public static List <KeyValuePair <object, object> > EncodeSubject(string value) { X509Name name; object val; List <KeyValuePair <object, object> > list = new List <KeyValuePair <object, object> >(); foreach (string tmp in value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)) { string[] it = tmp.Split(new char[] { '=' }); if (it.Length != 2) { throw new ArgumentException("Invalid subject."); } name = (X509Name)Enum.Parse(typeof(X509Name), it[0].Trim()); switch (name) { case X509Name.C: // Country code is printable string val = it[1].Trim(); break; case X509Name.E: // email address in Verisign certificates val = new GXAsn1Ia5String(it[1].Trim()); break; default: val = new GXAsn1Utf8String(it[1].Trim()); break; } string oid = X509NameConverter.GetString(name); list.Add(new KeyValuePair <object, object>(new GXAsn1ObjectIdentifier(oid), val)); } return(list); }
// https://tools.ietf.org/html/rfc5280#section-4.1 private void Init(byte[] data) { rawData = data; GXAsn1Sequence seq = (GXAsn1Sequence)GXAsn1Converter.FromByteArray(data); if (seq.Count != 3) { throw new GXDLMSCertificateException("Invalid Certificate Version. Wrong number of elements in sequence."); } if (!(seq[0] is GXAsn1Sequence)) { PkcsType type = GXAsn1Converter.GetCertificateType(data, seq); switch (type) { case PkcsType.Pkcs8: throw new GXDLMSCertificateException("Invalid Certificate. This is PKCS 8 private key, not x509 certificate."); case PkcsType.Pkcs10: throw new GXDLMSCertificateException("Invalid Certificate. This is PKCS 10 certification requests, not x509 certificate."); } throw new GXDLMSCertificateException("Invalid Certificate Version."); } GXAsn1Sequence reqInfo = (GXAsn1Sequence)seq[0]; if ((reqInfo[0] is GXAsn1Integer)) { throw new GXDLMSCertificateException("Invalid Certificate. DLMS certificate version number must be 3."); } Version = (CertificateVersion)((GXAsn1Context)reqInfo[0])[0]; if (reqInfo[1] is sbyte) { SerialNumber = Convert.ToUInt64(reqInfo[1]); } else { SerialNumber = new BigInteger(((GXAsn1Integer)reqInfo[1]).Value); } string tmp = ((GXAsn1Sequence)reqInfo[2])[0].ToString(); // Signature Algorithm SignatureAlgorithm = HashAlgorithmConverter.FromString(tmp); if (SignatureAlgorithm != HashAlgorithm.Sha256WithEcdsa) { throw new Exception("DLMS certificate must be signed with ecdsa-with-SHA256."); } // Optional. if (((GXAsn1Sequence)reqInfo[2]).Count > 1) { SignatureParameters = ((GXAsn1Sequence)reqInfo[2])[1]; } // Issuer Issuer = GXAsn1Converter.GetSubject((GXAsn1Sequence)reqInfo[3]); bool basicConstraintsExists = false; // Validity ValidFrom = (DateTime)((GXAsn1Sequence)reqInfo[4])[0]; ValidTo = (DateTime)((GXAsn1Sequence)reqInfo[4])[1]; Subject = GXAsn1Converter.GetSubject((GXAsn1Sequence)reqInfo[5]); string CN = X509NameConverter.GetString(X509Name.CN); // Subject public key Info GXAsn1Sequence subjectPKInfo = (GXAsn1Sequence)reqInfo[6]; PublicKey = GXPublicKey.FromRawBytes(((GXAsn1BitString)subjectPKInfo[1]).Value); GXEcdsa.Validate(PublicKey); // Get Standard Extensions. if (reqInfo.Count > 7) { foreach (GXAsn1Sequence s in (GXAsn1Sequence)((GXAsn1Context)reqInfo[7])[0]) { GXAsn1ObjectIdentifier id = (GXAsn1ObjectIdentifier)s[0]; object value = s[1]; X509CertificateType t = X509CertificateTypeConverter.FromString(id.ToString()); switch (t) { case X509CertificateType.SubjectKeyIdentifier: SubjectKeyIdentifier = (byte[])value; break; case X509CertificateType.AuthorityKeyIdentifier: foreach (GXAsn1Context it in (GXAsn1Sequence)value) { switch (it.Index) { case 0: //Authority Key Identifier. AuthorityKeyIdentifier = (byte[])it[0]; break; case 1: { StringBuilder sb = new StringBuilder(); //authorityCertIssuer foreach (KeyValuePair <object, object> it2 in ((GXAsn1Sequence)((GXAsn1Context)it[0])[0])) { if (sb.Length != 0) { sb.Append(", "); } sb.Append(X509NameConverter.FromString(Convert.ToString(it2.Key))); sb.Append("="); sb.Append(Convert.ToString(it2.Value)); } AuthorityCertIssuer = sb.ToString(); } break; case 2: //Authority cert serial number . AuthorityCertificationSerialNumber = (byte[])it[0]; break; default: throw new ArgumentOutOfRangeException("Invalid context." + it.Index); } } break; case X509CertificateType.KeyUsage: if (value is GXAsn1BitString) { // critical is optional. BOOLEAN DEFAULT FALSE, KeyUsage = (KeyUsage)((GXAsn1BitString)value).ToInteger(); } else if (value is bool?) { value = s[2]; KeyUsage = (KeyUsage)((GXAsn1BitString)value).ToInteger(); } else { throw new ArgumentException("Invalid key usage."); } break; case X509CertificateType.BasicConstraints: basicConstraintsExists = true; if (value is GXAsn1Sequence) { if (((GXAsn1Sequence)value).Count != 0) { BasicConstraints = (bool)((GXAsn1Sequence)value)[0]; } } else if (value is bool?) { BasicConstraints = (bool)value; } else { throw new ArgumentException("Invalid key usage."); } break; default: System.Diagnostics.Debug.WriteLine("Unknown extensions: " + t.ToString()); break; } } } if (!basicConstraintsExists) { // Verify that subject Common Name includes system title. bool commonNameFound = false; foreach (KeyValuePair <object, object> it in (GXAsn1Sequence)reqInfo[5]) { if (CN == it.Key.ToString()) { if (Convert.ToString(it.Value).Length != 16) { throw new GXDLMSCertificateException("System title is not included in Common Name."); } commonNameFound = true; break; } } if (!commonNameFound) { throw new GXDLMSCertificateException("Common name doesn't exist."); } } if (KeyUsage == KeyUsage.None) { throw new Exception("Key usage not present. It's mandotory."); } if ((KeyUsage & (KeyUsage.KeyCertSign | KeyUsage.CrlSign)) != 0 && !basicConstraintsExists) { throw new Exception("Basic Constraints value not present. It's mandotory."); } PublicKeyAlgorithm = HashAlgorithmConverter.FromString(((GXAsn1Sequence)seq[1])[0].ToString()); if (PublicKeyAlgorithm != HashAlgorithm.Sha256WithEcdsa) { throw new Exception("DLMS certificate must be signed with ecdsa-with-SHA256."); } // Optional. if (((GXAsn1Sequence)seq[1]).Count > 1) { PublicKeyParameters = ((GXAsn1Sequence)seq[1])[1]; } ///////////////////////////// //Get signature. Signature = ((GXAsn1BitString)seq[2]).Value; }