internal ECDsaCng MakeECDsa(COSE.Algorithm alg, COSE.EllipticCurve crv)
{
ECCurve curve;
switch (alg)
{
case COSE.Algorithm.ES256:
switch (crv)
{
case COSE.EllipticCurve.P256:
case COSE.EllipticCurve.P256K:
curve = ECCurve.NamedCurves.nistP256;
break;
default:
throw new ArgumentOutOfRangeException(string.Format("Missing or unknown crv {0}", crv.ToString()));
}
break;
case COSE.Algorithm.ES384:
switch (crv) // https://www.iana.org/assignments/cose/cose.xhtml#elliptic-curves
{
case COSE.EllipticCurve.P384:
curve = ECCurve.NamedCurves.nistP384;
break;
default:
throw new ArgumentOutOfRangeException(string.Format("Missing or unknown crv {0}", crv.ToString()));
}
break;
case COSE.Algorithm.ES512:
switch (crv) // https://www.iana.org/assignments/cose/cose.xhtml#elliptic-curves
{
case COSE.EllipticCurve.P521:
curve = ECCurve.NamedCurves.nistP521;
break;
default:
throw new ArgumentOutOfRangeException(string.Format("Missing or unknown crv {0}", crv.ToString()));
}
break;
default:
throw new ArgumentOutOfRangeException(string.Format("Missing or unknown alg {0}", alg.ToString()));
}
return(new ECDsaCng(curve));
}
internal ECDsa MakeECDsa(COSE.Algorithm alg, COSE.EllipticCurve crv)
{
ECCurve curve;
switch (alg)
{
case COSE.Algorithm.ES256:
switch (crv)
{
case COSE.EllipticCurve.P256:
case COSE.EllipticCurve.P256K:
curve = ECCurve.NamedCurves.nistP256;
break;
default:
throw new ArgumentOutOfRangeException(nameof(crv), $"Missing or unknown crv {crv}");
}
break;
case COSE.Algorithm.ES384:
switch (crv) // https://www.iana.org/assignments/cose/cose.xhtml#elliptic-curves
{
case COSE.EllipticCurve.P384:
curve = ECCurve.NamedCurves.nistP384;
break;
default:
throw new ArgumentOutOfRangeException(nameof(crv), $"Missing or unknown crv {crv}");
}
break;
case COSE.Algorithm.ES512:
switch (crv) // https://www.iana.org/assignments/cose/cose.xhtml#elliptic-curves
{
case COSE.EllipticCurve.P521:
curve = ECCurve.NamedCurves.nistP521;
break;
default:
throw new ArgumentOutOfRangeException(nameof(crv), $"Missing or unknown crv {crv}");
}
break;
default:
throw new ArgumentOutOfRangeException(nameof(alg), $"Missing or unknown alg {alg}");
}
return(ECDsa.Create(curve));
}
public CredentialPublicKey(X509Certificate2 cert, int alg)
{
_cpk = CBORObject.NewMap();
var keyAlg = cert.GetKeyAlgorithm();
_type = CoseKeyTypeFromOid[keyAlg];
_alg = (COSE.Algorithm)alg;
_cpk.Add(COSE.KeyCommonParameter.KeyType, _type);
_cpk.Add(COSE.KeyCommonParameter.Alg, alg);
if (COSE.KeyType.RSA == _type)
{
var keyParams = cert.GetRSAPublicKey().ExportParameters(false);
_cpk.Add(COSE.KeyTypeParameter.N, keyParams.Modulus);
_cpk.Add(COSE.KeyTypeParameter.E, keyParams.Exponent);
}
if (COSE.KeyType.EC2 == _type)
{
var ecDsaPubKey = (ECDsaCng)cert.GetECDsaPublicKey();
var keyParams = ecDsaPubKey.ExportParameters(false);
if (keyParams.Curve.Oid.FriendlyName.Equals(ECCurve.NamedCurves.nistP256.Oid.FriendlyName))
{
_cpk.Add(COSE.KeyTypeParameter.Crv, COSE.EllipticCurve.P256);
}
if (keyParams.Curve.Oid.FriendlyName.Equals("secP256k1"))
{
_cpk.Add(COSE.KeyTypeParameter.Crv, COSE.EllipticCurve.P256K);
}
if (keyParams.Curve.Oid.FriendlyName.Equals(ECCurve.NamedCurves.nistP384.Oid.FriendlyName))
{
_cpk.Add(COSE.KeyTypeParameter.Crv, COSE.EllipticCurve.P384);
}
if (keyParams.Curve.Oid.FriendlyName.Equals(ECCurve.NamedCurves.nistP521.Oid.FriendlyName))
{
_cpk.Add(COSE.KeyTypeParameter.Crv, COSE.EllipticCurve.P521);
}
_cpk.Add(COSE.KeyTypeParameter.X, keyParams.Q.X);
_cpk.Add(COSE.KeyTypeParameter.Y, keyParams.Q.Y);
}
}
internal static byte[] SignData(COSE.KeyType kty, COSE.Algorithm alg, byte[] data, ECDsa ecdsa = null, RSA rsa = null, byte[] expandedPrivateKey = null)
{
switch (kty)
{
case COSE.KeyType.EC2:
{
var signature = ecdsa.SignData(data, CryptoUtils.HashAlgFromCOSEAlg((int)alg));
return(EcDsaSigFromSig(signature, ecdsa.KeySize));
}
case COSE.KeyType.RSA:
{
RSASignaturePadding padding;
switch (alg) // https://www.iana.org/assignments/cose/cose.xhtml#algorithms
{
case COSE.Algorithm.PS256:
case COSE.Algorithm.PS384:
case COSE.Algorithm.PS512:
padding = RSASignaturePadding.Pss;
break;
case COSE.Algorithm.RS1:
case COSE.Algorithm.RS256:
case COSE.Algorithm.RS384:
case COSE.Algorithm.RS512:
padding = RSASignaturePadding.Pkcs1;
break;
default:
throw new ArgumentOutOfRangeException(nameof(alg), $"Missing or unknown alg {alg}");
}
return(rsa.SignData(data, CryptoUtils.HashAlgFromCOSEAlg((int)alg), padding));
}
case COSE.KeyType.OKP:
{
Key privateKey = Key.Import(SignatureAlgorithm.Ed25519, expandedPrivateKey, KeyBlobFormat.RawPrivateKey);
return(SignatureAlgorithm.Ed25519.Sign(privateKey, data));
}
default:
throw new ArgumentOutOfRangeException(nameof(kty), $"Missing or unknown kty {kty}");
}
}
public bool IsSameAlg(COSE.Algorithm alg)
{
return(_alg.Equals(alg));
}
internal CredentialPublicKey MakeCredentialPublicKey(COSE.KeyType kty, COSE.Algorithm alg, byte[] n, byte[] e)
{
return(MakeCredentialPublicKey(kty, alg, null, null, null, n, e));
}
internal CredentialPublicKey MakeCredentialPublicKey(COSE.KeyType kty, COSE.Algorithm alg, COSE.EllipticCurve crv, byte[] x)
{
return(MakeCredentialPublicKey(kty, alg, crv, x, null, null, null));
}
internal async void MakeAssertionResponse(COSE.KeyType kty, COSE.Algorithm alg, COSE.EllipticCurve crv = COSE.EllipticCurve.P256)
{
const string rp = "fido2.azurewebsites.net";
byte[] rpId = Encoding.UTF8.GetBytes(rp);
var rpIdHash = SHA256.Create().ComputeHash(rpId);
var flags = AuthenticatorFlags.AT | AuthenticatorFlags.ED | AuthenticatorFlags.UP | AuthenticatorFlags.UV;
const ushort signCount = 0xf1d0;
var aaguid = new Guid("F1D0F1D0-F1D0-F1D0-F1D0-F1D0F1D0F1D0");
var credentialID = new byte[] { 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, };
CredentialPublicKey cpk = null;
ECDsa ecdsa = null;
RSA rsa = null;
byte[] expandedPrivateKey = null;
switch (kty)
{
case COSE.KeyType.EC2:
{
ecdsa = MakeECDsa(alg, crv);
var ecparams = ecdsa.ExportParameters(true);
cpk = MakeCredentialPublicKey(kty, alg, crv, ecparams.Q.X, ecparams.Q.Y);
break;
}
case COSE.KeyType.RSA:
{
rsa = RSA.Create();
var rsaparams = rsa.ExportParameters(true);
cpk = MakeCredentialPublicKey(kty, alg, rsaparams.Modulus, rsaparams.Exponent);
break;
}
case COSE.KeyType.OKP:
{
MakeEdDSA(out var privateKeySeed, out var publicKey, out expandedPrivateKey);
cpk = MakeCredentialPublicKey(kty, alg, COSE.EllipticCurve.Ed25519, publicKey);
break;
}
throw new ArgumentOutOfRangeException(nameof(kty), $"Missing or unknown kty {kty}");
}
var acd = new AttestedCredentialData(aaguid, credentialID, cpk);
var extBytes = CBORObject.NewMap().Add("testing", true).EncodeToBytes();
var exts = new Extensions(extBytes);
var ad = new AuthenticatorData(rpIdHash, flags, signCount, acd, exts);
var authData = ad.ToByteArray();
var challenge = new byte[128];
var rng = RandomNumberGenerator.Create();
rng.GetBytes(challenge);
var clientData = new
{
Type = "webauthn.get",
Challenge = challenge,
Origin = rp,
};
var clientDataJson = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(clientData));
var sha = SHA256.Create();
var hashedClientDataJson = sha.ComputeHash(clientDataJson);
byte[] data = new byte[authData.Length + hashedClientDataJson.Length];
Buffer.BlockCopy(authData, 0, data, 0, authData.Length);
Buffer.BlockCopy(hashedClientDataJson, 0, data, authData.Length, hashedClientDataJson.Length);
byte[] signature = null;
switch (kty)
{
case COSE.KeyType.EC2:
{
signature = ecdsa.SignData(data, CryptoUtils.algMap[(int)alg]);
break;
}
case COSE.KeyType.RSA:
{
RSASignaturePadding padding;
switch (alg) // https://www.iana.org/assignments/cose/cose.xhtml#algorithms
{
case COSE.Algorithm.PS256:
case COSE.Algorithm.PS384:
case COSE.Algorithm.PS512:
padding = RSASignaturePadding.Pss;
break;
case COSE.Algorithm.RS1:
case COSE.Algorithm.RS256:
case COSE.Algorithm.RS384:
case COSE.Algorithm.RS512:
padding = RSASignaturePadding.Pkcs1;
break;
default:
throw new ArgumentOutOfRangeException(nameof(alg), $"Missing or unknown alg {alg}");
}
signature = rsa.SignData(data, CryptoUtils.algMap[(int)alg], padding);
break;
}
case COSE.KeyType.OKP:
{
signature = Ed25519.Sign(data, expandedPrivateKey);
break;
}
default:
throw new ArgumentOutOfRangeException(nameof(kty), $"Missing or unknown kty {kty}");
}
if (kty == COSE.KeyType.EC2)
{
signature = EcDsaSigFromSig(signature, ecdsa.KeySize);
}
var userHandle = new byte[16];
rng.GetBytes(userHandle);
var assertion = new AuthenticatorAssertionRawResponse.AssertionResponse()
{
AuthenticatorData = authData,
Signature = signature,
ClientDataJson = clientDataJson,
UserHandle = userHandle,
};
var lib = new Fido2(new Fido2Configuration()
{
ServerDomain = rp,
ServerName = rp,
Origin = rp,
});
var existingCredentials = new List <PublicKeyCredentialDescriptor>();
var cred = new PublicKeyCredentialDescriptor
{
Type = PublicKeyCredentialType.PublicKey,
Id = new byte[] { 0xf1, 0xd0 }
};
existingCredentials.Add(cred);
var options = lib.GetAssertionOptions(existingCredentials, null, null);
options.Challenge = challenge;
var response = new AuthenticatorAssertionRawResponse()
{
Response = assertion,
Type = PublicKeyCredentialType.PublicKey,
Id = new byte[] { 0xf1, 0xd0 },
RawId = new byte[] { 0xf1, 0xd0 },
};
IsUserHandleOwnerOfCredentialIdAsync callback = (args) =>
{
return(Task.FromResult(true));
};
var res = await lib.MakeAssertionAsync(response, options, cpk.GetBytes(), signCount - 1, callback);
}
public CredentialPublicKey(CBORObject cpk)
{
_cpk = cpk;
_type = (COSE.KeyType)cpk[CBORObject.FromObject(COSE.KeyCommonParameter.KeyType)].AsInt32();
_alg = (COSE.Algorithm)cpk[CBORObject.FromObject(COSE.KeyCommonParameter.Alg)].AsInt32();
}
internal static async Task <AssertionVerificationResult> MakeAssertionResponse(COSE.KeyType kty, COSE.Algorithm alg, COSE.EllipticCurve crv = COSE.EllipticCurve.P256, CredentialPublicKey cpk = null, ushort signCount = 0, ECDsa ecdsa = null, RSA rsa = null, byte[] expandedPrivateKey = null)
{
const string rp = "https://www.passwordless.dev";
byte[] rpId = Encoding.UTF8.GetBytes(rp);
var rpIdHash = SHA256.Create().ComputeHash(rpId);
var flags = AuthenticatorFlags.AT | AuthenticatorFlags.ED | AuthenticatorFlags.UP | AuthenticatorFlags.UV;
var aaguid = new Guid("F1D0F1D0-F1D0-F1D0-F1D0-F1D0F1D0F1D0");
var credentialID = new byte[] { 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, 0xf1, 0xd0, };
if (cpk == null)
{
switch (kty)
{
case COSE.KeyType.EC2:
{
if (ecdsa == null)
{
ecdsa = MakeECDsa(alg, crv);
}
var ecparams = ecdsa.ExportParameters(true);
cpk = MakeCredentialPublicKey(kty, alg, crv, ecparams.Q.X, ecparams.Q.Y);
break;
}
case COSE.KeyType.RSA:
{
if (rsa == null)
{
rsa = RSA.Create();
}
var rsaparams = rsa.ExportParameters(true);
cpk = MakeCredentialPublicKey(kty, alg, rsaparams.Modulus, rsaparams.Exponent);
break;
}
case COSE.KeyType.OKP:
{
byte[] publicKey = null;
if (expandedPrivateKey == null)
{
MakeEdDSA(out var privateKeySeed, out publicKey, out expandedPrivateKey);
}
cpk = MakeCredentialPublicKey(kty, alg, COSE.EllipticCurve.Ed25519, publicKey);
break;
}
throw new ArgumentOutOfRangeException(nameof(kty), $"Missing or unknown kty {kty}");
}
}
var acd = new AttestedCredentialData(aaguid, credentialID, cpk);
var extBytes = CBORObject.NewMap().Add("testing", true).EncodeToBytes();
var exts = new Extensions(extBytes);
var ad = new AuthenticatorData(rpIdHash, flags, (uint)(signCount + 1), acd, exts);
var authData = ad.ToByteArray();
var challenge = new byte[128];
var rng = RandomNumberGenerator.Create();
rng.GetBytes(challenge);
var clientData = new
{
Type = "webauthn.get",
Challenge = challenge,
Origin = rp,
};
var clientDataJson = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(clientData));
var sha = SHA256.Create();
var hashedClientDataJson = sha.ComputeHash(clientDataJson);
byte[] data = new byte[authData.Length + hashedClientDataJson.Length];
Buffer.BlockCopy(authData, 0, data, 0, authData.Length);
Buffer.BlockCopy(hashedClientDataJson, 0, data, authData.Length, hashedClientDataJson.Length);
byte[] signature = SignData(kty, alg, data, ecdsa, rsa, expandedPrivateKey);
var userHandle = new byte[16];
rng.GetBytes(userHandle);
var assertion = new AuthenticatorAssertionRawResponse.AssertionResponse()
{
AuthenticatorData = authData,
Signature = signature,
ClientDataJson = clientDataJson,
UserHandle = userHandle,
};
var lib = new Fido2(new Fido2Configuration()
{
ServerDomain = rp,
ServerName = rp,
Origin = rp,
});
var existingCredentials = new List <PublicKeyCredentialDescriptor>();
var cred = new PublicKeyCredentialDescriptor
{
Type = PublicKeyCredentialType.PublicKey,
Id = new byte[] { 0xf1, 0xd0 }
};
existingCredentials.Add(cred);
var options = lib.GetAssertionOptions(existingCredentials, null, null);
options.Challenge = challenge;
var response = new AuthenticatorAssertionRawResponse()
{
Response = assertion,
Type = PublicKeyCredentialType.PublicKey,
Id = new byte[] { 0xf1, 0xd0 },
RawId = new byte[] { 0xf1, 0xd0 },
};
IsUserHandleOwnerOfCredentialIdAsync callback = (args) =>
{
return(Task.FromResult(true));
};
return(await lib.MakeAssertionAsync(response, options, cpk.GetBytes(), signCount, callback));
}
internal static CredentialPublicKey MakeCredentialPublicKey(COSE.KeyType kty, COSE.Algorithm alg, COSE.EllipticCurve?crv, byte[] x, byte[] y, byte[] n, byte[] e)
{
var cpk = CBORObject.NewMap();
cpk.Add(COSE.KeyCommonParameter.KeyType, kty);
cpk.Add(COSE.KeyCommonParameter.Alg, alg);
switch (kty)
{
case COSE.KeyType.EC2:
cpk.Add(COSE.KeyTypeParameter.X, x);
cpk.Add(COSE.KeyTypeParameter.Y, y);
cpk.Add(COSE.KeyTypeParameter.Crv, crv);
break;
case COSE.KeyType.RSA:
cpk.Add(COSE.KeyTypeParameter.N, n);
cpk.Add(COSE.KeyTypeParameter.E, e);
break;
case COSE.KeyType.OKP:
cpk.Add(COSE.KeyTypeParameter.X, x);
cpk.Add(COSE.KeyTypeParameter.Crv, crv);
break;
default:
throw new ArgumentOutOfRangeException(nameof(kty), kty, "Invalid COSE key type");
}
return(new CredentialPublicKey(cpk));
}
public PubKeyCredParam(COSE.Algorithm alg, PublicKeyCredentialType type = PublicKeyCredentialType.PublicKey)
{
Type = type;
Alg = alg;
}
public CredentialPublicKey(CborMap cpk)
{
_cpk = cpk;
_type = (COSE.KeyType)(int) cpk[COSE.KeyCommonParameter.KeyType];
_alg = (COSE.Algorithm)(int) cpk[COSE.KeyCommonParameter.Alg];
}
internal void Add(string key, COSE.Algorithm value)
{
items.Add(new(new CborTextString(key), new CborInteger((int)value)));
}
internal void Add(COSE.KeyCommonParameter key, COSE.Algorithm value)
{
items.Add(new(new CborInteger((int)key), new CborInteger((int)value)));
}
