Starts a new AWS session with an MFA Code

new-awssession.ps1

function New-AWSSession {
<#
.SYNOPSIS
  Authenticates with AWS using MFA
.DESCRIPTION
  Authenticates the current IAM user with AWS via the assigned MFA device
.PARAMETER MFA
  The MFA Code to authenticate with
.PARAMETER Profile
  The AWS Profile to authenticate or "Default" if absent
.EXAMPLE
  New-AWSSession 123456
  Authenticates the current IAM with the Default Profile and the MFA Code 123456
.EXAMPLE
  New-AWSSession -MFA 123456
  Authenticates the current IAM with the Default Profile and the MFA Code 123456
.EXAMPLE
  New-AWSSession -Profile my-project 123456
  Authenticates the current IAM with the "my-profile" Profile and the MFA Code 123456
.EXAMPLE
  New-AWSSession 123456 my-project
  Authenticates the current IAM with the "my-profile" Profile and the MFA Code 123456
#>
  [CmdletBinding(ConfirmImpact='Low')]
  Param(
    [Parameter(Position=1, ValueFromPipeline, Mandatory=$true)]
    [string] $MFA,
    [Parameter(Position=2, Mandatory=$false)]
    [string] $Profile = "Default"
  )

  $env:AWS_ACCESS_KEY_ID            = ""
  $env:AWS_SECRET_ACCESS_KEY        = ""
  $env:AWS_SESSION_TOKEN            = ""
  $env:AWS_SESSION_TOKEN_EXPIRATION = ""
  $aws_identity = aws sts get-caller-identity --output json | ConvertFrom-Json
  $aws_user = ($aws_identity.Arn -split("/"))[-1]
  $aws_arn = "arn:aws:iam::$($aws_identity.Account):mfa/$aws_user"
  Write-Verbose "Authenticating ARN $aws_arn"
  $aws_creds = aws sts get-session-token --serial-number $aws_arn --token-code $MFA --duration-seconds 129600 --output json | ConvertFrom-Json
  $env:AWS_ACCESS_KEY_ID            = $aws_creds.Credentials.AccessKeyId
  $env:AWS_SECRET_ACCESS_KEY        = $aws_creds.Credentials.SecretAccessKey
  $env:AWS_SESSION_TOKEN            = $aws_creds.Credentials.SessionToken
  $env:AWS_SESSION_TOKEN_EXPIRATION = $aws_creds.Credentials.Expiration
}

This function should be sourced in your environment

. .\new-aws-session.ps1

Or included in your PowerShell profile.ps1