Introducing the following GRUB commands to manage certificate/binary
hashes.
1. append_list_dbx:
Show the list of distrusted certificates and binary/certificate
hashes from the dbx list.
2. append_add_db_hash:
Add the trusted binary hash to the db list.
3. append_add_dbx_hash:
Add the distrusted certificate/binary hash to the dbx list.
Note that if signature verification (check_appended_signatures) is set to yes,
the append_add_db_hash and append_add_dbx_hash commands only accept the file
‘hash_file’ that is signed with an appended signature.
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Tested-by: Sridhar Markonda <sridharm@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Introducing the following GRUB commands to manage the certificates.
1. append_list_db:
Show the list of trusted certificates from the db list
2. append_add_db_cert:
Add the trusted certificate to the db list
3. append_add_dbx_cert:
Add the distrusted certificate to the dbx list
4. append_verify:
Verify the signed file using db list
Note that if signature verification (check_appended_signatures) is set to yes,
the append_add_db_cert and append_add_dbx_cert commands only accept the file
‘X509_certificate’ that is signed with an appended signature.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Tested-by: Sridhar Markonda <sridharm@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signature verification: verify the kernel against lists of hashes that are
either in dbx or db list. If it is not in the dbx list then the trusted keys
from the db list are used to verify the signature.
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
If secure boot is enabled with static key management mode, the trusted
certificates will be extracted from the GRUB ELF Note and added to db list.
If secure boot is enabled with dynamic key management mode, the trusted
certificates and certificate/binary hash will be extracted from the PKS
and added to db list. The distrusted certificates, certificate/binary hash
are read from the PKS and added to dbx list. Both dbx and db lists usage is
added by a subsequent patch.
Note:
- If db does not exist in the PKS storage, then read the static keys as a db
default keys from the GRUB ELF Note and add them into the db list.
- If the certificate or the certificate hash exists in the dbx list, then do not
add that certificate/certificate hash to the db list.
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Introducing the appended signature key management environment variable. It is
automatically set to either "static" or "dynamic" based on the Platform KeyStore.
"static": Enforce static key management signature verification. This is the
default. When the GRUB is locked down, user cannot change the value
by setting the appendedsig_key_mgmt variable back to "dynamic".
"dynamic": Enforce dynamic key management signature verification. When the GRUB
is locked down, user cannot change the value by setting the
appendedsig_key_mgmt variable back to "static".
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Building on the parsers and the ability to embed X.509 certificates, as well
as the existing gcrypt functionality, add a module for verifying appended
signatures.
This includes a signature verifier that requires that the Linux kernel and
GRUB modules have appended signatures for verification.
Signature verification must be enabled by setting check_appended_signatures.
If secure boot is enabled with enforce mode when the appendedsig module is
loaded, signature verification will be enabled, and trusted keys will be
extracted from the GRUB ELF Note and stored in the db and locked automatically.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This code allows us to parse:
- X.509 certificates: at least enough to verify the signatures on the PKCS#7
messages. We expect that the certificates embedded in GRUB will be leaf
certificates, not CA certificates. The parser enforces this.
- X.509 certificates support the Extended Key Usage extension and handle it by
verifying that the certificate has a Code Signing usage.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> # EKU support
Reported-by: Michal Suchanek <msuchanek@suse.com> # key usage issue
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This code allows us to parse:
- PKCS#7 signed data messages. Only a single signer info is supported, which
is all that the Linux sign-file utility supports creating out-of-the-box.
Only RSA, SHA-256 and SHA-512 are supported. Any certificate embedded in
the PKCS#7 message will be ignored.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This code allows us to parse ASN1 node and allocating memory to store it.
It will work for anything where the size libtasn1 returns is right:
- Integers
- Octet strings
- DER encoding of other structures
It will _not_ work for things where libtasn1 size requires adjustment:
- Strings that require an extra NULL byte at the end
- Bit strings because libtasn1 returns the length in bits, not bytes.
If the function returns a non-NULL value, the caller must free it.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Sudhakar Kuppusamy