KEYS: Introduce load_pgp_public_keyring()

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

-------------------------------------------------

Preload PGP keys from 'pubring.gpg', placed in certs/ of the kernel source
directory.
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NTianxing Zhang <zhangtianxing3@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

certs/Kconfig

@@ -83,4 +83,11 @@ config SYSTEM_BLACKLIST_HASH_LIST
 	  wrapper to incorporate the list into the kernel.  Each <hash> should
 	  be a string of hex digits.
 
+config PGP_PRELOAD_PUBLIC_KEYS
+	bool "Preload PGP public keys"
+	select PGP_PRELOAD
+	default n
+	help
+	  Provide a keyring of PGP public keys.
+
 endmenu

certs/Makefile

@@ -21,6 +21,13 @@ $(obj)/system_certificates.o: $(obj)/x509_certificate_list
 # Cope with signing_key.x509 existing in $(srctree) not $(objtree)
 AFLAGS_system_certificates.o := -I$(srctree)
 
+ifdef CONFIG_PGP_PRELOAD_PUBLIC_KEYS
+ifeq ($(shell ls $(srctree)/certs/pubring.gpg 2> /dev/null), $(srctree)/certs/pubring.gpg)
+AFLAGS_system_certificates.o += -DHAVE_PUBRING_GPG
+$(obj)/system_certificates.o: $(srctree)/certs/pubring.gpg
+endif
+endif
+
 quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
       cmd_extract_certs  = scripts/extract-cert $(2) $@
 

certs/system_certificates.S

@@ -35,3 +35,21 @@ system_certificate_list_size:
 #else
 	.long __cert_list_end - __cert_list_start
 #endif
+
+	.align 8
+	.globl pgp_public_keys
+pgp_public_keys:
+__pgp_key_list_start:
+#ifdef HAVE_PUBRING_GPG
+	.incbin "certs/pubring.gpg"
+#endif
+__pgp_key_list_end:
+
+	.align 8
+	.globl pgp_public_keys_size
+pgp_public_keys_size:
+#ifdef CONFIG_64BIT
+	.quad __pgp_key_list_end - __pgp_key_list_start
+#else
+	.long __pgp_key_list_end - __pgp_key_list_start
+#endif

certs/system_keyring.c

@@ -11,6 +11,7 @@
 #include <linux/cred.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/pgp.h>
 #include <linux/verification.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
@@ -187,6 +188,27 @@ static __init int load_system_certificate_list(void)
 }
 late_initcall(load_system_certificate_list);
 
+#ifdef CONFIG_PGP_PRELOAD_PUBLIC_KEYS
+extern __initconst const u8 pgp_public_keys[];
+extern __initconst const unsigned long pgp_public_keys_size;
+
+/*
+ * Load a list of PGP keys.
+ */
+static __init int load_pgp_public_keyring(void)
+{
+	pr_notice("Load PGP public keys\n");
+
+	if (preload_pgp_keys(pgp_public_keys,
+			     pgp_public_keys_size,
+			     builtin_trusted_keys) < 0)
+		pr_err("Can't load PGP public keys\n");
+
+	return 0;
+}
+late_initcall(load_pgp_public_keyring);
+#endif /* CONFIG_PGP_PRELOAD_PUBLIC_KEYS */
+
 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
 
 /**