Create a certificate store for boot certificates used for secure IPL.
Load certificates from the `boot-certs` parameter of s390-ccw-virtio
machine type option into the cert store.
Currently, only X.509 certificates in PEM format are supported, as the
QEMU command line accepts certificates in PEM format only.
Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
---
docs/specs/s390x-secure-ipl.rst | 16 +++
hw/s390x/cert-store.c | 221 ++++++++++++++++++++++++++++++++
hw/s390x/cert-store.h | 41 ++++++
hw/s390x/ipl.c | 10 ++
hw/s390x/ipl.h | 3 +
hw/s390x/meson.build | 1 +
include/hw/s390x/ipl/qipl.h | 2 +
7 files changed, 294 insertions(+)
create mode 100644 docs/specs/s390x-secure-ipl.rst
create mode 100644 hw/s390x/cert-store.c
create mode 100644 hw/s390x/cert-store.h
diff --git a/docs/specs/s390x-secure-ipl.rst b/docs/specs/s390x-secure-ipl.rst
new file mode 100644
index 0000000000..7ddac98a37
--- /dev/null
+++ b/docs/specs/s390x-secure-ipl.rst
@@ -0,0 +1,16 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+s390 Certificate Store and Functions
+====================================
+
+s390 Certificate Store
+----------------------
+
+A certificate store is implemented for s390-ccw guests to retain within
+memory all certificates provided by the user via the command-line, which
+are expected to be stored somewhere on the host's file system. The store
+will keep track of the number of certificates, their respective size,
+and a summation of the sizes.
+
+Note: A maximum of 64 certificates are allowed to be stored in the certificate
+store.
diff --git a/hw/s390x/cert-store.c b/hw/s390x/cert-store.c
new file mode 100644
index 0000000000..f642d50795
--- /dev/null
+++ b/hw/s390x/cert-store.c
@@ -0,0 +1,221 @@
+/*
+ * S390 certificate store implementation
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Zhuoying Cai <zycai@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "cert-store.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/config-file.h"
+#include "hw/s390x/ebcdic.h"
+#include "hw/s390x/s390-virtio-ccw.h"
+#include "qemu/cutils.h"
+#include "crypto/x509-utils.h"
+#include "qapi/qapi-types-machine-s390x.h"
+
+static BootCertificatesList *s390_get_boot_certs(void)
+{
+ return S390_CCW_MACHINE(qdev_get_machine())->boot_certs;
+}
+
+static S390IPLCertificate *init_cert(char *path, Error **errp)
+{
+ int rc;
+ char *buf;
+ size_t size;
+ size_t der_len;
+ char name[CERT_NAME_MAX_LEN];
+ g_autofree gchar *filename = NULL;
+ S390IPLCertificate *cert = NULL;
+ g_autofree uint8_t *cert_der = NULL;
+ Error *local_err = NULL;
+
+ filename = g_path_get_basename(path);
+
+ if (!g_file_get_contents(path, &buf, &size, NULL)) {
+ error_setg(errp, "Failed to load certificate: %s", path);
+ return NULL;
+ }
+
+ rc = qcrypto_x509_convert_cert_der((uint8_t *)buf, size,
+ &cert_der, &der_len, &local_err);
+ if (rc != 0) {
+ error_propagate_prepend(errp, local_err,
+ "Failed to initialize certificate: %s: ", path);
+ g_free(buf);
+ return NULL;
+ }
+
+ cert = g_new0(S390IPLCertificate, 1);
+ cert->size = size;
+ /*
+ * Store DER length only - reused for size calculation.
+ * cert_der is discarded because DER certificate data will be used once
+ * and can be regenerated from cert->raw.
+ */
+ cert->der_size = der_len;
+ /* store raw pointer - ownership transfers to cert */
+ cert->raw = (uint8_t *)buf;
+
+ /*
+ * Left justified certificate name with padding on the right with blanks.
+ * Convert certificate name to EBCDIC.
+ */
+ strpadcpy(name, CERT_NAME_MAX_LEN, filename, ' ');
+ ebcdic_put(cert->name, name, CERT_NAME_MAX_LEN);
+
+ return cert;
+}
+
+static void update_cert_store(S390IPLCertificateStore *cert_store,
+ S390IPLCertificate *cert)
+{
+ size_t data_buf_size;
+ size_t keyid_buf_size;
+ size_t hash_buf_size;
+ size_t cert_buf_size;
+
+ /* length field is word aligned for later DIAG use */
+ keyid_buf_size = ROUND_UP(CERT_KEY_ID_LEN, 4);
+ hash_buf_size = ROUND_UP(CERT_HASH_LEN, 4);
+ cert_buf_size = ROUND_UP(cert->der_size, 4);
+ data_buf_size = keyid_buf_size + hash_buf_size + cert_buf_size;
+
+ if (cert_store->largest_cert_size < data_buf_size) {
+ cert_store->largest_cert_size = data_buf_size;
+ }
+
+ g_assert(cert_store->count < MAX_CERTIFICATES);
+
+ cert_store->certs[cert_store->count] = *cert;
+ cert_store->total_bytes += data_buf_size;
+ cert_store->count++;
+}
+
+static GPtrArray *get_cert_paths(Error **errp)
+{
+ struct stat st;
+ BootCertificatesList *path_list = NULL;
+ BootCertificatesList *list = NULL;
+ gchar *cert_path;
+ GDir *dir = NULL;
+ const gchar *filename;
+ bool is_empty;
+ g_autoptr(GError) err = NULL;
+ g_autoptr(GPtrArray) cert_path_builder = g_ptr_array_new_full(0, g_free);
+
+ path_list = s390_get_boot_certs();
+
+ for (list = path_list; list; list = list->next) {
+ cert_path = list->value->path;
+
+ if (g_strcmp0(cert_path, "") == 0) {
+ error_setg(errp, "Empty path in certificate path list is not allowed");
+ goto fail;
+ }
+
+ if (stat(cert_path, &st) != 0) {
+ error_setg(errp, "Failed to stat path '%s': %s",
+ cert_path, g_strerror(errno));
+ goto fail;
+ }
+
+ if (S_ISREG(st.st_mode)) {
+ if (!g_str_has_suffix(cert_path, ".pem")) {
+ error_setg(errp, "Certificate file '%s' must have a .pem extension",
+ cert_path);
+ goto fail;
+ }
+
+ g_ptr_array_add(cert_path_builder, g_strdup(cert_path));
+ } else if (S_ISDIR(st.st_mode)) {
+ dir = g_dir_open(cert_path, 0, &err);
+ if (dir == NULL) {
+ error_setg(errp, "Failed to open directory '%s': %s",
+ cert_path, err->message);
+
+ goto fail;
+ }
+
+ is_empty = true;
+ while ((filename = g_dir_read_name(dir))) {
+ is_empty = false;
+
+ if (g_str_has_suffix(filename, ".pem")) {
+ g_ptr_array_add(cert_path_builder,
+ g_build_filename(cert_path, filename, NULL));
+ } else {
+ warn_report("skipping '%s': not a .pem file", filename);
+ }
+ }
+
+ if (is_empty) {
+ warn_report("'%s' directory is empty", cert_path);
+ }
+
+ g_dir_close(dir);
+ } else {
+ error_setg(errp, "Path '%s' is neither a file nor a directory", cert_path);
+ goto fail;
+ }
+ }
+
+ qapi_free_BootCertificatesList(path_list);
+ return g_steal_pointer(&cert_path_builder);
+
+fail:
+ qapi_free_BootCertificatesList(path_list);
+ return NULL;
+}
+
+void s390_ipl_create_cert_store(S390IPLCertificateStore *cert_store)
+{
+ GPtrArray *cert_path_builder;
+ Error *err = NULL;
+
+ /* If cert store is already populated, then no work to do */
+ if (cert_store->count) {
+ return;
+ }
+
+ cert_path_builder = get_cert_paths(&err);
+ if (cert_path_builder == NULL) {
+ error_report_err(err);
+ exit(1);
+ }
+
+ if (cert_path_builder->len == 0) {
+ g_ptr_array_free(cert_path_builder, TRUE);
+ return;
+ }
+
+ if (cert_path_builder->len > MAX_CERTIFICATES - 1) {
+ error_report("Cert store exceeds maximum of %d certificates", MAX_CERTIFICATES);
+ g_ptr_array_free(cert_path_builder, TRUE);
+ exit(1);
+ }
+
+ cert_store->largest_cert_size = 0;
+ cert_store->total_bytes = 0;
+
+ for (int i = 0; i < cert_path_builder->len; i++) {
+ g_autofree S390IPLCertificate *cert = init_cert(
+ (char *) cert_path_builder->pdata[i],
+ &err);
+ if (!cert) {
+ error_report_err(err);
+ g_ptr_array_free(cert_path_builder, TRUE);
+ exit(1);
+ }
+
+ update_cert_store(cert_store, cert);
+ }
+
+ g_ptr_array_free(cert_path_builder, TRUE);
+}
diff --git a/hw/s390x/cert-store.h b/hw/s390x/cert-store.h
new file mode 100644
index 0000000000..50e36e2389
--- /dev/null
+++ b/hw/s390x/cert-store.h
@@ -0,0 +1,41 @@
+/*
+ * S390 certificate store
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Zhuoying Cai <zycai@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_S390_CERT_STORE_H
+#define HW_S390_CERT_STORE_H
+
+#include "hw/s390x/ipl/qipl.h"
+#include "crypto/x509-utils.h"
+
+#define CERT_NAME_MAX_LEN 64
+
+#define CERT_KEY_ID_LEN QCRYPTO_HASH_DIGEST_LEN_SHA256
+#define CERT_HASH_LEN QCRYPTO_HASH_DIGEST_LEN_SHA256
+
+struct S390IPLCertificate {
+ uint8_t name[CERT_NAME_MAX_LEN];
+ size_t size;
+ size_t der_size;
+ uint8_t *raw;
+};
+typedef struct S390IPLCertificate S390IPLCertificate;
+
+struct S390IPLCertificateStore {
+ uint16_t count;
+ size_t largest_cert_size;
+ size_t total_bytes;
+ S390IPLCertificate certs[MAX_CERTIFICATES];
+};
+typedef struct S390IPLCertificateStore S390IPLCertificateStore;
+QEMU_BUILD_BUG_MSG(sizeof(S390IPLCertificateStore) != 5656,
+ "size of S390IPLCertificateStore is wrong");
+
+void s390_ipl_create_cert_store(S390IPLCertificateStore *cert_store);
+
+#endif
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index d34adb5522..ea108fe370 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -36,6 +36,7 @@
#include "qemu/option.h"
#include "qemu/ctype.h"
#include "standard-headers/linux/virtio_ids.h"
+#include "cert-store.h"
#define KERN_IMAGE_START 0x010000UL
#define LINUX_MAGIC_ADDR 0x010008UL
@@ -425,6 +426,13 @@ void s390_ipl_convert_loadparm(char *ascii_lp, uint8_t *ebcdic_lp)
}
}
+S390IPLCertificateStore *s390_ipl_get_certificate_store(void)
+{
+ S390IPLState *ipl = get_ipl_device();
+
+ return &ipl->cert_store;
+}
+
static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
{
CcwDevice *ccw_dev = NULL;
@@ -718,6 +726,8 @@ void s390_ipl_prepare_cpu(S390CPU *cpu)
cpu->env.psw.addr = ipl->start_addr;
cpu->env.psw.mask = IPL_PSW_MASK;
+ s390_ipl_create_cert_store(&ipl->cert_store);
+
if (!ipl->kernel || ipl->iplb_valid) {
cpu->env.psw.addr = ipl->bios_start_addr;
if (!ipl->iplb_valid) {
diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
index 85be03de1b..0c773ac8ce 100644
--- a/hw/s390x/ipl.h
+++ b/hw/s390x/ipl.h
@@ -13,6 +13,7 @@
#ifndef HW_S390_IPL_H
#define HW_S390_IPL_H
+#include "cert-store.h"
#include "cpu.h"
#include "exec/target_page.h"
#include "system/address-spaces.h"
@@ -35,6 +36,7 @@ int s390_ipl_pv_unpack(struct S390PVResponse *pv_resp);
void s390_ipl_prepare_cpu(S390CPU *cpu);
IplParameterBlock *s390_ipl_get_iplb(void);
IplParameterBlock *s390_ipl_get_iplb_pv(void);
+S390IPLCertificateStore *s390_ipl_get_certificate_store(void);
enum s390_reset {
/* default is a reset not triggered by a CPU e.g. issued by QMP */
@@ -64,6 +66,7 @@ struct S390IPLState {
IplParameterBlock iplb;
IplParameterBlock iplb_pv;
QemuIplParameters qipl;
+ S390IPLCertificateStore cert_store;
uint64_t start_addr;
uint64_t compat_start_addr;
uint64_t bios_start_addr;
diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
index 8866012ddc..80d3d4a74d 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -17,6 +17,7 @@ s390x_ss.add(files(
'sclpcpu.c',
'sclpquiesce.c',
'tod.c',
+ 'cert-store.c',
))
s390x_ss.add(when: 'CONFIG_KVM', if_true: files(
'tod-kvm.c',
diff --git a/include/hw/s390x/ipl/qipl.h b/include/hw/s390x/ipl/qipl.h
index 6824391111..e505f44020 100644
--- a/include/hw/s390x/ipl/qipl.h
+++ b/include/hw/s390x/ipl/qipl.h
@@ -20,6 +20,8 @@
#define LOADPARM_LEN 8
#define NO_LOADPARM "\0\0\0\0\0\0\0\0"
+#define MAX_CERTIFICATES 64
+
/*
* The QEMU IPL Parameters will be stored at absolute address
* 204 (0xcc) which means it is 32-bit word aligned but not
--
2.52.0