public void ExtensionIssuerAltName(byte type, string name)
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
byte[] lengthBytes = EncodeLength(name.Length);
byte[] valueBytes = System.Text.Encoding.UTF8.GetBytes(name);
int length = name.Length;
byte[] nameDER = new byte[1 + lengthBytes.Length + valueBytes.Length];
nameDER[0] = (byte)(0x80 | type);
Array.Copy(lengthBytes, 0, nameDER, 1, lengthBytes.Length);
Array.Copy(valueBytes, 0, nameDER, 1 + lengthBytes.Length, valueBytes.Length);
byte[] bytes = new byte[nameDER.Length + 2];
bytes[0] = 0x30; // it's a sequence
bytes[1] = (byte)nameDER.Length;
Array.Copy(nameDER, 0, bytes, 2, nameDER.Length);
AsnExtension extension = new AsnExtension(new AsnOid("2.5.29.18"), false, bytes);
extensions.extensions.Add(extension);
}
public static AsnExtensions Decode(byte[] source, ref int pos)
{
AsnExtensions instance = new AsnExtensions();
//instance.CheckContextTag(source, ref pos);
pos++;
long len = instance.GetLength(source, ref pos);
instance.extensions = new List <AsnExtension>();
long start = pos;
while (pos < start + len)
{
instance.extensions.Add(AsnExtension.Decode(source, ref pos));
}
return(instance);
}
// TODO: note 4.1.2.9 of RFC5280 - there are some additional requirements on CAs
// especially regarding the optional path length stuff
public void ExtensionBasicConstraints(bool ca)
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
AsnBoolean caFlag = new AsnBoolean(ca);
int length = caFlag.Encode();
byte[] bytes = new byte[length + 2];
bytes[0] = 0x30; // it's a sequence
bytes[1] = (byte)length;
Array.Copy(caFlag.derValue, 0, bytes, 2, caFlag.derValue.Length);
AsnExtension extension = new AsnExtension(new AsnOid("2.5.29.19"), true, bytes);
extensions.extensions.Add(extension);
}
public void ExtensionSubjectKeyIdentifier()
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
subjectPKInfo.Encode();
byte[] hash = SHA1.Create().ComputeHash(subjectPKInfo.publicKey.value);
byte[] der = new byte[2 + hash.Length];
der[0] = 0x04; // it's an octet string
der[1] = (byte)hash.Length;
Array.Copy(hash, 0, der, 2, hash.Length);
AsnExtension extension = new AsnExtension(new AsnOid("2.5.29.14"), false, der);
extensions.extensions.Add(extension);
}
public static AsnExtension Decode(byte[] source, ref int pos)
{
AsnExtension instance = new AsnExtension();
pos++;
long len = instance.GetLength(source, ref pos);
instance.extnID = AsnOid.Decode(source, ref pos);
if (source[pos] == 0x1)
{
instance.critical = AsnBoolean.Decode(source, ref pos);
}
instance.extnValue = AsnOctetstring.Decode(source, ref pos);
return(instance);
}
public void ExtensionAuthorityKeyIdentifier()
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
AsnOid oid = new AsnOid("2.5.29.35");
subjectPKInfo.Encode();
byte[] hash = SHA1.Create().ComputeHash(subjectPKInfo.publicKey.value);
byte[] der = new byte[4 + hash.Length];
der[0] = 0x30; //it's a sequence
der[1] = (byte)(hash.Length + 2);
der[2] = 0x80; // context tag indicating option 0 (see 4.2.1.1 of RFC 5280)
// I feel there should be a 0x04 here to indicate octet string but OpenSSL omits this
der[3] = (byte)hash.Length;
Array.Copy(der, 4, hash, 0, hash.Length);
AsnExtension extension = new AsnExtension(oid, false, der);
extensions.extensions.Add(extension);
}
public void ExtensionExtendedKeyUsage(bool serverAuth, bool clientAuth, bool codeSigning, bool emailProtection, bool timeStamping, bool ocspSigning)
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
AsnOid oid = new AsnOid("2.5.29.37");
// maintain a list of OIDs for the uses
List <AsnOid> uses = new List <AsnOid>();
if (serverAuth)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.1"));
}
if (clientAuth)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.2"));
}
if (codeSigning)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.3"));
}
if (emailProtection)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.4"));
}
if (timeStamping)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.8"));
}
if (ocspSigning)
{
uses.Add(new AsnOid("1.3.6.1.5.5.7.3.9"));
}
int length = 0;
foreach (AsnOid use in uses)
{
length += use.Encode();
}
byte[] lengthBytes = EncodeLength(length);
byte[] der = new byte[1 + lengthBytes.Length + length];
der[0] = 0x30; // it's a sequence
int pos = 1;
Array.Copy(lengthBytes, 0, der, pos, lengthBytes.Length);
pos += lengthBytes.Length;
foreach (AsnOid use in uses)
{
Array.Copy(use.derValue, 0, der, pos, use.derValue.Length);
pos += use.derValue.Length;
}
AsnExtension extension = new AsnExtension(oid, false, der);
extensions.extensions.Add(extension);
}
// TODO: need to cater for multiple alternative names, and different types
public void ExtensionSubjectAltName(string name)
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
int pos = name.IndexOf(':');
string typeName = name.Substring(0, pos);
string nameValue = name.Substring(pos + 1);
byte type = 0;
switch (typeName)
{
case "Other":
type = 0;
break;
case "rfc822":
case "email":
type = 1;
break;
case "DNS":
type = 2;
break;
case "x400":
type = 3;
break;
case "dirName":
type = 4;
break;
case "ediParty":
type = 5;
break;
case "URI":
type = 6;
break;
case "IP":
type = 7;
break;
case "OID":
type = 8;
break;
}
byte[] lengthBytes = EncodeLength(nameValue.Length);
byte[] valueBytes = System.Text.Encoding.UTF8.GetBytes(nameValue);
int length = nameValue.Length;
byte[] nameDER = new byte[1 + lengthBytes.Length + valueBytes.Length];
nameDER[0] = (byte)(0x80 | type);
Array.Copy(lengthBytes, 0, nameDER, 1, lengthBytes.Length);
Array.Copy(valueBytes, 0, nameDER, 1 + lengthBytes.Length, valueBytes.Length);
byte[] bytes = new byte[nameDER.Length + 2];
bytes[0] = 0x30; // it's a sequence
bytes[1] = (byte)nameDER.Length;
Array.Copy(nameDER, 0, bytes, 2, nameDER.Length);
AsnExtension extension = new AsnExtension(new AsnOid("2.5.29.17"), false, bytes);
extensions.extensions.Add(extension);
}
public void ExtensionKeyUsage(bool signature, bool nonRepudiation, bool keyEncipherment, bool dataEncipherment, bool keyAgreement, bool keyCertSign, bool crlSign, bool encipherOnly, bool decipherOnly)
{
if (extensions == null)
{
extensions = new AsnExtensions();
}
ushort val = 0;
byte unused = 0;
// construct an octet string to put in the value of this extension
if (signature)
{
val |= 0x8000;
}
if (nonRepudiation)
{
val |= 0x4000;
}
if (keyEncipherment)
{
val |= 0x2000;
}
if (dataEncipherment)
{
val |= 0x1000;
}
if (keyAgreement)
{
val |= 0x0800;
}
if (keyCertSign)
{
val |= 0x0400;
}
if (crlSign)
{
val |= 0x0200;
}
if (encipherOnly)
{
val |= 0x0100;
}
if (decipherOnly)
{
val |= 0x0080;
}
// find unused bits bit masking first bit and shift right
int bitpos = 0;
int bytesToCopy = 2;
while ((val & (1 << bitpos)) == 0)
{
unused++;
bitpos++;
}
if (unused > 8)
{
unused = (byte)(unused % 8);
bytesToCopy--;
}
// store value as octet string
byte[] bytes = new byte[bytesToCopy + 3];
bytes[0] = 0x03; // this is a bitstring
bytes[1] = (byte)(bytesToCopy + 1); // it's two bytes long
bytes[2] = unused; // number of unused bits
if (bytesToCopy == 1)
{
bytes[3] = (byte)((val & 0xff00) >> 8);
}
else
{
bytes[3] = (byte)((val & 0xff00) >> 8);
bytes[4] = (byte)(val & 0xff);
}
AsnExtension extension = new AsnExtension(new AsnOid("2.5.29.15"), true, bytes);
extensions.extensions.Add(extension);
}
