UTCM

0.1.0

Private/Get-UTCMTokenContext.ps1

                                function Get-UTCMTokenContext {

    <#

    .SYNOPSIS

        Decodes a JWT access token and extracts identity and scope claims.

    #>

    [CmdletBinding()]

    [OutputType([hashtable])]

    param(

        [Parameter(Mandatory)]

        [string]$Token

    )

    try {

        # Decode the JWT payload (second segment)

        $parts   = $Token.Split('.')

        $payload = $parts[1]

        # Convert Base64url to standard Base64

        $payload = $payload -replace '-','+' -replace '_','/'

        # Fix Base64 padding

        switch ($payload.Length % 4) {

            2 { $payload += '==' }

            3 { $payload += '='  }

        }

        $json   = [System.Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($payload))

        $claims = $json | ConvertFrom-Json

        @{

            Account    = $claims.upn  ?? $claims.unique_name ?? $claims.preferred_username ?? $claims.app_displayname ?? $claims.azp ?? 'Unknown'

            TenantId   = $claims.tid  ?? 'Unknown'

            ObjectId   = $claims.oid  ?? 'Unknown'

            AppId      = $claims.appid ?? $claims.azp ?? 'Unknown'

            Scopes     = if ($claims.scp) { $claims.scp -split ' ' } elseif ($claims.roles) { $claims.roles } else { @() }

            ExpiresOn  = if ($claims.exp) { [DateTimeOffset]::FromUnixTimeSeconds($claims.exp).LocalDateTime } else { $script:TokenExpiry }

            AuthMethod = if ($claims.scp) { 'Delegated' } else { 'Application' }

        }

    }

    catch {

        Write-Warning "[UTCM] Could not decode token claims: $_"

        @{

            Account    = 'Unknown'

            TenantId   = 'Unknown'

            ObjectId   = 'Unknown'

            AppId      = 'Unknown'

            Scopes     = @()

            ExpiresOn  = $script:TokenExpiry

            AuthMethod = 'Unknown'

        }

    }

}