ima: Support platform keyring for kernel appraisal

On secure boot enabled systems, the bootloader verifies the kernel
image and possibly the initramfs signatures based on a set of keys. A
soft reboot(kexec) of the system, with the same kernel image and
initramfs, requires access to the original keys to verify the
signatures.

This patch allows IMA-appraisal access to those original keys, now
loaded on the platform keyring, needed for verifying the kernel image
and initramfs signatures.

[zohar@linux.ibm.com: only use platform keyring if it's enabled (Thiago)]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Nayna Jain 2018-12-09 01:57:05 +05:30 committed by Mimi Zohar
parent 386b49f51d
commit d7cecb676d
1 changed files with 12 additions and 2 deletions

View File

@ -289,12 +289,22 @@ int ima_appraise_measurement(enum ima_hooks func,
case EVM_IMA_XATTR_DIGSIG:
set_bit(IMA_DIGSIG, &iint->atomic_flags);
rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
(const char *)xattr_value, rc,
(const char *)xattr_value,
xattr_len,
iint->ima_hash->digest,
iint->ima_hash->length);
if (rc == -EOPNOTSUPP) {
status = INTEGRITY_UNKNOWN;
} else if (rc) {
break;
}
if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
func == KEXEC_KERNEL_CHECK)
rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
(const char *)xattr_value,
xattr_len,
iint->ima_hash->digest,
iint->ima_hash->length);
if (rc) {
cause = "invalid-signature";
status = INTEGRITY_FAIL;
} else {