/// <summary>
/// Create self signed cert
/// </summary>
/// <param name="signature"></param>
/// <param name="subject"></param>
/// <returns></returns>
internal static AsymmetricAlgorithm CreateCsr(this SignatureType signature, string subject,
out CertificateRequest csr)
{
AsymmetricAlgorithm alg = null;
try {
if (signature.IsRSA())
{
var rsa = RSA.Create();
alg = rsa;
csr = new CertificateRequest(X500DistinguishedNameEx.Create(subject),
rsa, signature.ToHashAlgorithmName(), signature.ToRSASignaturePadding());
return(alg);
}
if (signature.IsECC())
{
var ecdsa = ECDsa.Create();
alg = ecdsa;
csr = new CertificateRequest(X500DistinguishedNameEx.Create(subject),
ecdsa, signature.ToHashAlgorithmName());
return(alg);
}
throw new ArgumentException("Bad signature");
}
catch {
alg?.Dispose();
throw;
}
}
/// <summary>
/// To DER algorithm identifier
/// </summary>
/// <param name="signature"></param>
/// <returns></returns>
public static byte[] ToAlgorithmIdentifier(this SignatureType signature)
{
var hashAlgorithm = signature.ToHashAlgorithmName();
string oid;
if (signature.IsRSA())
{
var padding = signature.ToRSASignaturePadding();
if (padding == RSASignaturePadding.Pkcs1)
{
if (hashAlgorithm == HashAlgorithmName.SHA256)
{
oid = Oids.RsaPkcs1Sha256;
}
else if (hashAlgorithm == HashAlgorithmName.SHA384)
{
oid = Oids.RsaPkcs1Sha384;
}
else if (hashAlgorithm == HashAlgorithmName.SHA512)
{
oid = Oids.RsaPkcs1Sha512;
}
else
{
throw new ArgumentOutOfRangeException(nameof(hashAlgorithm),
$"The hash algorithm {hashAlgorithm.Name} is not supported.");
}
using (var writer = new AsnWriter(AsnEncodingRules.DER)) {
writer.PushSequence();
writer.WriteObjectIdentifier(oid);
writer.WriteNull();
writer.PopSequence();
return(writer.Encode());
}
}
if (padding == RSASignaturePadding.Pss)
{
int saltLen;
if (hashAlgorithm == HashAlgorithmName.SHA256)
{
saltLen = 256 / 8;
oid = Oids.Sha256;
}
else if (hashAlgorithm == HashAlgorithmName.SHA384)
{
saltLen = 384 / 8;
oid = Oids.Sha384;
}
else if (hashAlgorithm == HashAlgorithmName.SHA512)
{
saltLen = 512 / 8;
oid = Oids.Sha512;
}
else
{
throw new ArgumentOutOfRangeException(nameof(hashAlgorithm),
$"The hash algorithm {hashAlgorithm.Name} is not supported.");
}
using (var writer = new AsnWriter(AsnEncodingRules.DER)) {
writer.WritePssSignatureAlgorithmIdentifier(saltLen, oid);
return(writer.Encode());
}
}
throw new ArgumentOutOfRangeException(nameof(signature),
"Specified Padding is not supported.");
}
if (hashAlgorithm == HashAlgorithmName.SHA256)
{
oid = Oids.ECDsaWithSha256;
}
else if (hashAlgorithm == HashAlgorithmName.SHA384)
{
oid = Oids.ECDsaWithSha384;
}
else if (hashAlgorithm == HashAlgorithmName.SHA512)
{
oid = Oids.ECDsaWithSha512;
}
else
{
throw new ArgumentOutOfRangeException(nameof(hashAlgorithm),
$"The hash algorithm {hashAlgorithm.Name} is not supported.");
}
using (var writer = new AsnWriter(AsnEncodingRules.DER)) {
writer.PushSequence();
writer.WriteObjectIdentifier(oid);
writer.PopSequence();
return(writer.Encode());
}
}
