Re: [PATCH 4/6] integrity: check whether imputed trust is enabled

2023-08-02 Thread Mimi Zohar
On Fri, 2023-07-14 at 11:34 -0400, Nayna Jain wrote:
> trust_moklist() is specific to UEFI enabled systems. Other platforms
> rely only on the Kconfig.
> 
> Define a generic wrapper named imputed_trust_enabled().
> 
> Signed-off-by: Nayna Jain 

Reviewed-off-by: Mimi Zohar 



[PATCH 4/6] integrity: check whether imputed trust is enabled

2023-07-14 Thread Nayna Jain
trust_moklist() is specific to UEFI enabled systems. Other platforms
rely only on the Kconfig.

Define a generic wrapper named imputed_trust_enabled().

Signed-off-by: Nayna Jain 
---
 security/integrity/digsig.c   |  2 +-
 security/integrity/integrity.h|  5 +++--
 .../integrity/platform_certs/keyring_handler.c|  2 +-
 .../integrity/platform_certs/machine_keyring.c| 15 ++-
 4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 6f31ffe23c48..48d505cacd81 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -113,7 +113,7 @@ 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_MACHINE && trust_moklist())
+   if (id == INTEGRITY_KEYRING_MACHINE && imputed_trust_enabled())
set_machine_trusted_keys(keyring[id]);
if (id == INTEGRITY_KEYRING_IMA)
load_module_cert(keyring[id]);
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 7167a6e99bdc..d7553c93f5c0 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -320,13 +320,14 @@ static inline void __init add_to_platform_keyring(const 
char *source,
 
 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
 void __init add_to_machine_keyring(const char *source, const void *data, 
size_t len);
-bool __init trust_moklist(void);
+bool __init imputed_trust_enabled(void);
 #else
 static inline void __init add_to_machine_keyring(const char *source,
  const void *data, size_t len)
 {
 }
-static inline bool __init trust_moklist(void)
+
+static inline bool __init imputed_trust_enabled(void)
 {
return false;
 }
diff --git a/security/integrity/platform_certs/keyring_handler.c 
b/security/integrity/platform_certs/keyring_handler.c
index 1649d047e3b8..b3e5df136e50 100644
--- a/security/integrity/platform_certs/keyring_handler.c
+++ b/security/integrity/platform_certs/keyring_handler.c
@@ -61,7 +61,7 @@ __init efi_element_handler_t get_handler_for_db(const 
efi_guid_t *sig_type)
 __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
 {
if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) {
-   if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && 
trust_moklist())
+   if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && 
imputed_trust_enabled())
return add_to_machine_keyring;
else
return add_to_platform_keyring;
diff --git a/security/integrity/platform_certs/machine_keyring.c 
b/security/integrity/platform_certs/machine_keyring.c
index 9482e16cb2ca..58cd72b193e6 100644
--- a/security/integrity/platform_certs/machine_keyring.c
+++ b/security/integrity/platform_certs/machine_keyring.c
@@ -60,7 +60,7 @@ static __init bool uefi_check_trust_mok_keys(void)
return false;
 }
 
-bool __init trust_moklist(void)
+static bool __init trust_moklist(void)
 {
static bool initialized;
static bool trust_mok;
@@ -75,3 +75,16 @@ bool __init trust_moklist(void)
 
return trust_mok;
 }
+
+/*
+ * Provides platform specific check for trusting imputed keys before loading
+ * on .machine keyring. UEFI systems enable this trust based on a variable,
+ * and for other platforms, it is always enabled.
+ */
+bool __init imputed_trust_enabled(void)
+{
+   if (efi_enabled(EFI_BOOT))
+   return trust_moklist();
+
+   return true;
+}
-- 
2.31.1