Configure AWS Credentials
=========================
Authenticate to AWS in GitHub Actions! Works especially well with [AWS Secrets
Manager](https://github.com/aws-actions/aws-secretsmanager-get-secrets).

Quick Start (OIDC, recommended)
-------------------------------
1. Create an IAM Identity Provider in your AWS account for GitHub OIDC. (See 
[OIDC configuration](#oidc-configuration) below for details.)
2. Create an IAM Role in your AWS account with a trust policy that allows GitHub
Actions to assume it:
    <details>
    <summary>GitHub OIDC Trust Policy</summary>

    ```json
    {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Effect": "Allow",
          "Principal": {
            "Federated": "arn:aws:iam::<AWS_ACCOUNT_ID>:oidc-provider/token.actions.githubusercontent.com"
          },
          "Action": "sts:AssumeRoleWithWebIdentity",
          "Condition": {
            "StringEquals": {
              "token.actions.githubusercontent.com:aud": "sts.amazonaws.com",
              "token.actions.githubusercontent.com:sub": "repo:<GITHUB_ORG>/<GITHUB_REPOSITORY>:ref:refs/heads/<GITHUB_BRANCH>"
            }
          }
        }
      ]
    }
    ```
    </details>
3. Attach permissions to the IAM Role that allow it to access the AWS resources 
you need.
4. Add the following to your GitHub Actions workflow:
    <details>
    <summary>Example Workflow</summary>

    ```yaml
    # Need ID token write permission to use OIDC
    permissions:
      id-token: write
    jobs:
      run_job_with_aws:
        runs-on: ubuntu-latest
        steps:
          - name: Configure AWS Credentials
            uses: aws-actions/configure-aws-credentials@main # Or a specific version
            with:
              role-to-assume: <Role ARN you created in step 2>
              aws-region: <AWS Region you want to use>
          - name: Additional steps
            run: |
              # Your commands that require AWS credentials
              aws sts get-caller-identity 
    ```
    </details>
That's it! Your GitHub Actions workflow can now access AWS resources using the
IAM Role you created. Other authentication scenarios are also supported (see
below).

Security Recommendations
------------------------
* Use temporary credentials when possible. OIDC is recommended because it
  provides temporary credentials and it's easy to set up.
* Do not store credentials in your repository's code. Consider using
  [git-secrets](https://github.com/awslabs/git-secrets) to prevent committing
  secrets to your repository.
* [Grant least privilege](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#grant-least-privilege)
  to your workflows. Grant only those permissions that are necessary for the
  workflow to run.
* [Monitor the activity](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#keep-a-log)
  of the credentials used in workflows.
* Periodically rotate any long-lived credentials that you use.
* Store sensitive information in a secure way, such as using
  [AWS Secrets Manager](https://aws.amazon.com/secrets-manager/) or
  [GitHub Secrets](https://docs.github.com/en/actions/security-guides/encrypted-secrets).

Other Authentication Scenarios
------------------------------
This action supports five different authentication methods that are configured
by specifying different inputs.

1. Use a `core.getIDToken()` call to authenticate via OIDC.
2. Re-export existing long-lived IAM credentials (access key ID and secret
   access key) as environment variables.
3. Use static credentials stored in GitHub Secrets to fetch temporary
   credentials via STS AssumeRole.
4. Use a Web Identity Token to fetch temporary credentials via STS
   AssumeRoleWithWebIdentity.
5. Use credentials stored in the Action environment to fetch temporary
   credentials via STS AssumeRole.

Because we use the AWS JavaScript SDK, we always will use the [credential
resolution flow for Node.js](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html).
Depending on your inputs, the action might override parts of this flow.

<details>
<summary>Inputs and their effects on the credential resolution flow</summary>

| **Identity Used**                        | `aws-access-key-id` | `role-to-assume` | `web-identity-token-file` | `role-chaining` |
| ---------------------------------------- | ------------------- | ---------------- | ------------------------- | --------------- |
| [✅ Recommended] GitHub OIDC             |                     | ✔                |                           |                 |
| IAM User (no AssumeRole)                 | ✔                   |                  |                           |                 |
| AssumeRole using static IAM credentials  | ✔                   | ✔                |                           |                 |
| AssumeWithWebIdentity use a token file   |                     | ✔                | ✔                         |                 |
| AssumeRole using existing credentials    |                     | ✔                |                           | ✔               |

*Note: `role-chaining` is not always necessary to use existing credentials.
If you're getting a "Credentials loaded by the SDK do not match" error,
try enabling this option.*
</details>

Additionally, **`aws-region`** is always required.

*Note: If you use GitHub Enterprise Server, you must use the you may need to
adjust examples here to match your environment.*

Additional Options
------------------
### Options
See [action.yml](./action.yml) for more detail.
<details>
<summary>Options list and descriptions</summary>

|          Option           |                                            Description                                            | Required |
|---------------------------|---------------------------------------------------------------------------------------------------|----------|
| aws-region                | Which AWS region to use                                                                           |    Yes   |
| role-to-assume            | Role for which to fetch credentials. Only required for some authentication types.                 |    No    |
| aws-access-key-id         | AWS access key to use. Only required for some authentication types.                               |    No    |
| aws-secret-access-key     | AWS secret key to use. Only required for some authentication types.                               |    No    |
| aws-session-token         | AWS session token to use. Used in uncommon authentication scenarios.                              |    No    |
| role-chaining             | Use existing credentials from the environment to assume a new role.                               |    No    |
| audience                  | The JWT audience when using OIDC. Used in non-default AWS partitions, like China regions.         |    No    |
| http-proxy                | An HTTP proxy to use for API calls.                                                               |    No    |
| mask-aws-account-id       | AWS account IDs are not considered secret. Setting this will hide account IDs from output anyway. |    No    |
| role-duration-seconds     | The assumed role duration in seconds, if assuming a role. Defaults to 1 hour (3600 seconds). Acceptable values range from 15 minutes (900 seconds) to 12 hours (43200 seconds). |    No    |
| role-external-id          | The external ID of the role to assume. Only needed if your role requires it.                      |    No    |
| role-session-name         | Defaults to "GitHubActions", but may be changed if required.                                      |    No    |
| role-skip-session-tagging | Skips session tagging if set.                                                                     |    No    |
| inline-session-policy     | You may further restrict the assumed role policy by defining an inline policy here.               |    No    |
| managed-session-policies  | You may further restrict the assumed role policy by specifying a managed policy here.             |    No    |
| output-credentials        | When set, outputs fetched credentials as action step output. (Outputs aws-access-key-id, aws-secret-access-key, aws-session-token, aws-account-id, authenticated-arn, and aws-expiration). Defaults to false.                   |    No    |
| output-env-credentials       | When set, outputs fetched credentials as environment variables (AWS_REGION, AWS_DEFAULT_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN). Defaults to true. Set to false if you need to avoid setting/changing env variables. You'd probably want to use output-credentials if you disable this. (NOTE: Setting to false will prevent the aws-account-id from being exported as a step output). |    No    |
| unset-current-credentials | When set, attempts to unset any existing credentials in your action runner.                       |    No    |
| disable-retry             | Disabled retry/backoff logic for assume role calls. By default, retries are enabled.              |    No    |
| retry-max-attempts        | Limits the number of retry attempts before giving up. Defaults to 12.                             |    No    |
| special-characters-workaround | Uncommonly, some environments cannot tolerate special characters in a secret key. This option will retry fetching credentials until the secret access key does not contain special characters. This option overrides disable-retry and retry-max-attempts. | No |
| use-existing-credentials  | When set, the action will check if existing credentials are valid and exit if they are. Defaults to false. |    No    |
| allowed-account-ids       | A comma-delimited list of expected AWS account IDs. The action will fail if we receive credentials for the wrong account. |    No    |
| force-skip-oidc           | When set, the action will skip using GitHub OIDC provider even if the id-token permission is set. |    No    |
| action-timeout-s          | Global timeout for the action in seconds. If set to a value greater than 0, the action will fail if it takes longer than this time to complete. |    No    |
</details>

#### Adjust the retry mechanism
You can configure retry settings for if the STS call fails. By default, we
retry with exponential backoff `12` times. You can disable this behavior
altogether by setting the `disable-retry` input to `true`, or you can configure
the number of times it retries with the `retry-max-attempts` input.

#### Mask account ID
Your account ID is not masked by default in workflow logs. You can set the
`mask-aws-account-id` input to `true` to mask your account ID in workflow logs
if desired.

#### Unset current credentials
Sometimes, existing credentials in your runner can get in the way of the
intended outcome. You can set the `unset-current-credentials` input to `true` to
work around this issue.

#### Use an HTTP proxy

If need use an HTTP proxy you can set it in the action manually. Additionally
this action will always consider the `HTTP_PROXY` environment variable.

<details>
<summary>Proxy configuration</summary>

Manually configured proxy:
```yaml
uses: aws-actions/configure-aws-credentials@v5.1.0
with:
  aws-region: us-east-2
  role-to-assume: my-github-actions-role
  http-proxy: "http://companydomain.com:3128"
```

Proxy configured in the environment variable:
```bash
# Your environment configuration
HTTP_PROXY="http://companydomain.com:3128"
```
</details>

#### Special characters in AWS_SECRET_ACCESS_KEY
Some edge cases are unable to properly parse an `AWS_SECRET_ACCESS_KEY` if it
contains special characters. For more information, please see the
[AWS CLI documentation](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-troubleshooting.html#tshoot-signature-does-not-match).
If you set the `special-characters-workaround` option, this action will
continually retry fetching credentials until we get one that does not have
special characters. This option overrides the `disable-retry` and
`retry-max-attempts` options. We recommend that you do not enable this option
unless required, because retrying APIs infinitely until they succeed is not best
practice.

Session Naming and Policies
---------------------------
The default session name is "GitHubActions", and you can modify it by specifying
the desired name in `role-session-name`.

*Note: you might find it helpful to set the `role-session-name` to `${{ github.run_id }}` 
so as to clarify in audit logs which AWS actions were performed by which workflow 
run.*

The session will be tagged with the
following tags: (Refer to [GitHub's documentation for `GITHUB_` environment
variable definitions](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/using-environment-variables#default-environment-variables))

| Key        | Value             |
| ---------- | ----------------- |
| GitHub     | "Actions"         |
| Repository | GITHUB_REPOSITORY |
| Workflow   | GITHUB_WORKFLOW   |
| Action     | GITHUB_ACTION     |
| Actor      | GITHUB_ACTOR      |
| Branch     | GITHUB_REF        |
| Commit     | GITHUB_SHA        |

_Note: all tag values must conform to
[the tag requirements](https://docs.aws.amazon.com/STS/latest/APIReference/API_Tag.html).
Particularly, `GITHUB_WORKFLOW` will be truncated if it's too long. If
`GITHUB_ACTOR` or `GITHUB_WORKFLOW` contain invalid characters, the characters
will be replaced with an '*'._

The action will use session tagging by default unless you are using OIDC.

### Session policies
Session policies are not required, but they allow you to limit the scope of the
fetched credentials without making changes to IAM roles. You can specify inline
session policies right in your workflow file, or refer to an existing managed
session policy by its ARN.

#### Inline session policies
An IAM policy in stringified JSON format that you want to use as an inline
session policy. Depending on preferences, the JSON could be written on a single
line.

<details>
<summary>Inline session policy examples</summary>

```yaml
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
         inline-session-policy: '{"Version":"2012-10-17","Statement":[{"Sid":"Stmt1","Effect":"Allow","Action":"s3:List*","Resource":"*"}]}'
```
Or we can have a nicely formatted JSON as well:
```yaml
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
         inline-session-policy: >-
          {
           "Version": "2012-10-17",
           "Statement": [
            {
             "Sid":"Stmt1",
             "Effect":"Allow",
             "Action":"s3:List*",
             "Resource":"*"
            }
           ]
          }
```
</details>

#### Managed session policies
The Amazon Resource Names (ARNs) of the IAM managed policies that you want to
use as managed session policies. The policies must exist in the same account as
the role.

<details>
<summary>Managed session policy examples</summary>

```yaml
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
         managed-session-policies: arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess
```
And we can pass multiple managed policies likes this:
```yaml
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
         managed-session-policies: |
          arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess
          arn:aws:iam::aws:policy/AmazonS3OutpostsReadOnlyAccess
```
</details>

OIDC Configuration
-------------------
We recommend using [GitHub's OIDC
provider](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services)
to get short-lived AWS credentials needed for your actions. When using OIDC, you
configure IAM to accept JWTs from GitHub's OIDC endpoint. This action will
then create a JWT unique to the workflow run using the OIDC endpoint, and it
will use the JWT to assume the specified role with short-term credentials. 

To get this to work
1. Configure your workflow to use the `id-token: write` permission.
2. Configure your audience, if required.
3. In your AWS account, configure IAM to trust GitHub's OIDC identity provider.
4. Configure an IAM role with appropriate claim limits and permission scope.

   *Note*: Naming your role "GitHubActions" has been reported to not work. See
   [#953](https://github.com/aws-actions/configure-aws-credentials/issues/953).

5. Specify that role's ARN when setting up this action.

### OIDC Audience

When the JWT is created, an audience needs to be specified. Normally, you would
use `sts.amazonaws.com`, and this action uses this by default if you don't
specify one. This will work for most cases. Changing the default audience may
be necessary when using non-default AWS partitions, such as China regions.
You can specify the audience through the `audience` input:

```yaml
    - name: Configure AWS Credentials for China region audience
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        audience: sts.amazonaws.com.cn
        aws-region: cn-northwest-1
        role-to-assume: arn:aws-cn:iam::123456789100:role/my-github-actions-role
```

### Configuring IAM to trust GitHub
To use GitHub's OIDC provider, you must first set up federation in your AWS
account. This involves creating an IAM Identity Provider that trusts GitHub's
OIDC endpoint. You can create an IAM Identity Provider in the AWS Management 
Console by specifying the following details:
- **Provider Type**: OIDC
- **Provider URL**: `https://token.actions.githubusercontent.com`
- **Audience**: `sts.amazonaws.com` (or your custom audience if you specified
  one in the `audience` input)

Prior versions of this documentation gave instructions for specifying the
certificate fingerprint, but this is no longer necessary. The thumbprint, if 
specified, will be ignored.

You can also create the IAM Identity Provider using the AWS CLI:

```bash
aws iam create-open-id-connect-provider \
    --url https://token.actions.githubusercontent.com \
    --client-id-list sts.amazonaws.com 
```

### Claims and scoping permissions
To align with the Amazon IAM best practice of [granting least
privilege](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#grant-least-privilege),
the assume role policy document should contain a
[`Condition`](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html)
that specifies a subject (`sub`) allowed to assume the role. [GitHub also
recommends](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect#defining-trust-conditions-on-cloud-roles-using-oidc-claims)
filtering for the correct audience (`aud`). See [AWS IAM
documentation](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_iam-condition-keys.html#condition-keys-wif)
on which claims you can filter for in your trust policies.

Without a subject (`sub`) condition, any GitHub user or repository could
potentially assume the role. The subject can be scoped to a GitHub organization
and repository as shown in the CloudFormation template. However, scoping it down
to your org and repo may cause the role assumption to fail in some cases. See
[Example subject claims](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect#example-subject-claims)
for specific details on what the subject value will be depending on your
workflow. You can also [customize your subject claim](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect#customizing-the-token-claims)
if you want full control over the information you can filter for in your trust
policy. If you aren't sure what your subject (`sub`) key is, you can add the
[`actions-oidc-debugger`](https://github.com/github/actions-oidc-debugger)
action to your workflow to see the value of the subject (`sub`) key, as well as
other claims.

Additional claim conditions can be added for higher specificity as explained in
the [GitHub documentation](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect).
Due to implementation details, not every OIDC claim is presently supported by
IAM.

### Further information about OIDC

For further information on OIDC and GitHub Actions, please see:

* [AWS docs: Creating OpenID Connect (OIDC) identity providers](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_providers_create_oidc.html)
* [AWS docs: IAM JSON policy elements: Condition](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html)
* [GitHub docs: About security hardening with OpenID Connect](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect)
* [GitHub docs: Configuring OpenID Connect in Amazon Web Services](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services)
* [GitHub changelog: GitHub Actions: Secure cloud deployments with OpenID Connect](https://github.blog/changelog/2021-10-27-github-actions-secure-cloud-deployments-with-openid-connect/)

Examples
--------

### AssumeRoleWithWebIdentity
```yaml
    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName
```
In this example, the Action will load the OIDC token from the GitHub-provided
environment variable and use it to assume the role
`arn:aws:iam::123456789100:role/my-github-actions-role` with the session name
`MySessionName`.

### AssumeRole with role previously assumed by action in same workflow
```yaml
    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName
    - name: Configure other AWS Credentials
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::987654321000:role/my-second-role
        role-session-name: MySessionName
        role-chaining: true
```
In this two-step example, the first step will use OIDC to assume the role
`arn:aws:iam::123456789100:role/my-github-actions-role` just as in the prior
example. Following that, a second step will use this role to assume a different
role, `arn:aws:iam::987654321000:role/my-second-role`.

### AssumeRole with static IAM credentials in repository secrets
```yaml
    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
        aws-region: us-east-2
        role-to-assume: ${{ secrets.AWS_ROLE_TO_ASSUME }}
        role-external-id: ${{ secrets.AWS_ROLE_EXTERNAL_ID }}
        role-duration-seconds: 1200
        role-session-name: MySessionName
```
In this example, the secret `AWS_ROLE_TO_ASSUME` contains a string like
`arn:aws:iam::123456789100:role/my-github-actions-role`.  To assume a role in
the same account as the static credentials, you can simply specify the role
name, like `role-to-assume: my-github-actions-role`.

### Retrieving credentials from step output, AssumeRole with temporary credentials
```yaml
    - name: Configure AWS Credentials 1
      id: creds
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        output-credentials: true
    - name: get caller identity 1
      run: |
        aws sts get-caller-identity
    - name: Configure AWS Credentials 2
      uses: aws-actions/configure-aws-credentials@v5.1.0
      with:
        aws-region: us-east-2
        aws-access-key-id: ${{ steps.creds.outputs.aws-access-key-id }}
        aws-secret-access-key: ${{ steps.creds.outputs.aws-secret-access-key }}
        aws-session-token: ${{ steps.creds.outputs.aws-session-token }}
        role-to-assume: arn:aws:iam::123456789100:role/my-other-github-actions-role
    - name: get caller identity2
      run: |
        aws sts get-caller-identity
```
This example shows that you can reference the fetched credentials as outputs if
`output-credentials` is set to true. This example also shows that you can use
the `aws-session-token` input in a situation where session tokens are fetched
and passed to this action.

Versioning
----------
Starting with version 5.0.0, this action uses semantic-style release tags and
[immutable releases](https://docs.github.com/en/code-security/supply-chain-security/understanding-your-software-supply-chain/immutable-releases).
A floating version tag (vN) is also provided for convenience: this tag will
move to the latest major version (vN -> vN.2.1, vM -> vM.0.0, etc.).

License
-------
This code is made available under the MIT license.

Security Disclosures
--------------------
If you would like to report a potential security issue in this project, please
do not create a GitHub issue. Instead, please follow the instructions
[here](https://aws.amazon.com/security/vulnerability-reporting/) or
[email AWS security](mailto:aws-security@amazon.com) directly.
