2025-05-07 11:20:40 +08:00

290 lines
11 KiB
C#

#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using System.Collections;
using System.IO;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Asn1.X509;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Agreement.Srp;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Math;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Security;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities.IO;
namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Tls
{
/// <summary>(D)TLS SRP key exchange (RFC 5054).</summary>
public class TlsSrpKeyExchange
: AbstractTlsKeyExchange
{
protected static TlsSigner CreateSigner(int keyExchange)
{
switch (keyExchange)
{
case KeyExchangeAlgorithm.SRP:
return null;
case KeyExchangeAlgorithm.SRP_RSA:
return new TlsRsaSigner();
case KeyExchangeAlgorithm.SRP_DSS:
return new TlsDssSigner();
default:
throw new ArgumentException("unsupported key exchange algorithm");
}
}
protected TlsSigner mTlsSigner;
protected TlsSrpGroupVerifier mGroupVerifier;
protected byte[] mIdentity;
protected byte[] mPassword;
protected AsymmetricKeyParameter mServerPublicKey = null;
protected Srp6GroupParameters mSrpGroup = null;
protected Srp6Client mSrpClient = null;
protected Srp6Server mSrpServer = null;
protected BigInteger mSrpPeerCredentials = null;
protected BigInteger mSrpVerifier = null;
protected byte[] mSrpSalt = null;
protected TlsSignerCredentials mServerCredentials = null;
[Obsolete("Use constructor taking an explicit 'groupVerifier' argument")]
public TlsSrpKeyExchange(int keyExchange, IList supportedSignatureAlgorithms, byte[] identity, byte[] password)
: this(keyExchange, supportedSignatureAlgorithms, new DefaultTlsSrpGroupVerifier(), identity, password)
{
}
public TlsSrpKeyExchange(int keyExchange, IList supportedSignatureAlgorithms, TlsSrpGroupVerifier groupVerifier,
byte[] identity, byte[] password)
: base(keyExchange, supportedSignatureAlgorithms)
{
this.mTlsSigner = CreateSigner(keyExchange);
this.mGroupVerifier = groupVerifier;
this.mIdentity = identity;
this.mPassword = password;
this.mSrpClient = new Srp6Client();
}
public TlsSrpKeyExchange(int keyExchange, IList supportedSignatureAlgorithms, byte[] identity,
TlsSrpLoginParameters loginParameters)
: base(keyExchange, supportedSignatureAlgorithms)
{
this.mTlsSigner = CreateSigner(keyExchange);
this.mIdentity = identity;
this.mSrpServer = new Srp6Server();
this.mSrpGroup = loginParameters.Group;
this.mSrpVerifier = loginParameters.Verifier;
this.mSrpSalt = loginParameters.Salt;
}
public override void Init(TlsContext context)
{
base.Init(context);
if (this.mTlsSigner != null)
{
this.mTlsSigner.Init(context);
}
}
public override void SkipServerCredentials()
{
if (mTlsSigner != null)
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
public override void ProcessServerCertificate(Certificate serverCertificate)
{
if (mTlsSigner == null)
throw new TlsFatalAlert(AlertDescription.unexpected_message);
if (serverCertificate.IsEmpty)
throw new TlsFatalAlert(AlertDescription.bad_certificate);
X509CertificateStructure x509Cert = serverCertificate.GetCertificateAt(0);
SubjectPublicKeyInfo keyInfo = x509Cert.SubjectPublicKeyInfo;
try
{
this.mServerPublicKey = PublicKeyFactory.CreateKey(keyInfo);
}
catch (Exception e)
{
throw new TlsFatalAlert(AlertDescription.unsupported_certificate, e);
}
if (!mTlsSigner.IsValidPublicKey(this.mServerPublicKey))
throw new TlsFatalAlert(AlertDescription.certificate_unknown);
TlsUtilities.ValidateKeyUsage(x509Cert, KeyUsage.DigitalSignature);
base.ProcessServerCertificate(serverCertificate);
}
public override void ProcessServerCredentials(TlsCredentials serverCredentials)
{
if ((mKeyExchange == KeyExchangeAlgorithm.SRP) || !(serverCredentials is TlsSignerCredentials))
throw new TlsFatalAlert(AlertDescription.internal_error);
ProcessServerCertificate(serverCredentials.Certificate);
this.mServerCredentials = (TlsSignerCredentials)serverCredentials;
}
public override bool RequiresServerKeyExchange
{
get { return true; }
}
public override byte[] GenerateServerKeyExchange()
{
mSrpServer.Init(mSrpGroup, mSrpVerifier, TlsUtilities.CreateHash(HashAlgorithm.sha1), mContext.SecureRandom);
BigInteger B = mSrpServer.GenerateServerCredentials();
ServerSrpParams srpParams = new ServerSrpParams(mSrpGroup.N, mSrpGroup.G, mSrpSalt, B);
DigestInputBuffer buf = new DigestInputBuffer();
srpParams.Encode(buf);
if (mServerCredentials != null)
{
/*
* RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
*/
SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
mContext, mServerCredentials);
IDigest d = TlsUtilities.CreateHash(signatureAndHashAlgorithm);
SecurityParameters securityParameters = mContext.SecurityParameters;
d.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
d.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
buf.UpdateDigest(d);
byte[] hash = new byte[d.GetDigestSize()];
d.DoFinal(hash, 0);
byte[] signature = mServerCredentials.GenerateCertificateSignature(hash);
DigitallySigned signed_params = new DigitallySigned(signatureAndHashAlgorithm, signature);
signed_params.Encode(buf);
}
return buf.ToArray();
}
public override void ProcessServerKeyExchange(Stream input)
{
SecurityParameters securityParameters = mContext.SecurityParameters;
SignerInputBuffer buf = null;
Stream teeIn = input;
if (mTlsSigner != null)
{
buf = new SignerInputBuffer();
teeIn = new TeeInputStream(input, buf);
}
ServerSrpParams srpParams = ServerSrpParams.Parse(teeIn);
if (buf != null)
{
DigitallySigned signed_params = ParseSignature(input);
ISigner signer = InitVerifyer(mTlsSigner, signed_params.Algorithm, securityParameters);
buf.UpdateSigner(signer);
if (!signer.VerifySignature(signed_params.Signature))
throw new TlsFatalAlert(AlertDescription.decrypt_error);
}
this.mSrpGroup = new Srp6GroupParameters(srpParams.N, srpParams.G);
if (!mGroupVerifier.Accept(mSrpGroup))
throw new TlsFatalAlert(AlertDescription.insufficient_security);
this.mSrpSalt = srpParams.S;
/*
* RFC 5054 2.5.3: The client MUST abort the handshake with an "illegal_parameter" alert if
* B % N = 0.
*/
try
{
this.mSrpPeerCredentials = Srp6Utilities.ValidatePublicValue(mSrpGroup.N, srpParams.B);
}
catch (CryptoException e)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter, e);
}
this.mSrpClient.Init(mSrpGroup, TlsUtilities.CreateHash(HashAlgorithm.sha1), mContext.SecureRandom);
}
public override void ValidateCertificateRequest(CertificateRequest certificateRequest)
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
public override void ProcessClientCredentials(TlsCredentials clientCredentials)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
public override void GenerateClientKeyExchange(Stream output)
{
BigInteger A = mSrpClient.GenerateClientCredentials(mSrpSalt, mIdentity, mPassword);
TlsSrpUtilities.WriteSrpParameter(A, output);
mContext.SecurityParameters.srpIdentity = Arrays.Clone(mIdentity);
}
public override void ProcessClientKeyExchange(Stream input)
{
/*
* RFC 5054 2.5.4: The server MUST abort the handshake with an "illegal_parameter" alert if
* A % N = 0.
*/
try
{
this.mSrpPeerCredentials = Srp6Utilities.ValidatePublicValue(mSrpGroup.N, TlsSrpUtilities.ReadSrpParameter(input));
}
catch (CryptoException e)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter, e);
}
mContext.SecurityParameters.srpIdentity = Arrays.Clone(mIdentity);
}
public override byte[] GeneratePremasterSecret()
{
try
{
BigInteger S = mSrpServer != null
? mSrpServer.CalculateSecret(mSrpPeerCredentials)
: mSrpClient.CalculateSecret(mSrpPeerCredentials);
// TODO Check if this needs to be a fixed size
return BigIntegers.AsUnsignedByteArray(S);
}
catch (CryptoException e)
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter, e);
}
}
protected virtual ISigner InitVerifyer(TlsSigner tlsSigner, SignatureAndHashAlgorithm algorithm,
SecurityParameters securityParameters)
{
ISigner signer = tlsSigner.CreateVerifyer(algorithm, this.mServerPublicKey);
signer.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
signer.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
return signer;
}
}
}
#pragma warning restore
#endif