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 <[email protected]> --- docs/specs/s390x-secure-ipl.rst | 16 +++ hw/s390x/cert-store.c | 211 ++++++++++++++++++++++++++++++++ hw/s390x/cert-store.h | 41 +++++++ hw/s390x/ipl.c | 19 +++ hw/s390x/ipl.h | 3 + hw/s390x/meson.build | 1 + include/hw/s390x/ipl/qipl.h | 2 + 7 files changed, 293 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..cf16911d09 --- /dev/null +++ b/hw/s390x/cert-store.c @@ -0,0 +1,211 @@ +/* + * S390 certificate store implementation + * + * Copyright 2025 IBM Corp. + * Author(s): Zhuoying Cai <[email protected]> + * + * 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_x509(size_t size, uint8_t *raw, Error **errp) +{ + S390IPLCertificate *cert = NULL; + g_autofree uint8_t *cert_der = NULL; + size_t der_len = size; + int rc; + + rc = qcrypto_x509_convert_cert_der(raw, size, &cert_der, &der_len, errp); + if (rc != 0) { + return NULL; + } + + cert = g_new0(S390IPLCertificate, 1); + cert->size = size; + cert->der_size = der_len; + /* store raw pointer - ownership transfers to cert */ + cert->raw = raw; + + return cert; +} + +static S390IPLCertificate *init_cert(char *path, Error **errp) +{ + char *buf; + size_t size; + char vc_name[VC_NAME_LEN_BYTES]; + g_autofree gchar *filename = NULL; + S390IPLCertificate *cert = 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; + } + + cert = init_cert_x509(size, (uint8_t *)buf, &local_err); + if (cert == NULL) { + error_propagate_prepend(errp, local_err, + "Failed to initialize certificate: %s: ", path); + g_free(buf); + return NULL; + } + + /* + * 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(cert->vc_name, vc_name, VC_NAME_LEN_BYTES); + + 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->max_cert_size < data_buf_size) { + cert_store->max_cert_size = data_buf_size; + } + + 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; + 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(); + if (path_list == NULL) { + return g_steal_pointer(&cert_path_builder); + } + + 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; + } + + while ((filename = g_dir_read_name(dir))) { + if (g_str_has_suffix(filename, ".pem")) { + g_ptr_array_add(cert_path_builder, + g_build_filename(cert_path, filename, NULL)); + } + } + + 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; + + 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->max_cert_size = 0; + cert_store->total_bytes = 0; + + for (int i = 0; i < cert_path_builder->len; i++) { + 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..17a945a147 --- /dev/null +++ b/hw/s390x/cert-store.h @@ -0,0 +1,41 @@ +/* + * S390 certificate store + * + * Copyright 2025 IBM Corp. + * Author(s): Zhuoying Cai <[email protected]> + * + * 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 VC_NAME_LEN_BYTES 64 + +#define CERT_KEY_ID_LEN QCRYPTO_HASH_DIGEST_LEN_SHA256 +#define CERT_HASH_LEN QCRYPTO_HASH_DIGEST_LEN_SHA256 + +struct S390IPLCertificate { + uint8_t vc_name[VC_NAME_LEN_BYTES]; + size_t size; + size_t der_size; + uint8_t *raw; +}; +typedef struct S390IPLCertificate S390IPLCertificate; + +struct S390IPLCertificateStore { + uint16_t count; + size_t max_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 3843d2a850..38d5fff154 100644 --- a/hw/s390x/ipl.c +++ b/hw/s390x/ipl.c @@ -35,6 +35,7 @@ #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 @@ -424,6 +425,20 @@ 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_has_certificate(void) +{ + S390IPLState *ipl = get_ipl_device(); + + return ipl->cert_store.count > 0; +} + static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb) { CcwDevice *ccw_dev = NULL; @@ -719,6 +734,10 @@ void s390_ipl_prepare_cpu(S390CPU *cpu) if (!ipl->kernel || ipl->iplb_valid) { cpu->env.psw.addr = ipl->bios_start_addr; + /* initialize cert store if it's empty */ + if (!s390_has_certificate()) { + 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 8f83c7da29..bee72dfbb3 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 -- 2.51.1
