TlsCryptoUtilities
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Nist;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.Rosstandart;
using Org.BouncyCastle.Asn1.X509;
using System;
namespace Org.BouncyCastle.Tls.Crypto
{
public abstract class TlsCryptoUtilities
{
private static readonly byte[] Tls13Prefix = new byte[6] {
116,
108,
115,
49,
51,
32
};
public static int GetHash(short hashAlgorithm)
{
switch (hashAlgorithm) {
case 1:
return 1;
case 2:
return 2;
case 3:
return 3;
case 4:
return 4;
case 5:
return 5;
case 6:
return 6;
default:
throw new ArgumentException("specified HashAlgorithm invalid: " + HashAlgorithm.GetText(hashAlgorithm));
}
}
public static int GetHashForHmac(int macAlgorithm)
{
switch (macAlgorithm) {
case 1:
return 1;
case 2:
return 2;
case 3:
return 4;
case 4:
return 5;
case 5:
return 6;
default:
throw new ArgumentException("specified MacAlgorithm not an HMAC: " + MacAlgorithm.GetText(macAlgorithm));
}
}
public static int GetHashForPrf(int prfAlgorithm)
{
switch (prfAlgorithm) {
case 0:
case 1:
throw new ArgumentException("legacy PRF not a valid algorithm");
case 2:
case 4:
return 4;
case 3:
case 5:
return 5;
case 7:
return 7;
case 8:
return 8;
default:
throw new ArgumentException("unknown PrfAlgorithm: " + PrfAlgorithm.GetText(prfAlgorithm));
}
}
public static int GetHashInternalSize(int cryptoHashAlgorithm)
{
switch (cryptoHashAlgorithm) {
case 1:
case 2:
case 3:
case 4:
case 7:
case 8:
return 64;
case 5:
case 6:
return 128;
default:
throw new ArgumentException();
}
}
public static int GetHashOutputSize(int cryptoHashAlgorithm)
{
switch (cryptoHashAlgorithm) {
case 1:
return 16;
case 2:
return 20;
case 3:
return 28;
case 4:
case 7:
case 8:
return 32;
case 5:
return 48;
case 6:
return 64;
default:
throw new ArgumentException();
}
}
public static DerObjectIdentifier GetOidForHash(int cryptoHashAlgorithm)
{
switch (cryptoHashAlgorithm) {
case 1:
return PkcsObjectIdentifiers.MD5;
case 2:
return X509ObjectIdentifiers.IdSha1;
case 3:
return NistObjectIdentifiers.IdSha224;
case 4:
return NistObjectIdentifiers.IdSha256;
case 5:
return NistObjectIdentifiers.IdSha384;
case 6:
return NistObjectIdentifiers.IdSha512;
case 8:
return RosstandartObjectIdentifiers.id_tc26_gost_3411_12_256;
default:
throw new ArgumentException();
}
}
public static int GetSignature(short signatureAlgorithm)
{
switch (signatureAlgorithm) {
case 1:
return 1;
case 2:
return 2;
case 3:
return 3;
case 4:
return 4;
case 5:
return 5;
case 6:
return 6;
case 7:
return 7;
case 8:
return 8;
case 9:
return 9;
case 10:
return 10;
case 11:
return 11;
case 26:
return 26;
case 27:
return 27;
case 28:
return 28;
case 64:
return 64;
case 65:
return 65;
default:
throw new ArgumentException("specified SignatureAlgorithm invalid: " + SignatureAlgorithm.GetText(signatureAlgorithm));
}
}
public static TlsSecret HkdfExpandLabel(TlsSecret secret, int cryptoHashAlgorithm, string label, byte[] context, int length)
{
return HkdfExpandLabel(secret, cryptoHashAlgorithm, label.AsSpan(), context.AsSpan(), length);
}
public unsafe static TlsSecret HkdfExpandLabel(TlsSecret secret, int cryptoHashAlgorithm, ReadOnlySpan<char> label, ReadOnlySpan<byte> context, int length)
{
int length2 = label.Length;
if (length2 < 1)
throw new TlsFatalAlert(80);
int length3 = context.Length;
int num = Tls13Prefix.Length + length2;
int num2 = 2 + (1 + num) + (1 + length3);
Span<byte> span;
if (num2 <= 512) {
int num3 = num2;
span = new Span<byte>(stackalloc byte[(int)(uint)num3], num3);
} else
span = new byte[num2];
Span<byte> span2 = span;
TlsUtilities.CheckUint16(length);
TlsUtilities.WriteUint16(length, span2);
TlsUtilities.CheckUint8(num);
TlsUtilities.WriteUint8(num, span2.Slice(2, span2.Length - 2));
Tls13Prefix.CopyTo(span2.Slice(3, span2.Length - 3));
int num4 = 2 + (1 + Tls13Prefix.Length);
for (int i = 0; i < length2; i++) {
span2[num4 + i] = (byte)label[i];
}
TlsUtilities.WriteOpaque8(context, span2.Slice(2 + (1 + num)));
return secret.HkdfExpand(cryptoHashAlgorithm, span2, length);
}
}
}