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Modify our DH kex to generate a private component that is twice the size of the hash that a given algorithm produces, with a minimum of 1024 bits.

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Fixes issue #304.

Avoid using TryParse in diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1.
Improve test coverage.
This commit is contained in:
Gert Driesen
2017-09-26 21:57:37 +02:00
parent b5d07629e8
commit 79c0f90db3
10 changed files with 185 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/Renci.SshNet.Tests/Classes/Security/KeyExchangeDiffieHellmanGroup14Sha1Test.cs
+50 -3
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@@ -1,13 +1,60 @@
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Renci.SshNet.Common;
using Renci.SshNet.Security;
using Renci.SshNet.Tests.Common;
namespace Renci.SshNet.Tests.Classes.Security
{
/// <summary>
/// Represents "diffie-hellman-group14-sha1" algorithm implementation.
/// </summary>
[TestClass]
public class KeyExchangeDiffieHellmanGroup14Sha1Test : TestBase
{
private static readonly byte[] SecondOkleyGroup =
{
0x00,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc9, 0x0f, 0xda, 0xa2,
0x21, 0x68, 0xc2, 0x34, 0xc4, 0xc6, 0x62, 0x8b, 0x80, 0xdc, 0x1c, 0xd1,
0x29, 0x02, 0x4e, 0x08, 0x8a, 0x67, 0xcc, 0x74, 0x02, 0x0b, 0xbe, 0xa6,
0x3b, 0x13, 0x9b, 0x22, 0x51, 0x4a, 0x08, 0x79, 0x8e, 0x34, 0x04, 0xdd,
0xef, 0x95, 0x19, 0xb3, 0xcd, 0x3a, 0x43, 0x1b, 0x30, 0x2b, 0x0a, 0x6d,
0xf2, 0x5f, 0x14, 0x37, 0x4f, 0xe1, 0x35, 0x6d, 0x6d, 0x51, 0xc2, 0x45,
0xe4, 0x85, 0xb5, 0x76, 0x62, 0x5e, 0x7e, 0xc6, 0xf4, 0x4c, 0x42, 0xe9,
0xa6, 0x37, 0xed, 0x6b, 0x0b, 0xff, 0x5c, 0xb6, 0xf4, 0x06, 0xb7, 0xed,
0xee, 0x38, 0x6b, 0xfb, 0x5a, 0x89, 0x9f, 0xa5, 0xae, 0x9f, 0x24, 0x11,
0x7c, 0x4b, 0x1f, 0xe6, 0x49, 0x28, 0x66, 0x51, 0xec, 0xe4, 0x5b, 0x3d,
0xc2, 0x00, 0x7c, 0xb8, 0xa1, 0x63, 0xbf, 0x05, 0x98, 0xda, 0x48, 0x36,
0x1c, 0x55, 0xd3, 0x9a, 0x69, 0x16, 0x3f, 0xa8, 0xfd, 0x24, 0xcf, 0x5f,
0x83, 0x65, 0x5d, 0x23, 0xdc, 0xa3, 0xad, 0x96, 0x1c, 0x62, 0xf3, 0x56,
0x20, 0x85, 0x52, 0xbb, 0x9e, 0xd5, 0x29, 0x07, 0x70, 0x96, 0x96, 0x6d,
0x67, 0x0c, 0x35, 0x4e, 0x4a, 0xbc, 0x98, 0x04, 0xf1, 0x74, 0x6c, 0x08,
0xca, 0x18, 0x21, 0x7c, 0x32, 0x90, 0x5e, 0x46, 0x2e, 0x36, 0xce, 0x3b,
0xe3, 0x9e, 0x77, 0x2c, 0x18, 0x0e, 0x86, 0x03, 0x9b, 0x27, 0x83, 0xa2,
0xec, 0x07, 0xa2, 0x8f, 0xb5, 0xc5, 0x5d, 0xf0, 0x6f, 0x4c, 0x52, 0xc9,
0xde, 0x2b, 0xcb, 0xf6, 0x95, 0x58, 0x17, 0x18, 0x39, 0x95, 0x49, 0x7c,
0xea, 0x95, 0x6a, 0xe5, 0x15, 0xd2, 0x26, 0x18, 0x98, 0xfa, 0x05, 0x10,
0x15, 0x72, 0x8e, 0x5a, 0x8a, 0xac, 0xaa, 0x68, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff
};
private KeyExchangeDiffieHellmanGroup14Sha1 _group14;
protected override void OnInit()
{
base.OnInit();
_group14 = new KeyExchangeDiffieHellmanGroup14Sha1();
}
[TestMethod]
public void GroupPrimeShouldBeSecondOakleyGroup()
{
var bytes = _group14.GroupPrime.ToByteArray().Reverse();
Assert.IsTrue(SecondOkleyGroup.IsEqualTo(bytes));
}
[TestMethod]
public void NameShouldBeDiffieHellmanGroup14Sha1()
{
Assert.AreEqual("diffie-hellman-group14-sha1", _group14.Name);
}
}
}
src/Renci.SshNet.Tests/Classes/Security/KeyExchangeDiffieHellmanGroup1Sha1Test.cs
+30 -31
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@@ -5,48 +5,47 @@ using Renci.SshNet.Tests.Common;
namespace Renci.SshNet.Tests.Classes.Security
{
/// <summary>
///This is a test class for KeyExchangeDiffieHellmanGroup1Sha1Test and is intended
///to contain all KeyExchangeDiffieHellmanGroup1Sha1Test Unit Tests
///</summary>
[TestClass]
public class KeyExchangeDiffieHellmanGroup1Sha1Test : TestBase
{
/// <summary>
///A test for KeyExchangeDiffieHellmanGroup1Sha1 Constructor
///</summary>
[TestMethod]
[Ignore] // placeholder for actual test
public void KeyExchangeDiffieHellmanGroup1Sha1ConstructorTest()
private static readonly byte[] SecondOkleyGroup =
{
0x00,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc9, 0x0f, 0xda, 0xa2,
0x21, 0x68, 0xc2, 0x34, 0xc4, 0xc6, 0x62, 0x8b, 0x80, 0xdc, 0x1c, 0xd1,
0x29, 0x02, 0x4e, 0x08, 0x8a, 0x67, 0xcc, 0x74, 0x02, 0x0b, 0xbe, 0xa6,
0x3b, 0x13, 0x9b, 0x22, 0x51, 0x4a, 0x08, 0x79, 0x8e, 0x34, 0x04, 0xdd,
0xef, 0x95, 0x19, 0xb3, 0xcd, 0x3a, 0x43, 0x1b, 0x30, 0x2b, 0x0a, 0x6d,
0xf2, 0x5f, 0x14, 0x37, 0x4f, 0xe1, 0x35, 0x6d, 0x6d, 0x51, 0xc2, 0x45,
0xe4, 0x85, 0xb5, 0x76, 0x62, 0x5e, 0x7e, 0xc6, 0xf4, 0x4c, 0x42, 0xe9,
0xa6, 0x37, 0xed, 0x6b, 0x0b, 0xff, 0x5c, 0xb6, 0xf4, 0x06, 0xb7, 0xed,
0xee, 0x38, 0x6b, 0xfb, 0x5a, 0x89, 0x9f, 0xa5, 0xae, 0x9f, 0x24, 0x11,
0x7c, 0x4b, 0x1f, 0xe6, 0x49, 0x28, 0x66, 0x51, 0xec, 0xe6, 0x53, 0x81,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};
private KeyExchangeDiffieHellmanGroup1Sha1 _group1;
protected override void OnInit()
{
KeyExchangeDiffieHellmanGroup1Sha1 target = new KeyExchangeDiffieHellmanGroup1Sha1();
Assert.Inconclusive("TODO: Implement code to verify target");
base.OnInit();
_group1 = new KeyExchangeDiffieHellmanGroup1Sha1();
}
/// <summary>
///A test for GroupPrime
///</summary>
[TestMethod]
[Ignore] // placeholder for actual test
public void GroupPrimeTest()
public void GroupPrimeShouldBeSecondOakleyGroup()
{
KeyExchangeDiffieHellmanGroup1Sha1 target = new KeyExchangeDiffieHellmanGroup1Sha1(); // TODO: Initialize to an appropriate value
BigInteger actual;
actual = target.GroupPrime;
Assert.Inconclusive("Verify the correctness of this test method.");
var bytes = _group1.GroupPrime.ToByteArray().Reverse();
Assert.IsTrue(SecondOkleyGroup.IsEqualTo(bytes));
SecondOkleyGroup.Reverse().DebugPrint();
}
/// <summary>
///A test for Name
///</summary>
[TestMethod]
[Ignore] // placeholder for actual test
public void NameTest()
public void NameShouldBeDiffieHellmanGroup1Sha1()
{
KeyExchangeDiffieHellmanGroup1Sha1 target = new KeyExchangeDiffieHellmanGroup1Sha1(); // TODO: Initialize to an appropriate value
string actual;
actual = target.Name;
Assert.Inconclusive("Verify the correctness of this test method.");
Assert.AreEqual("diffie-hellman-group1-sha1", _group1.Name);
}
}
}
}
src/Renci.SshNet/Renci.SshNet.csproj
+1
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@@ -47,6 +47,7 @@
<ItemGroup>
<Reference Include="System" />
<Reference Include="System.Core" />
<Reference Include="System.Numerics" />
<Reference Include="System.Xml" />
</ItemGroup>
<ItemGroup>
src/Renci.SshNet/Security/KeyExchangeDiffieHellman.cs
+18 -8
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@@ -8,7 +8,7 @@ namespace Renci.SshNet.Security
/// <summary>
/// Represents base class for Diffie Hellman key exchange algorithm
/// </summary>
public abstract class KeyExchangeDiffieHellman : KeyExchange
internal abstract class KeyExchangeDiffieHellman : KeyExchange
{
/// <summary>
/// Specifies key exchange group number.
@@ -43,7 +43,7 @@ namespace Renci.SshNet.Security
/// <summary>
/// Specifies random generated number.
/// </summary>
protected BigInteger _randomValue;
protected BigInteger _privateExponent;
/// <summary>
/// Specifies host key data.
@@ -55,6 +55,14 @@ namespace Renci.SshNet.Security
/// </summary>
protected byte[] _signature;
/// <summary>
/// Gets the size, in bits, of the computed hash code.
/// </summary>
/// <value>
/// The size, in bits, of the computed hash code.
/// </value>
protected abstract int HashSize { get; }
/// <summary>
/// Validates the exchange hash.
/// </summary>
@@ -102,14 +110,16 @@ namespace Renci.SshNet.Security
if (_prime.IsZero)
throw new ArgumentNullException("_prime");
var bitLength = _prime.BitLength;
// generate private component that is twice the hash size (RFC 4419) with a minimum
// of 1024 bits (whatever is less)
var privateComponentSize = Math.Max(HashSize * 2, 1024);
do
{
_randomValue = BigInteger.Random(bitLength);
_clientExchangeValue = BigInteger.ModPow(_group, _randomValue, _prime);
// create private component
_privateExponent = BigInteger.Random(privateComponentSize);
// generate public component
_clientExchangeValue = BigInteger.ModPow(_group, _privateExponent, _prime);
} while (_clientExchangeValue < 1 || _clientExchangeValue > (_prime - 1));
}
@@ -123,7 +133,7 @@ namespace Renci.SshNet.Security
{
_serverExchangeValue = serverExchangeValue;
_hostKey = hostKey;
SharedKey = BigInteger.ModPow(serverExchangeValue, _randomValue, _prime);
SharedKey = BigInteger.ModPow(serverExchangeValue, _privateExponent, _prime);
_signature = signature;
}
}
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroup14Sha1.cs
+31 -6
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@@ -1,5 +1,4 @@
using Renci.SshNet.Common;
using System.Globalization;
namespace Renci.SshNet.Security
{
@@ -8,7 +7,35 @@ namespace Renci.SshNet.Security
/// </summary>
internal class KeyExchangeDiffieHellmanGroup14Sha1 : KeyExchangeDiffieHellmanGroupSha1
{
private const string SecondOkleyGroup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
/// <summary>
/// https://tools.ietf.org/html/rfc2409#section-6.2
/// </summary>
private static readonly byte[] SecondOkleyGroupReversed =
{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x68, 0xaa, 0xac, 0x8a,
0x5a, 0x8e, 0x72, 0x15, 0x10, 0x05, 0xfa, 0x98, 0x18, 0x26, 0xd2, 0x15,
0xe5, 0x6a, 0x95, 0xea, 0x7c, 0x49, 0x95, 0x39, 0x18, 0x17, 0x58, 0x95,
0xf6, 0xcb, 0x2b, 0xde, 0xc9, 0x52, 0x4c, 0x6f, 0xf0, 0x5d, 0xc5, 0xb5,
0x8f, 0xa2, 0x07, 0xec, 0xa2, 0x83, 0x27, 0x9b, 0x03, 0x86, 0x0e, 0x18,
0x2c, 0x77, 0x9e, 0xe3, 0x3b, 0xce, 0x36, 0x2e, 0x46, 0x5e, 0x90, 0x32,
0x7c, 0x21, 0x18, 0xca, 0x08, 0x6c, 0x74, 0xf1, 0x04, 0x98, 0xbc, 0x4a,
0x4e, 0x35, 0x0c, 0x67, 0x6d, 0x96, 0x96, 0x70, 0x07, 0x29, 0xd5, 0x9e,
0xbb, 0x52, 0x85, 0x20, 0x56, 0xf3, 0x62, 0x1c, 0x96, 0xad, 0xa3, 0xdc,
0x23, 0x5d, 0x65, 0x83, 0x5f, 0xcf, 0x24, 0xfd, 0xa8, 0x3f, 0x16, 0x69,
0x9a, 0xd3, 0x55, 0x1c, 0x36, 0x48, 0xda, 0x98, 0x05, 0xbf, 0x63, 0xa1,
0xb8, 0x7c, 0x00, 0xc2, 0x3d, 0x5b, 0xe4, 0xec, 0x51, 0x66, 0x28, 0x49,
0xe6, 0x1f, 0x4b, 0x7c, 0x11, 0x24, 0x9f, 0xae, 0xa5, 0x9f, 0x89, 0x5a,
0xfb, 0x6b, 0x38, 0xee, 0xed, 0xb7, 0x06, 0xf4, 0xb6, 0x5c, 0xff, 0x0b,
0x6b, 0xed, 0x37, 0xa6, 0xe9, 0x42, 0x4c, 0xf4, 0xc6, 0x7e, 0x5e, 0x62,
0x76, 0xb5, 0x85, 0xe4, 0x45, 0xc2, 0x51, 0x6d, 0x6d, 0x35, 0xe1, 0x4f,
0x37, 0x14, 0x5f, 0xf2, 0x6d, 0x0a, 0x2b, 0x30, 0x1b, 0x43, 0x3a, 0xcd,
0xb3, 0x19, 0x95, 0xef, 0xdd, 0x04, 0x34, 0x8e, 0x79, 0x08, 0x4a, 0x51,
0x22, 0x9b, 0x13, 0x3b, 0xa6, 0xbe, 0x0b, 0x02, 0x74, 0xcc, 0x67, 0x8a,
0x08, 0x4e, 0x02, 0x29, 0xd1, 0x1c, 0xdc, 0x80, 0x8b, 0x62, 0xc6, 0xc4,
0x34, 0xc2, 0x68, 0x21, 0xa2, 0xda, 0x0f, 0xc9, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0x00
};
/// <summary>
/// Gets algorithm name.
@@ -28,10 +55,8 @@ namespace Renci.SshNet.Security
{
get
{
BigInteger prime;
BigInteger.TryParse(SecondOkleyGroup, NumberStyles.AllowHexSpecifier, NumberFormatInfo.CurrentInfo, out prime);
return prime;
return new BigInteger(SecondOkleyGroupReversed);
}
}
}
}
}
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroup1Sha1.cs
+17 -6
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@@ -1,14 +1,27 @@
using Renci.SshNet.Common;
using System.Globalization;
namespace Renci.SshNet.Security
{
/// <summary>
/// Represents "diffie-hellman-group1-sha1" algorithm implementation.
/// </summary>
public class KeyExchangeDiffieHellmanGroup1Sha1 : KeyExchangeDiffieHellmanGroupSha1
internal class KeyExchangeDiffieHellmanGroup1Sha1 : KeyExchangeDiffieHellmanGroupSha1
{
private const string SecondOkleyGroup = @"00FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF";
private static readonly byte[] SecondOkleyGroupReversed =
{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x81, 0x53, 0xe6, 0xec,
0x51, 0x66, 0x28, 0x49, 0xe6, 0x1f, 0x4b, 0x7c, 0x11, 0x24, 0x9f, 0xae,
0xa5, 0x9f, 0x89, 0x5a, 0xfb, 0x6b, 0x38, 0xee, 0xed, 0xb7, 0x06, 0xf4,
0xb6, 0x5c, 0xff, 0x0b, 0x6b, 0xed, 0x37, 0xa6, 0xe9, 0x42, 0x4c, 0xf4,
0xc6, 0x7e, 0x5e, 0x62, 0x76, 0xb5, 0x85, 0xe4, 0x45, 0xc2, 0x51, 0x6d,
0x6d, 0x35, 0xe1, 0x4f, 0x37, 0x14, 0x5f, 0xf2, 0x6d, 0x0a, 0x2b, 0x30,
0x1b, 0x43, 0x3a, 0xcd, 0xb3, 0x19, 0x95, 0xef, 0xdd, 0x04, 0x34, 0x8e,
0x79, 0x08, 0x4a, 0x51, 0x22, 0x9b, 0x13, 0x3b, 0xa6, 0xbe, 0x0b, 0x02,
0x74, 0xcc, 0x67, 0x8a, 0x08, 0x4e, 0x02, 0x29, 0xd1, 0x1c, 0xdc, 0x80,
0x8b, 0x62, 0xc6, 0xc4, 0x34, 0xc2, 0x68, 0x21, 0xa2, 0xda, 0x0f, 0xc9,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0x00
};
/// <summary>
/// Gets algorithm name.
@@ -28,9 +41,7 @@ namespace Renci.SshNet.Security
{
get
{
BigInteger prime;
BigInteger.TryParse(SecondOkleyGroup, NumberStyles.AllowHexSpecifier, NumberFormatInfo.CurrentInfo, out prime);
return prime;
return new BigInteger(SecondOkleyGroupReversed);
}
}
}
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroupExchangeSha1.cs
+12 -1
View File
@@ -3,7 +3,7 @@
/// <summary>
/// Represents "diffie-hellman-group-exchange-sha1" algorithm implementation.
/// </summary>
public class KeyExchangeDiffieHellmanGroupExchangeSha1 : KeyExchangeDiffieHellmanGroupExchangeShaBase
internal class KeyExchangeDiffieHellmanGroupExchangeSha1 : KeyExchangeDiffieHellmanGroupExchangeShaBase
{
/// <summary>
/// Gets algorithm name.
@@ -12,5 +12,16 @@
{
get { return "diffie-hellman-group-exchange-sha1"; }
}
/// <summary>
/// Gets the size, in bits, of the computed hash code.
/// </summary>
/// <value>
/// The size, in bits, of the computed hash code.
/// </value>
protected override int HashSize
{
get { return 160; }
}
}
}
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroupExchangeSha256.cs
+12 -1
View File
@@ -5,7 +5,7 @@ namespace Renci.SshNet.Security
/// <summary>
/// Represents "diffie-hellman-group-exchange-sha256" algorithm implementation.
/// </summary>
public class KeyExchangeDiffieHellmanGroupExchangeSha256 : KeyExchangeDiffieHellmanGroupExchangeShaBase
internal class KeyExchangeDiffieHellmanGroupExchangeSha256 : KeyExchangeDiffieHellmanGroupExchangeShaBase
{
/// <summary>
/// Gets algorithm name.
@@ -15,6 +15,17 @@ namespace Renci.SshNet.Security
get { return "diffie-hellman-group-exchange-sha256"; }
}
/// <summary>
/// Gets the size, in bits, of the computed hash code.
/// </summary>
/// <value>
/// The size, in bits, of the computed hash code.
/// </value>
protected override int HashSize
{
get { return 256; }
}
/// <summary>
/// Hashes the specified data bytes.
/// </summary>
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroupExchangeShaBase.cs
+2 -3
View File
@@ -1,12 +1,11 @@
using Renci.SshNet.Messages;
using Renci.SshNet.Messages.Transport;
using Renci.SshNet.Messages.Transport;
namespace Renci.SshNet.Security
{
/// <summary>
/// Base class for "diffie-hellman-group-exchange" algorithms.
/// </summary>
public abstract class KeyExchangeDiffieHellmanGroupExchangeShaBase : KeyExchangeDiffieHellman
internal abstract class KeyExchangeDiffieHellmanGroupExchangeShaBase : KeyExchangeDiffieHellman
{
private const int MinimumGroupSize = 1024;
private const int PreferredGroupSize = 1024;
src/Renci.SshNet/Security/KeyExchangeDiffieHellmanGroupSha1.cs
+12 -2
View File
@@ -1,6 +1,5 @@
using System;
using Renci.SshNet.Common;
using Renci.SshNet.Messages;
using Renci.SshNet.Messages.Transport;
namespace Renci.SshNet.Security
@@ -8,7 +7,7 @@ namespace Renci.SshNet.Security
/// <summary>
/// Represents "diffie-hellman-group1-sha1" algorithm implementation.
/// </summary>
public abstract class KeyExchangeDiffieHellmanGroupSha1 : KeyExchangeDiffieHellman
internal abstract class KeyExchangeDiffieHellmanGroupSha1 : KeyExchangeDiffieHellman
{
/// <summary>
/// Gets the group prime.
@@ -18,6 +17,17 @@ namespace Renci.SshNet.Security
/// </value>
public abstract BigInteger GroupPrime { get; }
/// <summary>
/// Gets the size, in bits, of the computed hash code.
/// </summary>
/// <value>
/// The size, in bits, of the computed hash code.
/// </value>
protected override int HashSize
{
get { return 160; }
}
/// <summary>
/// Calculates key exchange hash value.
/// </summary>