Files
MicrOBU/microbu-esp32c5/external/vanetza-idf/tools/pki/ea_response.cpp
T
Ashin Walpola 0e9525162d Keep the colleague's microbu-esp32c5 tree in this repository
obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).
2026-09-23 17:46:40 +02:00

75 lines
2.7 KiB
C++

#include "ea_response.hpp"
#include "asn1.hpp"
#include "exception.hpp"
#include "hashed_id8.hpp"
#include "security_module.hpp"
#include "signed_data.hpp"
#include "validation.hpp"
#include <vanetza/asn1/security/EtsiTs102941Data.h>
#include <vanetza/asn1/security/InnerEcResponse.h>
#include <vanetza/common/its_aid.hpp>
namespace vanetza
{
namespace pki
{
EnrolmentResponse parse_enrolment_response(SecurityModule& security, const ByteBuffer& decrypted,
const Certificate& ea_certificate)
{
SignedData outer;
if (!outer.decode(decrypted)) {
throw DecodingFailure("decoding signed enrolment response failed");
}
if (outer->content->present != Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
throw DecodingFailure("enrolment response content is not signedData");
}
const Vanetza_Security_SignedData_t& sd = *outer->content->choice.signedData;
// Per TS 102 941 §6.2.3.2.2 the EA signs enrolment responses with signer = digest(EA cert).
const HashedId8 ea_hid8 = ea_certificate.calculate_hashed_id8(security);
if (sd.signer.present != Vanetza_Security_SignerIdentifier_PR_digest) {
throw DecodingFailure("enrolment response must have signer = digest");
}
if (sd.signer.choice.digest != ea_hid8.octets) {
throw VerificationFailure("enrolment response signer digest does not match EA certificate");
}
if (sd.tbsData->headerInfo.psid != aid::SCR) {
throw DecodingFailure("enrolment response PSID is not SCR");
}
if (!validate(security, sd, ea_certificate.raw())) {
throw VerificationFailure("enrolment response signature does not verify against EA certificate");
}
const Vanetza_Security_Opaque_t* inner_opaque = get_signed_payload(outer->content);
if (!inner_opaque) {
throw DecodingFailure("enrolment response carries no unsecured signed payload");
}
EnrolmentResponseData inner = EnrolmentResponseData::from_opaque(*inner_opaque);
if (inner->version != Vanetza_Security_Version_v1) {
throw DecodingFailure("inner EtsiTs102941Data version is not v1");
}
const Vanetza_Security_InnerEcResponse_t& ec_resp = inner->content.choice.enrolmentResponse;
EnrolmentResponse result;
result.code = EnrolmentResponseCode { ec_resp.responseCode };
result.request_hash.assign(ec_resp.requestHash.buf, ec_resp.requestHash.buf + ec_resp.requestHash.size);
if (ec_resp.certificate) {
result.certificate = Certificate(*ec_resp.certificate);
}
if (ec_resp.responseCode == Vanetza_Security_EnrolmentResponseCode_ok && !result.certificate) {
throw DecodingFailure("enrolment response code is ok but no certificate is included");
}
return result;
}
} // namespace pki
} // namespace vanetza