[RFC][PATCH 12/12] KEYS: Introduce load_pgp_public_keyring()

[Roberto Sassu]

Preload PGP keys from 'pubring.gpg', placed in the kernel source directory.

Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
 certs/Kconfig          |  7 +++++++
 certs/Makefile         |  3 +++
 certs/system_keyring.c | 25 +++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/certs/Kconfig b/certs/Kconfig
index c94e93d8bccf..71be583e55a4 100644
--- a/certs/Kconfig
+++ b/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
diff --git a/certs/Makefile b/certs/Makefile
index 5d0999b9e21b..4338af9182e3 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -4,6 +4,9 @@
 #
 
 obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
+ifdef CONFIG_PGP_PRELOAD_PUBLIC_KEYS
+certs/system_keyring.o: pubring.gpg
+endif
 obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o
 ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
 obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index e4c59a5c7a9d..5dacb124133f 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -189,6 +189,31 @@ 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 u8 pgp_public_keys_end[];
+asm(".section .init.data,\"aw\"\n"
+	"pgp_public_keys:\n"
+	".incbin \"pubring.gpg\"\n"
+	"pgp_public_keys_end:");
+
+/*
+ * 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_end - pgp_public_keys,
+			     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
 
 /**
-- 
2.17.1