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@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Gary Hook <gary.hook@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
Changes since v6:
* when sev_do_cmd() and sev_platform_shutdown() fails then propogate
the error status code from sev_do_cmd() because it can give us
much better reason for the failure.
drivers/crypto/ccp/psp-dev.c | 110 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 108fc06bcdb3..b9f594cb10c1 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -390,6 +390,113 @@ static int sev_ioctl_do_pek_cert_import(struct sev_issue_cmd *argp)
return ret;
}
+static int sev_ioctl_do_pdh_cert_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, err;
+
+ 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 || !input.cert_chain_address)
+ goto cmd;
+
+ /* allocate a physically contiguous buffer to store the PDH blob */
+ if (!access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len) ||
+ (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)) {
+ 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;
+
+ /* allocate a physically contiguous buffer to store the cert chain blob */
+ if (!access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len) ||
+ (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)) {
+ ret = -EFAULT;
+ goto e_free_pdh;
+ }
+
+ 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:
+ ret = sev_platform_init(NULL, &argp->error);
+ if (ret)
+ goto e_free_cert;
+
+ ret = sev_do_cmd(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 (sev_platform_shutdown(&err)) {
+ /*
+ * If both sev_do_cmd() and sev_platform_shutdown() commands
+ * failed then propogate the error code from the sev_do_cmd()
+ * because it contains a useful status code for the command
+ * failure.
+ */
+ if (ret)
+ goto e_free_cert;
+
+ ret = -EIO;
+ argp->error = err;
+ goto e_free_cert;
+ }
+
+ 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;
@@ -425,6 +532,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
case SEV_PEK_CERT_IMPORT:
ret = sev_ioctl_do_pek_cert_import(&input);
break;
+ case SEV_PDH_CERT_EXPORT:
+ ret = sev_ioctl_do_pdh_cert_export(&input);
+ break;
default:
ret = -EINVAL;
goto out;
--
2.9.5
