aws

AWS IAM MFA

July 28, 2020

Here’s how to give AWS IAM users the ability to manage their own (MFA) Multi Factor Authentication. MFA makes your AWS console secure. AWS IAM users will be able to turn on MFA, using virtual devices such as Google Authenticator to secure their cloud accounts. Here’s the policy.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AllowViewAccountInfo",
      "Effect": "Allow",
      "Action": "iam:ListVirtualMFADevices",
      "Resource": "*"
    },
    {
      "Sid": "AllowManageOwnVirtualMFADevice",
      "Effect": "Allow",
      "Action": [
        "iam:CreateVirtualMFADevice",
        "iam:DeleteVirtualMFADevice"
      ],
      "Resource": "arn:aws:iam::*:mfa/${aws:username}"
    },
    {
      "Sid": "AllowManageOwnUserMFA",
      "Effect": "Allow",
      "Action": [
        "iam:DeactivateMFADevice",
        "iam:EnableMFADevice",
        "iam:ListUsers",
        "iam:GetUser",
        "iam:ListMFADevices",
        "iam:ResyncMFADevice"
      ],
      "Resource": "arn:aws:iam::*:user/${aws:username}"
    }
  ]
}

AWS IAM Self Manage Policy

July 28, 2020

Here’s the permission needed for an AWS user to manage their own IAM account. The policy allows them to view their own account information, change their own passwords, rotate access keys and certificates, and manage their own git credentials.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowViewAccountInfo",
            "Effect": "Allow",
            "Action": [
                "iam:GetAccountPasswordPolicy",
                "iam:GetAccountSummary"
            ],
            "Resource": "*"
        },
        {
            "Sid": "AllowManageOwnPasswords",
            "Effect": "Allow",
            "Action": [
                "iam:ChangePassword",
                "iam:GetUser"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        },
        {
            "Sid": "AllowManageOwnAccessKeys",
            "Effect": "Allow",
            "Action": [
                "iam:CreateAccessKey",
                "iam:DeleteAccessKey",
                "iam:GetAccessKeyLastUsed",
                "iam:ListAccessKeys",
                "iam:UpdateAccessKey"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        },
        {
            "Sid": "AllowManageOwnSigningCertificates",
            "Effect": "Allow",
            "Action": [
                "iam:DeleteSigningCertificate",
                "iam:ListSigningCertificates",
                "iam:UpdateSigningCertificate",
                "iam:UploadSigningCertificate"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        },
        {
            "Sid": "AllowManageOwnSSHPublicKeys",
            "Effect": "Allow",
            "Action": [
                "iam:DeleteSSHPublicKey",
                "iam:GetSSHPublicKey",
                "iam:ListSSHPublicKeys",
                "iam:UpdateSSHPublicKey",
                "iam:UploadSSHPublicKey"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        },
        {
            "Sid": "AllowManageOwnGitCredentials",
            "Effect": "Allow",
            "Action": [
                "iam:CreateServiceSpecificCredential",
                "iam:DeleteServiceSpecificCredential",
                "iam:ListServiceSpecificCredentials",
                "iam:ResetServiceSpecificCredential",
                "iam:UpdateServiceSpecificCredential"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        }
    ]
}

{ "Version": "2012-10-17", "Statement": [ { "Sid": "AllowViewAccountInfo", "Effect": "Allow", "Action": [ "iam:GetAccountPasswordPolicy", "iam:GetAccountSummary" ], "Resource": "*" }, { "Sid": "AllowManageOwnPasswords", "Effect": "Allow", "Action": [ "iam:ChangePassword", "iam:GetUser" ], "Resource": "arn:aws:iam::*:user/${aws:username}" }, { "Sid": "AllowManageOwnAccessKeys", "Effect": "Allow", "Action": [ "iam:CreateAccessKey", "iam:DeleteAccessKey", "iam:GetAccessKeyLastUsed", "iam:ListAccessKeys", "iam:UpdateAccessKey" ], "Resource": "arn:aws:iam::*:user/${aws:username}" }, { "Sid": "AllowManageOwnSigningCertificates", "Effect": "Allow", "Action": [ "iam:DeleteSigningCertificate", "iam:ListSigningCertificates", "iam:UpdateSigningCertificate", "iam:UploadSigningCertificate" ], "Resource": "arn:aws:iam::*:user/${aws:username}" }, { "Sid": "AllowManageOwnSSHPublicKeys", "Effect": "Allow", "Action": [ "iam:DeleteSSHPublicKey", "iam:GetSSHPublicKey", "iam:ListSSHPublicKeys", "iam:UpdateSSHPublicKey", "iam:UploadSSHPublicKey" ], "Resource": "arn:aws:iam::*:user/${aws:username}" }, { "Sid": "AllowManageOwnGitCredentials", "Effect": "Allow", "Action": [ "iam:CreateServiceSpecificCredential", "iam:DeleteServiceSpecificCredential", "iam:ListServiceSpecificCredentials", "iam:ResetServiceSpecificCredential", "iam:UpdateServiceSpecificCredential" ], "Resource": "arn:aws:iam::*:user/${aws:username}" } ] }

AWS LightSail Restrict IP Address

July 27, 2020

AWS LightSail now has the ability to restrict IP addresses in their firewall rules. LightSail instances can now be secured by limiting firewall rules from an IP CIDR block or a single IP address. For example, you can restrict who can SSH into your instance by limiting it to just your IP address, so only you can SSH into your machine. Another feature AWS added in their LightSail firewall is support for ping, which could be helpful for monitoring and checks.

AWS Rotate IAM Keys

July 26, 2020

Here’s a script that will rotate AWS IAM keys.

#!/bin/bash
# set files
user='johndoe'
newkey='/root/new-access-key.json'
oldkey='/root/old-access-key.json'
credentials='/root/.aws/credentials'
# get old credentials
aws iam list-access-keys --user-name $user > $oldkey
okey=$(jq .AccessKeyMetadata[0].AccessKeyId $oldkey | tr -d \")
# create new key
aws iam create-access-key --user-name $user > $newkey
# get new access keys and new secret
nkey=$(jq .AccessKey.AccessKeyId $newkey | tr -d \")
nsecret=$(jq .AccessKey.SecretAccessKey $newkey | tr -d \")
# backup old credentials
cp /root/.aws/credentials /root/.aws/credentials-backup
# store the new key
echo '[default]' > $credentials
echo 'aws_access_key_id = ' $nkey >> $credentials
echo 'aws_secret_access_key = '$nsecret >> $credentials
sleep 10
# delete old key
aws iam delete-access-key --user-name $user --access-key-id $okey
rm $newkey
rm $oldkey

The script performs the following:

Retrieves the current key
Creates a new key
Backup the current credentials file
Create a new credentials file
Deletes the old key
Deletes the temp files
Done

LightSail Upstream Error 515

July 6, 2020

If you use LightSail, AWS provides an easy way for you to connect to LightSail instances via Web SSH. I normally use a terminal (ssh client) to connect to LightSail instances, but using Web SSH is very convenient. If you try to do an OS upgrade, for example from Ubuntu 18.04 LTS to Ubuntu 20.04 LTS, you will break Web SSH. AWS has added a special Web SSH configuration on LightSail base images. The error you’ll get is “Upstream Error 515.” The only way to fix this is to get AWS Support to help you apply the fix. It’s not a make or break it deal, but it can be a nuisance if you prefer to use AWS Web SSH instead of a terminal. If you need a more secure SSH connection, consider uploading your ssh-key to the server, and disable password login.

AWS CLI V2

June 28, 2020

How to install AWS CLI version 2.

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
unzip awscliv2.zip
sudo ./aws/install