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Commit 76a2b524 authored by Brijesh Singh's avatar Brijesh Singh
Browse files

crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command 



The SEV_PDH_CERT_EXPORT command can be used to export the PDH and its
certificate chain. The command is defined in SEV spec section 5.10.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-crypto@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Acked-by: default avatarGary R Hook <gary.hook@amd.com>
parent 7360e4b1

drivers/crypto/ccp/psp-dev.c

+97 −0
Original line number Diff line number Diff line
@@ -443,6 +443,100 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp) 
	return ret;

}



static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp)

{

	struct sev_user_data_pdh_cert_export input;

	void *pdh_blob = NULL, *cert_blob = NULL;

	struct sev_data_pdh_cert_export *data;

	int ret;



	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))

		return -EFAULT;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	/* Userspace wants to query the certificate length. */

	if (!input.pdh_cert_address ||

	    !input.pdh_cert_len ||

	    !input.cert_chain_address)

		goto cmd;



	/* Allocate a physically contiguous buffer to store the PDH blob. */

	if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||

	    !access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len)) {

		ret = -EFAULT;

		goto e_free;

	}



	/* Allocate a physically contiguous buffer to store the cert chain blob. */

	if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||

	    !access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len)) {

		ret = -EFAULT;

		goto e_free;

	}



	pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);

	if (!pdh_blob) {

		ret = -ENOMEM;

		goto e_free;

	}



	data->pdh_cert_address = __psp_pa(pdh_blob);

	data->pdh_cert_len = input.pdh_cert_len;



	cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);

	if (!cert_blob) {

		ret = -ENOMEM;

		goto e_free_pdh;

	}



	data->cert_chain_address = __psp_pa(cert_blob);

	data->cert_chain_len = input.cert_chain_len;



cmd:

	/* If platform is not in INIT state then transition it to INIT. */

	if (psp_master->sev_state != SEV_STATE_INIT) {

		ret = __sev_platform_init_locked(&argp->error);

		if (ret)

			goto e_free_cert;

	}



	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);



	/* If we query the length, FW responded with expected data. */

	input.cert_chain_len = data->cert_chain_len;

	input.pdh_cert_len = data->pdh_cert_len;



	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {

		ret = -EFAULT;

		goto e_free_cert;

	}



	if (pdh_blob) {

		if (copy_to_user((void __user *)input.pdh_cert_address,

				 pdh_blob, input.pdh_cert_len)) {

			ret = -EFAULT;

			goto e_free_cert;

		}

	}



	if (cert_blob) {

		if (copy_to_user((void __user *)input.cert_chain_address,

				 cert_blob, input.cert_chain_len))

			ret = -EFAULT;

	}



e_free_cert:

	kfree(cert_blob);

e_free_pdh:

	kfree(pdh_blob);

e_free:

	kfree(data);

	return ret;

}



static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)

{

	void __user *argp = (void __user *)arg;
@@ -483,6 +577,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) 
	case SEV_PEK_CERT_IMPORT:

		ret = sev_ioctl_do_pek_import(&input);

		break;

	case SEV_PDH_CERT_EXPORT:

		ret = sev_ioctl_do_pdh_export(&input);

		break;

	default:

		ret = -EINVAL;

		goto out;