(+) f_verifySignedMessageECDSA - check message signature function (a68f9679) · Commits · ITS - Intelligent Transport Systems / ttcn / SEC TS 103 096-3

lib_system/LibItsSecurity_Functions.ttcn

+68 −0

Original line number	Diff line number	Diff line
		@@ -92,6 +92,74 @@ module LibItsSecurity_Functions {
		return ''O;
		} // End of function f_signWithEcdsa

		function f_verifySignedMessageECDSA(
		in Ieee1609Dot2Data p_msg,
		in template (omit) EtsiTs103097Certificate p_signer := omit,
		in template(omit) PublicVerificationKey p_verification_key := omit
		) return boolean {
		var octetstring v_signer_hash;
		var PublicVerificationKey v_verification_key;

		if(ischosen(p_msg.content.signedData.signer.self_)){
		if(not ispresent(p_verification_key)){
		return false; // unsupported yet
		}
		v_verification_key := valueof(p_verification_key);
		select(f_getHashAlgorithmOfVerificationKey(v_verification_key)){
		case (sha256){
		v_signer_hash := f_hashWithSha256(''O);
		}
		case (sha384){
		v_signer_hash := f_hashWithSha384(''O);
		}
		case else {
		return false;
		}
		}
		}else{
		var EtsiTs103097Certificate v_signer;
		if(ischosen(p_msg.content.signedData.signer.certificate)){
		var integer v_length := lengthof(p_msg.content.signedData.signer.certificate);
		if(v_length < 1) {
		return false;
		}
		v_signer := p_msg.content.signedData.signer.certificate[v_length - 1];
		}else if(ischosen(p_msg.content.signedData.signer.digest)){
		if(ispresent(p_signer)) {
		v_signer := valueof(p_signer);
		}else{
		var charstring v_certificate_id;
		if(not f_getCertificateFromDigest(p_msg.content.signedData.signer.digest, v_signer, v_certificate_id)){
		return false;
		}
		}
		}else{
		return false;
		}
		if(not ischosen(v_signer.toBeSigned.verifyKeyIndicator.verificationKey)){
		return false;
		}
		v_verification_key := v_signer.toBeSigned.verifyKeyIndicator.verificationKey;
		select(f_getHashAlgorithmOfVerificationKey(v_verification_key)){
		case (sha256){
		v_signer_hash := f_hashWithSha256(bit2oct(encvalue(v_signer)));
		}
		case (sha384){
		v_signer_hash := f_hashWithSha384(bit2oct(encvalue(v_signer)));
		}
		case else {
		return false;
		}
		}
		}

		return f_verifyEcdsa(
		bit2oct(encvalue(p_msg.content.signedData.tbsData)),
		v_signer_hash,
		p_msg.content.signedData.signature_,
		v_verification_key);
		}

		function f_verifyEcdsa(
		in octetstring p_tbs,
		in octetstring p_issuer,