[RFC PATCH v3 04/13] keys: Add new verification type (VERIFYING_CLAVIS_SIGNATURE)

[Eric Snowberg]

> On Oct 17, 2024, at 1:20 PM, Jarkko Sakkinen <jarkko at kernel.org> wrote:
> 
> On Thu, 2024-10-17 at 09:55 -0600, Eric Snowberg wrote:
>> Add a new verification type called VERIFYING_CLAVIS_SIGNATURE.  This
>> new
>> usage will be used for validating keys added to the new clavis LSM
>> keyring.
>> This will be introduced in a follow-on patch.
>> 
>> Signed-off-by: Eric Snowberg <eric.snowberg at oracle.com>
>> ---
>>  crypto/asymmetric_keys/asymmetric_type.c | 1 +
>>  crypto/asymmetric_keys/pkcs7_verify.c    | 1 +
>>  include/linux/verification.h             | 2 ++
>>  3 files changed, 4 insertions(+)
>> 
>> diff --git a/crypto/asymmetric_keys/asymmetric_type.c
>> b/crypto/asymmetric_keys/asymmetric_type.c
>> index 43af5fa510c0..d7bf95c77f4a 100644
>> --- a/crypto/asymmetric_keys/asymmetric_type.c
>> +++ b/crypto/asymmetric_keys/asymmetric_type.c
>> @@ -25,6 +25,7 @@ const char *const
>> key_being_used_for[NR__KEY_BEING_USED_FOR] = {
>>   [VERIFYING_KEY_SIGNATURE] = "key sig",
>>   [VERIFYING_KEY_SELF_SIGNATURE] = "key self sig",
>>   [VERIFYING_UNSPECIFIED_SIGNATURE] = "unspec sig",
>> + [VERIFYING_CLAVIS_SIGNATURE] = "clavis sig",
>>  };
>>  EXPORT_SYMBOL_GPL(key_being_used_for);
>>  
>> diff --git a/crypto/asymmetric_keys/pkcs7_verify.c
>> b/crypto/asymmetric_keys/pkcs7_verify.c
>> index f0d4ff3c20a8..1dc80e68ce96 100644
>> --- a/crypto/asymmetric_keys/pkcs7_verify.c
>> +++ b/crypto/asymmetric_keys/pkcs7_verify.c
>> @@ -428,6 +428,7 @@ int pkcs7_verify(struct pkcs7_message *pkcs7,
>>   }
>>   /* Authattr presence checked in parser */
>>   break;
>> + case VERIFYING_CLAVIS_SIGNATURE:
>>   case VERIFYING_UNSPECIFIED_SIGNATURE:
>>   if (pkcs7->data_type != OID_data) {
>>   pr_warn("Invalid unspecified sig (not pkcs7-
>> data)\n");
>> diff --git a/include/linux/verification.h
>> b/include/linux/verification.h
>> index cb2d47f28091..02d2d70e2324 100644
>> --- a/include/linux/verification.h
>> +++ b/include/linux/verification.h
>> @@ -36,6 +36,8 @@ enum key_being_used_for {
>>   VERIFYING_KEY_SIGNATURE,
>>   VERIFYING_KEY_SELF_SIGNATURE,
>>   VERIFYING_UNSPECIFIED_SIGNATURE,
>> + /* Add new entries above, keep VERIFYING_CLAVIS_SIGNATURE at
>> the end. */
>> + VERIFYING_CLAVIS_SIGNATURE,
>>   NR__KEY_BEING_USED_FOR
>>  };
>>  extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
> 
> This looks as good as it can get. Just wondering that does this Clavis
> thing connect with the TPM2 asymmetric keys that I've been working on?
> I.e. can they be used in tandem. I should really update that patch set
> (latest from April).

With some changes, I think they could be used in tandem.  If I'm looking at 
the correct series, tpm2_key_rsa_describe would need to be changed to 
return a unique identifier, instead of "TPM2/RSA".  This identifier could be 
used instead of the skid when creating a Clavis ACL.  There would probably 
also need to be a new system kernel keyring containing these TPM keys. 
Similar to the builtin, secondary, machine, etc.