public ECDSASignature(byte[] derSig)
{
try
{
var decoder = new Asn1InputStream(derSig);
var seq = decoder.ReadObject() as DerSequence;
if ((seq == null) || (seq.Count != 2))
throw new FormatException(InvalidDERSignature);
R = ((DerInteger) seq[0]).Value;
S = ((DerInteger) seq[1]).Value;
}
catch (Exception ex)
{
throw new FormatException(InvalidDERSignature, ex);
}
}
/// <summary>Create a base ASN.1 object from a byte array.</summary>
/// <param name="data">The byte array to parse.</param>
/// <returns>The base ASN.1 object represented by the byte array.</returns>
/// <exception cref="IOException">If there is a problem parsing the data.</exception>
public static Asn1Object FromByteArray(
byte[] data)
{
try
{
MemoryStream input = new MemoryStream(data, false);
Asn1InputStream asn1 = new Asn1InputStream(input, data.Length);
Asn1Object result = asn1.ReadObject();
if(input.Position != input.Length)
throw new IOException("extra data found after object");
return result;
}
catch(InvalidCastException)
{
throw new IOException("cannot recognise object in byte array");
}
}
/// <summary>Create a base ASN.1 object from a byte array.</summary>
/// <param name="data">The byte array to parse.</param>
/// <returns>The base ASN.1 object represented by the byte array.</returns>
/// <exception cref="IOException">If there is a problem parsing the data.</exception>
public static Asn1Object FromByteArray(
byte[] data)
{
try
{
MemoryStream input = new MemoryStream(data, false);
Asn1InputStream asn1 = new Asn1InputStream(input, data.Length);
Asn1Object result = asn1.ReadObject();
if (input.Position != input.Length)
{
throw new IOException("extra data found after object");
}
return(result);
}
catch (InvalidCastException)
{
throw new IOException("cannot recognise object in byte array");
}
}
public static string DumpDer(byte[] der)
{
StringBuilder builder = new StringBuilder();
Asn1InputStream decoder = new Asn1InputStream(der);
DerSequence seq = (DerSequence)decoder.ReadObject();
builder.AppendLine("Version : " + Encoders.Hex.EncodeData(seq[0].GetDerEncoded()));
builder.AppendLine("Private : " + Encoders.Hex.EncodeData(seq[1].GetDerEncoded()));
builder.AppendLine("Params : " + Encoders.Hex.EncodeData(((DerTaggedObject)seq[2]).GetObject().GetDerEncoded()));
builder.AppendLine("Public : " + Encoders.Hex.EncodeData(seq[3].GetDerEncoded()));
#if !PORTABLE
decoder.Close();
#else
decoder.Dispose();
#endif
return builder.ToString();
}
public static ECKey FromDER(byte[] der)
{
// To understand this code, see the definition of the ASN.1 format for EC private keys in the OpenSSL source
// code in ec_asn1.c:
//
// ASN1_SEQUENCE(EC_PRIVATEKEY) = {
// ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
// ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
// ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
// ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
// } ASN1_SEQUENCE_END(EC_PRIVATEKEY)
//
Asn1InputStream decoder = new Asn1InputStream(der);
DerSequence seq = (DerSequence)decoder.ReadObject();
CheckArgument(seq.Count == 4, "Input does not appear to be an ASN.1 OpenSSL EC private key");
CheckArgument(((DerInteger)seq[0]).Value.Equals(BigInteger.One),
"Input is of wrong version");
byte[] bits = ((DerOctetString)seq[1]).GetOctets();
#if !PORTABLE
decoder.Close();
#else
decoder.Dispose();
#endif
return new ECKey(bits, true);
}
