Commit d7cecb67 authored Dec 09, 2018 by Nayna Jain Committed by Mimi Zohar Dec 12, 2018

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>

parent 386b49f5

security/integrity/ima/ima_appraise.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -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 {

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