select prin.name [Grantor], prin2.name [Grantee], perm.*
from sys.server_permissions perm
    left join sys.server_principals prin
        on perm.grantor_principal_id =prin.principal_id
    left join sys.server_principals prin2
        on perm.grantee_principal_id =prin2.principal_id

DECLARE  @_msparam_0 nvarchar(4000);

SET @_msparam_0 = '##MS_AgentSigningCertificate##';

SELECT ascii(prmssn.state) AS [PermissionState]
    , null AS [Code]
    , grantor_principal.name AS [Grantor]
    , prmssn.type AS [SqlCodePP]
    , CASE WHEN (prmssn.class=4 or prmssn.class=101 ) THEN
                CASE (SELECT oc.type FROM sys.server_principals AS oc WHERE oc.principal_id = prmssn.major_id)
                    WHEN 'R' THEN CASE prmssn.class
                    WHEN 4 THEN 201
                    ELSE 301
                END
            WHEN 'A' THEN 202
            ELSE
                CASE prmssn.class
                    WHEN 4 THEN 200
                    ELSE 101
                END
            END
        ELSE prmssn.class
        END AS [HiddenObjectClass]
FROM sys.server_permissions AS prmssn
    INNER JOIN sys.server_principals AS grantor_principal ON
        grantor_principal.principal_id = prmssn.grantor_principal_id
    INNER JOIN sys.server_principals AS grantee_principal ON
        grantee_principal.principal_id = prmssn.grantee_principal_id
WHERE (prmssn.class = 100)
    AND (grantee_principal.name = @_msparam_0);