LibItsSecurity_Functions.ttcn3

/**
 *  @author   ETSI / STF481
 *  @version  $URL$
 *            $Id$
 *  @desc     Module containing functions for Security Protocol
 *
 */
module LibItsSecurity_Functions {
    
    // Libcommon
    import from LibCommon_BasicTypesAndValues all;
    import from LibCommon_DataStrings all;

    // LibItsCommon
    import from LibItsCommon_Functions all;
    
    // LibItsSecurity
    import from LibItsSecurity_TypesAndValues all;
    import from LibItsSecurity_Templates all;
    import from LibItsSecurity_Pixits all;
    import from LibItsSecurity_TestSystem all;
    
    group helpersFunctions {
        
        /**
        * @desc    Produces a 256-bit (32-byte) hash value
        * @param   p_toBeHashedData Data to be used to calculate the hash value
        * @return  The hash value
        */
        function f_hashWithSha256(
                                  in octetstring p_toBeHashedData
        ) return Oct32 {
            return fx_hashWithSha256(p_toBeHashedData);
        } // End of function f_hashWithSha256
        
        /**
        * @desc    Produces a Elliptic Curve Digital Signature Algorithm (ECDSA) signaturee
        * @param   p_toBeSignedSecuredMessage    The data to be signed
        * @return  The signature value
        */
        function f_signWithEcdsaNistp256WithSha256(
                                                   in Oct32 p_toBeSignedSecuredMessage
        ) runs on ItsSecurityBaseComponent return octetstring {
            return fx_signWithEcdsaNistp256WithSha256(
                p_toBeSignedSecuredMessage,
                vc_signingPrivateKey
            );
            
        } // End of function f_signWithEcdsaNistp256WithSha256
        
        /**
        * @desc Compute the HashedId8 value from the hash value
        * @param p_hash The hash value
        * @return The HashedId8 value
        * @verdict
        */
        function f_HashedId8FromSha256(
                                       in Oct32 p_hash
        ) return HashedId8 {
            return substr(p_hash, lengthof(p_hash) - 8, 8);
        } // End of function f_HashedId8FromSha256
        
        /**
        * @desc Compute the HashedId3 value from the HashedId8 value
        * @param p_hashp_hashedId8 The HashedId8 value
        * @return The HashedId3 value
        * @verdict Unchanged
        */
        function f_HashedId3FromHashedId8(
                                          in HashedId8 p_hashedId8
        ) return HashedId3 {
            return substr(p_hashedId8, lengthof(p_hashedId8) - 3, 3);
        }  // End of function f_HashedId3FromHashedId8
        
        /**
        * @desc    Verify the signature of the specified data
        * @param   p_toBeVerifiedData          The data to be verified
        * @param   p_signature                 The signature
        * @param   p_ecdsaNistp256PublicKeyX   The public key (x coordinate)
        * @param   p_ecdsaNistp256PublicKeyY   The public key (y coordinate)
        * @return  true on success, false otherwise
        */
        function f_verifyWithEcdsaNistp256WithSha256(
                                                     in octetstring p_toBeVerifiedData,
                                                     in octetstring p_signature,
                                                     in octetstring p_ecdsaNistp256PublicKeyX,
                                                     in octetstring p_ecdsaNistp256PublicKeyY
        ) return boolean {
            return fx_verifyWithEcdsaNistp256WithSha256(
                p_toBeVerifiedData,
                p_signature,
                p_ecdsaNistp256PublicKeyX,
                p_ecdsaNistp256PublicKeyY);
        } // End of function f_verifyWithEcdsaNistp256WithSha256
        
        /**
        * @desc    Calculate digest over the certificate
        * @param   p_cert The certificate
        * @return  the digest
        * @see Draft ETSI TS 103 097 V1.1.13 Clause 4.2.13   HashedId8
        */
        function f_calculateDigestFromCertificate(
                                                  in Certificate p_cert
        ) return HashedId8 {
            var octetstring v_toBeHashedData;
            var octetstring v_hash;
            
            // Search for digest in the signer_infos field first
            for (var integer v_counter := 0; v_counter < lengthof(p_cert.signer_infos); v_counter := v_counter + 1) {
                if (p_cert.signer_infos[v_counter].type_ == e_certificate_digest_with_sha256) {
                    return p_cert.signer_infos[v_counter].signerInfo.digest;
                }
            } // End of 'for' statement
            
            // Digest not found, compute it
            log ("f_calculateDigestFromCertificate: Not found in certificate, compute it");
            v_toBeHashedData := bit2oct(encvalue(p_cert));
            v_hash := f_hashWithSha256(v_toBeHashedData);
            return substr(v_hash, lengthof(v_hash) - 8, 8);
        }
        
        group hostSignatureHelpers {
            
            function f_prepareCertificates(
                                           in template (omit) charstring p_certificateName,
                                           out Certificate p_aaCertificate,
                                           out Certificate p_atCertificate
            ) runs on ItsSecurityBaseComponent return boolean {
                
                // Load certificates if required
                if (ispresent(p_certificateName) and (valueof(p_certificateName) != cc_taCertA)) {
                    if (f_readCertificate(valueof(p_certificateName) & ".AA_CERT", p_aaCertificate) == false) {
                        return false;
                    }
                    if (f_readCertificate(valueof(p_certificateName) & ".AT_CERT", p_atCertificate) == false) {
                        return false;
                    }
                } else {
                    p_aaCertificate := vc_aaCertificate;
                    p_atCertificate := vc_atCertificate;
                }
                // Store the certificte to build this message
                vc_lastAtCertificateUsed := p_atCertificate;
                
                return true;
            } // End of function f_prepareCertificates
            
            /**
            * @desc Build a template of a secured beacon to be used for the Test Adapter secured beaconing processing
            */
            function f_buildSecuredMessagePayloadToBeSigned(
                                                            in boolean p_includeCertificate := false
            ) runs on ItsSecurityBaseComponent return ToBeSignedSecuredMessage {
                
                // Local variables
                var template (value) ToBeSignedSecuredMessage v_toBeSignedSecuredMessage;
                
                // Build the beacon template
                if (p_includeCertificate == true) {
                    v_toBeSignedSecuredMessage := m_toBeSignedSecuredMessage(
                        { // Field HeaderFields
                            m_header_field_signer_info(
                                m_signerInfo_certificate(
                                    vc_atCertificate
                                ) // End of template m_signerInfo_certificate
                            ), // End of template m_header_field_signer_info
                            m_header_field_generation_time(oct2int('BBBBBBBB'O)),   // To be replaced by TA with generation time
                            m_header_field_generation_location(
                                vc_location
                            )
                        }, // End of field HeaderFields
                        m_payload_signed(
                            'AAAAAAAAAA'O                                           // To be replaced by TA with real payload
                        ),
                        e_signature
                    );
                } else {
                    v_toBeSignedSecuredMessage := m_toBeSignedSecuredMessage(
                        { // Field HeaderFields
                            m_header_field_signer_info(
                                m_signerInfo_digest(
                                    vc_atCertificate.signer_infos[0].signerInfo.digest
                                ) // End of template m_signerInfo_certificate
                            ), // End of template m_header_field_signer_info
                            m_header_field_generation_time(oct2int('BBBBBBBB'O)),   // To be replaced by TA with generation time
                            m_header_field_generation_location(
                                vc_location
                            )
                        }, // End of field HeaderFields
                        m_payload_signed(
                            'AAAAAAAAAA'O                                           // To be replaced by TA with real payload
                        ),
                        e_signature
                    );
                }
                
                return valueof(v_toBeSignedSecuredMessage);
            }
            
            /**