@@ -51,7 +51,8 @@ man1_MANS = \
ndctl-update-security.1 \
ndctl-disable-security.1 \
ndctl-freeze-security.1 \
- ndctl-sanitize.1
+ ndctl-sanitize.1 \
+ nvdimm-upcall.1
CLEANFILES = $(man1_MANS)
new file mode 100644
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+
+nvdimm-upcall(1)
+================
+
+NAME
+----
+nvdimm-upcall - upcall helper for keyutils
+
+SYNOPSIS
+--------
+[verse]
+'nvdimm-upcall' [key_id]
+
+DESCRIPTION
+-----------
+nvdimm-upcall is called by request-key from keyutils and not meant to be used
+directly by the user. It expects to read from /etc/nvdimm.passwd to retrieve
+the description and passphrase for the NVDIMM key.
+
+The nvdimm.passwd is formatted as:
+<description id>:<passphrase with padded 0 to 32bytes>
+cdab-0a-07e0-feffffff:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+
+In order for this util to be called, /etc/request-key.conf must be appended
+with the following line:
+create logon nvdimm* * /usr/sbin/nvdimm-upcall %k
+
+include::../copyright.txt[]
+
+SEE ALSO
+--------
+http://pmem.io/documents/NVDIMM_DSM_Interface-V1.7.pdf
@@ -123,6 +123,7 @@ make check
%{_unitdir}/ndctl-monitor.service
%{_udevrulesdir}/80-ndctl.rules
%{udevdir}/ndctl-udev
+%{_sbindir}/nvdimm-upcall
%files -n daxctl
%defattr(-,root,root)
@@ -1,6 +1,7 @@
include $(top_srcdir)/Makefile.am.in
bin_PROGRAMS = ndctl
+sbin_PROGRAMS = nvdimm-upcall
ndctl_SOURCES = ndctl.c \
bus.c \
@@ -56,3 +57,7 @@ ndctl_udevdir = $(UDEVDIR)
ndctl_udev_PROGRAMS = ndctl-udev
ndctl_udev_SOURCES = ndctl-udev.c
ndctl_udev_LDADD = lib/libndctl.la
+
+nvdimm_upcall_SOURCES = nvdimm-upcall.c
+
+nvdimm_upcall_LDADD = $(KEYUTILS_LIBS)
new file mode 100644
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2018 Intel Corporation. All rights reserved. */
+
+/*
+ * Used by /sbin/request-key for handling nvdimm upcall of key requests
+ * for security DSMs.
+ */
+
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <keyutils.h>
+#include <syslog.h>
+
+#define PASSPHRASE_SIZE 32
+#define PASS_PATH "/etc/nvdimm.passwd"
+
+static FILE *fp;
+
+static int get_passphrase_from_id(const char *id, char *pass, int *psize)
+{
+ ssize_t rc = 0;
+ size_t size;
+ char *line = NULL;
+ char *tmp, *id_tok, *secret;
+ int found = 0;
+
+ fp = fopen(PASS_PATH, "r+");
+ if (!fp) {
+ syslog(LOG_ERR, "fopen: %s\n", strerror(errno));
+ return -errno;
+ }
+
+ while ((rc = getline(&line, &size, fp)) != -1) {
+ id_tok = strtok_r(line, ":", &tmp);
+ if (!id_tok)
+ break;
+ if (strcmp(id_tok, id) == 0) {
+ secret = tmp;
+ found = 1;
+ rc = 0;
+ break;
+ }
+ }
+
+ if (rc == 0 && found && secret) {
+ memset(pass, 0, PASSPHRASE_SIZE*2+1);
+ size = MIN(strlen(secret), (PASSPHRASE_SIZE*2+1));
+ memcpy(pass, secret, size);
+ *psize = size-1;
+ } else
+ rc = -ENXIO;
+
+ free(line);
+ fclose(fp);
+ return rc;
+}
+
+static char *get_key_desc(char *buf)
+{
+ char *tmp = &buf[0];
+ int count = 0;
+
+ while (*tmp != '\0') {
+ if (*tmp == ';')
+ count++;
+ if (count == 4) {
+ tmp++;
+ return tmp;
+ }
+ tmp++;
+ }
+
+ return NULL;
+}
+
+int main(int argc, const char **argv)
+{
+ key_serial_t key;
+ int rc;
+ char *buf, *desc, *dimm_id;
+ char pass[PASSPHRASE_SIZE * 2 + 1];
+ int size = 0;
+
+ if (argc < 2) {
+ syslog(LOG_ERR, "Incorrect number of arguments\n");
+ return -EINVAL;
+ }
+
+ syslog(LOG_DEBUG, "key passed in: %s\n", argv[1]);
+ key = strtol(argv[1], NULL, 10);
+ if (key < 0) {
+ syslog(LOG_ERR, "Invalid key format: %s\n", strerror(errno));
+ return -errno;
+ }
+
+ rc = keyctl_describe_alloc(key, &buf);
+ if (rc < 0) {
+ syslog(LOG_ERR, "keyctl_describe_alloc failed: %s\n",
+ strerror(errno));
+ rc = -errno;
+ goto out;
+ }
+
+ desc = get_key_desc(buf);
+ if (!desc) {
+ syslog(LOG_ERR, "Can't find key description\n");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ strtok_r(desc, ":", &dimm_id);
+ rc = get_passphrase_from_id(dimm_id, pass, &size);
+ if (rc < 0) {
+ syslog(LOG_ERR, "failed to retrieve passphrase\n");
+ goto out;
+ }
+
+ rc = keyctl_instantiate(key, pass, size, 0);
+ if (rc < 0) {
+ syslog(LOG_ERR, "keyctl_instantiate failed: %s\n",
+ strerror(errno));
+ rc = -errno;
+ goto out;
+ }
+
+ out:
+ if (rc < 0)
+ keyctl_negate(key, 1, KEY_REQKEY_DEFL_DEFAULT);
+
+ return rc;
+}
Adding a reference upcall helper for request-key in order to retrieve the security passphrase from userspace to provide to the kernel. The reference app uses keyutils API to respond to the upcall from the kernel and is invoked by /sbin/request-key of the keyutils. Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- Documentation/ndctl/Makefile.am | 3 - Documentation/ndctl/nvdimm-upcall.txt | 33 ++++++++ ndctl.spec.in | 1 ndctl/Makefile.am | 5 + ndctl/nvdimm-upcall.c | 138 +++++++++++++++++++++++++++++++++ 5 files changed, 179 insertions(+), 1 deletion(-) create mode 100644 Documentation/ndctl/nvdimm-upcall.txt create mode 100644 ndctl/nvdimm-upcall.c