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fix: correct truncated legacy fingerprint lookup table #24

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Merged
bonk-dev merged 1 commit into from
Jul 16, 2026
Merged

fix: correct truncated legacy fingerprint lookup table #24

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10 changes: 5 additions & 5 deletions Directory.Build.props
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Original file line number Diff line number Diff line change
Expand Up @@ -11,11 +11,11 @@
<RepositoryType>git</RepositoryType>
<PackageTags>siemens;s7</PackageTags>

<PackageVersion>1.1.2</PackageVersion>
<AssemblyVersion>1.1.2</AssemblyVersion>
<FileVersion>1.1.2</FileVersion>
<Version>1.1.2</Version>
<PackageReleaseNotes>Internal naming changes</PackageReleaseNotes>
<PackageVersion>1.1.3</PackageVersion>
<AssemblyVersion>1.1.3</AssemblyVersion>
<FileVersion>1.1.3</FileVersion>
<Version>1.1.3</Version>
<PackageReleaseNotes>Fix legacy challenge fingerprint derivation for the final lookup-table block.</PackageReleaseNotes>

<PackageIcon>nuget-icon.png</PackageIcon>
</PropertyGroup>
Expand Down
28 changes: 27 additions & 1 deletion HarpoS7.Tests/Fingerprint/HarpoFingerprintTests.cs
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Expand Up @@ -5,6 +5,32 @@ namespace HarpoS7.Tests.Fingerprint;

public class HarpoFingerprintTests
{
[Test]
public void LookupTablesCoverEveryComputedBlock()
{
for (var index = 0; index < FingerprintConsts.Data1Collection.Length; index++)
{
var operations = FingerprintConsts.Data1Collection[index].Length / 3;
var requiredBytes = operations * 128;
var availableBytes = FingerprintConsts.Data2Collection[index].Length * sizeof(ushort);
Assert.That(
availableBytes,
Is.GreaterThanOrEqualTo(requiredBytes),
$"Fingerprint table {index} is too short for its computed indices");
}
}

[Test]
public void FingerprintChallengeHandlesCapturedLegacyRenewalEdgeCase()
{
Span<byte> fingerprint = stackalloc byte[FingerprintConsts.FingerprintLength];
var challenge = Convert.FromHexString("5B15B4694FC38A775E6778F0770C6E7A3118200D");

HarpoFingerprint.FingerprintChallenge(fingerprint, challenge);

Assert.That(Convert.ToHexString(fingerprint), Is.EqualTo("6AB5811DE6D28746"));
}

public static IEnumerable<TestCaseData> FingerprintSubProcedureCases
{
get
Expand Down Expand Up @@ -1003,4 +1029,4 @@ public void FingerprintChallenge()
var expectedFingerprint = new byte[8] { 0xe2, 0x87, 0xc1, 0xcb, 0x65, 0x9b, 0x9e, 0xdf }.AsSpan();
Assert.That(expectedFingerprint.SequenceEqual(fingerprint));
}
}
}
4 changes: 2 additions & 2 deletions HarpoS7/Fingerprint/FingerprintConsts.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -524,7 +524,7 @@ public static class FingerprintConsts
0xd7b1, 0xe73f, 0x7a90, 0xb821, 0xc54b, 0xabd6, 0x7552, 0x4a40, 0xf0d3, 0x2dbf, 0x1fc5, 0xcc99, 0x8111,
0x4305, 0x7080, 0xe835, 0xbf4, 0x43f, 0x6a5f, 0x2ab3, 0xf854, 0x1f7f, 0x3491, 0xd376, 0xd0bb, 0x7bc7,
0xed86, 0x7fbc, 0x2e5b, 0xc137, 0x8bcb, 0xe9ad, 0xb41c, 0xd4ce, 0x77d5, 0xc22f, 0x929f, 0xb6b2, 0xd74f,
0xe11d, 0xf565, 0x823f, 0x518b, 0xa857, 0xbf08
0xe11d, 0xf565, 0x823f, 0x518b, 0xa857, 0xbf08, 0x4c28
},
new ushort[]
{
Expand Down Expand Up @@ -2710,4 +2710,4 @@ public static class FingerprintConsts
0xbc27, 0xf54d, 0x261
},
};
}
}