On 8/27/25 10:35 AM, Jared Rossi wrote:
>
> On 8/18/25 5:43 PM, Zhuoying Cai wrote:
>> DIAG 320 subcode 2 provides verification-certificates (VCs) that are in the
>> certificate store. Only X509 certificates in DER format and SHA-256 hash
>> type are recognized.
>>
>> The subcode value is denoted by setting the second-left-most bit
>> of an 8-byte field.
>>
>> The Verification Certificate Block (VCB) contains the output data
>> when the operation completes successfully. It includes a common
>> header followed by zero or more Verification Certificate Entries (VCEs),
>> depending on the VCB input length and the VC range (from the first VC
>> index to the last VC index) in the certificate store.
>>
>> Each VCE contains information about a certificate retrieved from
>> the S390IPLCertificateStore, such as the certificate name, key type,
>> key ID length, hash length, and the raw certificate data.
>> The key ID and hash are extracted from the raw certificate by the crypto API.
>>
>> Note: SHA2-256 VC hash type is required for retrieving the hash
>> (fingerprint) of the certificate.
>>
>> Signed-off-by: Zhuoying Cai <[email protected]>
>> ---
>> docs/specs/s390x-secure-ipl.rst | 13 ++
>> include/hw/s390x/ipl/diag320.h | 49 ++++++
>> target/s390x/diag.c | 286 +++++++++++++++++++++++++++++++-
>> 3 files changed, 347 insertions(+), 1 deletion(-)
>>
> [snip...]
>> +static VCEntry *diag_320_build_vce(S390IPLCertificate qcert, uint32_t
>> vce_len, int idx)
>> +{
>> + g_autofree VCEntry *vce = NULL;
>> + int rc;
>> +
>> + /*
>> + * Construct VCE
>> + * Allocate enough memory for all certificate data (key id, hash and
>> certificate).
>> + * Unused area following the VCE field contains zeros.
>> + */
>> + vce = g_malloc0(vce_len);
>> + rc = build_vce_header(vce, qcert, idx);
>> + if (rc) {
>> + vce->len = cpu_to_be32(VCE_INVALID_LEN);
>> + goto out;
>> + }
>> + vce->len = cpu_to_be32(VCE_HEADER_LEN);
>> +
>> + rc = build_vce_data(vce, qcert);
>> + if (rc) {
>> + vce->len = cpu_to_be32(VCE_INVALID_LEN);
>> + }
>> +
>> +out:
>> + return g_steal_pointer(&vce);
>> +}
>> +
>> +static int handle_diag320_store_vc(S390CPU *cpu, uint64_t addr, uint64_t
>> r1, uintptr_t ra,
>> + S390IPLCertificateStore *qcs)
>> +{
>> + g_autofree VCBlock *vcb = NULL;
>> + size_t vce_offset;
>> + size_t remaining_space;
>> + uint32_t vce_len;
>> + uint16_t first_vc_index;
>> + uint16_t last_vc_index;
>> + uint32_t in_len;
>> +
>> + vcb = g_new0(VCBlock, 1);
>> + if (s390_cpu_virt_mem_read(cpu, addr, r1, vcb, sizeof(*vcb))) {
>> + s390_cpu_virt_mem_handle_exc(cpu, ra);
>> + return -1;
>> + }
>> +
>> + in_len = be32_to_cpu(vcb->in_len);
>> + first_vc_index = be16_to_cpu(vcb->first_vc_index);
>> + last_vc_index = be16_to_cpu(vcb->last_vc_index);
>> +
>> + if (in_len % TARGET_PAGE_SIZE != 0) {
>> + return DIAG_320_RC_INVAL_VCB_LEN;
>> + }
>> +
>> + if (first_vc_index > last_vc_index) {
>> + return DIAG_320_RC_BAD_RANGE;
>> + }
>> +
>> + if (first_vc_index == 0) {
>> + /*
>> + * Zero is a valid index for the first and last VC index.
>> + * Zero index results in the VCB header and zero certificates
>> returned.
>> + */
>> + if (last_vc_index == 0) {
>> + goto out;
>> + }
>> +
>> + /* DIAG320 certificate store remains a one origin for cert entries
>> */
>> + vcb->first_vc_index = 1;
>> + first_vc_index = 1;
>> + }
>> +
>> + vce_offset = VCB_HEADER_LEN;
>> + vcb->out_len = VCB_HEADER_LEN;
>> + remaining_space = in_len - VCB_HEADER_LEN;
>> +
>> + for (int i = first_vc_index - 1; i < last_vc_index && i < qcs->count;
>> i++) {
>> + VCEntry *vce;
>> + S390IPLCertificate qcert = qcs->certs[i];
>> + /*
>> + * Each VCE is word aligned.
>> + * Each variable length field within the VCE is also word aligned.
>> + */
>> + vce_len = VCE_HEADER_LEN +
>> + ROUND_UP(qcert.key_id_size, 4) +
>> + ROUND_UP(qcert.hash_size, 4) +
>> + ROUND_UP(qcert.der_size, 4);
>> +
>> + /*
>> + * If there is no more space to store the cert,
>> + * set the remaining verification cert count and
>> + * break early.
>> + */
>> + if (remaining_space < vce_len) {
>> + vcb->remain_ct = cpu_to_be16(last_vc_index - i);
>> + break;
>> + }
> What is the significance of remain_ct != 0?
>
> Should there be an error or warning that there was not enough space?
>
remain_ct != 0 indicates insufficient memory to acquire all requested
certificates.
I'll add a check in the caller function and report an error if not all
certificates can be retrieved.
>> +
>> + vce = diag_320_build_vce(qcert, vce_len, i);
>> +
>> + /* Write VCE */
>> + if (s390_cpu_virt_mem_write(cpu, addr + vce_offset, r1,
>> + vce, be32_to_cpu(vce->len))) {
>> + s390_cpu_virt_mem_handle_exc(cpu, ra);
>> + return -1;
> Missing vce free in this early return?
>
>> + }
>> +
>> + vce_offset += be32_to_cpu(vce->len);
>> + vcb->out_len += be32_to_cpu(vce->len);
>> + remaining_space -= be32_to_cpu(vce->len);
>> + vcb->stored_ct++;
>> +
>> + g_free(vce);
>> + }
>> +
>> + vcb->out_len = cpu_to_be32(vcb->out_len);
>> + vcb->stored_ct = cpu_to_be16(vcb->stored_ct);
>> +
>> +out:
>> + /*
>> + * Write VCB header
>> + * All VCEs have been populated with the latest information
>> + * and write VCB header last.
>> + */
>> + if (s390_cpu_virt_mem_write(cpu, addr, r1, vcb, VCB_HEADER_LEN)) {
>> + s390_cpu_virt_mem_handle_exc(cpu, ra);
>> + return -1;
>> + }
>> +
>> + return DIAG_320_RC_OK;
>> +}
>> +
>> void handle_diag_320(CPUS390XState *env, uint64_t r1, uint64_t r3,
>> uintptr_t ra)
>> {
>> S390CPU *cpu = env_archcpu(env);
>> @@ -256,7 +532,8 @@ void handle_diag_320(CPUS390XState *env, uint64_t r1,
>> uint64_t r3, uintptr_t ra)
>> * for now.
>> */
>> uint32_t ism_word0 = cpu_to_be32(DIAG_320_ISM_QUERY_SUBCODES |
>> - DIAG_320_ISM_QUERY_VCSI);
>> + DIAG_320_ISM_QUERY_VCSI |
>> + DIAG_320_ISM_STORE_VC);
>>
>> if (s390_cpu_virt_mem_write(cpu, addr, r1, &ism_word0,
>> sizeof(ism_word0))) {
>> s390_cpu_virt_mem_handle_exc(cpu, ra);
>> @@ -282,6 +559,13 @@ void handle_diag_320(CPUS390XState *env, uint64_t r1,
>> uint64_t r3, uintptr_t ra)
>> }
>> env->regs[r1 + 1] = rc;
>> break;
>> + case DIAG_320_SUBC_STORE_VC:
>> + rc = handle_diag320_store_vc(cpu, addr, r1, ra, qcs);
>> + if (rc == -1) {
>> + return;
>> + }
>> + env->regs[r1 + 1] = rc;
>> + break;
>> default:
>> env->regs[r1 + 1] = DIAG_320_RC_NOT_SUPPORTED;
>> break;
> Regards,
> Jared Rossi
