[Copilot]

Users encountering TLS certificate failures had to manually re-run with --refresh-trust-store. This change detects certificate errors automatically and retries with a fresh trust store transparently.

Changes

Dcm4cheUtils (dcm4che_utils.py)

• _CERT_ERROR_PATTERNS — class-level list of Java/dcm4che SSL error strings used for detection (SSLHandshakeException, PKIX path building failed, ValidatorException, etc.)
• _MAX_RETRY_ATTEMPTS = 2 — named constant for retry limit
• _build_commands(trust_store_option) — extracted command string construction so it can be called after a trust store refresh
• __init__ — stores _trust_store_cache_dir, _tls_cipher, _other_options to support rebuilding commands mid-session
• _is_certificate_error(stderr) — detects cert errors in both bytes and str stderr
• _refresh_trust_store() — force-refreshes trust store and rebuilds _findscu_str/_getscu_str
• _execute_findscu_with_xml_output, _execute_findscu_with_xml_output_per_study, retrieve_by_StudyInstanceUID — all now loop up to _MAX_RETRY_ATTEMPTS, calling _refresh_trust_store() and retrying on a first-attempt cert error

Tests (test_dcm4che_utils.py)

• 7 new unit tests covering _is_certificate_error (positive/negative cases, bytes/str), _refresh_trust_store command rebuild, and retry behaviour in both findscu and getscu paths

Original prompt

---

This section details on the original issue you should resolve

<issue_title>--refresh-trust-store could be automatically enabled if an exception catches a certificate error</issue_title>
<issue_description>Instead of having users manually run it, would be better to try doing this automatically if an error is detected when trying to download.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes --refresh-trust-store could be automatically enabled if an exception catches a certificate error #61

---

🔒 GitHub Advanced Security automatically protects Copilot coding agent pull requests. You can protect all pull requests by enabling Advanced Security for your repositories. Learn more about Advanced Security.