Merge tag 'tpmdd-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

Pull tpm updates from Jarkko Sakkinen:

 - Restrict linking of keys to .ima and .evm keyrings based on
   digitalSignature attribute in the certificate

 - PowerVM: load machine owner keys into the .machine [1] keyring

 - PowerVM: load module signing keys into the secondary trusted keyring
   (keys blessed by the vendor)

 - tpm_tis_spi: half-duplex transfer mode

 - tpm_tis: retry corrupted transfers

 - Apply revocation list (.mokx) to an all system keyrings (e.g.
   .machine keyring)

Link: https://blogs.oracle.com/linux/post/the-machine-keyring [1]

* tag 'tpmdd-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  certs: Reference revocation list for all keyrings
  tpm/tpm_tis_synquacer: Use module_platform_driver macro to simplify the code
  tpm: remove redundant variable len
  tpm_tis: Resend command to recover from data transfer errors
  tpm_tis: Use responseRetry to recover from data transfer errors
  tpm_tis: Move CRC check to generic send routine
  tpm_tis_spi: Add hardware wait polling
  KEYS: Replace all non-returning strlcpy with strscpy
  integrity: PowerVM support for loading third party code signing keys
  integrity: PowerVM machine keyring enablement
  integrity: check whether imputed trust is enabled
  integrity: remove global variable from machine_keyring.c
  integrity: ignore keys failing CA restrictions on non-UEFI platform
  integrity: PowerVM support for loading CA keys on machine keyring
  integrity: Enforce digitalSignature usage in the ima and evm keyrings
  KEYS: DigitalSignature link restriction
  tpm_tis: Revert "tpm_tis: Disable interrupts on ThinkPad T490s"

1 files changed, 44 insertions, 0 deletions

diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c
index 276bdb627498..6b69ea40da23 100644
--- a/crypto/asymmetric_keys/restrict.c
+++ b/crypto/asymmetric_keys/restrict.c
@@ -148,6 +148,50 @@ int restrict_link_by_ca(struct key *dest_keyring,
 	return 0;
 }
 
+/**
+ * restrict_link_by_digsig - Restrict additions to a ring of digsig keys
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @trust_keyring: A ring of keys that can be used to vouch for the new cert.
+ *
+ * Check if the new certificate has digitalSignature usage set. If it is,
+ * then mark the new certificate as being ok to link. Afterwards verify
+ * the new certificate against the ones in the trust_keyring.
+ *
+ * Returns 0 if the new certificate was accepted, -ENOKEY if the
+ * certificate is not a digsig. -ENOPKG if the signature uses unsupported
+ * crypto, or some other error if there is a matching certificate but
+ * the signature check cannot be performed.
+ */
+int restrict_link_by_digsig(struct key *dest_keyring,
+			    const struct key_type *type,
+			    const union key_payload *payload,
+			    struct key *trust_keyring)
+{
+	const struct public_key *pkey;
+
+	if (type != &key_type_asymmetric)
+		return -EOPNOTSUPP;
+
+	pkey = payload->data[asym_crypto];
+
+	if (!pkey)
+		return -ENOPKG;
+
+	if (!test_bit(KEY_EFLAG_DIGITALSIG, &pkey->key_eflags))
+		return -ENOKEY;
+
+	if (test_bit(KEY_EFLAG_CA, &pkey->key_eflags))
+		return -ENOKEY;
+
+	if (test_bit(KEY_EFLAG_KEYCERTSIGN, &pkey->key_eflags))
+		return -ENOKEY;
+
+	return restrict_link_by_signature(dest_keyring, type, payload,
+					  trust_keyring);
+}
+
 static bool match_either_id(const struct asymmetric_key_id **pair,
 			    const struct asymmetric_key_id *single)
 {