POWERPC_SECURE_BOOT_H). > +#ifdef CONFIG_PPC_SECURE_BOOT > +extern struct device_node *is_powerpc_secvar_supported(void); > +extern bool get_powerpc_secureboot(void); You don't need 'extern' for functions in headers. > +#else > +static inline struct device_node *is_powerpc_secvar_supported(void) > +{ > + return NULL; > +} > + > +static inline bool get_powerpc_secureboot(void) > +{ > + return false; > +} > + > +#endif > +#endif > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile > index ea0c69236789..d310ebb4e526 100644 > --- a/arch/powerpc/kernel/Makefile > +++ b/arch/powerpc/kernel/Makefile > @@ -157,6 +157,8 @@ endif > obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o > obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o > > +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o > + > # Disable GCOV, KCOV & sanitizers in odd or sensitive code > GCOV_PROFILE_prom_init.o := n > KCOV_INSTRUMENT_prom_init.o := n > diff --git a/arch/powerpc/kernel/secboot.c b/arch/powerpc/kernel/secboot.c > new file mode 100644 > index 000000000000..5ea0d52d64ef > --- /dev/null > +++ b/arch/powerpc/kernel/secboot.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> > + * > + * secboot.c > + * - util function to get powerpc secboot state That's not really necessary. > + */ > +#include <linux/types.h> > +#include <linux/of.h> > +#include <asm/secboot.h> > + > +struct device_node *is_powerpc_secvar_supported(void) This is a pretty weird signature. The "is_" implies it will return a bool, but then it actually returns a device node *. > +{ > + struct device_node *np; > + int status; > + > + np = of_find_node_by_name(NULL, "ibm,secureboot"); > + if (!np) { > + pr_info("secureboot node is not found\n"); > + return NULL; > + } There's no good reason to search by name. You should just search by compatible. eg. of_find_compatible_node() > + status = of_device_is_compatible(np, "ibm,secureboot-v3"); > + if (!status) { > + pr_info("Secure variables are not supported by this firmware\n"); > + return NULL; > + } > + > + return np; > +} > + > +bool get_powerpc_secureboot(void) > +{ > + struct device_node *np; > + struct device_node *secvar_np; > + const u64 *psecboot; > + u64 secboot = 0; > + > + np = is_powerpc_secvar_supported(); > + if (!np) > + goto disabled; > + > + /* Fail-safe for any failure related to secvar */ > + secvar_np = of_get_child_by_name(np, "secvar"); Finding a child by name is not ideal, it encodes the structure of the tree in the API. It's better to just search by compatible. eg. of_find_compatible_node("ibm,secvar-v1") You should also define what that means, ie. write a little snippet of doc to define what the expected properties are and their meaning and so on. > + if (!secvar_np) { > + pr_err("Expected secure variables support, fail-safe\n"); I'm a bit confused by this. This is the exact opposite of what I understand fail-safe to mean. We shouldn't tell the user the system is securely booted unless we're 100% sure it is. Right? > + goto enabled; > + } > + > + if (!of_device_is_available(secvar_np)) { > + pr_err("Secure variables support is in error state, fail-safe\n"); > + goto enabled; > + } It seems a little weird to use the status property to indicate ok/error and then also have a "secure-mode" property. Wouldn't just "secure-mode" be sufficient with several states to represent what we need? > + psecboot = of_get_property(secvar_np, "secure-mode", NULL); > + if (!psecboot) > + goto enabled; Please use of_read_property_u64() or similar. > + secboot = be64_to_cpup((__be64 *)psecboot); > + if (!(secboot & (~0x0))) I'm not sure what that's trying to do. > + goto disabled; > + > +enabled: > + pr_info("secureboot mode enabled\n"); > + return true; > + > +disabled: > + pr_info("secureboot mode disabled\n"); > + return false; > +} cheers ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 1/2] powerpc: detect the secure boot mode of the system 2019-09-02 11:52 ` Michael Ellerman (?) @ 2019-09-05 11:32 ` Nayna -1 siblings, 0 replies; 13+ messages in thread From: Nayna @ 2019-09-05 11:32 UTC (permalink / raw) To: Michael Ellerman, Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson On 09/02/2019 07:52 AM, Michael Ellerman wrote: > Hi Nayna, Hi Michael, > > Sorry I've taken so long to get to this series, there's just too many > patches that need reviewing :/ No problem. I understand. Thanks for reviewing. > > Nayna Jain <nayna@linux.ibm.com> writes: >> Secure boot on POWER defines different IMA policies based on the secure >> boot state of the system. > The terminology throughout is a bit vague, we have POWER, PowerPC, Linux > on POWER etc. > > What this patch is talking about is a particular implemention of secure > boot on some OpenPOWER machines running bare metal - am I right? > > So saying "Secure boot on POWER defines different IMA policies" is a bit > broad I think. Really we've just decided that a way to implement secure > boot is to use IMA policies. I think the idea was to convey that the same design can be reused or extended as needed. But I agree for now it is currently only OpenPOWER machines running on bare metal, I will fix the wordings to use "PowerNV" consistently. > >> This patch defines a function to detect the secure boot state of the >> system. >> >> The PPC_SECURE_BOOT config represents the base enablement of secureboot >> on POWER. >> >> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> >> --- >> arch/powerpc/Kconfig | 11 +++++ >> arch/powerpc/include/asm/secboot.h | 27 ++++++++++++ >> arch/powerpc/kernel/Makefile | 2 + >> arch/powerpc/kernel/secboot.c | 71 ++++++++++++++++++++++++++++++ >> 4 files changed, 111 insertions(+) >> create mode 100644 arch/powerpc/include/asm/secboot.h >> create mode 100644 arch/powerpc/kernel/secboot.c >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index 77f6ebf97113..c902a39124dc 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -912,6 +912,17 @@ config PPC_MEM_KEYS >> >> If unsure, say y. >> >> +config PPC_SECURE_BOOT >> + prompt "Enable PowerPC Secure Boot" > How about "Enable secure boot support" Yes. Sounds better. > >> + bool >> + default n > The default is 'n', so you don't need that default line. Sure. > >> + depends on PPC64 > Should it just depend on POWERNV for now? AFAIK there's nothing in here > that's necessarily going to be shared with the guest secure boot code is > there? Yes. sounds good. > >> + help >> + Linux on POWER with firmware secure boot enabled needs to define >> + security policies to extend secure boot to the OS.This config >> + allows user to enable OS Secure Boot on PowerPC systems that >> + have firmware secure boot support. > Again POWER vs PowerPC. > > I think something like: > > "Enable support for secure boot on some systems that have firmware > support for it. If in doubt say N." Sure. > > >> diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h > secure_boot.h would be fine. Sure. > >> new file mode 100644 >> index 000000000000..e726261bb00b >> --- /dev/null >> +++ b/arch/powerpc/include/asm/secboot.h >> @@ -0,0 +1,27 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +/* >> + * PowerPC secure boot definitions >> + * >> + * Copyright (C) 2019 IBM Corporation >> + * Author: Nayna Jain <nayna@linux.ibm.com> > I prefer to not have email addresses in copyright headers, as they just > bit rot. Your email is in the git log. Sure. > >> + * >> + */ >> +#ifndef POWERPC_SECBOOT_H >> +#define POWERPC_SECBOOT_H > We usually do _ASM_POWERPC_SECBOOT_H (or _ASM_POWERPC_SECURE_BOOT_H). Sure. > >> +#ifdef CONFIG_PPC_SECURE_BOOT >> +extern struct device_node *is_powerpc_secvar_supported(void); >> +extern bool get_powerpc_secureboot(void); > You don't need 'extern' for functions in headers. Yes. will fix. > >> +#else >> +static inline struct device_node *is_powerpc_secvar_supported(void) >> +{ >> + return NULL; >> +} >> + >> +static inline bool get_powerpc_secureboot(void) >> +{ >> + return false; >> +} >> + >> +#endif >> +#endif >> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile >> index ea0c69236789..d310ebb4e526 100644 >> --- a/arch/powerpc/kernel/Makefile >> +++ b/arch/powerpc/kernel/Makefile >> @@ -157,6 +157,8 @@ endif >> obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o >> obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o >> >> +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o >> + >> # Disable GCOV, KCOV & sanitizers in odd or sensitive code >> GCOV_PROFILE_prom_init.o := n >> KCOV_INSTRUMENT_prom_init.o := n >> diff --git a/arch/powerpc/kernel/secboot.c b/arch/powerpc/kernel/secboot.c >> new file mode 100644 >> index 000000000000..5ea0d52d64ef >> --- /dev/null >> +++ b/arch/powerpc/kernel/secboot.c >> @@ -0,0 +1,71 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2019 IBM Corporation >> + * Author: Nayna Jain <nayna@linux.ibm.com> >> + * >> + * secboot.c >> + * - util function to get powerpc secboot state > That's not really necessary. Sure. > >> + */ >> +#include <linux/types.h> >> +#include <linux/of.h> >> +#include <asm/secboot.h> >> + >> +struct device_node *is_powerpc_secvar_supported(void) > This is a pretty weird signature. The "is_" implies it will return a > bool, but then it actually returns a device node *. Yes. Agree. Will fix. > >> +{ >> + struct device_node *np; >> + int status; >> + >> + np = of_find_node_by_name(NULL, "ibm,secureboot"); >> + if (!np) { >> + pr_info("secureboot node is not found\n"); >> + return NULL; >> + } > There's no good reason to search by name. You should just search by compatible. > > eg. of_find_compatible_node() Sure. > >> + status = of_device_is_compatible(np, "ibm,secureboot-v3"); >> + if (!status) { >> + pr_info("Secure variables are not supported by this firmware\n"); >> + return NULL; >> + } >> + >> + return np; >> +} >> + >> +bool get_powerpc_secureboot(void) >> +{ >> + struct device_node *np; >> + struct device_node *secvar_np; >> + const u64 *psecboot; >> + u64 secboot = 0; >> + >> + np = is_powerpc_secvar_supported(); >> + if (!np) >> + goto disabled; >> + >> + /* Fail-safe for any failure related to secvar */ >> + secvar_np = of_get_child_by_name(np, "secvar"); > Finding a child by name is not ideal, it encodes the structure of the > tree in the API. It's better to just search by compatible. > > eg. of_find_compatible_node("ibm,secvar-v1") > > You should also define what that means, ie. write a little snippet of > doc to define what the expected properties are and their meaning and so > on. It is part of the skiboot patches (https://patchwork.ozlabs.org/patch/1157346/) Sure. I will add one in the kernel as well. > >> + if (!secvar_np) { >> + pr_err("Expected secure variables support, fail-safe\n"); > I'm a bit confused by this. This is the exact opposite of what I > understand fail-safe to mean. We shouldn't tell the user the system is > securely booted unless we're 100% sure it is. Right? Yes. Thanks for pointing this out. "Fail secure" is the correct term. This is the situation where secure variables are supported. Any failure reading the secure variables may be an attack, so we fail securely. > >> + goto enabled; >> + } >> + >> + if (!of_device_is_available(secvar_np)) { >> + pr_err("Secure variables support is in error state, fail-safe\n"); >> + goto enabled; >> + } > It seems a little weird to use the status property to indicate ok/error > and then also have a "secure-mode" property. Wouldn't just "secure-mode" > be sufficient with several states to represent what we need? Before we check in which mode the system booted (e.g. setup, user, etc) using "secure mode" property, the "status" check helps to ensure that the system secure boot initialized correctly. We will look into combining the two variables. > >> + psecboot = of_get_property(secvar_np, "secure-mode", NULL); >> + if (!psecboot) >> + goto enabled; > Please use of_read_property_u64() or similar. Sure. > >> + secboot = be64_to_cpup((__be64 *)psecboot); >> + if (!(secboot & (~0x0))) > I'm not sure what that's trying to do. We are exposing secure modes from the skiboot to the kernel via a bitfield, partitioned into generic modes and backend specific modes. I will update this code so that it is clearer. Thanks & Regards, - Nayna ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules 2019-08-19 12:35 ` Nayna Jain @ 2019-08-19 12:35 ` Nayna Jain -1 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Michael Ellerman, Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther, Nayna Jain POWER secure boot relies on the kernel IMA security subsystem to perform the OS kernel image signature verification. Since each secure boot mode has different IMA policy requirements, dynamic definition of the policy rules based on the runtime secure boot mode of the system is required. On systems that support secure boot, but have it disabled, only measurement policy rules of the kernel image and modules are defined. This patch defines the arch-specific implementation to retrieve the secure boot mode of the system and accordingly configures the IMA policy rules. This patch provides arch-specific IMA policies if PPC_SECURE_BOOT config is enabled. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> --- arch/powerpc/Kconfig | 2 ++ arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ include/linux/ima.h | 3 +- 4 files changed, 55 insertions(+), 2 deletions(-) create mode 100644 arch/powerpc/kernel/ima_arch.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c902a39124dc..42109682b727 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT bool default n depends on PPC64 + depends on IMA + depends on IMA_ARCH_POLICY help Linux on POWER with firmware secure boot enabled needs to define security policies to extend secure boot to the OS.This config diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index d310ebb4e526..520b1c814197 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -157,7 +157,7 @@ endif obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o # Disable GCOV, KCOV & sanitizers in odd or sensitive code GCOV_PROFILE_prom_init.o := n diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c new file mode 100644 index 000000000000..ac90fac83338 --- /dev/null +++ b/arch/powerpc/kernel/ima_arch.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + * ima_arch.c + * - initialize ima policies for PowerPC Secure Boot + */ + +#include <linux/ima.h> +#include <asm/secboot.h> + +bool arch_ima_get_secureboot(void) +{ + return get_powerpc_secureboot(); +} + +/* + * File signature verification is not needed, include only measurements + */ +static const char *const default_arch_rules[] = { + "measure func=KEXEC_KERNEL_CHECK", + "measure func=MODULE_CHECK", + NULL +}; + +/* Both file signature verification and measurements are needed */ +static const char *const sb_arch_rules[] = { + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", +#if IS_ENABLED(CONFIG_MODULE_SIG) + "measure func=MODULE_CHECK", +#else + "measure func=MODULE_CHECK template=ima-modsig", + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", +#endif + NULL +}; + +/* + * On PowerPC, file measurements are to be added to the IMA measurement list + * irrespective of the secure boot state of the system. Signature verification + * is conditionally enabled based on the secure boot state. + */ +const char *const *arch_get_ima_policy(void) +{ + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) + return sb_arch_rules; + return default_arch_rules; +} diff --git a/include/linux/ima.h b/include/linux/ima.h index a20ad398d260..10af09b5b478 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -29,7 +29,8 @@ extern void ima_kexec_cmdline(const void *buf, int size); extern void ima_add_kexec_buffer(struct kimage *image); #endif -#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) +#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) \ + || defined(CONFIG_PPC_SECURE_BOOT) extern bool arch_ima_get_secureboot(void); extern const char * const *arch_get_ima_policy(void); #else -- 2.20.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules @ 2019-08-19 12:35 ` Nayna Jain 0 siblings, 0 replies; 13+ messages in thread From: Nayna Jain @ 2019-08-19 12:35 UTC (permalink / raw) To: linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Nayna Jain, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson POWER secure boot relies on the kernel IMA security subsystem to perform the OS kernel image signature verification. Since each secure boot mode has different IMA policy requirements, dynamic definition of the policy rules based on the runtime secure boot mode of the system is required. On systems that support secure boot, but have it disabled, only measurement policy rules of the kernel image and modules are defined. This patch defines the arch-specific implementation to retrieve the secure boot mode of the system and accordingly configures the IMA policy rules. This patch provides arch-specific IMA policies if PPC_SECURE_BOOT config is enabled. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> --- arch/powerpc/Kconfig | 2 ++ arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ include/linux/ima.h | 3 +- 4 files changed, 55 insertions(+), 2 deletions(-) create mode 100644 arch/powerpc/kernel/ima_arch.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c902a39124dc..42109682b727 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT bool default n depends on PPC64 + depends on IMA + depends on IMA_ARCH_POLICY help Linux on POWER with firmware secure boot enabled needs to define security policies to extend secure boot to the OS.This config diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index d310ebb4e526..520b1c814197 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -157,7 +157,7 @@ endif obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o # Disable GCOV, KCOV & sanitizers in odd or sensitive code GCOV_PROFILE_prom_init.o := n diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c new file mode 100644 index 000000000000..ac90fac83338 --- /dev/null +++ b/arch/powerpc/kernel/ima_arch.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <nayna@linux.ibm.com> + * + * ima_arch.c + * - initialize ima policies for PowerPC Secure Boot + */ + +#include <linux/ima.h> +#include <asm/secboot.h> + +bool arch_ima_get_secureboot(void) +{ + return get_powerpc_secureboot(); +} + +/* + * File signature verification is not needed, include only measurements + */ +static const char *const default_arch_rules[] = { + "measure func=KEXEC_KERNEL_CHECK", + "measure func=MODULE_CHECK", + NULL +}; + +/* Both file signature verification and measurements are needed */ +static const char *const sb_arch_rules[] = { + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", +#if IS_ENABLED(CONFIG_MODULE_SIG) + "measure func=MODULE_CHECK", +#else + "measure func=MODULE_CHECK template=ima-modsig", + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", +#endif + NULL +}; + +/* + * On PowerPC, file measurements are to be added to the IMA measurement list + * irrespective of the secure boot state of the system. Signature verification + * is conditionally enabled based on the secure boot state. + */ +const char *const *arch_get_ima_policy(void) +{ + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) + return sb_arch_rules; + return default_arch_rules; +} diff --git a/include/linux/ima.h b/include/linux/ima.h index a20ad398d260..10af09b5b478 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -29,7 +29,8 @@ extern void ima_kexec_cmdline(const void *buf, int size); extern void ima_add_kexec_buffer(struct kimage *image); #endif -#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) +#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) \ + || defined(CONFIG_PPC_SECURE_BOOT) extern bool arch_ima_get_secureboot(void); extern const char * const *arch_get_ima_policy(void); #else -- 2.20.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules 2019-08-19 12:35 ` Nayna Jain @ 2019-09-02 11:52 ` Michael Ellerman -1 siblings, 0 replies; 13+ messages in thread From: Michael Ellerman @ 2019-09-02 11:52 UTC (permalink / raw) To: Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther, Nayna Jain Hi Nayna, Some more comments below. Nayna Jain <nayna@linux.ibm.com> writes: > POWER secure boot relies on the kernel IMA security subsystem to > perform the OS kernel image signature verification. Again this is just a design choice we've made, it's not specified anywhere or anything like that. And it only applies to bare metal secure boot, at least so far. AIUI. > Since each secure > boot mode has different IMA policy requirements, dynamic definition of > the policy rules based on the runtime secure boot mode of the system is > required. On systems that support secure boot, but have it disabled, > only measurement policy rules of the kernel image and modules are > defined. It's probably worth mentioning that we intend to use this in our Linux-based boot loader, which uses kexec, and that's one of the reasons why we're particularly interested in defining the rules for kexec? > This patch defines the arch-specific implementation to retrieve the > secure boot mode of the system and accordingly configures the IMA policy > rules. > > This patch provides arch-specific IMA policies if PPC_SECURE_BOOT > config is enabled. > > Signed-off-by: Nayna Jain <nayna@linux.ibm.com> > --- > arch/powerpc/Kconfig | 2 ++ > arch/powerpc/kernel/Makefile | 2 +- > arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ > include/linux/ima.h | 3 +- > 4 files changed, 55 insertions(+), 2 deletions(-) > create mode 100644 arch/powerpc/kernel/ima_arch.c > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index c902a39124dc..42109682b727 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT > bool > default n > depends on PPC64 > + depends on IMA > + depends on IMA_ARCH_POLICY > help > Linux on POWER with firmware secure boot enabled needs to define > security policies to extend secure boot to the OS.This config > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile > index d310ebb4e526..520b1c814197 100644 > --- a/arch/powerpc/kernel/Makefile > +++ b/arch/powerpc/kernel/Makefile > @@ -157,7 +157,7 @@ endif > obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o > obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o > > -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o > +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o > > # Disable GCOV, KCOV & sanitizers in odd or sensitive code > GCOV_PROFILE_prom_init.o := n > diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c > new file mode 100644 > index 000000000000..ac90fac83338 > --- /dev/null > +++ b/arch/powerpc/kernel/ima_arch.c > @@ -0,0 +1,50 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> > + * > + * ima_arch.c > + * - initialize ima policies for PowerPC Secure Boot > + */ > + > +#include <linux/ima.h> > +#include <asm/secboot.h> > + > +bool arch_ima_get_secureboot(void) > +{ > + return get_powerpc_secureboot(); > +} > + > +/* > + * File signature verification is not needed, include only measurements > + */ > +static const char *const default_arch_rules[] = { > + "measure func=KEXEC_KERNEL_CHECK", > + "measure func=MODULE_CHECK", > + NULL > +}; The rules above seem fairly self explanatory. > + > +/* Both file signature verification and measurements are needed */ > +static const char *const sb_arch_rules[] = { > + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", > + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", > +#if IS_ENABLED(CONFIG_MODULE_SIG) > + "measure func=MODULE_CHECK", > +#else > + "measure func=MODULE_CHECK template=ima-modsig", > + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", > +#endif But these ones are not so obvious, at least to me who knows very little about IMA. Can you add a one line comment to each of the ones in here saying what it does and why we want it? > + NULL > +}; > + > +/* > + * On PowerPC, file measurements are to be added to the IMA measurement list > + * irrespective of the secure boot state of the system. Why? Just because we think it's useful? Would be good to provide some further justification. * Signature verification > + * is conditionally enabled based on the secure boot state. > + */ > +const char *const *arch_get_ima_policy(void) > +{ > + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) > + return sb_arch_rules; > + return default_arch_rules; > +} > diff --git a/include/linux/ima.h b/include/linux/ima.h > index a20ad398d260..10af09b5b478 100644 > --- a/include/linux/ima.h > +++ b/include/linux/ima.h > @@ -29,7 +29,8 @@ extern void ima_kexec_cmdline(const void *buf, int size); > extern void ima_add_kexec_buffer(struct kimage *image); > #endif > > -#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) > +#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) \ > + || defined(CONFIG_PPC_SECURE_BOOT) > extern bool arch_ima_get_secureboot(void); > extern const char * const *arch_get_ima_policy(void); > #else cheers ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules @ 2019-09-02 11:52 ` Michael Ellerman 0 siblings, 0 replies; 13+ messages in thread From: Michael Ellerman @ 2019-09-02 11:52 UTC (permalink / raw) To: Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Nayna Jain, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson Hi Nayna, Some more comments below. Nayna Jain <nayna@linux.ibm.com> writes: > POWER secure boot relies on the kernel IMA security subsystem to > perform the OS kernel image signature verification. Again this is just a design choice we've made, it's not specified anywhere or anything like that. And it only applies to bare metal secure boot, at least so far. AIUI. > Since each secure > boot mode has different IMA policy requirements, dynamic definition of > the policy rules based on the runtime secure boot mode of the system is > required. On systems that support secure boot, but have it disabled, > only measurement policy rules of the kernel image and modules are > defined. It's probably worth mentioning that we intend to use this in our Linux-based boot loader, which uses kexec, and that's one of the reasons why we're particularly interested in defining the rules for kexec? > This patch defines the arch-specific implementation to retrieve the > secure boot mode of the system and accordingly configures the IMA policy > rules. > > This patch provides arch-specific IMA policies if PPC_SECURE_BOOT > config is enabled. > > Signed-off-by: Nayna Jain <nayna@linux.ibm.com> > --- > arch/powerpc/Kconfig | 2 ++ > arch/powerpc/kernel/Makefile | 2 +- > arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ > include/linux/ima.h | 3 +- > 4 files changed, 55 insertions(+), 2 deletions(-) > create mode 100644 arch/powerpc/kernel/ima_arch.c > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index c902a39124dc..42109682b727 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT > bool > default n > depends on PPC64 > + depends on IMA > + depends on IMA_ARCH_POLICY > help > Linux on POWER with firmware secure boot enabled needs to define > security policies to extend secure boot to the OS.This config > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile > index d310ebb4e526..520b1c814197 100644 > --- a/arch/powerpc/kernel/Makefile > +++ b/arch/powerpc/kernel/Makefile > @@ -157,7 +157,7 @@ endif > obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o > obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o > > -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o > +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o > > # Disable GCOV, KCOV & sanitizers in odd or sensitive code > GCOV_PROFILE_prom_init.o := n > diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c > new file mode 100644 > index 000000000000..ac90fac83338 > --- /dev/null > +++ b/arch/powerpc/kernel/ima_arch.c > @@ -0,0 +1,50 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 IBM Corporation > + * Author: Nayna Jain <nayna@linux.ibm.com> > + * > + * ima_arch.c > + * - initialize ima policies for PowerPC Secure Boot > + */ > + > +#include <linux/ima.h> > +#include <asm/secboot.h> > + > +bool arch_ima_get_secureboot(void) > +{ > + return get_powerpc_secureboot(); > +} > + > +/* > + * File signature verification is not needed, include only measurements > + */ > +static const char *const default_arch_rules[] = { > + "measure func=KEXEC_KERNEL_CHECK", > + "measure func=MODULE_CHECK", > + NULL > +}; The rules above seem fairly self explanatory. > + > +/* Both file signature verification and measurements are needed */ > +static const char *const sb_arch_rules[] = { > + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", > + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", > +#if IS_ENABLED(CONFIG_MODULE_SIG) > + "measure func=MODULE_CHECK", > +#else > + "measure func=MODULE_CHECK template=ima-modsig", > + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", > +#endif But these ones are not so obvious, at least to me who knows very little about IMA. Can you add a one line comment to each of the ones in here saying what it does and why we want it? > + NULL > +}; > + > +/* > + * On PowerPC, file measurements are to be added to the IMA measurement list > + * irrespective of the secure boot state of the system. Why? Just because we think it's useful? Would be good to provide some further justification. * Signature verification > + * is conditionally enabled based on the secure boot state. > + */ > +const char *const *arch_get_ima_policy(void) > +{ > + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) > + return sb_arch_rules; > + return default_arch_rules; > +} > diff --git a/include/linux/ima.h b/include/linux/ima.h > index a20ad398d260..10af09b5b478 100644 > --- a/include/linux/ima.h > +++ b/include/linux/ima.h > @@ -29,7 +29,8 @@ extern void ima_kexec_cmdline(const void *buf, int size); > extern void ima_add_kexec_buffer(struct kimage *image); > #endif > > -#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) > +#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) \ > + || defined(CONFIG_PPC_SECURE_BOOT) > extern bool arch_ima_get_secureboot(void); > extern const char * const *arch_get_ima_policy(void); > #else cheers ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules 2019-09-02 11:52 ` Michael Ellerman @ 2019-09-05 12:31 ` Nayna -1 siblings, 0 replies; 13+ messages in thread From: Nayna @ 2019-09-05 12:31 UTC (permalink / raw) To: Michael Ellerman, Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Paul Mackerras, Benjamin Herrenschmidt, Ard Biesheuvel, Jeremy Kerr, Matthew Garret, Mimi Zohar, Claudio Carvalho, Elaine Palmer, George Wilson, Eric Ricther On 09/02/2019 07:52 AM, Michael Ellerman wrote: > Hi Nayna, Hi Michael, > > Some more comments below. > > Nayna Jain <nayna@linux.ibm.com> writes: >> POWER secure boot relies on the kernel IMA security subsystem to >> perform the OS kernel image signature verification. > Again this is just a design choice we've made, it's not specified > anywhere or anything like that. And it only applies to bare metal secure > boot, at least so far. AIUI. Yes. I will make it consistent to use "PowerNV". >> Since each secure >> boot mode has different IMA policy requirements, dynamic definition of >> the policy rules based on the runtime secure boot mode of the system is >> required. On systems that support secure boot, but have it disabled, >> only measurement policy rules of the kernel image and modules are >> defined. > It's probably worth mentioning that we intend to use this in our > Linux-based boot loader, which uses kexec, and that's one of the reasons > why we're particularly interested in defining the rules for kexec? Yes. Agreed. I will update patch description to add this. > >> This patch defines the arch-specific implementation to retrieve the >> secure boot mode of the system and accordingly configures the IMA policy >> rules. >> >> This patch provides arch-specific IMA policies if PPC_SECURE_BOOT >> config is enabled. >> >> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> >> --- >> arch/powerpc/Kconfig | 2 ++ >> arch/powerpc/kernel/Makefile | 2 +- >> arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ >> include/linux/ima.h | 3 +- >> 4 files changed, 55 insertions(+), 2 deletions(-) >> create mode 100644 arch/powerpc/kernel/ima_arch.c >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index c902a39124dc..42109682b727 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT >> bool >> default n >> depends on PPC64 >> + depends on IMA >> + depends on IMA_ARCH_POLICY >> help >> Linux on POWER with firmware secure boot enabled needs to define >> security policies to extend secure boot to the OS.This config >> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile >> index d310ebb4e526..520b1c814197 100644 >> --- a/arch/powerpc/kernel/Makefile >> +++ b/arch/powerpc/kernel/Makefile >> @@ -157,7 +157,7 @@ endif >> obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o >> obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o >> >> -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o >> +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o >> >> # Disable GCOV, KCOV & sanitizers in odd or sensitive code >> GCOV_PROFILE_prom_init.o := n >> diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c >> new file mode 100644 >> index 000000000000..ac90fac83338 >> --- /dev/null >> +++ b/arch/powerpc/kernel/ima_arch.c >> @@ -0,0 +1,50 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2019 IBM Corporation >> + * Author: Nayna Jain <nayna@linux.ibm.com> >> + * >> + * ima_arch.c >> + * - initialize ima policies for PowerPC Secure Boot >> + */ >> + >> +#include <linux/ima.h> >> +#include <asm/secboot.h> >> + >> +bool arch_ima_get_secureboot(void) >> +{ >> + return get_powerpc_secureboot(); >> +} >> + >> +/* >> + * File signature verification is not needed, include only measurements >> + */ >> +static const char *const default_arch_rules[] = { >> + "measure func=KEXEC_KERNEL_CHECK", >> + "measure func=MODULE_CHECK", >> + NULL >> +}; > The rules above seem fairly self explanatory. > >> + >> +/* Both file signature verification and measurements are needed */ >> +static const char *const sb_arch_rules[] = { >> + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", >> + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", >> +#if IS_ENABLED(CONFIG_MODULE_SIG) >> + "measure func=MODULE_CHECK", >> +#else >> + "measure func=MODULE_CHECK template=ima-modsig", >> + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", >> +#endif > But these ones are not so obvious, at least to me who knows very little > about IMA. > > Can you add a one line comment to each of the ones in here saying what > it does and why we want it? Sure. > >> + NULL >> +}; >> + >> +/* >> + * On PowerPC, file measurements are to be added to the IMA measurement list >> + * irrespective of the secure boot state of the system. > Why? Just because we think it's useful? Would be good to provide some > further justification. Sure. I will clarify this in the next version. Thanks & Regards, - Nayna ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules @ 2019-09-05 12:31 ` Nayna 0 siblings, 0 replies; 13+ messages in thread From: Nayna @ 2019-09-05 12:31 UTC (permalink / raw) To: Michael Ellerman, Nayna Jain, linuxppc-dev, linux-integrity, linux-kernel Cc: Ard Biesheuvel, Eric Ricther, Claudio Carvalho, Mimi Zohar, Matthew Garret, Paul Mackerras, Jeremy Kerr, Elaine Palmer, George Wilson On 09/02/2019 07:52 AM, Michael Ellerman wrote: > Hi Nayna, Hi Michael, > > Some more comments below. > > Nayna Jain <nayna@linux.ibm.com> writes: >> POWER secure boot relies on the kernel IMA security subsystem to >> perform the OS kernel image signature verification. > Again this is just a design choice we've made, it's not specified > anywhere or anything like that. And it only applies to bare metal secure > boot, at least so far. AIUI. Yes. I will make it consistent to use "PowerNV". >> Since each secure >> boot mode has different IMA policy requirements, dynamic definition of >> the policy rules based on the runtime secure boot mode of the system is >> required. On systems that support secure boot, but have it disabled, >> only measurement policy rules of the kernel image and modules are >> defined. > It's probably worth mentioning that we intend to use this in our > Linux-based boot loader, which uses kexec, and that's one of the reasons > why we're particularly interested in defining the rules for kexec? Yes. Agreed. I will update patch description to add this. > >> This patch defines the arch-specific implementation to retrieve the >> secure boot mode of the system and accordingly configures the IMA policy >> rules. >> >> This patch provides arch-specific IMA policies if PPC_SECURE_BOOT >> config is enabled. >> >> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> >> --- >> arch/powerpc/Kconfig | 2 ++ >> arch/powerpc/kernel/Makefile | 2 +- >> arch/powerpc/kernel/ima_arch.c | 50 ++++++++++++++++++++++++++++++++++ >> include/linux/ima.h | 3 +- >> 4 files changed, 55 insertions(+), 2 deletions(-) >> create mode 100644 arch/powerpc/kernel/ima_arch.c >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index c902a39124dc..42109682b727 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -917,6 +917,8 @@ config PPC_SECURE_BOOT >> bool >> default n >> depends on PPC64 >> + depends on IMA >> + depends on IMA_ARCH_POLICY >> help >> Linux on POWER with firmware secure boot enabled needs to define >> security policies to extend secure boot to the OS.This config >> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile >> index d310ebb4e526..520b1c814197 100644 >> --- a/arch/powerpc/kernel/Makefile >> +++ b/arch/powerpc/kernel/Makefile >> @@ -157,7 +157,7 @@ endif >> obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o >> obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o >> >> -obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o >> +obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o >> >> # Disable GCOV, KCOV & sanitizers in odd or sensitive code >> GCOV_PROFILE_prom_init.o := n >> diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c >> new file mode 100644 >> index 000000000000..ac90fac83338 >> --- /dev/null >> +++ b/arch/powerpc/kernel/ima_arch.c >> @@ -0,0 +1,50 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2019 IBM Corporation >> + * Author: Nayna Jain <nayna@linux.ibm.com> >> + * >> + * ima_arch.c >> + * - initialize ima policies for PowerPC Secure Boot >> + */ >> + >> +#include <linux/ima.h> >> +#include <asm/secboot.h> >> + >> +bool arch_ima_get_secureboot(void) >> +{ >> + return get_powerpc_secureboot(); >> +} >> + >> +/* >> + * File signature verification is not needed, include only measurements >> + */ >> +static const char *const default_arch_rules[] = { >> + "measure func=KEXEC_KERNEL_CHECK", >> + "measure func=MODULE_CHECK", >> + NULL >> +}; > The rules above seem fairly self explanatory. > >> + >> +/* Both file signature verification and measurements are needed */ >> +static const char *const sb_arch_rules[] = { >> + "measure func=KEXEC_KERNEL_CHECK template=ima-modsig", >> + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig", >> +#if IS_ENABLED(CONFIG_MODULE_SIG) >> + "measure func=MODULE_CHECK", >> +#else >> + "measure func=MODULE_CHECK template=ima-modsig", >> + "appraise func=MODULE_CHECK appraise_type=imasig|modsig", >> +#endif > But these ones are not so obvious, at least to me who knows very little > about IMA. > > Can you add a one line comment to each of the ones in here saying what > it does and why we want it? Sure. > >> + NULL >> +}; >> + >> +/* >> + * On PowerPC, file measurements are to be added to the IMA measurement list >> + * irrespective of the secure boot state of the system. > Why? Just because we think it's useful? Would be good to provide some > further justification. Sure. I will clarify this in the next version. Thanks & Regards, - Nayna ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2019-09-05 12:35 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-08-19 12:35 [PATCH v5 0/2] powerpc: Enabling IMA arch specific secure boot policies Nayna Jain 2019-08-19 12:35 ` Nayna Jain 2019-08-19 12:35 ` [PATCH v5 1/2] powerpc: detect the secure boot mode of the system Nayna Jain 2019-08-19 12:35 ` Nayna Jain 2019-09-02 11:52 ` Michael Ellerman 2019-09-02 11:52 ` Michael Ellerman 2019-09-05 11:32 ` Nayna 2019-08-19 12:35 ` [PATCH v5 2/2] powerpc: Add support to initialize ima policy rules Nayna Jain 2019-08-19 12:35 ` Nayna Jain 2019-09-02 11:52 ` Michael Ellerman 2019-09-02 11:52 ` Michael Ellerman 2019-09-05 12:31 ` Nayna 2019-09-05 12:31 ` Nayna
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