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ima: enable loading of build time generated key on .ima keyring

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The kernel currently only loads the kernel module signing key onto the
builtin trusted keyring. Load the module signing key onto the IMA keyring
as well.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Nayna Jain 2021-04-09 10:35:07 -04:00 committed by Mimi Zohar
parent 0165f4ca22
commit 6cbdfb3d91
4 changed files with 61 additions and 11 deletions
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13
certs/system_certificates.S
View File

@ -8,9 +8,11 @@
.globl system_certificate_list
system_certificate_list:
__cert_list_start:
#ifdef CONFIG_MODULE_SIG
__module_cert_start:
#if defined(CONFIG_MODULE_SIG) || defined(CONFIG_IMA_APPRAISE_MODSIG)
.incbin "certs/signing_key.x509"
#endif
__module_cert_end:
.incbin "certs/x509_certificate_list"
__cert_list_end:
@ -35,3 +37,12 @@ system_certificate_list_size:
#else
.long __cert_list_end - __cert_list_start
#endif
.align 8
.globl module_cert_size
module_cert_size:
#ifdef CONFIG_64BIT
.quad __module_cert_end - __module_cert_start
#else
.long __module_cert_end - __module_cert_start
#endif

50
certs/system_keyring.c
View File

@ -27,6 +27,7 @@ static struct key *platform_trusted_keys;
extern __initconst const u8 system_certificate_list[];
extern __initconst const unsigned long system_certificate_list_size;
extern __initconst const unsigned long module_cert_size;
/**
* restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
@ -132,19 +133,11 @@ static __init int system_trusted_keyring_init(void)
*/
device_initcall(system_trusted_keyring_init);
/*
* Load the compiled-in list of X.509 certificates.
*/
static __init int load_system_certificate_list(void)
static __init int load_cert(const u8 *p, const u8 *end, struct key *keyring)
{
key_ref_t key;
const u8 *p, *end;
size_t plen;
pr_notice("Loading compiled-in X.509 certificates\n");
p = system_certificate_list;
end = p + system_certificate_list_size;
while (p < end) {
/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
* than 256 bytes in size.
@ -159,7 +152,7 @@ static __init int load_system_certificate_list(void)
if (plen > end - p)
goto dodgy_cert;
key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1),
key = key_create_or_update(make_key_ref(keyring, 1),
"asymmetric",
NULL,
p,
@ -186,6 +179,43 @@ dodgy_cert:
pr_err("Problem parsing in-kernel X.509 certificate list\n");
return 0;
}
__init int load_module_cert(struct key *keyring)
{
const u8 *p, *end;
if (!IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG))
return 0;
pr_notice("Loading compiled-in module X.509 certificates\n");
p = system_certificate_list;
end = p + module_cert_size;
return load_cert(p, end, keyring);
}
/*
* Load the compiled-in list of X.509 certificates.
*/
static __init int load_system_certificate_list(void)
{
const u8 *p, *end;
unsigned long size;
pr_notice("Loading compiled-in X.509 certificates\n");
#ifdef CONFIG_MODULE_SIG
p = system_certificate_list;
size = system_certificate_list_size;
#else
p = system_certificate_list + module_cert_size;
size = system_certificate_list_size - module_cert_size;
#endif
end = p + size;
return load_cert(p, end, builtin_trusted_keys);
}
late_initcall(load_system_certificate_list);
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION

7
include/keys/system_keyring.h
View File

@ -16,9 +16,16 @@ extern int restrict_link_by_builtin_trusted(struct key *keyring,
const struct key_type *type,
const union key_payload *payload,
struct key *restriction_key);
extern __init int load_module_cert(struct key *keyring);
#else
#define restrict_link_by_builtin_trusted restrict_link_reject
static inline __init int load_module_cert(struct key *keyring)
{
return 0;
}
#endif
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING

2
security/integrity/digsig.c
View File

@ -111,6 +111,8 @@ static int __init __integrity_init_keyring(const unsigned int id,
} else {
if (id == INTEGRITY_KEYRING_PLATFORM)
set_platform_trusted_keys(keyring[id]);
if (id == INTEGRITY_KEYRING_IMA)
load_module_cert(keyring[id]);
}
return err;