secured_message.cpp

#include <vanetza/asn1/asn1c_wrapper.hpp>
#include <vanetza/asn1/security_profile.hpp>
#include VANETZA_ASN1_SECURITY_HEADER(Certificate.h)
#include VANETZA_ASN1_SECURITY_HEADER(EtsiTs103097Data.h)
#include <vanetza/common/byte_buffer.hpp>
#include <vanetza/common/byte_buffer_sink.hpp>
#include <vanetza/net/packet.hpp>
#include <vanetza/security/backend.hpp>
#include <vanetza/security/v3/asn1_conversions.hpp>
#include <vanetza/security/v3/secured_message.hpp>
 
#include <boost/iostreams/stream.hpp>
#include <boost/optional/optional.hpp>
#include <boost/variant/static_visitor.hpp>
 
// asn1c quirk
struct Vanetza_Security_Certificate : public Vanetza_Security_CertificateBase {};
 
namespace vanetza
{
namespace security
{
namespace v3
{
 
namespace
{
 
const asn1::SignedData* get_signed_data(const asn1::EtsiTs103097Data* data)
{
    if (data && data->content && data->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        return data->content->choice.signedData;
    } else {
        return nullptr;
    }
}
 
const asn1::HeaderInfo* get_header_info(const asn1::EtsiTs103097Data* data)
{
    const asn1::SignedData* signed_data = get_signed_data(data);
    if (signed_data) {
        return &signed_data->tbsData->headerInfo;
    } else {
        return nullptr;
    }
}
 
HashedId8 make_hashed_id8(const asn1::HashedId8& asn)
{
    HashedId8 result;
    std::copy_n(asn.buf, std::min(asn.size, result.size()), result.data());
    return result;
}
 
ByteBuffer copy_octets(const OCTET_STRING_t& octets)
{
    ByteBuffer buffer(octets.size);
    std::memcpy(buffer.data(), octets.buf, octets.size);
    return buffer;
}
 
ByteBuffer get_x_coordinate(const asn1::EccP256CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0:
            return copy_octets(point.choice.compressed_y_0);
            break;
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1:
            return copy_octets(point.choice.compressed_y_1);
            break;
        case Vanetza_Security_EccP256CurvePoint_PR_x_only:
            return copy_octets(point.choice.x_only);
            break;
        case Vanetza_Security_EccP256CurvePoint_PR_uncompressedP256:
            return copy_octets(point.choice.uncompressedP256.x);
            break;
        default:
            return ByteBuffer {};
            break;
    }
}
 
ByteBuffer get_x_coordinate(const asn1::EccP384CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0:
            return copy_octets(point.choice.compressed_y_0);
            break;
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1:
            return copy_octets(point.choice.compressed_y_1);
            break;
        case Vanetza_Security_EccP384CurvePoint_PR_x_only:
            return copy_octets(point.choice.x_only);
            break;
        case Vanetza_Security_EccP384CurvePoint_PR_uncompressedP384:
            return copy_octets(point.choice.uncompressedP384.x);
            break;
        default:
            return ByteBuffer {};
            break;
    }
}
 
} // namespace
 
SecuredMessage SecuredMessage::with_signed_data()
{
    SecuredMessage secured_message;
    secured_message->protocolVersion = 3;
    secured_message->content = asn1::allocate<asn1::Ieee1609Dot2Content>();
    secured_message->content->present = Vanetza_Security_Ieee1609Dot2Content_PR_signedData;
    secured_message->content->choice.signedData = asn1::allocate<asn1::SignedData>();
    secured_message->content->choice.signedData->tbsData = asn1::allocate<asn1::ToBeSignedData>();
    secured_message->content->choice.signedData->tbsData->payload = asn1::allocate<asn1::SignedDataPayload>();
    secured_message->content->choice.signedData->tbsData->payload->data = asn1::allocate<asn1::Ieee1609Dot2Data>();
    secured_message->content->choice.signedData->tbsData->payload->data->protocolVersion = 3;
    secured_message->content->choice.signedData->tbsData->payload->data->content = asn1::allocate<asn1::Ieee1609Dot2Content>();
    secured_message->content->choice.signedData->tbsData->payload->data->content->present = Vanetza_Security_Ieee1609Dot2Content_PR_unsecuredData;
    return secured_message;
}
 
SecuredMessage SecuredMessage::with_signed_data_hash()
{
    SecuredMessage secured_message;
    secured_message->protocolVersion = 3;
    secured_message->content = asn1::allocate<asn1::Ieee1609Dot2Content>();
    secured_message->content->present = Vanetza_Security_Ieee1609Dot2Content_PR_signedData;
    secured_message->content->choice.signedData = asn1::allocate<asn1::SignedData>();
    secured_message->content->choice.signedData->tbsData = asn1::allocate<asn1::ToBeSignedData>();
    secured_message->content->choice.signedData->tbsData->payload = asn1::allocate<asn1::SignedDataPayload>();
    secured_message->content->choice.signedData->tbsData->payload->extDataHash = asn1::allocate<asn1::HashedData>();
    secured_message->content->choice.signedData->tbsData->payload->extDataHash->present = Vanetza_Security_HashedData_PR_sha256HashedData;
    return secured_message;
}
 
SecuredMessage SecuredMessage::with_encrypted_data()
{
    SecuredMessage secured_message;
    secured_message->protocolVersion = 3;
    secured_message->content = asn1::allocate<asn1::Ieee1609Dot2Content>();
    secured_message->content->present = Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData;
    return secured_message;
}
 
SecuredMessage::SecuredMessage() :
    asn1::asn1c_oer_wrapper<asn1::EtsiTs103097Data>(asn_DEF_Vanetza_Security_EtsiTs103097Data)
{
}
 
uint8_t SecuredMessage::protocol_version() const
{
    return m_struct->protocolVersion;
}
 
boost::optional<HashedId8> SecuredMessage::certificate_id() const
{
    return get_certificate_id(signer_identifier());
}
 
ItsAid SecuredMessage::its_aid() const
{
    ItsAid aid = 0;
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data && signed_data->tbsData) {
        aid = signed_data->tbsData->headerInfo.psid;
    }
    return aid;
}
 
void SecuredMessage::set_its_aid(ItsAid its_aid)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        asn1::SignedData* signed_data = m_struct->content->choice.signedData;
        if (signed_data && signed_data->tbsData) {
            signed_data->tbsData->headerInfo.psid = its_aid;
        }
    }
}
 
void SecuredMessage::set_generation_time(Time64 time)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        if (m_struct->content->choice.signedData->tbsData->headerInfo.generationTime == nullptr) {
            m_struct->content->choice.signedData->tbsData->headerInfo.generationTime = asn1::allocate<asn1::Time64>();
        }
        asn_uint642INTEGER(m_struct->content->choice.signedData->tbsData->headerInfo.generationTime, time);
    }
}
 
void SecuredMessage::set_generation_location(const asn1::ThreeDLocation& location)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        if (m_struct->content->choice.signedData->tbsData->headerInfo.generationLocation == nullptr) {
            m_struct->content->choice.signedData->tbsData->headerInfo.generationLocation = asn1::allocate<asn1::ThreeDLocation>();
        }
        m_struct->content->choice.signedData->tbsData->headerInfo.generationLocation->latitude = location.latitude;
        m_struct->content->choice.signedData->tbsData->headerInfo.generationLocation->longitude = location.longitude;
        m_struct->content->choice.signedData->tbsData->headerInfo.generationLocation->elevation = location.elevation;
    }
}
 
std::list<HashedId3> SecuredMessage::get_inline_p2pcd_request() const
{
    std::list<HashedId3> requests;
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        const asn1::SequenceOfHashedId3* inline_p2pcd_request = m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest;
        if (inline_p2pcd_request) {
            for (int i = 0; i < inline_p2pcd_request->list.count; i++) {
                HashedId3 new_elem = truncate(convert(*inline_p2pcd_request->list.array[i]));
                requests.push_back(new_elem);
            }
        }
    }
    return requests;
}
 
void SecuredMessage::set_inline_p2pcd_request(std::list<HashedId3> requests)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        assert(m_struct->content->choice.signedData);
        assert(m_struct->content->choice.signedData->tbsData);
 
        if (m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest) {
            asn1::reset(m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest);
        }
 
        for (HashedId3 request : requests) {
            this->add_inline_p2pcd_request(request);
        }
    }
}
 
void SecuredMessage::add_inline_p2pcd_request(HashedId3 unknown_certificate_digest)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        if (m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest == nullptr) {
            m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest = asn1::allocate<asn1::SequenceOfHashedId3>();
        }
        Vanetza_Security_HashedId3_t* asn_digest = OCTET_STRING_new_fromBuf(&asn_DEF_Vanetza_Security_HashedId3,
                reinterpret_cast<char*>(unknown_certificate_digest.data()), unknown_certificate_digest.size());
        ASN_SEQUENCE_ADD(m_struct->content->choice.signedData->tbsData->headerInfo.inlineP2pcdRequest, asn_digest);
    }
}
 
void SecuredMessage::set_dummy_signature()
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        asn1::SignedData* signed_data = m_struct->content->choice.signedData;
        if (signed_data) {
            // Reset the signature structure
            asn1::reset(signed_data->signature);
 
            // Set the signature type to ECDSA NIST P256
            signed_data->signature.present = Vanetza_Security_Signature_PR_ecdsaNistP256Signature;
 
            // Initialize rSig part of the signature
            signed_data->signature.choice.ecdsaNistP256Signature.rSig.present = Vanetza_Security_EccP256CurvePoint_PR_x_only;
            std::vector<uint8_t> dummy_r(32, 0); // Correct length for P256 signature part
            dummy_r[0] = 0; // Ensure the leading byte is set to zero if needed
            assign(&signed_data->signature.choice.ecdsaNistP256Signature.rSig.choice.x_only, dummy_r);
 
            // Initialize sSig part of the signature
            std::vector<uint8_t> dummy_s(32, 0); // Correct length for P256 signature part
            assign(&signed_data->signature.choice.ecdsaNistP256Signature.sSig, dummy_s);
        }
    }
}
 
void SecuredMessage::set_signature(const Signature& signature)
{
    if (m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData) {
        asn1::SignedData* signed_data = m_struct->content->choice.signedData;
        if (signed_data) {
            // Reset the signature structure
            asn1::reset(signed_data->signature);
 
            // Set the signature type to ECDSA NIST P256
            switch (signature.type)
            {
            case vanetza::security::KeyType::NistP256:
                signed_data->signature.present = Vanetza_Security_Signature_PR_ecdsaNistP256Signature;
                // Initialize rSig and sSig part of the signature
 
                // Check the type (x_only, y-1, y-0 or uncompressed ??????)
                signed_data->signature.choice.ecdsaNistP256Signature.rSig.present = Vanetza_Security_EccP256CurvePoint_PR_x_only;
                assign(&signed_data->signature.choice.ecdsaNistP256Signature.rSig.choice.x_only, signature.r);
                assign(&signed_data->signature.choice.ecdsaNistP256Signature.sSig, signature.s);
                break;
            case vanetza::security::KeyType::BrainpoolP256r1 :
                signed_data->signature.present = Vanetza_Security_Signature_PR_ecdsaBrainpoolP256r1Signature;
                // Check the type (x_only, y-1, y-0 or uncompressed ??????)
                signed_data->signature.choice.ecdsaBrainpoolP256r1Signature.rSig.present = Vanetza_Security_EccP256CurvePoint_PR_x_only;
                assign(&signed_data->signature.choice.ecdsaBrainpoolP256r1Signature.rSig.choice.x_only, signature.r);
                assign(&signed_data->signature.choice.ecdsaBrainpoolP256r1Signature.sSig, signature.s);
                break;
            case vanetza::security::KeyType::BrainpoolP384r1 :
                signed_data->signature.present = Vanetza_Security_Signature_PR_ecdsaBrainpoolP384r1Signature;
                // Check the type (x_only, y-1, y-0 or uncompressed ??????)
                signed_data->signature.choice.ecdsaBrainpoolP384r1Signature.rSig.present = Vanetza_Security_EccP384CurvePoint_PR_x_only;
                assign(&signed_data->signature.choice.ecdsaBrainpoolP384r1Signature.rSig.choice.x_only, signature.r);
                assign(&signed_data->signature.choice.ecdsaBrainpoolP384r1Signature.sSig, signature.s);
                break;
            default:
                this->set_dummy_signature();
                break;
            }
        }
    }
}
 
void SecuredMessage::set_signature(const SomeEcdsaSignature& signature)
{
    struct signature_visitor : public boost::static_visitor<asn1::Signature>
    {
        asn1::Signature operator()(const EcdsaSignature& signature) const
        {
            asn1::Signature final_signature = {};
            final_signature.present = Vanetza_Security_Signature_PR_ecdsaNistP256Signature;
            assign(&final_signature.choice.ecdsaNistP256Signature.sSig, signature.s);
            final_signature.choice.ecdsaNistP256Signature.rSig = to_asn1(signature.R);
            return final_signature;
        }
 
        asn1::Signature operator()(const EcdsaSignatureFuture& signature) const
        {
            return this->operator()(signature.get());
        }
    };
 
    asn1::reset(m_struct->content->choice.signedData->signature);
    m_struct->content->choice.signedData->signature = boost::apply_visitor(signature_visitor(), signature);
}
 
PacketVariant SecuredMessage::payload() const
{
    ByteBuffer buffer;
    switch (m_struct->content->present) {
        case Vanetza_Security_Ieee1609Dot2Content_PR_unsecuredData:
            buffer = get_payload(&m_struct->content->choice.unsecuredData);
            break;
        case Vanetza_Security_Ieee1609Dot2Content_PR_signedData:
            buffer = get_payload(m_struct->content->choice.signedData);
            break;
        default:
            // empty buffer as fallback
            break;
    }
 
    return CohesivePacket { std::move(buffer), OsiLayer::Network };
}
 
void SecuredMessage::set_payload(const ByteBuffer& payload)
{
    switch (m_struct->content->present) {
        case Vanetza_Security_Ieee1609Dot2Content_PR_unsecuredData:
            vanetza::security::v3::set_payload(&m_struct->content->choice.unsecuredData, payload);
            break;
        case Vanetza_Security_Ieee1609Dot2Content_PR_signedData:
            vanetza::security::v3::set_payload(&m_struct->content->choice.signedData->tbsData->payload->data->content->choice.unsecuredData, payload);
            break;
        default:
          // cannot copy payload into secured message
          break;
    }
}
 
void SecuredMessage::set_external_payload_hash(const Sha256Digest& hash)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData);
    asn1::HashedData* hashed_data = m_struct->content->choice.signedData->tbsData->payload->extDataHash;
    asn1::reset(hashed_data);
    hashed_data->present = Vanetza_Security_HashedData_PR_sha256HashedData;
    OCTET_STRING_fromBuf(&hashed_data->choice.sha256HashedData, reinterpret_cast<const char*>(hash.data()), hash.size());
}
 
HashAlgorithm SecuredMessage::hash_id() const
{
    HashAlgorithm algo = HashAlgorithm::Unspecified;
 
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data) {
        switch (signed_data->hashId) {
            case Vanetza_Security_HashAlgorithm_sha256:
                algo = HashAlgorithm::SHA256;
                break;
            case Vanetza_Security_HashAlgorithm_sha384:
                algo = HashAlgorithm::SHA384;
                break;
            default:
                break;
        }
    }
 
    return algo;
}
 
void SecuredMessage::set_hash_id(HashAlgorithm hash)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData);
    switch (hash) {
        case HashAlgorithm::SHA256:
            m_struct->content->choice.signedData->hashId = Vanetza_Security_HashAlgorithm_sha256;
            break;
        case HashAlgorithm::SHA384:
            m_struct->content->choice.signedData->hashId = Vanetza_Security_HashAlgorithm_sha384;
            break;
        default:
            m_struct->content->choice.signedData->hashId = -1;
    }
}
 
void SecuredMessage::set_signer_identifier_self()
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData);
    asn1::SignerIdentifier* signer = &m_struct->content->choice.signedData->signer;
    asn1::reset(signer);
    signer->present = Vanetza_Security_SignerIdentifier_PR_self;
}
 
void SecuredMessage::set_signer_identifier(const HashedId8& digest)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData);
    asn1::SignerIdentifier* signer = &m_struct->content->choice.signedData->signer;
    asn1::reset(signer);
    signer->present = Vanetza_Security_SignerIdentifier_PR_digest;
    OCTET_STRING_fromBuf(&signer->choice.digest, reinterpret_cast<const char*>(digest.data()), digest.size());
}
 
void SecuredMessage::set_signer_identifier(const Certificate& cert)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData);
    asn1::SignerIdentifier* signer = &m_struct->content->choice.signedData->signer;
    asn1::reset(signer);
    signer->present = Vanetza_Security_SignerIdentifier_PR_certificate;
    ASN_SEQUENCE_ADD(&signer->choice.certificate, asn1::copy(asn_DEF_Vanetza_Security_EtsiTs103097Certificate, cert.content()));
}
 
void SecuredMessage::get_aes_ccm_ciphertext(ByteBuffer &ccm_ciphertext, std::array<uint8_t, 12> &nonce) const
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData);
 
    const asn1::SymmetricCiphertext &symmetric_ciphertext = m_struct->content->choice.encryptedData.ciphertext;
    assert(symmetric_ciphertext.present == Vanetza_Security_SymmetricCiphertext_PR_aes128ccm);
 
    const asn1::AesCcmCiphertext &aes_ccm_ciphertext = symmetric_ciphertext.choice.aes128ccm;
    ccm_ciphertext = copy_octets(aes_ccm_ciphertext.ccmCiphertext);
    std::memcpy(nonce.data(), aes_ccm_ciphertext.nonce.buf, nonce.size());
}
 
void SecuredMessage::set_aes_ccm_ciphertext(const ByteBuffer &ccm_ciphertext, const std::array<uint8_t, 12> &nonce)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData);
 
    asn1::SymmetricCiphertext &symmetric_ciphertext = m_struct->content->choice.encryptedData.ciphertext;
    CHOICE_variant_set_presence(&asn_DEF_Vanetza_Security_SymmetricCiphertext, &symmetric_ciphertext, Vanetza_Security_SymmetricCiphertext_PR_aes128ccm);
 
    asn1::AesCcmCiphertext &aes_ccm_ciphertext = symmetric_ciphertext.choice.aes128ccm;
    OCTET_STRING_fromBuf(&aes_ccm_ciphertext.ccmCiphertext, reinterpret_cast<const char *>(ccm_ciphertext.data()), ccm_ciphertext.size());
    OCTET_STRING_fromBuf(&aes_ccm_ciphertext.nonce, reinterpret_cast<const char *>(nonce.data()), nonce.size());
}
 
void SecuredMessage::set_cert_recip_info(const HashedId8& recipient_id,
                                         const std::array<uint8_t, 16>& ecies_ciphertext,
                                         const std::array<uint8_t, 16>& ecies_tag,
                                         const PublicKey& ecies_pub_key)
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData);
 
    // own the RecipientInfo until it is handed to the message (exception safety)
    auto cert_recip_info = asn1::make_unique<asn1::RecipientInfo>();
    CHOICE_variant_set_presence(&asn_DEF_Vanetza_Security_RecipientInfo, cert_recip_info.get(), Vanetza_Security_RecipientInfo_PR_certRecipInfo);
 
    asn1::PKRecipientInfo &pk_recip_info = cert_recip_info->choice.certRecipInfo;
    // Set recipient certificate digest
    OCTET_STRING_fromBuf(&pk_recip_info.recipientId, reinterpret_cast<const char *>(recipient_id.data()), recipient_id.size());
 
    asn1::EncryptedDataEncryptionKey &enc_data_enc_key = pk_recip_info.encKey;
    asn1::EciesP256EncryptedKey *ecies_enc_key = nullptr;
    if (ecies_pub_key.type == KeyType::NistP256) {
        enc_data_enc_key.present = Vanetza_Security_EncryptedDataEncryptionKey_PR_eciesNistP256;
        ecies_enc_key = &enc_data_enc_key.choice.eciesNistP256;
    } else if (ecies_pub_key.type == KeyType::BrainpoolP256r1) {
        enc_data_enc_key.present = Vanetza_Security_EncryptedDataEncryptionKey_PR_eciesBrainpoolP256r1;
        ecies_enc_key = &enc_data_enc_key.choice.eciesBrainpoolP256r1;
    } else {
        throw std::invalid_argument("Unsupported EC curve");
    }
 
    // Set ECIES ciphertext and tag
    OCTET_STRING_fromBuf(&ecies_enc_key->c, reinterpret_cast<const char *>(ecies_ciphertext.data()), ecies_ciphertext.size());
    OCTET_STRING_fromBuf(&ecies_enc_key->t, reinterpret_cast<const char *>(ecies_tag.data()), ecies_tag.size());
 
    // Set ECIES ephemeral public key
    ecies_enc_key->v = to_asn1(make_ecc_point(ecies_pub_key));
 
    ASN_SEQUENCE_ADD(&m_struct->content->choice.encryptedData.recipients.list, cert_recip_info.release());
}
 
bool SecuredMessage::check_psk_match(const std::array<uint8_t, 16>& psk) const
{
    assert(m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData);
 
    // Wrap the given PSK into a PSKRecipientInfo_t to calculate the HashedId8
    asn1::asn1c_oer_wrapper<asn1::SymmetricEncryptionKey> psk_key(asn_DEF_Vanetza_Security_SymmetricEncryptionKey);
    asn1::SymmetricEncryptionKey *psk_key_ptr = &(*psk_key);
    CHOICE_variant_set_presence(
        &asn_DEF_Vanetza_Security_SymmetricEncryptionKey,
        psk_key_ptr,
        Vanetza_Security_SymmetricEncryptionKey_PR_aes128Ccm);
    OCTET_STRING_fromBuf(&psk_key_ptr->choice.aes128Ccm, reinterpret_cast<const char *>(psk.data()), psk.size());
 
    ByteBuffer bytes = psk_key.encode();
    Sha256Digest psk_digest = calculate_sha256_digest(bytes.data(), bytes.size());
    HashedId8 psk_id = create_hashed_id8(psk_digest);
 
    // Check every RecipientInfo for a PSKRecipientInfo with matching PSK
    const auto &recipient_list = m_struct->content->choice.encryptedData.recipients.list;
 
    for (int i = 0; i < recipient_list.count; i++) {
        const asn1::RecipientInfo &recipient_info = *recipient_list.array[i];
        if (recipient_info.present != Vanetza_Security_RecipientInfo_PR_pskRecipInfo) {
            continue;
        }
 
        HashedId8 message_psk_id;
        std::memcpy(message_psk_id.data(), recipient_info.choice.pskRecipInfo.buf, message_psk_id.size());
        if (psk_id == message_psk_id) {
            return true;
        }
    }
 
    return false;
}
 
bool SecuredMessage::is_signed() const
{
    return m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_signedData;
}
 
bool SecuredMessage::is_encrypted() const
{
    return m_struct->content->present == Vanetza_Security_Ieee1609Dot2Content_PR_encryptedData;
}
 
boost::optional<SecuredMessage::Time64> SecuredMessage::generation_time() const
{
    boost::optional<Time64> gen_time;
    auto header_info = get_header_info(m_struct);
    if (header_info) {
        std::uintmax_t tmp;
        if (asn_INTEGER2umax(header_info->generationTime, &tmp) == 0) {
            gen_time = tmp;
        }
    }
    return gen_time;
}
 
boost::optional<Signature> SecuredMessage::signature() const
{
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data) {
        const asn1::Signature& asn = signed_data->signature;
        Signature sig;
        switch (asn.present)
        {
            case Vanetza_Security_Signature_PR_ecdsaNistP256Signature:
                sig.type = KeyType::NistP256;
                sig.r = get_x_coordinate(asn.choice.ecdsaNistP256Signature.rSig);
                sig.s = copy_octets(asn.choice.ecdsaNistP256Signature.sSig);
                break;
            case Vanetza_Security_Signature_PR_ecdsaBrainpoolP256r1Signature:
                sig.type = KeyType::BrainpoolP256r1;
                sig.r = get_x_coordinate(asn.choice.ecdsaBrainpoolP256r1Signature.rSig);
                sig.s = copy_octets(asn.choice.ecdsaBrainpoolP256r1Signature.sSig);
                break;
            case Vanetza_Security_Signature_PR_ecdsaBrainpoolP384r1Signature:
                sig.type = KeyType::BrainpoolP384r1;
                sig.r = get_x_coordinate(asn.choice.ecdsaBrainpoolP384r1Signature.rSig);
                sig.s = copy_octets(asn.choice.ecdsaBrainpoolP384r1Signature.sSig);
                break;
            default:
                return boost::none;
        }
        return sig;
    }
 
    return boost::none;
}
 
SecuredMessage::SignerIdentifier SecuredMessage::signer_identifier() const
{
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data) {
        if (signed_data->signer.present == Vanetza_Security_SignerIdentifier_PR_digest) {
            const asn1::HashedId8* digest = &signed_data->signer.choice.digest;
            return digest;
        } else if (signed_data->signer.present == Vanetza_Security_SignerIdentifier_PR_certificate) {
            const asn1::SequenceOfCertificate& certificates = signed_data->signer.choice.certificate;
            // TS 103 097 v1.3.1 contraints this to exactly one certificate in clause 5.2
            if (certificates.list.count == 1) {
                const asn1::Certificate* cert = certificates.list.array[0];
                return cert;
            }
        }
    }
 
    return static_cast<asn1::HashedId8*>(nullptr);
}
 
ByteBuffer SecuredMessage::signing_payload() const
{
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data) {
        return asn1::encode_oer(asn_DEF_Vanetza_Security_ToBeSignedData, signed_data->tbsData);
    } else {
        return ByteBuffer {};
    }
}
 
void SecuredMessage::set_requested_certificate(const Certificate& cert)
{
    const asn1::SignedData* signed_data = get_signed_data(m_struct);
    if (signed_data && signed_data->tbsData) {
        if (signed_data->tbsData->headerInfo.requestedCertificate) {
            ASN_STRUCT_FREE(asn_DEF_Vanetza_Security_Certificate, signed_data->tbsData->headerInfo.requestedCertificate);
        }
        signed_data->tbsData->headerInfo.requestedCertificate =
            static_cast<Vanetza_Security_Certificate*>(asn1::copy(asn_DEF_Vanetza_Security_Certificate, cert.content()));
    }
}
 
size_t get_size(const SecuredMessage& message)
{
    return message.size();
}
 
void serialize(OutputArchive& ar, const SecuredMessage& msg)
{
    ByteBuffer buffer = msg.encode();
    ar.save_binary(buffer.data(), buffer.size());
}
 
size_t deserialize(InputArchive& ar, SecuredMessage& msg)
{
    std::size_t len = ar.remaining_bytes();
    // TODO optimize decoding step without buffer allocation
    ByteBuffer buffer;
    buffer.resize(len);
    ar.load_binary(buffer.data(), len);
    return msg.decode(buffer) ? len : 0;
}
 
ByteBuffer get_payload(const asn1::Opaque* unsecured)
{
    ByteBuffer buffer;
    buffer.reserve(unsecured->size);
    std::copy_n(unsecured->buf, unsecured->size, std::back_inserter(buffer));
    return buffer;
}
 
ByteBuffer convert_to_payload(vanetza::DownPacket packet)
{
    ByteBuffer buf;
    byte_buffer_sink sink(buf);
 
    boost::iostreams::stream_buffer<byte_buffer_sink> stream(sink);
    OutputArchive ar(stream);
 
    serialize(ar, packet);
 
    stream.close();
    return buf;
}
 
void set_payload(asn1::Opaque* unsecured, const ByteBuffer& buffer)
{
    OCTET_STRING_fromBuf(unsecured, reinterpret_cast<const char*>(buffer.data()), buffer.size());
}
 
ByteBuffer get_payload(const asn1::SignedData* signed_data)
{
    ByteBuffer buffer;
    if (signed_data->tbsData && signed_data->tbsData->payload) {
        const asn1::SignedDataPayload* signed_payload = signed_data->tbsData->payload;
        if (signed_payload->data && signed_payload->data->content) {
            const asn1::Ieee1609Dot2Content* content = signed_payload->data->content;
            if (content->present == Vanetza_Security_Ieee1609Dot2Content_PR_unsecuredData) {
                buffer = get_payload(&content->choice.unsecuredData);
            }
        }
    }
    return buffer;
}
 
boost::optional<HashedId8> get_certificate_id(const SecuredMessage::SignerIdentifier& identifier)
{
    using result_type = boost::optional<HashedId8>;
    struct cert_id_visitor : public boost::static_visitor<result_type> {
        result_type operator()(const asn1::HashedId8* digest) const
        {
            return digest ? make_hashed_id8(*digest) : result_type { };
        }
 
        result_type operator()(const asn1::Certificate* cert) const
        {
            return cert ? calculate_digest(*cert) : result_type { };
        }
    };
    return boost::apply_visitor(cert_id_visitor(), identifier);
}
 
bool contains_certificate(const SecuredMessage::SignerIdentifier& identifier)
{
    struct visitor : public boost::static_visitor<bool> {
        bool operator()(const asn1::HashedId8*) const
        {
            return false;
        }
 
        bool operator()(const asn1::Certificate*) const
        {
            return true;
        }
    };
    return boost::apply_visitor(visitor(), identifier);
}
 
const asn1::Certificate* get_certificate(const SecuredMessage::SignerIdentifier& identifier)
{
    struct visitor : public boost::static_visitor<const asn1::Certificate*> {
        const asn1::Certificate* operator()(const asn1::HashedId8*) const
        {
            return nullptr;
        }
 
        const asn1::Certificate* operator()(const asn1::Certificate* cert) const
        {
            return cert;
        }
    };
    return boost::apply_visitor(visitor(), identifier);
}
 
} // namespace v3
} // namespace security
} // namespace vanetza