internal static string GetSubject(GXAsn1Sequence values)
{
object value;
StringBuilder sb = new StringBuilder();
foreach (KeyValuePair <object, object> it in values)
{
sb.Append(X509NameConverter.FromString(it.Key.ToString()));
sb.Append('=');
value = it.Value;
sb.Append(value);
sb.Append(", ");
}
// Remove last comma.
if (sb.Length != 0)
{
sb.Length = sb.Length - 2;
}
return(sb.ToString());
}
// 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;
}