diff mbox series

[v7,11/17] KEYS: Introduce link restriction for machine keys

Message ID 20211116001545.2639333-12-eric.snowberg@oracle.com (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show
Series Enroll kernel keys thru MOK | expand

Commit Message

Eric Snowberg Nov. 16, 2021, 12:15 a.m. UTC
Introduce a new link restriction that includes the trusted builtin,
secondary and machine keys. The restriction is based on the key to be
added being vouched for by a key in any of these three keyrings.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v3: Initial version
v4: moved code under CONFIG_INTEGRITY_MOK_KEYRING
v5: Rename to machine keyring
v6: Change subject name (suggested by Mimi)
    Rename restrict_link_by_builtin_secondary_and_ca_trusted
      to restrict_link_by_builtin_secondary_and_machine (suggested by
      Mimi)
v7: Unmodified from v6
---
 certs/system_keyring.c        | 23 +++++++++++++++++++++++
 include/keys/system_keyring.h |  6 ++++++
 2 files changed, 29 insertions(+)

Comments

Mimi Zohar Nov. 19, 2021, 12:20 a.m. UTC | #1
Hi Eric,

On Mon, 2021-11-15 at 19:15 -0500, Eric Snowberg wrote:
> Introduce a new link restriction that includes the trusted builtin,
> secondary and machine keys. The restriction is based on the key to be
> added being vouched for by a key in any of these three keyrings.
> 
> Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> ---
> v3: Initial version
> v4: moved code under CONFIG_INTEGRITY_MOK_KEYRING
> v5: Rename to machine keyring
> v6: Change subject name (suggested by Mimi)
>     Rename restrict_link_by_builtin_secondary_and_ca_trusted
>       to restrict_link_by_builtin_secondary_and_machine (suggested by
>       Mimi)
> v7: Unmodified from v6
> ---
>  certs/system_keyring.c        | 23 +++++++++++++++++++++++
>  include/keys/system_keyring.h |  6 ++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> index bc7e44fc82c2..71a00add9805 100644
> --- a/certs/system_keyring.c
> +++ b/certs/system_keyring.c
> @@ -99,6 +99,29 @@ void __init set_machine_trusted_keys(struct key *keyring)
>  {
>  	machine_trusted_keys = keyring;
>  }
> +
> +/**

This begins the start of kernel doc. 

> + * restrict_link_by_builtin_secondary_and_machine

Missing are the parameter defintions.  Please refer to
Documentation/doc-guide/kernel-doc.rst for details.

Mimi

> + *
> + * Restrict the addition of keys into a keyring based on the key-to-be-added
> + * being vouched for by a key in either the built-in, the secondary, or
> + * the machine keyrings.
> + */
> +int restrict_link_by_builtin_secondary_and_machine(
> +	struct key *dest_keyring,
> +	const struct key_type *type,
> +	const union key_payload *payload,
> +	struct key *restrict_key)
> +{
> +	if (machine_trusted_keys && type == &key_type_keyring &&
> +	    dest_keyring == secondary_trusted_keys &&
> +	    payload == &machine_trusted_keys->payload)
> +		/* Allow the machine keyring to be added to the secondary */
> +		return 0;
> +
> +	return restrict_link_by_builtin_and_secondary_trusted(dest_keyring, type,
> +							      payload, restrict_key);
> +}
>  #endif
>  
>  /*
> diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
> index 98c9b10cdc17..2419a735420f 100644
> --- a/include/keys/system_keyring.h
> +++ b/include/keys/system_keyring.h
> @@ -39,8 +39,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
>  #endif
>  
>  #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
> +extern int restrict_link_by_builtin_secondary_and_machine(
> +	struct key *dest_keyring,
> +	const struct key_type *type,
> +	const union key_payload *payload,
> +	struct key *restrict_key);
>  extern void __init set_machine_trusted_keys(struct key *keyring);
>  #else
> +#define restrict_link_by_builtin_secondary_and_machine restrict_link_by_builtin_trusted
>  static inline void __init set_machine_trusted_keys(struct key *keyring)
>  {
>  }
Eric Snowberg Nov. 19, 2021, 2:50 a.m. UTC | #2
> On Nov 18, 2021, at 5:20 PM, Mimi Zohar <zohar@linux.ibm.com> wrote:
> 
> Hi Eric,
> 
> On Mon, 2021-11-15 at 19:15 -0500, Eric Snowberg wrote:
>> Introduce a new link restriction that includes the trusted builtin,
>> secondary and machine keys. The restriction is based on the key to be
>> added being vouched for by a key in any of these three keyrings.
>> 
>> Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
>> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
>> ---
>> v3: Initial version
>> v4: moved code under CONFIG_INTEGRITY_MOK_KEYRING
>> v5: Rename to machine keyring
>> v6: Change subject name (suggested by Mimi)
>>    Rename restrict_link_by_builtin_secondary_and_ca_trusted
>>      to restrict_link_by_builtin_secondary_and_machine (suggested by
>>      Mimi)
>> v7: Unmodified from v6
>> ---
>> certs/system_keyring.c        | 23 +++++++++++++++++++++++
>> include/keys/system_keyring.h |  6 ++++++
>> 2 files changed, 29 insertions(+)
>> 
>> diff --git a/certs/system_keyring.c b/certs/system_keyring.c
>> index bc7e44fc82c2..71a00add9805 100644
>> --- a/certs/system_keyring.c
>> +++ b/certs/system_keyring.c
>> @@ -99,6 +99,29 @@ void __init set_machine_trusted_keys(struct key *keyring)
>> {
>> 	machine_trusted_keys = keyring;
>> }
>> +
>> +/**
> 
> This begins the start of kernel doc. 
> 
>> + * restrict_link_by_builtin_secondary_and_machine
> 
> Missing are the parameter defintions.  Please refer to
> Documentation/doc-guide/kernel-doc.rst for details.

I’ll add this in the next round, thanks.
diff mbox series

Patch

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index bc7e44fc82c2..71a00add9805 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -99,6 +99,29 @@  void __init set_machine_trusted_keys(struct key *keyring)
 {
 	machine_trusted_keys = keyring;
 }
+
+/**
+ * restrict_link_by_builtin_secondary_and_machine
+ *
+ * Restrict the addition of keys into a keyring based on the key-to-be-added
+ * being vouched for by a key in either the built-in, the secondary, or
+ * the machine keyrings.
+ */
+int restrict_link_by_builtin_secondary_and_machine(
+	struct key *dest_keyring,
+	const struct key_type *type,
+	const union key_payload *payload,
+	struct key *restrict_key)
+{
+	if (machine_trusted_keys && type == &key_type_keyring &&
+	    dest_keyring == secondary_trusted_keys &&
+	    payload == &machine_trusted_keys->payload)
+		/* Allow the machine keyring to be added to the secondary */
+		return 0;
+
+	return restrict_link_by_builtin_and_secondary_trusted(dest_keyring, type,
+							      payload, restrict_key);
+}
 #endif
 
 /*
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index 98c9b10cdc17..2419a735420f 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -39,8 +39,14 @@  extern int restrict_link_by_builtin_and_secondary_trusted(
 #endif
 
 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
+extern int restrict_link_by_builtin_secondary_and_machine(
+	struct key *dest_keyring,
+	const struct key_type *type,
+	const union key_payload *payload,
+	struct key *restrict_key);
 extern void __init set_machine_trusted_keys(struct key *keyring);
 #else
+#define restrict_link_by_builtin_secondary_and_machine restrict_link_by_builtin_trusted
 static inline void __init set_machine_trusted_keys(struct key *keyring)
 {
 }