Create a certificate store for boot certificates used for secure IPL.
Load certificates from the -boot-certificate option into the cert store.
Currently, only x509 certificates in DER format and uses SHA-256 hashing
algorithm are supported, as these are the types required for secure boot
on s390.
Signed-off-by: Zhuoying Cai <zy...@linux.ibm.com>
---
hw/s390x/cert-store.c | 249 ++++++++++++++++++++++++++++++++++++
hw/s390x/cert-store.h | 50 ++++++++
hw/s390x/ipl.c | 9 ++
hw/s390x/ipl.h | 3 +
hw/s390x/meson.build | 1 +
include/hw/s390x/ipl/qipl.h | 3 +
6 files changed, 315 insertions(+)
create mode 100644 hw/s390x/cert-store.c
create mode 100644 hw/s390x/cert-store.h
diff --git a/hw/s390x/cert-store.c b/hw/s390x/cert-store.c
new file mode 100644
index 0000000000..1aa8aea040
--- /dev/null
+++ b/hw/s390x/cert-store.c
@@ -0,0 +1,249 @@
+/*
+ * S390 certificate store implementation
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Zhuoying Cai <zy...@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "cert-store.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/config-file.h"
+#include "hw/s390x/ebcdic.h"
+#include "qemu/cutils.h"
+#include "cert-store.h"
+
+#ifdef CONFIG_GNUTLS
+#include <gnutls/x509.h>
+#include <gnutls/gnutls.h>
+#endif /* #define CONFIG_GNUTLS */
+
+static const char *s390_get_boot_certificates(void)
+{
+ QemuOpts *opts;
+ const char *path;
+
+ opts = qemu_find_opts_singleton("boot-certificates");
+ path = qemu_opt_get(opts, "boot-certificates");
+
+ return path;
+}
+
+static size_t cert2buf(char *path, size_t max_size, char **cert_buf)
+{
+ size_t size;
+ g_autofree char *buf;
+ buf = g_malloc(max_size);
+
+ if (!g_file_get_contents(path, &buf, &size, NULL) ||
+ size == 0 || size > max_size) {
+ return 0;
+ }
+
+ *cert_buf = g_steal_pointer(&buf);
+
+ return size;
+}
+
+#ifdef CONFIG_GNUTLS
+int g_init_cert(uint8_t *raw_cert, size_t cert_size, gnutls_x509_crt_t *g_cert)
+{
+ int rc;
+
+ if (gnutls_x509_crt_init(g_cert) < 0) {
+ return -1;
+ }
+
+ gnutls_datum_t datum_cert = {raw_cert, cert_size};
+ rc = gnutls_x509_crt_import(*g_cert, &datum_cert, GNUTLS_X509_FMT_DER);
+ if (rc) {
+ gnutls_x509_crt_deinit(*g_cert);
+ return rc;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_GNUTLS */
+
+static int init_cert_x509_der(size_t size, char *raw, S390IPLCertificate
**qcert)
+{
+#ifdef CONFIG_GNUTLS
+ gnutls_x509_crt_t g_cert = NULL;
+ g_autofree S390IPLCertificate *q_cert;
+ size_t key_id_size;
+ size_t hash_size;
+ int rc;
+
+ rc = g_init_cert((uint8_t *)raw, size, &g_cert);
+ if (rc) {
+ if (rc == GNUTLS_E_ASN1_TAG_ERROR) {
+ error_report("The certificate is not in DER format");
+ }
+ return -1;
+ }
+
+ rc = gnutls_x509_crt_get_key_id(g_cert, GNUTLS_KEYID_USE_SHA256, NULL,
&key_id_size);
+ if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) {
+ error_report("Failed to get certificate key ID size");
+ goto out;
+ }
+
+ rc = gnutls_x509_crt_get_fingerprint(g_cert, GNUTLS_DIG_SHA256, NULL,
&hash_size);
+ if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) {
+ error_report("Failed to get certificate hash size");
+ goto out;
+ }
+
+ q_cert = g_malloc(sizeof(*q_cert));
+ q_cert->size = size;
+ q_cert->key_id_size = key_id_size;
+ q_cert->hash_size = hash_size;
+ q_cert->raw = raw;
+ q_cert->format = GNUTLS_X509_FMT_DER;
+ *qcert = g_steal_pointer(&q_cert);
+
+ gnutls_x509_crt_deinit(g_cert);
+
+ return 0;
+out:
+ gnutls_x509_crt_deinit(g_cert);
+ return -1;
+#else
+ error_report("Cryptographic library is not enabled")
+ return -1;
+#endif /* #define CONFIG_GNUTLS */
+}
+
+static int check_path_type(const char *path)
+{
+ struct stat path_stat;
+
+ stat(path, &path_stat);
+
+ if (S_ISDIR(path_stat.st_mode)) {
+ return S_IFDIR;
+ } else if (S_ISREG(path_stat.st_mode)) {
+ return S_IFREG;
+ } else {
+ return -1;
+ }
+}
+
+static int init_cert(char *paths, S390IPLCertificate **qcert)
+{
+ char *buf;
+ char vc_name[VC_NAME_LEN_BYTES];
+ const gchar *filename;
+ size_t size;
+
+ filename = g_path_get_basename(paths);
+
+ size = cert2buf(paths, CERT_MAX_SIZE, &buf);
+ if (size == 0) {
+ error_report("Failed to load certificate: %s", paths);
+ return -1;
+ }
+
+ if (init_cert_x509_der(size, buf, qcert) < 0) {
+ error_report("Failed to initialize certificate: %s", paths);
+ return -1;
+ }
+
+ /*
+ * Left justified certificate name with padding on the right with blanks.
+ * Convert certificate name to EBCDIC.
+ */
+ strpadcpy(vc_name, VC_NAME_LEN_BYTES, filename, ' ');
+ ebcdic_put((*qcert)->vc_name, vc_name, VC_NAME_LEN_BYTES);
+
+ return 0;
+}
+
+static void update_cert_store(S390IPLCertificateStore *cert_store,
+ S390IPLCertificate *qcert)
+{
+ size_t data_size;
+
+ data_size = qcert->size + qcert->key_id_size + qcert->hash_size;
+
+ if (cert_store->max_cert_size < data_size) {
+ cert_store->max_cert_size = data_size;
+ }
+
+ cert_store->certs[cert_store->count] = *qcert;
+ cert_store->total_bytes += data_size;
+ cert_store->count++;
+}
+
+static GPtrArray *get_cert_paths(void)
+{
+ const char *path;
+ gchar **paths;
+ int path_type;
+ GDir *dir = NULL;
+ const gchar *filename;
+ GPtrArray *cert_path_builder;
+
+ cert_path_builder = g_ptr_array_new();
+
+ path = s390_get_boot_certificates();
+ if (path == NULL) {
+ return cert_path_builder;
+ }
+
+ paths = g_strsplit(path, ":", -1);
+ while (*paths) {
+ /* skip empty certificate path */
+ if (!strcmp(*paths, "")) {
+ paths += 1;
+ continue;
+ }
+
+ path_type = check_path_type(*paths);
+ if (path_type == S_IFREG) {
+ g_ptr_array_add(cert_path_builder, (gpointer) *paths);
+ } else if (path_type == S_IFDIR) {
+ dir = g_dir_open(*paths, 0, NULL);
+
+ while ((filename = g_dir_read_name(dir))) {
+ gchar *cert_path = NULL;
+ cert_path = g_build_filename(*paths, filename, NULL);
+ g_ptr_array_add(cert_path_builder, (gpointer) cert_path);
+ }
+
+ g_dir_close(dir);
+ }
+
+ paths += 1;
+ }
+
+ return cert_path_builder;
+}
+
+void s390_ipl_create_cert_store(S390IPLCertificateStore *cert_store)
+{
+ GPtrArray *cert_path_builder;
+
+ cert_path_builder = get_cert_paths();
+ if (cert_path_builder->len == 0) {
+ g_ptr_array_free(cert_path_builder, true);
+ return;
+ }
+
+ cert_store->max_cert_size = 0;
+ cert_store->total_bytes = 0;
+
+ for (int i = 0; i < cert_path_builder->len; i++) {
+ S390IPLCertificate *qcert = NULL;
+ if (init_cert((char *) cert_path_builder->pdata[i], &qcert) < 0) {
+ continue;
+ }
+
+ update_cert_store(cert_store, qcert);
+ }
+
+ 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..80141c07da
--- /dev/null
+++ b/hw/s390x/cert-store.h
@@ -0,0 +1,50 @@
+/*
+ * S390 certificate store
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Zhuoying Cai <zy...@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef HW_S390_CERT_STORE_H
+#define HW_S390_CERT_STORE_H
+
+#include "hw/s390x/ipl/qipl.h"
+
+#ifdef CONFIG_GNUTLS
+#include <gnutls/x509.h>
+#include <gnutls/gnutls.h>
+#endif /* #define CONFIG_GNUTLS */
+
+#define VC_NAME_LEN_BYTES 64
+
+struct S390IPLCertificate {
+ uint8_t vc_name[VC_NAME_LEN_BYTES];
+ size_t size;
+ size_t key_id_size;
+ size_t hash_size;
+ char *raw;
+#ifdef CONFIG_GNUTLS
+ gnutls_x509_crt_fmt_t format;
+#endif /* #define CONFIG_GNUTLS */
+};
+typedef struct S390IPLCertificate S390IPLCertificate;
+
+struct S390IPLCertificateStore {
+ uint16_t count;
+ size_t max_cert_size;
+ size_t total_bytes;
+ S390IPLCertificate certs[MAX_CERTIFICATES];
+} QEMU_PACKED;
+typedef struct S390IPLCertificateStore S390IPLCertificateStore;
+
+#ifdef CONFIG_GNUTLS
+int g_init_cert(uint8_t *raw_cert, size_t cert_size, gnutls_x509_crt_t
*g_cert);
+#endif /* #define CONFIG_GNUTLS */
+
+void s390_ipl_create_cert_store(S390IPLCertificateStore *cert_store);
+
+#endif
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index ce6f6078d7..b0810c9191 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
@@ -423,6 +424,13 @@ 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;
@@ -716,6 +724,7 @@ void s390_ipl_prepare_cpu(S390CPU *cpu)
if (!ipl->kernel || ipl->iplb_valid) {
cpu->env.psw.addr = ipl->bios_start_addr;
+ s390_ipl_create_cert_store(&ipl->cert_store);
if (!ipl->iplb_valid) {
ipl->iplb_valid = s390_init_all_iplbs(ipl);
} else {
diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
index 8e3882d506..8c2a442255 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/address-spaces.h"
#include "hw/qdev-core.h"
@@ -31,6 +32,7 @@ int s390_ipl_pv_unpack(void);
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 */
@@ -59,6 +61,7 @@ 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 610b29bf76..8f0cfaa056 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -16,6 +16,7 @@ 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..b8e7d1da71 100644
--- a/include/hw/s390x/ipl/qipl.h
+++ b/include/hw/s390x/ipl/qipl.h
@@ -20,6 +20,9 @@
#define LOADPARM_LEN 8
#define NO_LOADPARM "\0\0\0\0\0\0\0\0"
+#define MAX_CERTIFICATES 64
+#define CERT_MAX_SIZE (1024 * 8)
+
/*
* The QEMU IPL Parameters will be stored at absolute address
* 204 (0xcc) which means it is 32-bit word aligned but not
--
2.49.0
