Keep vanetza-idf in obu-firmware, so a plain clone builds the firmware

obu-firmware builds against the vanetza-idf C-ITS library, which until now
came from the colleague's microbu-esp32c5 tree beside the repository and was
not tracked here, so a clone of this repository could not build the firmware
it ships. The library alone is now part of obu-firmware, as
obu-firmware/external/vanetza-idf: their external/vanetza-idf at commit
cf4b99f, unchanged (9775 files; see its PROVENANCE.md). CMake takes it from
there by default; -DVANETZA_IDF_DIR still points the build elsewhere.

The rest of the colleague's tree (their own VAM firmware, PKI tooling,
station-link Python tools, the V2X2MAP bridge) stays out of this repository
and gitignored; nothing is pushed to their repository. NOTES.md, docs/06,
TODO.md and the pcap verifier's usage line point at the new location.

obu-firmware/external/vanetza-idf/vanetza/security/verify_service.hpp

@@ -0,0 +1,98 @@
+#ifndef VERIFY_SERVICE_HPP_BR4ISDBH
+#define VERIFY_SERVICE_HPP_BR4ISDBH
+
+#include <boost/optional.hpp>
+#include <vanetza/common/its_aid.hpp>
+#include <vanetza/security/certificate_validity.hpp>
+#include <vanetza/security/hashed_id.hpp>
+#include <vanetza/security/secured_message.hpp>
+
+namespace vanetza
+{
+namespace security
+{
+
+/**
+ * SN-VERIFY.confirm report codes
+ * 
+ * "Configuration_Problem" is not found in TS 103 723-8 V1.1.1 but indicates a
+ * problem with the verification subsystem itself, e.g. a programming error.
+ * 
+ * \see TS 102 723-8 v1.1.1 table 5
+ */
+enum class VerificationReport
+{
+    Success,
+    False_Signature,
+    Invalid_Certificate,
+    Revoked_Certificate,
+    Inconsistent_Chain,
+    Invalid_Timestamp,
+    Duplicate_Message,
+    Invalid_Mobility_Data,
+    Unsigned_Message,
+    Signer_Certificate_Not_Found,
+    Unsupported_Signer_Identifier_Type,
+    Incompatible_Protocol,
+    Configuration_Problem,
+};
+
+// mandatory parameters of SN-VERIFY.request (TS 102 723-8 V1.1.1)
+struct VerifyRequest
+{
+    VerifyRequest(SecuredMessageView msg) : secured_message(msg) {}
+    SecuredMessageView secured_message; /*< contains security header and payload */
+};
+
+// parameters of SN-VERIFY.confirm (TS 102 723-8 V1.1.1)
+struct VerifyConfirm
+{
+    VerificationReport report; // mandatory
+    ItsAid its_aid; // mandatory
+    ByteBuffer permissions; // mandatory
+    CertificateValidity certificate_validity; // non-standard extension
+    boost::optional<HashedId8> certificate_id; // optional
+};
+
+/**
+ * Equivalent of SN-VERIFY service in TS 102 723-8 V1.1.1
+ */
+class VerifyService
+{
+public:
+    virtual ~VerifyService() = default;
+    virtual VerifyConfirm verify(const VerifyRequest&) = 0;
+};
+
+// forward declaration
+namespace v3 { class CertificateCache; }
+
+/**
+ * Get insecure dummy verify service without any checks
+ */
+class DummyVerifyService : public VerifyService
+{
+public:
+    /**
+     * \param report predefined confirm report result
+     * \param validity predefined certificate validity result 
+     */
+    DummyVerifyService(VerificationReport report, CertificateValidity validity);
+    VerifyConfirm verify(const VerifyRequest&) override;
+
+    /**
+     * \brief register certificate cache for optional permission lookup
+     * \param cache certificate cache
+     */
+    void use_certificate_cache(v3::CertificateCache* cache);
+
+private:
+    VerificationReport m_report;
+    CertificateValidity m_validity;
+    v3::CertificateCache* m_cert_cache = nullptr;
+};
+
+} // namespace security
+} // namespace vanetza
+
+#endif /* VERIFY_SERVICE_HPP_BR4ISDBH */