internal/functions/ConvertFrom-JWTtoken.ps1
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function ConvertFrom-JWTtoken { <# .SYNOPSIS Converts access tokens to readable objects .DESCRIPTION Converts access tokens to readable objects .PARAMETER Token The Token to convert .EXAMPLE PS C:\> ConvertFrom-JWTtoken -Token $Token Converts the content from variable $token to an object #> [cmdletbinding()] param( [Parameter(Mandatory = $true)] [string] $Token ) # Validate as per https://tools.ietf.org/html/rfc7519 - Access and ID tokens are fine, Refresh tokens will not work if ((-not $Token.Contains(".")) -or (-not $Token.StartsWith("eyJ"))) { Stop-PSFFunction -Message "Invalid data or not an access token" -EnableException -Tag JWT } # Split the token in its parts $tokenParts = $Token.Split(".") # Work on header $tokenHeader = [System.Text.Encoding]::UTF8.GetString( (ConvertFrom-Base64StringWithNoPadding $tokenParts[0]) ) $tokenHeaderJSON = $tokenHeader | ConvertFrom-Json # Work on payload $tokenPayload = [System.Text.Encoding]::UTF8.GetString( (ConvertFrom-Base64StringWithNoPadding $tokenParts[1]) ) $tokenPayloadJSON = $tokenPayload | ConvertFrom-Json # Work on signature $tokenSignature = ConvertFrom-Base64StringWithNoPadding $tokenParts[2] # Output $resultObject = New-Object MSGraph.Core.JWTAccessTokenInfo -Property @{ Header = $tokenHeader Payload = $tokenPayload Signature = $tokenSignature Algorithm = $tokenHeaderJSON.alg Type = $tokenHeaderJSON.typ ApplicationID = $tokenPayloadJSON.appid ApplicationName = $tokenPayloadJSON.app_displayname Audience = $tokenPayloadJSON.aud AuthenticationMethod = $tokenPayloadJSON.amr ExpirationTime = ([datetime]"1970-01-01Z00:00:00").AddSeconds($tokenPayloadJSON.exp).ToUniversalTime() GivenName = $tokenPayloadJSON.given_name IssuedAt = ([datetime]"1970-01-01Z00:00:00").AddSeconds($tokenPayloadJSON.iat).ToUniversalTime() Name = $tokenPayloadJSON.name NotBefore = ([datetime]"1970-01-01Z00:00:00").AddSeconds($tokenPayloadJSON.nbf).ToUniversalTime() OID = $tokenPayloadJSON.oid Plattform = $tokenPayloadJSON.platf Scope = $tokenPayloadJSON.scp SID = $tokenPayloadJSON.onprem_sid SourceIPAddr = $tokenPayloadJSON.ipaddr SureName = $tokenPayloadJSON.family_name TenantID = $tokenPayloadJSON.tid UniqueName = $tokenPayloadJSON.unique_name UPN = $tokenPayloadJSON.upn Version = $tokenPayloadJSON.ver } #$output $resultObject } |