diff mbox series

certs: Reference revocation list for all keyrings

Message ID 20230117171506.3888602-1-eric.snowberg@oracle.com
State New
Headers
Series certs: Reference revocation list for all keyrings |

Commit Message

Eric Snowberg Jan. 17, 2023, 5:15 p.m. UTC 
  Systems booted with shim have a Forbidden Signature Database called mokx.
During boot, hashes and certs contained within the mokx are loaded into the
blacklist keyring.  When calling verify_pkcs7_message_sig the contents of
the blacklist keyring (or revocation list) are referenced when validating
keys on the platform keyring. Currently, when validating against the
secondary or builtin keyrings, the revocation list is not referenced.  Move
up the check to allow the revocation list to be used with all keyrings,
including the secondary and builtin, allowing the system owner to take
corrective action should a vulnerability be found within keys contained
within either keyring.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
 certs/system_keyring.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Jarkko Sakkinen Jan. 21, 2023, 3:20 a.m. UTC | #1 
On Tue, Jan 17, 2023 at 12:15:06PM -0500, Eric Snowberg wrote:
> Systems booted with shim have a Forbidden Signature Database called mokx.
> During boot, hashes and certs contained within the mokx are loaded into the
> blacklist keyring.  When calling verify_pkcs7_message_sig the contents of
> the blacklist keyring (or revocation list) are referenced when validating
> keys on the platform keyring. Currently, when validating against the
> secondary or builtin keyrings, the revocation list is not referenced.  Move
> up the check to allow the revocation list to be used with all keyrings,
> including the secondary and builtin, allowing the system owner to take
> corrective action should a vulnerability be found within keys contained
> within either keyring.
> 
> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> ---
>  certs/system_keyring.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> index 5042cc54fa5e..865a0510fdeb 100644
> --- a/certs/system_keyring.c
> +++ b/certs/system_keyring.c
> @@ -243,6 +243,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
>  	if (ret < 0)
>  		goto error;
>  
> +	ret = is_key_on_revocation_list(pkcs7);
> +	if (ret != -ENOKEY) {
> +		pr_devel("PKCS#7 key is on revocation list\n");
> +		goto error;
> +	}
> +
>  	if (!trusted_keys) {
>  		trusted_keys = builtin_trusted_keys;
>  	} else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) {
> @@ -262,12 +268,6 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
>  			pr_devel("PKCS#7 platform keyring is not available\n");
>  			goto error;
>  		}
> -
> -		ret = is_key_on_revocation_list(pkcs7);
> -		if (ret != -ENOKEY) {
> -			pr_devel("PKCS#7 platform key is on revocation list\n");
> -			goto error;
> -		}
>  	}
>  	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
>  	if (ret < 0) {
> -- 
> 2.27.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko
Jarkko Sakkinen Jan. 21, 2023, 3:21 a.m. UTC | #2 
On Sat, Jan 21, 2023 at 03:20:46AM +0000, Jarkko Sakkinen wrote:
> On Tue, Jan 17, 2023 at 12:15:06PM -0500, Eric Snowberg wrote:
> > Systems booted with shim have a Forbidden Signature Database called mokx.
> > During boot, hashes and certs contained within the mokx are loaded into the
> > blacklist keyring.  When calling verify_pkcs7_message_sig the contents of
> > the blacklist keyring (or revocation list) are referenced when validating
> > keys on the platform keyring. Currently, when validating against the
> > secondary or builtin keyrings, the revocation list is not referenced.  Move
> > up the check to allow the revocation list to be used with all keyrings,
> > including the secondary and builtin, allowing the system owner to take
> > corrective action should a vulnerability be found within keys contained
> > within either keyring.
> > 
> > Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> > ---
> >  certs/system_keyring.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> > 
> > diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> > index 5042cc54fa5e..865a0510fdeb 100644
> > --- a/certs/system_keyring.c
> > +++ b/certs/system_keyring.c
> > @@ -243,6 +243,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
> >  	if (ret < 0)
> >  		goto error;
> >  
> > +	ret = is_key_on_revocation_list(pkcs7);
> > +	if (ret != -ENOKEY) {
> > +		pr_devel("PKCS#7 key is on revocation list\n");
> > +		goto error;
> > +	}
> > +
> >  	if (!trusted_keys) {
> >  		trusted_keys = builtin_trusted_keys;
> >  	} else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) {
> > @@ -262,12 +268,6 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
> >  			pr_devel("PKCS#7 platform keyring is not available\n");
> >  			goto error;
> >  		}
> > -
> > -		ret = is_key_on_revocation_list(pkcs7);
> > -		if (ret != -ENOKEY) {
> > -			pr_devel("PKCS#7 platform key is on revocation list\n");
> > -			goto error;
> > -		}
> >  	}
> >  	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
> >  	if (ret < 0) {
> > -- 
> > 2.27.0
> > 
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

Should I pick this?

BR, Jarkko
Mimi Zohar July 14, 2023, 10:11 p.m. UTC | #3 
On Tue, 2023-01-17 at 12:15 -0500, Eric Snowberg wrote:
> Systems booted with shim have a Forbidden Signature Database called mokx.
> During boot, hashes and certs contained within the mokx are loaded into the
> blacklist keyring.  When calling verify_pkcs7_message_sig the contents of
> the blacklist keyring (or revocation list) are referenced when validating
> keys on the platform keyring. Currently, when validating against the
> secondary or builtin keyrings, the revocation list is not referenced.  Move
> up the check to allow the revocation list to be used with all keyrings,
> including the secondary and builtin, allowing the system owner to take
> corrective action should a vulnerability be found within keys contained
> within either keyring.
> 
> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
diff mbox series

Patch

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 5042cc54fa5e..865a0510fdeb 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -243,6 +243,12 @@  int verify_pkcs7_message_sig(const void *data, size_t len,
 	if (ret < 0)
 		goto error;
 
+	ret = is_key_on_revocation_list(pkcs7);
+	if (ret != -ENOKEY) {
+		pr_devel("PKCS#7 key is on revocation list\n");
+		goto error;
+	}
+
 	if (!trusted_keys) {
 		trusted_keys = builtin_trusted_keys;
 	} else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) {
@@ -262,12 +268,6 @@  int verify_pkcs7_message_sig(const void *data, size_t len,
 			pr_devel("PKCS#7 platform keyring is not available\n");
 			goto error;
 		}
-
-		ret = is_key_on_revocation_list(pkcs7);
-		if (ret != -ENOKEY) {
-			pr_devel("PKCS#7 platform key is on revocation list\n");
-			goto error;
-		}
 	}
 	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
 	if (ret < 0) {