[PATCH v8 2/3] efi_loader: expose efi_image_parse() even if UEFI Secure Boot is disabled

Masahisa Kojima masahisa.kojima at linaro.org
Fri May 14 02:53:36 CEST 2021 

This is preparation for PE/COFF measurement support.
PE/COFF image hash calculation is same in both
UEFI Secure Boot image verification and measurement in
measured boot. PE/COFF image parsing functions are
gathered into efi_image_loader.c, and exposed even if
UEFI Secure Boot is not enabled.

This commit also adds the EFI_SIGNATURE_SUPPORT option
to decide if efi_signature.c shall be compiled.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---

Changes in v8:
- remove superfluous "depends on" in Kconfig

(no changes since v4)

Changes in v4:
- revert #ifdef instead of using "if (!IS_ENABLED())" statement,
  not to rely on the compiler optimization.

Changes in v3:
- hide EFI_SIGNATURE_SUPPORT option

Changes in v2:
- Remove all #ifdef from efi_image_loader.c and efi_signature.c
- Add EFI_SIGNATURE_SUPPORT option
- Explicitly include <u-boot/hash-checksum.h>
- Gather PE/COFF parsing functions into efi_image_loader.c
- Move efi_guid_t efi_guid_image_security_database in efi_var_common.c

 lib/efi_loader/Kconfig            |  5 +++
 lib/efi_loader/Makefile           |  2 +-
 lib/efi_loader/efi_image_loader.c | 64 ++++++++++++++++++++++++++++-
 lib/efi_loader/efi_signature.c    | 67 +------------------------------
 lib/efi_loader/efi_var_common.c   |  3 ++
 5 files changed, 73 insertions(+), 68 deletions(-)

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index eb5c4d6f29..98845b8ba3 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -175,6 +175,7 @@ config EFI_CAPSULE_AUTHENTICATE
 	select PKCS7_VERIFY
 	select IMAGE_SIGN_INFO
 	select HASH_CALCULATE
+	select EFI_SIGNATURE_SUPPORT
 	default n
 	help
 	  Select this option if you want to enable capsule
@@ -344,6 +345,7 @@ config EFI_SECURE_BOOT
 	select PKCS7_MESSAGE_PARSER
 	select PKCS7_VERIFY
 	select HASH_CALCULATE
+	select EFI_SIGNATURE_SUPPORT
 	default n
 	help
 	  Select this option to enable EFI secure boot support.
@@ -351,6 +353,9 @@ config EFI_SECURE_BOOT
 	  it is signed with a trusted key. To do that, you need to install,
 	  at least, PK, KEK and db.
 
+config EFI_SIGNATURE_SUPPORT
+	bool
+
 config EFI_ESRT
 	bool "Enable the UEFI ESRT generation"
 	depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index 8bd343e258..fd344cea29 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -63,7 +63,7 @@ obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += efi_smbios.o
 obj-$(CONFIG_EFI_RNG_PROTOCOL) += efi_rng.o
 obj-$(CONFIG_EFI_TCG2_PROTOCOL) += efi_tcg2.o
 obj-$(CONFIG_EFI_LOAD_FILE2_INITRD) += efi_load_initrd.o
-obj-y += efi_signature.o
+obj-$(CONFIG_EFI_SIGNATURE_SUPPORT) += efi_signature.o
 
 EFI_VAR_SEED_FILE := $(subst $\",,$(CONFIG_EFI_VAR_SEED_FILE))
 $(obj)/efi_var_seed.o: $(srctree)/$(EFI_VAR_SEED_FILE)
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index f53ef367ec..fe1ee198e2 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -213,7 +213,68 @@ static void efi_set_code_and_data_type(
 	}
 }
 
-#ifdef CONFIG_EFI_SECURE_BOOT
+/**
+ * efi_image_region_add() - add an entry of region
+ * @regs:	Pointer to array of regions
+ * @start:	Start address of region (included)
+ * @end:	End address of region (excluded)
+ * @nocheck:	flag against overlapped regions
+ *
+ * Take one entry of region [@start, @end[ and insert it into the list.
+ *
+ * * If @nocheck is false, the list will be sorted ascending by address.
+ *   Overlapping entries will not be allowed.
+ *
+ * * If @nocheck is true, the list will be sorted ascending by sequence
+ *   of adding the entries. Overlapping is allowed.
+ *
+ * Return:	status code
+ */
+efi_status_t efi_image_region_add(struct efi_image_regions *regs,
+				  const void *start, const void *end,
+				  int nocheck)
+{
+	struct image_region *reg;
+	int i, j;
+
+	if (regs->num >= regs->max) {
+		EFI_PRINT("%s: no more room for regions\n", __func__);
+		return EFI_OUT_OF_RESOURCES;
+	}
+
+	if (end < start)
+		return EFI_INVALID_PARAMETER;
+
+	for (i = 0; i < regs->num; i++) {
+		reg = &regs->reg[i];
+		if (nocheck)
+			continue;
+
+		/* new data after registered region */
+		if (start >= reg->data + reg->size)
+			continue;
+
+		/* new data preceding registered region */
+		if (end <= reg->data) {
+			for (j = regs->num - 1; j >= i; j--)
+				memcpy(&regs->reg[j + 1], &regs->reg[j],
+				       sizeof(*reg));
+			break;
+		}
+
+		/* new data overlapping registered region */
+		EFI_PRINT("%s: new region already part of another\n", __func__);
+		return EFI_INVALID_PARAMETER;
+	}
+
+	reg = &regs->reg[i];
+	reg->data = start;
+	reg->size = end - start;
+	regs->num++;
+
+	return EFI_SUCCESS;
+}
+
 /**
  * cmp_pe_section() - compare virtual addresses of two PE image sections
  * @arg1:	pointer to pointer to first section header
@@ -422,6 +483,7 @@ err:
 	return false;
 }
 
+#ifdef CONFIG_EFI_SECURE_BOOT
 /**
  * efi_image_unsigned_authenticate() - authenticate unsigned image with
  * SHA256 hash
diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c
index c7ec275414..bdd09881fc 100644
--- a/lib/efi_loader/efi_signature.c
+++ b/lib/efi_loader/efi_signature.c
@@ -15,18 +15,16 @@
 #include <crypto/public_key.h>
 #include <linux/compat.h>
 #include <linux/oid_registry.h>
+#include <u-boot/hash-checksum.h>
 #include <u-boot/rsa.h>
 #include <u-boot/sha256.h>
 
-const efi_guid_t efi_guid_image_security_database =
-		EFI_IMAGE_SECURITY_DATABASE_GUID;
 const efi_guid_t efi_guid_sha256 = EFI_CERT_SHA256_GUID;
 const efi_guid_t efi_guid_cert_rsa2048 = EFI_CERT_RSA2048_GUID;
 const efi_guid_t efi_guid_cert_x509 = EFI_CERT_X509_GUID;
 const efi_guid_t efi_guid_cert_x509_sha256 = EFI_CERT_X509_SHA256_GUID;
 const efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;
 
-#if defined(CONFIG_EFI_SECURE_BOOT) || defined(CONFIG_EFI_CAPSULE_AUTHENTICATE)
 static u8 pkcs7_hdr[] = {
 	/* SEQUENCE */
 	0x30, 0x82, 0x05, 0xc7,
@@ -539,68 +537,6 @@ out:
 	return !revoked;
 }
 
-/**
- * efi_image_region_add() - add an entry of region
- * @regs:	Pointer to array of regions
- * @start:	Start address of region (included)
- * @end:	End address of region (excluded)
- * @nocheck:	flag against overlapped regions
- *
- * Take one entry of region [@start, @end[ and insert it into the list.
- *
- * * If @nocheck is false, the list will be sorted ascending by address.
- *   Overlapping entries will not be allowed.
- *
- * * If @nocheck is true, the list will be sorted ascending by sequence
- *   of adding the entries. Overlapping is allowed.
- *
- * Return:	status code
- */
-efi_status_t efi_image_region_add(struct efi_image_regions *regs,
-				  const void *start, const void *end,
-				  int nocheck)
-{
-	struct image_region *reg;
-	int i, j;
-
-	if (regs->num >= regs->max) {
-		EFI_PRINT("%s: no more room for regions\n", __func__);
-		return EFI_OUT_OF_RESOURCES;
-	}
-
-	if (end < start)
-		return EFI_INVALID_PARAMETER;
-
-	for (i = 0; i < regs->num; i++) {
-		reg = &regs->reg[i];
-		if (nocheck)
-			continue;
-
-		/* new data after registered region */
-		if (start >= reg->data + reg->size)
-			continue;
-
-		/* new data preceding registered region */
-		if (end <= reg->data) {
-			for (j = regs->num - 1; j >= i; j--)
-				memcpy(&regs->reg[j + 1], &regs->reg[j],
-				       sizeof(*reg));
-			break;
-		}
-
-		/* new data overlapping registered region */
-		EFI_PRINT("%s: new region already part of another\n", __func__);
-		return EFI_INVALID_PARAMETER;
-	}
-
-	reg = &regs->reg[i];
-	reg->data = start;
-	reg->size = end - start;
-	regs->num++;
-
-	return EFI_SUCCESS;
-}
-
 /**
  * efi_sigstore_free - free signature store
  * @sigstore:	Pointer to signature store structure
@@ -846,4 +782,3 @@ struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name)
 
 	return efi_build_signature_store(db, db_size);
 }
-#endif /* CONFIG_EFI_SECURE_BOOT || CONFIG_EFI_CAPSULE_AUTHENTICATE */
diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index b11ed91a74..83479dd142 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -24,6 +24,9 @@ struct efi_auth_var_name_type {
 	const enum efi_auth_var_type type;
 };
 
+const efi_guid_t efi_guid_image_security_database =
+		EFI_IMAGE_SECURITY_DATABASE_GUID;
+
 static const struct efi_auth_var_name_type name_type[] = {
 	{u"PK", &efi_global_variable_guid, EFI_AUTH_VAR_PK},
 	{u"KEK", &efi_global_variable_guid, EFI_AUTH_VAR_KEK},
-- 
2.17.1

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