[test] add tbor sd fuzz targets

[David Zimmermann (zimmy87)]

No description provided.

[Copilot]

🟢 Approval recommended

The changes are additive test/fuzz targets with only minor maintainability/lint nits (e.g., unused imports, naming schema limits) noted.

Pull request overview

Adds new libFuzzer targets for TBOR “security domain” (SD) DDI commands, expanding fuzz coverage of request encoding/dispatch through the existing azihsm_ddi_tbor_test_harness::TestCtx harness.

Changes:

• Added 6 new TBOR SD fuzz targets (create peer/remote backup, reseal/restore backups, sealing-key generation).
• Registered the new fuzz binaries in fuzz/Cargo.toml so they can be built/invoked as individual fuzz targets.

File summaries

File	Description
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_sealing_key_gen.rs	New fuzz target for TborSdSealingKeyGenReq.
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_create_peer_backup.rs	New fuzz target for TborSdCreatePeerBackupReq.
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_create_remote_backup.rs	New fuzz target for TborSdCreateRemoteBackupReq.
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_reseal_remote_backup.rs	New fuzz target for TborSdResealRemoteBackupReq.
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_restore_local_backup.rs	New fuzz target for TborSdRestoreLocalBackupReq with bounded variable-length blobs.
fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_restore_peer_backup.rs	New fuzz target for TborSdRestorePeerBackupReq.
fuzz/Cargo.toml	Registers the new fuzz target binaries.

Review details

• Files reviewed: 7/7 changed files
• Comments generated: 6
• Review effort level: Lite

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[Copilot]

🟢 Approval recommended

The changes are additive fuzz targets with low risk to production code, and the only feedback is minor maintainability cleanup.

Review details

Suppressed comments (2)

fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_restore_local_backup.rs:19

• Avoid hard-coded length bounds here; the maximum size for pok_local_backup is already defined as MASKED_SD_LEN in azihsm_ddi_tbor_types. Using the constant keeps the fuzz target aligned with the TBOR schema if the envelope size changes.

fn bounded_pok(u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Vec<u8>> {
    let len = usize::arbitrary(u)? % (180 + 1);
    Ok(u.bytes(len)?.to_vec())
}

fuzz/fuzz_targets/ddi/tbor/fuzz_tbor_sd_restore_local_backup.rs:24

• Avoid hard-coded length bounds here; sd_mk_backup's maximum size is already available as SD_MK_BACKUP_LEN in azihsm_ddi_tbor_types. Reusing it prevents this fuzzer from silently diverging from the schema.

fn bounded_sd_mk(u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Vec<u8>> {
    let len = usize::arbitrary(u)? % (164 + 1);
    Ok(u.bytes(len)?.to_vec())
}

• Files reviewed: 7/7 changed files
• Comments generated: 0 new
• Review effort level: Lite