# ConvertFrom-Bearertoken
#
# Sample to convert Bearer/POP Tokens by decoding them
[CmdletBinding()]
param (
   [Parameter(ValueFromPipeline = $true)]
   [string]$token="eyJhbGciOiJSUzI1NiIsImtpZCI6Inp4ZndEckpfZHQ3Ymg4a0xWek9WcE1aazFxeDBYay1VYTVZc2FNVzJGUjAiLCJ0eXAiOiJKV1QifQ.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.m-21MVnZRHOA2fNpPB5bY64SFldUnJOecO4BhlIZbh0B299gNxhM9fcM76qlcLqdhghm2mfECf7AaPHZkzDjPlf1dIW9-tCR4Uai1nCD5CtGTg2QmLbkFrjoFDU4tsBU1hP0r3tUMdCXK4G8lqvWJjvjsNew7nbDF4bFCZYCLZg0tovt886IlIxAXei2hDXnqZpgMyJbMdgD0MxLpV3e1Zo3mYn9pKpVATU09dJU6-xdZgx8ljtTdmZ1aMN72Si1tfVZ6kA5NXZSVFBmJAJvhG7IeyidqRpBZNhG3GV9hImh3g6WE3PlnuuVnkUnVQOK_9gd8kjwUO4i_sM7igMKtQ"
)

begin{
   Write-Verbose "ConvertFrom-Bearertoken: Start"
}

process{
   Write-Verbose " Totals Token Length: $($token.length) Bytes"
   $tokens = $token.split(".")
   Write-Verbose "Found $($tokens.count) Tokens"

   $count=0
   foreach ($currenttoken in $tokens) {
      $count++
      Write-Verbose ("Decoding Token $count with Length $($currenttoken.length) Bytes")
      if (!$currenttoken.startswith("eyJ")) {
         Write-Verbose " Token does not start with ejJ and is not a Bearer Token"
         Continue
      }
      # replace "-" with "+", "_" with "/" and "%3d" with "="
      $currenttoken = $currenttoken.replace("-","+").replace("_","/").replace("%3d","=")
         # Append = until length is a multiple of 4
      if (($currenttoken.length % 4) -ne 0) {
         Write-Verbose " Token length is not a multiple of 4 - Adding padding"
         $currenttoken = $currenttoken + "".PadRight(4-($currenttoken.length % 4),"=")
      }
      # Decode the Base64 string tp byte array
      $bytes = [Convert]::FromBase64String($currenttoken)
      # Convert the byte array to a string
      $decodedString = [System.Text.Encoding]::ASCII.GetString($bytes)
      $decodedString | ConvertFrom-Json
   }

   Write-Verbose "Decode-Bearertoken: End"
}