Preload PGP keys from 'pubring.gpg', placed in certs/ of the kernel source
directory.
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
certs/Kconfig | 11 +++++++++++
certs/Makefile | 7 +++++++
certs/system_certificates.S | 18 ++++++++++++++++++
certs/system_keyring.c | 21 +++++++++++++++++++++
4 files changed, 57 insertions(+)
diff --git a/certs/Kconfig b/certs/Kconfig
index ae7f2e876a31..2f7fa68cd958 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -126,4 +126,15 @@ config SYSTEM_REVOCATION_KEYS
containing X.509 certificates to be included in the default blacklist
keyring.
+config PGP_PRELOAD_PUBLIC_KEYS
+ bool "Preload PGP public keys"
+ depends on SYSTEM_TRUSTED_KEYRING
+ select PGP_PRELOAD
+ default n
+ help
+ Load at boot time the PGP public keys from a reserved area (populated
+ with the content of 'certs/pubring.gpg' provided at kernel build
+ time), and add them to the built-in keyring. Invalid keys are ignored
+ and the loading continues.
+
endmenu
diff --git a/certs/Makefile b/certs/Makefile
index 279433783b10..c85e0ff560ca 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -22,6 +22,13 @@ $(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) $@
diff --git a/certs/system_certificates.S b/certs/system_certificates.S
index e1645e6f4d97..03b361bec758 100644
--- a/certs/system_certificates.S
+++ b/certs/system_certificates.S
@@ -47,3 +47,21 @@ module_cert_size:
#else
.long __module_cert_end - __module_cert_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
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 26a11b1dcd59..1612fb97a652 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -167,6 +167,27 @@ 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
/**
--
2.32.0
