$certsname = Get-ChildItem -Path Cert:\LocalMachine\AuthRoot | Select FriendlyName,Thumbprint
$output = "{`n`"data`":[`r`n`r`n"
foreach ($currentcert in $certsname)
{
    $line= "{ `"{#CERTID}`" : `"" + $($currentcert.Thumbprint) + "`" },`r`n{ `"{#CERT}`" : `"" + $($currentcert.friendlyname) + "`" },`r`n"
    $output+=$line
}

$output=$output -replace ",`r`n$","`r`n]`r`n}"

$output