private static Asn1Node AddString(Asn1Node parent, string name, string value)
{
var childNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
parent.AddChild(childNode);
var nameNode = new Asn1Node
{
Tag = Asn1Tag.OBJECT_IDENTIFIER,
Data = oidInstance.Encode(name)
};
childNode.AddChild(nameNode);
var valueNode = new Asn1Node();
if (value == null)
{
valueNode.Tag = Asn1Tag.TAG_NULL;
}
else
{
valueNode.Tag = Asn1Tag.PRINTABLE_STRING;
valueNode.Data = Encoding.ASCII.GetBytes(value);
}
childNode.AddChild(valueNode);
return(parent);
}
public static void GenerateCsr(int keysize, string domainname, string email, string city, string state, string country, string orgname, Stream output)
{
var keyPair = new RSACryptoServiceProvider(keysize);
var rootNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
var topSequenceNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
rootNode.AddChild(topSequenceNode);
var versionNode = new Asn1Node
{
Tag = Asn1Tag.INTEGER,
Data = new byte[] { 0 }
};
topSequenceNode.AddChild(versionNode);
var stringSequenceNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
topSequenceNode.AddChild(stringSequenceNode);
AddSubjectString(stringSequenceNode, "2.5.4.3", domainname);
AddSubjectString(stringSequenceNode, "2.5.4.7", city);
AddSubjectString(stringSequenceNode, "2.5.4.6", country);
AddSubjectString(stringSequenceNode, "2.5.4.8", state);
AddSubjectString(stringSequenceNode, "2.5.4.10", orgname);
AddSubjectString(stringSequenceNode, "1.2.840.113549.1.9.1", email);
var rsaNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
topSequenceNode.AddChild(AddString(rsaNode, "1.2.840.113549.1.1.1", null));
var publicKeyNode = new Asn1Node
{
Tag = Asn1Tag.BIT_STRING
};
rsaNode.AddChild(publicKeyNode);
var publicKeySequenceNode = new Asn1Node
{
Tag = Asn1Tag.SEQUENCE | Asn1TagClasses.CONSTRUCTED
};
publicKeyNode.AddChild(publicKeySequenceNode);
var publicKeyInfo = keyPair.ExportParameters(false);
publicKeySequenceNode.AddChild(new Asn1Node
{
Tag = Asn1Tag.INTEGER,
Data = publicKeyInfo.Modulus
});
publicKeySequenceNode.AddChild(new Asn1Node
{
Tag = Asn1Tag.INTEGER,
Data = publicKeyInfo.Exponent
});
topSequenceNode.AddChild(new Asn1Node
{
Tag = Asn1TagClasses.CONTEXT_SPECIFIC | Asn1TagClasses.CONSTRUCTED
});
byte[] signature;
using (var data = new MemoryStream(keysize))
{
topSequenceNode.SaveData(data);
signature = keyPair.SignData(data.GetBuffer(), 0, (int)data.Length, new SHA1CryptoServiceProvider());
}
AddString(rootNode, "1.2.840.113549.1.1.5", null);
rootNode.AddChild(new Asn1Node
{
Tag = Asn1Tag.BIT_STRING,
Data = signature
});
var csrOutput = new StreamWriter(output);
csrOutput.WriteLine("-----BEGIN CERTIFICATE REQUEST-----");
using (var data = new MemoryStream(keysize))
{
rootNode.SaveData(data);
var base64Data = Convert.ToBase64String(data.GetBuffer(), 0, (int)data.Length,
Base64FormattingOptions.InsertLineBreaks);
csrOutput.WriteLine(base64Data);
}
csrOutput.WriteLine("-----END CERTIFICATE REQUEST-----");
csrOutput.Flush();
}