# < Summary

Information

Class: | Renci.SshNet.Security.KeyExchangeECDH
Assembly: | Renci.SshNet
File(s): | \home\appveyor\projects\ssh-net\src\Renci.SshNet\Security\KeyExchangeECDH.cs

Line coverage
100%

Covered lines: | 42
Uncovered lines: | 0
Coverable lines: | 42
Total lines: | 106
Line coverage: | 100%

Branch coverage
N/A

Covered branches: | 0
Total branches: | 0
Branch coverage: | N/A

Method coverage

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# Metrics

Method | Branch coverage | Cyclomatic complexity | Line coverage
--- | --- | --- | ---
Start(...) | 100% | 1 | 100%
Finish() | 100% | 1 | 100%
Session_KeyExchangeEcdhReplyMessageReceived(...) | 100% | 1 | 100%
HandleServerEcdhReply(...) | 100% | 1 | 100%

# File(s)

## \home\appveyor\projects\ssh-net\src\Renci.SshNet\Security\KeyExchangeECDH.cs

| # | Line |  | Line coverage
--- | --- | --- | --- | ---
|  | `1` |  | `using System;`
|  | `2` |  | `using Renci.SshNet.Common;`
|  | `3` |  | `using Renci.SshNet.Messages.Transport;`
|  | `4` |  | ``
|  | `5` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Asn1.X9;`
|  | `6` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Crypto.Agreement;`
|  | `7` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Crypto.Generators;`
|  | `8` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Crypto.Parameters;`
|  | `9` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Math.EC;`
|  | `10` |  | `using Renci.SshNet.Security.Org.BouncyCastle.Security;`
|  | `11` |  | ``
|  | `12` |  | `namespace Renci.SshNet.Security`
|  | `13` |  | `{`
|  | `14` |  | `internal abstract class KeyExchangeECDH : KeyExchangeEC`
|  | `15` |  | `{`
|  | `16` |  | `/// <summary>`
|  | `17` |  | `/// Gets the parameter of the curve.`
|  | `18` |  | `/// </summary>`
|  | `19` |  | `/// <value>`
|  | `20` |  | `/// The parameter of the curve.`
|  | `21` |  | `/// </value>`
|  | `22` |  | `protected abstract X9ECParameters CurveParameter { get; }`
|  | `23` |  | ``
|  | `24` |  | `private ECDHCBasicAgreement _keyAgreement;`
|  | `25` |  | `private ECDomainParameters _domainParameters;`
|  | `26` |  | ``
|  | `27` |  | `/// <summary>`
|  | `28` |  | `/// Starts key exchange algorithm.`
|  | `29` |  | `/// </summary>`
|  | `30` |  | `/// <param name="session">The session.</param>`
|  | `31` |  | `/// <param name="message">Key exchange init message.</param>`
|  | `32` |  | `public override void Start(Session session, KeyExchangeInitMessage message)`
| 9 | `33` |  | `{`
| 9 | `34` |  | `base.Start(session, message);`
|  | `35` |  | ``
| 9 | `36` |  | `Session.RegisterMessage("SSH_MSG_KEX_ECDH_REPLY");`
|  | `37` |  | ``
| 9 | `38` |  | `Session.KeyExchangeEcdhReplyMessageReceived += Session_KeyExchangeEcdhReplyMessageReceived;`
|  | `39` |  | ``
| 9 | `40` |  | `_domainParameters = new ECDomainParameters(CurveParameter.Curve,`
| 9 | `41` |  | `CurveParameter.G,`
| 9 | `42` |  | `CurveParameter.N,`
| 9 | `43` |  | `CurveParameter.H,`
| 9 | `44` |  | `CurveParameter.GetSeed());`
|  | `45` |  | ``
| 9 | `46` |  | `var g = new ECKeyPairGenerator();`
| 9 | `47` |  | `g.Init(new ECKeyGenerationParameters(_domainParameters, new SecureRandom()));`
|  | `48` |  | ``
| 9 | `49` |  | `var aKeyPair = g.GenerateKeyPair();`
| 9 | `50` |  | `_keyAgreement = new ECDHCBasicAgreement();`
| 9 | `51` |  | `_keyAgreement.Init(aKeyPair.Private);`
| 9 | `52` |  | `_clientExchangeValue = ((ECPublicKeyParameters)aKeyPair.Public).Q.GetEncoded();`
|  | `53` |  | ``
| 9 | `54` |  | `SendMessage(new KeyExchangeEcdhInitMessage(_clientExchangeValue));`
| 9 | `55` |  | `}`
|  | `56` |  | ``
|  | `57` |  | `/// <summary>`
|  | `58` |  | `/// Finishes key exchange algorithm.`
|  | `59` |  | `/// </summary>`
|  | `60` |  | `public override void Finish()`
| 9 | `61` |  | `{`
| 9 | `62` |  | `base.Finish();`
|  | `63` |  | ``
| 9 | `64` |  | `Session.KeyExchangeEcdhReplyMessageReceived -= Session_KeyExchangeEcdhReplyMessageReceived;`
| 9 | `65` |  | `}`
|  | `66` |  | ``
|  | `67` |  | `private void Session_KeyExchangeEcdhReplyMessageReceived(object sender, MessageEventArgs<KeyExchangeEcdhReplyMes`
| 9 | `68` |  | `{`
| 9 | `69` |  | `var message = e.Message;`
|  | `70` |  | ``
|  | `71` |  | `// Unregister message once received`
| 9 | `72` |  | `Session.UnRegisterMessage("SSH_MSG_KEX_ECDH_REPLY");`
|  | `73` |  | ``
| 9 | `74` |  | `HandleServerEcdhReply(message.KS, message.QS, message.Signature);`
|  | `75` |  | ``
|  | `76` |  | `// When SSH_MSG_KEXDH_REPLY received key exchange is completed`
| 9 | `77` |  | `Finish();`
| 9 | `78` |  | `}`
|  | `79` |  | ``
|  | `80` |  | `/// <summary>`
|  | `81` |  | `/// Handles the server DH reply message.`
|  | `82` |  | `/// </summary>`
|  | `83` |  | `/// <param name="hostKey">The host key.</param>`
|  | `84` |  | `/// <param name="serverExchangeValue">The server exchange value.</param>`
|  | `85` |  | `/// <param name="signature">The signature.</param>`
|  | `86` |  | `private void HandleServerEcdhReply(byte[] hostKey, byte[] serverExchangeValue, byte[] signature)`
| 9 | `87` |  | `{`
| 9 | `88` |  | `_serverExchangeValue = serverExchangeValue;`
| 9 | `89` |  | `_hostKey = hostKey;`
| 9 | `90` |  | `_signature = signature;`
|  | `91` |  | ``
| 9 | `92` |  | `var cordSize = (serverExchangeValue.Length - 1) / 2;`
| 9 | `93` |  | `var x = new byte[cordSize];`
| 9 | `94` |  | `Buffer.BlockCopy(serverExchangeValue, 1, x, 0, x.Length); // first byte is format. should be checked and pas`
| 9 | `95` |  | `var y = new byte[cordSize];`
| 9 | `96` |  | `Buffer.BlockCopy(serverExchangeValue, cordSize + 1, y, 0, y.Length);`
|  | `97` |  | ``
| 9 | `98` |  | `var c = (FpCurve)_domainParameters.Curve;`
| 9 | `99` |  | `var q = c.CreatePoint(new Org.BouncyCastle.Math.BigInteger(1, x), new Org.BouncyCastle.Math.BigInteger(1, y)`
| 9 | `100` |  | `var publicKey = new ECPublicKeyParameters("ECDH", q, _domainParameters);`
|  | `101` |  | ``
| 9 | `102` |  | `var k1 = _keyAgreement.CalculateAgreement(publicKey);`
| 9 | `103` |  | `SharedKey = k1.ToByteArray().ToBigInteger2().ToByteArray().Reverse();`
| 9 | `104` |  | `}`
|  | `105` |  | `}`
|  | `106` |  | `}`

# Methods/Properties

Start(Renci.SshNet.Session,Renci.SshNet.Messages.Transport.KeyExchangeInitMessage)
Finish()
Session_KeyExchangeEcdhReplyMessageReceived(System.Object,Renci.SshNet.MessageEventArgs`1<Renci.SshNet.Messages.Transport.KeyExchangeEcdhReplyMessage>)
HandleServerEcdhReply(System.Byte[],System.Byte[],System.Byte[])