New-Jwt.ps1
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# https://www.reddit.com/r/PowerShell/comments/8bc3rb/generate_jwt_json_web_token_in_powershell/ function New-Jwt { param ( [Parameter(Mandatory = $true)] [ValidateSet("HS256", "HS384", "HS512")] [string]$Algorithm, [Parameter()] [string]$Type = "JWT", [Parameter(Mandatory = $true)] [string]$Issuer, [Parameter(Mandatory = $true)] [string]$Audience, [Parameter(Mandatory = $true)] [string]$Name, [Parameter()] [int]$ValidForSeconds = 30, [Parameter(Mandatory = $true)] [string]$SecretKey ) $exp = [datetimeoffset]::UtcNow.AddSeconds($ValidForSeconds).ToUnixTimeSeconds() $header = [ordered]@{alg = $Algorithm; typ = $type} $payload = [ordered]@{iss = $Issuer; exp = $exp; aud = $Audience; name = $Name} $headerjson = $header | ConvertTo-Json -Compress $payloadjson = $payload | ConvertTo-Json -Compress $headerjsonbase64 = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($headerjson)).Split('=')[0].Replace('+', '-').Replace('/', '_') $payloadjsonbase64 = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($payloadjson)).Split('=')[0].Replace('+', '-').Replace('/', '_') $ToBeSigned = $headerjsonbase64 + "." + $payloadjsonbase64 $SigningAlgorithm = switch ($Algorithm) { "HS256" {New-Object System.Security.Cryptography.HMACSHA256} "HS384" {New-Object System.Security.Cryptography.HMACSHA384} "HS512" {New-Object System.Security.Cryptography.HMACSHA512} } $SigningAlgorithm.Key = [System.Text.Encoding]::UTF8.GetBytes($SecretKey) $Signature = [Convert]::ToBase64String($SigningAlgorithm.ComputeHash([System.Text.Encoding]::UTF8.GetBytes($ToBeSigned))).Split('=')[0].Replace('+', '-').Replace('/', '_') $token = "$headerjsonbase64.$payloadjsonbase64.$Signature" $token } |