ci (authenticity): Strong-name signing for assemblies (#32)

* Strong-name signing for the assemblies

* ci(publish): split release workflow into build, sign, pack, sbom generation and publish jobs (#38)

Author: damyanpetev

.github/scripts/verify-strong-name.ps1

@@ -0,0 +1,137 @@
+<#
+.SYNOPSIS
+    Verifies that assemblies are strong-name signed with the approved Infragistics key.
+
+.DESCRIPTION
+    'sn.exe -vf' proves only that an assembly's strong name is internally consistent, so any valid
+    private key passes it. This script additionally compares each assembly's public key against a
+    value pinned in the repository and established out of band from the signing key.
+#>
+[CmdletBinding()]
+param(
+    [Parameter(Mandatory)]
+    [string[]]$Path,
+
+    [Parameter(Mandatory)]
+    [string]$ExpectedPublicKeyPath,
+
+    [string]$SnPath
+)
+
+$ErrorActionPreference = 'Stop'
+# Failures are aggregated per assembly, so sn.exe exit codes must not throw on their own.
+$PSNativeCommandUseErrorActionPreference = $false
+
+function ConvertTo-HexString([byte[]]$Bytes) {
+    return (-join ($Bytes | ForEach-Object { $_.ToString('x2') }))
+}
+
+if (-not (Test-Path -LiteralPath $ExpectedPublicKeyPath)) {
+    throw "Pinned public key file not found: $ExpectedPublicKeyPath"
+}
+
+$hexLines = @(
+    Get-Content -LiteralPath $ExpectedPublicKeyPath |
+        ForEach-Object { $_.Trim() } |
+        Where-Object { $_ -and -not $_.StartsWith('#') }
+)
+
+# A blank or malformed pin must fail loudly; otherwise the whole check silently becomes a no-op.
+if ($hexLines.Count -ne 1) {
+    throw "$ExpectedPublicKeyPath must contain exactly one non-comment line, but contains $($hexLines.Count)."
+}
+
+$expectedPublicKeyHex = $hexLines[0].ToLowerInvariant()
+if ($expectedPublicKeyHex -notmatch '^[0-9a-f]{320,}$' -or $expectedPublicKeyHex.Length % 2 -ne 0) {
+    throw "$ExpectedPublicKeyPath does not hold a public key blob (expected an even number of at least 320 hex characters)."
+}
+
+$expectedPublicKey = [byte[]]::new($expectedPublicKeyHex.Length / 2)
+for ($index = 0; $index -lt $expectedPublicKey.Length; $index++) {
+    $expectedPublicKey[$index] = [Convert]::ToByte($expectedPublicKeyHex.Substring($index * 2, 2), 16)
+}
+
+# SHA-1 is not a security choice here; it is the algorithm that defines a strong-name token.
+$digest = [System.Security.Cryptography.SHA1]::Create().ComputeHash($expectedPublicKey)
+$tokenBytes = $digest[-8..-1]
+[array]::Reverse($tokenBytes)
+$expectedToken = ConvertTo-HexString $tokenBytes
+
+if ($SnPath) {
+    if (-not (Test-Path -LiteralPath $SnPath -PathType Leaf)) {
+        throw "The specified sn.exe path does not exist: $SnPath"
+    }
+
+    $strongNameTool = Get-Item -LiteralPath $SnPath
+}
+else {
+    $strongNameCommand = Get-Command sn.exe -CommandType Application -ErrorAction SilentlyContinue |
+        Select-Object -First 1
+
+    if ($null -ne $strongNameCommand) {
+        $strongNameTool = Get-Item -LiteralPath $strongNameCommand.Path
+    }
+    else {
+        $windowsSdkRoot = Join-Path ${env:ProgramFiles(x86)} 'Microsoft SDKs\Windows'
+        $strongNameTool = Get-ChildItem -Path $windowsSdkRoot -Filter 'sn.exe' -Recurse -ErrorAction SilentlyContinue |
+            Sort-Object -Property @{
+                Expression = {
+                    $match = [regex]::Match($_.FullName, '\\v(?<version>\d+(?:\.\d+)*)A?\\', 'IgnoreCase')
+                    if ($match.Success) { [version]$match.Groups['version'].Value } else { [version]'0.0' }
+                }
+                Descending = $true
+            }, @{
+                Expression = { $_.FullName }
+                Descending = $true
+            } |
+            Select-Object -First 1
+    }
+}
+
+if ($null -eq $strongNameTool) {
+    throw 'Could not find sn.exe on PATH or under the Windows SDK directory. Pass -SnPath explicitly.'
+}
+
+Write-Verbose "Using sn.exe from '$($strongNameTool.FullName)'."
+
+$assemblies = @(Get-ChildItem -Path $Path -Filter '*.dll' -Recurse -File)
+if ($assemblies.Count -eq 0) {
+    throw "No assemblies were found under '$($Path -join ', ')'. Refusing to report success."
+}
+
+$problems = @()
+foreach ($assembly in $assemblies) {
+    $output = & $strongNameTool.FullName -vf $assembly.FullName
+    if ($LASTEXITCODE -ne 0) {
+        $problems += "$($assembly.FullName): strong-name verification failed. $(($output | Where-Object { $_ }) -join ' ')"
+        continue
+    }
+
+    $assemblyName = [System.Reflection.AssemblyName]::GetAssemblyName($assembly.FullName)
+    $token = $assemblyName.GetPublicKeyToken()
+    if ($null -eq $token -or $token.Length -eq 0) {
+        $problems += "$($assembly.FullName): not strong named."
+        continue
+    }
+
+    $actualToken = ConvertTo-HexString $token
+    if ($actualToken -ne $expectedToken) {
+        $problems += "$($assembly.FullName): public key token is $actualToken, expected $expectedToken."
+        continue
+    }
+
+    # Best effort: the token is a truncated hash, so compare the whole key when it is available.
+    $publicKey = $assemblyName.GetPublicKey()
+    if ($null -ne $publicKey -and $publicKey.Length -gt 0) {
+        $actualPublicKey = ConvertTo-HexString $publicKey
+        if ($actualPublicKey -ne $expectedPublicKeyHex) {
+            $problems += "$($assembly.FullName): public key does not match $ExpectedPublicKeyPath despite a matching token."
+        }
+    }
+}
+
+if ($problems.Count -gt 0) {
+    throw "Strong-name validation failed:`n$($problems -join "`n")"
+}
+
+Write-Host "Verified $($assemblies.Count) assemblies against public key token $expectedToken."