Functions/New-JsonWebKeySet.ps1
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function New-JsonWebKeySet { <# .SYNOPSIS Generates a JSON Web Key set. .DESCRIPTION Transforms an X509Certificate2 object into a JSON object known as a JSON Web Key (JWK) set. .PARAMETER Certificate The certificate that will be converted into a JSON Web Key. .PARAMETER KeyOperations The public key operation that this JWK will be used for. Verification is the default. .PARAMETER IncludeChain Tells the function to include the full certificate chain which includes not only the end-entity certificate, but also the issuing and root certificate in the x5c property (X.509 Certificate Chain). Not selecting this parameter will result in x5c property containing the end-entity certificate only. .PARAMETER Compress Omits white space and indented formatting in the output JSON Web Key set. .EXAMPLE $certThumbprint = "706428667193645C3B4704FC824BEDFCEBB4F038" $certPath = Join-Path -Path Cert:\LocalMachine\My -ChildPath $certThumbprint $verificationCert = Get-Item -Path $certPath $verificationCert | New-JsonWebKeySet -KeyOperations Verification Generates a JSON Web Key set for purposes of signature verification from certificate with thumbprint 706428667193645C3B4704FC824BEDFCEBB4F038. .INPUTS System.Security.Cryptography.X509Certificates.X509Certificate2 A X509Certificate2 object is received by the Certificate parameter. .OUTPUTS System.String .LINK https://tools.ietf.org/html/rfc7517 New-JsonWebToken #> [CmdletBinding()] [Alias('njwks', 'CreateJwkSet')] [OutputType([System.String])] Param ( [Parameter(Mandatory=$true,ValueFromPipeline=$true,Position=0)] [System.Security.Cryptography.X509Certificates.X509Certificate2]$Certificate, [Parameter(Mandatory=$false,Position=1)] [ValidateSet("Verification","Encryption")] [System.String]$KeyOperations="Verification", [Parameter(Mandatory=$false,Position=2)][Switch]$IncludeChain, [Parameter(Mandatory=$false,Position=3)][Switch]$Compress ) PROCESS { [string]$jwkSet = "" $encodedThumbprint = ConvertTo-Base64UrlEncodedString -Bytes ($Certificate.GetCertHash()) [string]$publicKeyUse = "" switch ($KeyOperations) { "Verification" { $publicKeyUse = "sig" } "Encryption" { $publicKeyUse = "enc" } default { $publicKeyUse = "sig" } } $X509CertificateChain = [List[String]]::new() if ($PSBoundParameters.ContainsKey("IncludeChain")) { [X509Chain]$certChain = [X509Chain]::new() $certChain.Build($Certificate) | Out-Null foreach ($chainElement in $certChain.ChainElements) { $rawData = $chainElement.Certificate.RawData $base64 = [Convert]::ToBase64String($rawData) $X509CertificateChain.Add($base64) } } else { $rawData = $Certificate.RawData $base64 = [Convert]::ToBase64String($rawData) $X509CertificateChain.Add($base64) } $key = $Certificate.PublicKey.Key if ($null -ne $key) { [RSAParameters]$parameters = $key.ExportParameters($false) [byte[]]$exp = $parameters.Exponent [byte[]]$mod = $parameters.Modulus [string]$encodedExponent = ConvertTo-Base64UrlEncodedString -Bytes $exp [string]$encodedModulus = ConvertTo-Base64UrlEncodedString -Bytes $mod } $jwkTable = [ordered]@{kty="RSA" use=$publicKeyUse e=$encodedExponent n=$encodedModulus kid=$encodedThumbprint x5t=$encodedThumbprint x5c=$X509CertificateChain} $jwkSetTable = [ordered]@{keys=$jwkTable} if ($PSBoundParameters.ContainsKey("Compress")) { $jwkSet = $jwkSetTable | ConvertTo-Json -Compress } else { $jwkSet = $jwkSetTable | ConvertTo-Json } return $jwkSet } } |