chore(main): release 5.0.0 (#1451)

* chore: update README with versioning and license info

* chore: fix typo

.github/integ_tests/tinyproxy.conf

@@ -0,0 +1,6 @@
+Port 9999
+Listen 127.0.0.1
+Timeout 600
+Allow 127.0.0.1
+LogFile "/home/runner/work/configure-aws-credentials/configure-aws-credentials/integ_proxy_log.txt"
+LogLevel Connect

.github/workflows/tests-integ-push.yml

@@ -0,0 +1,32 @@
+name: Run post-release integration test
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'dist/**'  
+  workflow_dispatch:
+
+jobs:
+  package_and_test:
+    name: Package dist files
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+      - name: Integation tests
+        uses: ./
+        with:
+          aws-region: us-west-2
+          role-to-assume: ${{ secrets.CAWSC_integ_role }}
+          role-session-name: IntegTestCAWSC
+      - name: Get caller identity
+        run: |
+          aws sts get-caller-identity

.github/workflows/tests-integ-release.yml

@@ -0,0 +1,202 @@
+name: Run pre-release integ tests
+on: 
+    pull_request_target:
+permissions:
+    contents: read
+
+jobs:
+  oidc:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    permissions: 
+        id-token: write
+    strategy: 
+        fail-fast: false
+        matrix:
+            os: [windows-latest, ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    name: OIDC login test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false
+      - name: Configure AWS credentials
+        uses: ./
+        with:
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.OIDC_integ_role }}
+      - name: Get Caller Identity
+        run: |
+            aws sts get-caller-identity
+
+  #can cut this test out if it's not necessary
+  static_assumeRole:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    strategy: 
+        fail-fast: false
+        matrix:
+            os: [windows-latest, ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    name: Static IAM creds test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false
+      - name: Configure AWS credentials
+        uses: ./
+        with:
+            aws-region: us-west-2
+            aws-access-key-id: ${{ secrets.STATIC_ak_id }}
+            aws-secret-access-key: ${{ secrets.STATIC_secret_ak }}
+            role-to-assume: ${{ secrets.STATIC_role }}
+      - name: Get Caller Identity
+        run: |
+          aws sts get-caller-identity
+
+  role_chaining:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    permissions: 
+        id-token: write
+    strategy: 
+        fail-fast: false
+        matrix:
+            os: [windows-latest, ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    name: Existing Creds + Role Chaining test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false    
+      - name: Configure AWS credentials
+        uses: ./
+        with:
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.ROLE_chaining_1 }}
+      - name: Get Caller Identity
+        run: |
+          aws sts get-caller-identity
+      - name: assume second role
+        uses: ./
+        with:
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.ROLE_chaining_2 }}
+            role-chaining: true
+      - name: get caller identity
+        run: |
+          aws sts get-caller-identity
+
+  inline_policy:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    permissions: 
+        id-token: write
+    strategy: 
+        fail-fast: false
+        matrix:
+            os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    name: Inline Policy Test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false  
+      - name: get creds w scoped down policy
+        uses: ./
+        with: 
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.INLINE_policy_role }}
+            inline-session-policy: '{"Version":"2012-10-17","Statement":[{"Sid":"Stmt1","Effect":"Allow","Action":"s3:ListAllMyBuckets","Resource":"*"}]}'
+    
+      #NOTE: This step should succeed. The role should have permission only to list all buckets.
+      - name: list buckets
+        run: aws s3 ls > /dev/null
+
+      #NOTE: This step should fail. we don't want the role to have permission to see the bucket contents.    
+      - name: try to list bucket contents
+        id: bucketContentsStep
+        continue-on-error: true
+        run: aws s3 ls s3://cawsc-integ-tests-bucket > /dev/null
+
+      #But the test fails if we could list the bucket contents.
+      - name: fail if we can list bucket contents
+        if: steps.bucketContentsStep.outcome == 'success'
+        run: exit 1
+
+  http-proxy:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    permissions:
+        id-token: write
+    runs-on: ubuntu-latest
+    name: HTTP Proxy Test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false  
+      - name: install tinyproxy
+        run: |
+          sudo apt-get update
+          sudo apt-get -y install tinyproxy
+      - name: start tinyproxy
+        run: tinyproxy -c .github/integ_tests/tinyproxy.conf
+      - name: Configure AWS credentials
+        continue-on-error: true
+        uses: ./
+        with:
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.OIDC_integ_role }}
+            http-proxy: http://127.0.0.1:9999
+            retry-max-attempts: 4
+      - name: checkout logs 
+        run: cat integ_proxy_log.txt
+      - name: check logs to see if successful call
+        run: grep -q "Request" integ_proxy_log.txt && echo "PROXY_CALL_LOGGED=1" >> $GITHUB_ENV || echo "PROXY_CALL_LOGGED=0" >> $GITHUB_ENV
+      - name: fail job if bad call 
+        if: ${{ env.PROXY_CALL_LOGGED != 1 }}
+        run: exit 1
+
+  token-file:
+    if: ${{ github.event.pull_request.user.login == 'aws-sdk-osds' && github.repository == 'aws-actions/configure-aws-credentials' }}
+    permissions:
+        id-token: write
+    strategy: 
+      fail-fast: false
+      matrix:
+        os: [windows-latest, ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    name: Token File Test
+    steps:
+      - name: checkout
+        uses: actions/checkout@v5
+        with:
+            fetch-depth: 0
+            persist-credentials: false
+      - name: fetch token and write to file
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            async function getIDTokenAction() {
+              const id_token = await core.getIDToken("sts.amazonaws.com");
+              return id_token;
+            }
+            const idToken = await getIDTokenAction();
+            fs.writeFileSync(".github/integ_tests/integ_token.txt", idToken, (err) => {
+              if (err) throw err;
+            });
+      - name: get creds with that file
+        uses: ./
+        with:
+            aws-region: us-west-2
+            role-to-assume: ${{ secrets.OIDC_integ_role }}
+            web-identity-token-file: .github/integ_tests/integ_token.txt
+            retry-max-attempts: 4
+      - name: check creds
+        run: aws sts get-caller-identity

.github/workflows/tests-unit.yml

@@ -2,6 +2,8 @@ on:
   [pull_request]
 
 name: Run unit tests
+permissions:
+  contents: read
 
 jobs:
   unit-test:
@@ -14,13 +16,13 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: "Checkout repository"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: "Setup node"
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v4.4.0
         with:
           node-version: 20
       - name: "Install dependencies"
-        uses: bahmutov/npm-install@v1
+        run: npm ci
       - name: "Run tests"
         run: npm run test --if-present
   lint:

.release-please-manifest.json

@@ -1,5 +1,5 @@
 {
   ".release-please-manifest.json": "4.0.2",
   "package.json": "4.0.2",
-  ".": "4.3.0"
+  ".": "5.0.0"
 }

CHANGELOG.md

@@ -2,17 +2,25 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
-## [4.3.0](https://github.com/aws-actions/configure-aws-credentials/compare/v4.3.0...v4.3.0) (2025-08-04)
+## [5.0.0](https://github.com/aws-actions/configure-aws-credentials/compare/v4.3.1...v5.0.0) (2025-09-03)
+
+
+### ⚠ BREAKING CHANGES
+
+* Cleanup input handling. Changes invalid boolean input behavior (see #1445)
+
+### Features
+
+* add skip OIDC option ([#1458](https://github.com/aws-actions/configure-aws-credentials/issues/1458)) ([8c45f6b](https://github.com/aws-actions/configure-aws-credentials/commit/8c45f6b08196feb86cfdbe431541d5571d9ab2c2))
+* Cleanup input handling. Changes invalid boolean input behavior (see [#1445](https://github.com/aws-actions/configure-aws-credentials/issues/1445)) ([74b3e27](https://github.com/aws-actions/configure-aws-credentials/commit/74b3e27aa80db064b5bb8c04b22fc607e817acf7))
+* support account id allowlist ([#1456](https://github.com/aws-actions/configure-aws-credentials/issues/1456)) ([c4be498](https://github.com/aws-actions/configure-aws-credentials/commit/c4be498953fc1da2707a50ce4b761a53af3d02af))
+
+## [4.3.1](https://github.com/aws-actions/configure-aws-credentials/compare/v4.3.0...v4.3.1) (2025-08-04)
 
 
 ### Bug Fixes
 
-* properly set proxy environment variable ([cbea708](https://github.com/aws-actions/configure-aws-credentials/commit/cbea70821e4ab985ad3be0e5a93390523e257cde))
-
-
-### Miscellaneous Chores
-
-* release 4.3.0 ([3f7c218](https://github.com/aws-actions/configure-aws-credentials/commit/3f7c2187213bafaa1ea60a850b27082cbf55dda0))
+* update readme to 4.3.1 ([#1424](https://github.com/aws-actions/configure-aws-credentials/issues/1424)) ([be2e7ad](https://github.com/aws-actions/configure-aws-credentials/commit/be2e7ad815e27b890489a89ce2717b0f9e26b56e))
 
 ## [4.3.0](https://github.com/aws-actions/configure-aws-credentials/compare/v4.2.1...v4.3.0) (2025-08-04)
 
@@ -27,6 +35,12 @@ All notable changes to this project will be documented in this file. See [standa
 
 * **docs:** readme samples versioning ([5b3c895](https://github.com/aws-actions/configure-aws-credentials/commit/5b3c89504689ea1ea2b6000b23a6a2aac463662a))
 * the wrong example region for China partition in README ([37fe9a7](https://github.com/aws-actions/configure-aws-credentials/commit/37fe9a740bcb30ee8cccd96feb90666c937311f2))
+* properly set proxy environment variable ([cbea708](https://github.com/aws-actions/configure-aws-credentials/commit/cbea70821e4ab985ad3be0e5a93390523e257cde))
+
+
+### Miscellaneous Chores
+
+* release 4.3.0 ([3f7c218](https://github.com/aws-actions/configure-aws-credentials/commit/3f7c2187213bafaa1ea60a850b27082cbf55dda0))
 
 ## [4.2.1](https://github.com/aws-actions/configure-aws-credentials/compare/v4.2.0...v4.2.1) (2025-05-14)
 

README.md

@@ -143,13 +143,15 @@ See [action.yml](./action.yml) for more detail.
 | 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, and aws-expiration). Defaults to false.                   |    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    |
 </details>
 
 #### Adjust the retry mechanism
@@ -178,7 +180,7 @@ this action will always consider the `HTTP_PROXY` environment variable.
 
 Manually configured proxy:
 ```yaml
-uses: aws-actions/configure-aws-credentials@v4.2.1
+uses: aws-actions/configure-aws-credentials@v4.3.1
 with:
   aws-region: us-east-2
   role-to-assume: my-github-actions-role
@@ -249,13 +251,13 @@ line.
 <summary>Inline session policy examples</summary>
 
 ```yaml
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       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@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
          inline-session-policy: >-
           {
@@ -281,13 +283,13 @@ the role.
 <summary>Managed session policy examples</summary>
 
 ```yaml
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       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@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
          managed-session-policies: |
           arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess
@@ -325,7 +327,7 @@ You can specify the audience through the `audience` input:
 
 ```yaml
     - name: Configure AWS Credentials for China region audience
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         audience: sts.amazonaws.com.cn
         aws-region: cn-northwest-1
@@ -399,7 +401,7 @@ Examples
 ### AssumeRoleWithWebIdentity
 ```yaml
     - name: Configure AWS Credentials
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         aws-region: us-east-2
         role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
@@ -413,13 +415,13 @@ environment variable and use it to assume the role
 ### AssumeRole with role previously assumed by action in same workflow
 ```yaml
     - name: Configure AWS Credentials
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       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@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         aws-region: us-east-2
         role-to-assume: arn:aws:iam::987654321000:role/my-second-role
@@ -434,7 +436,7 @@ 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@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
         aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
@@ -453,7 +455,7 @@ name, like `role-to-assume: my-github-actions-role`.
 ```yaml
     - name: Configure AWS Credentials 1
       id: creds
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         aws-region: us-east-2
         role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
@@ -462,7 +464,7 @@ name, like `role-to-assume: my-github-actions-role`.
       run: |
         aws sts get-caller-identity
     - name: Configure AWS Credentials 2
-      uses: aws-actions/configure-aws-credentials@v4.2.1
+      uses: aws-actions/configure-aws-credentials@v4.3.1
       with:
         aws-region: us-east-2
         aws-access-key-id: ${{ steps.creds.outputs.aws-access-key-id }}
@@ -478,6 +480,13 @@ This example shows that you can reference the fetched credentials as outputs if
 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.

action.yml

@@ -78,7 +78,15 @@ inputs:
     description: Some environments do not support special characters in AWS_SECRET_ACCESS_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. This option is disabled by default
     required: false
   use-existing-credentials:
+    required: false
     description: When enabled, this option will check if there are already valid credentials in the environment. If there are, new credentials will not be fetched. If there are not, the action will run as normal.
+  allowed-account-ids:
+    required: false
+    description: An option comma-delimited list of expected AWS account IDs. The action will fail if we receive credentials for the wrong account.
+  force-skip-oidc:
+    required: false
+    description: When enabled, this option will skip using GitHub OIDC provider even if the id-token permission is set. This is sometimes useful when using IAM instance credentials.
+
 outputs:
   aws-account-id:
     description: The AWS account ID for the provided credentials

biome.jsonc

@@ -12,6 +12,10 @@
       "performance": {
         "noDelete": "off"
       },
+      "correctness": {
+        // Specifying a radix disables interpretation of 0x as a number (needed for backwards compat)
+        "useParseIntRadix": "off"
+      },
       "complexity": {
         "noExtraBooleanCast": "off"
       }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "configure-aws-credentials",
   "description": "A GitHub Action to configure AWS credentials",
-  "version": "4.3.0",
+  "version": "5.0.0",
   "scripts": {
     "build": "tsc",
     "lint": "biome check --error-on-warnings ./src",
@@ -16,25 +16,25 @@
     "organization": true
   },
   "devDependencies": {
-    "@aws-sdk/credential-provider-env": "^3.858.0",
-    "@biomejs/biome": "2.1.3",
+    "@aws-sdk/credential-provider-env": "^3.879.0",
+    "@biomejs/biome": "2.2.2",
     "@smithy/property-provider": "^4.0.3",
-    "@types/node": "^24.1.0",
+    "@types/node": "^24.3.0",
     "@vercel/ncc": "^0.38.3",
     "@vitest/coverage-v8": "^3.2.4",
     "aws-sdk-client-mock": "^4.1.0",
-    "cpy-cli": "^5.0.0",
+    "cpy-cli": "^6.0.0",
     "del-cli": "^6.0.0",
     "json-schema": "^0.4.0",
-    "memfs": "^4.25.1",
+    "memfs": "^4.38.2",
     "standard-version": "^9.5.0",
     "typescript": "^5.8.3",
     "vitest": "^3.2.4"
   },
   "dependencies": {
     "@actions/core": "^1.11.1",
-    "@aws-sdk/client-sts": "^3.858.0",
-    "@smithy/node-http-handler": "^4.1.0",
+    "@aws-sdk/client-sts": "^3.873.0",
+    "@smithy/node-http-handler": "^4.1.1",
     "https-proxy-agent": "^7.0.6"
   },
   "keywords": [

release-please-config.json

@@ -6,8 +6,10 @@
       "bump-minor-pre-major": false,
       "bump-patch-for-minor-pre-major": false,
       "draft": false,
-      "prerelease": false
+      "prerelease": false,
+      "exclude-paths": [".github", "dist"]
     }
   },
+  "last-release-sha": "7474bc4690e29a8392af63c5b98e7449536d5c3a",
   "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
 }

src/CredentialsClient.ts

@@ -3,7 +3,7 @@ import { STSClient } from '@aws-sdk/client-sts';
 import type { AwsCredentialIdentity } from '@aws-sdk/types';
 import { NodeHttpHandler } from '@smithy/node-http-handler';
 import { HttpsProxyAgent } from 'https-proxy-agent';
-import { errorMessage } from './helpers';
+import { errorMessage, getCallerIdentity } from './helpers';
 
 const USER_AGENT = 'configure-aws-credentials-for-github-actions';
 
@@ -40,7 +40,11 @@ export class CredentialsClient {
     return this._stsClient;
   }
 
-  public async validateCredentials(expectedAccessKeyId?: string, roleChaining?: boolean) {
+  public async validateCredentials(
+    expectedAccessKeyId?: string,
+    roleChaining?: boolean,
+    expectedAccountIds?: string[],
+  ) {
     let credentials: AwsCredentialIdentity;
     try {
       credentials = await this.loadCredentials();
@@ -50,13 +54,27 @@ export class CredentialsClient {
     } catch (error) {
       throw new Error(`Credentials could not be loaded, please check your action inputs: ${errorMessage(error)}`);
     }
+    if (expectedAccountIds && expectedAccountIds.length > 0 && expectedAccountIds[0] !== '') {
+      let callerIdentity: Awaited<ReturnType<typeof getCallerIdentity>>;
+      try {
+        callerIdentity = await getCallerIdentity(this.stsClient);
+      } catch (error) {
+        throw new Error(`Could not validate account ID of credentials: ${errorMessage(error)}`);
+      }
+      if (!callerIdentity.Account || !expectedAccountIds.includes(callerIdentity.Account)) {
+        throw new Error(
+          `The account ID of the provided credentials (${
+            callerIdentity.Account ?? 'unknown'
+          }) does not match any of the expected account IDs: ${expectedAccountIds.join(', ')}`,
+        );
+      }
+    }
 
     if (!roleChaining) {
       const actualAccessKeyId = credentials.accessKeyId;
-
       if (expectedAccessKeyId && expectedAccessKeyId !== actualAccessKeyId) {
         throw new Error(
-          'Unexpected failure: Credentials loaded by the SDK do not match the access key ID configured by the action',
+          'Credentials loaded by the SDK do not match the expected access key ID configured by the action',
         );
       }
     }

src/assumeRole.ts

@@ -142,7 +142,11 @@ export async function assumeRole(params: assumeRoleParams) {
     PolicyArns: managedSessionPolicies?.length ? managedSessionPolicies : undefined,
   };
   const keys = Object.keys(commonAssumeRoleParams) as Array<keyof typeof commonAssumeRoleParams>;
-  keys.forEach((k) => commonAssumeRoleParams[k] === undefined && delete commonAssumeRoleParams[k]);
+  keys.forEach((k) => {
+    if (commonAssumeRoleParams[k] === undefined) {
+      delete commonAssumeRoleParams[k];
+    }
+  });
 
   // Instantiate STS client
   const stsClient = credentialsClient.stsClient;

src/cleanup/index.ts

@@ -1,5 +1,5 @@
 import * as core from '@actions/core';
-import { errorMessage } from '../helpers';
+import { errorMessage, getBooleanInput } from '../helpers';
 
 /**
  * When the GitHub Actions job is done, clean up any environment variables that
@@ -13,8 +13,8 @@ import { errorMessage } from '../helpers';
  */
 
 export function cleanup() {
-  const outputEnvCredentialsInput = core.getInput('output-env-credentials', { required: false }) || 'true';
-  if (outputEnvCredentialsInput === 'true') {
+  // Only attempt to change environment variables if we changed them in the first place
+  if (getBooleanInput('output-env-credentials', { required: false, default: true })) {
     try {
       // The GitHub Actions toolkit does not have an option to completely unset
       // environment variables, so we overwrite the current value with an empty
@@ -30,6 +30,7 @@ export function cleanup() {
     }
   }
 }
+
 /* c8 ignore start */
 if (require.main === module) {
   try {

src/helpers.ts

@@ -1,5 +1,5 @@
 import * as core from '@actions/core';
-import type { Credentials } from '@aws-sdk/client-sts';
+import type { Credentials, STSClient } from '@aws-sdk/client-sts';
 import { GetCallerIdentityCommand } from '@aws-sdk/client-sts';
 import type { CredentialsClient } from './CredentialsClient';
 
@@ -109,15 +109,19 @@ export function exportRegion(region: string, outputEnvCredentials?: boolean) {
   }
 }
 
-// Obtains account ID from STS Client and sets it as output
-export async function exportAccountId(credentialsClient: CredentialsClient, maskAccountId?: boolean) {
-  const client = credentialsClient.stsClient;
+export async function getCallerIdentity(client: STSClient): Promise<{ Account: string; Arn: string; UserId?: string }> {
   const identity = await client.send(new GetCallerIdentityCommand({}));
-  const accountId = identity.Account;
-  const arn = identity.Arn;
-  if (!accountId || !arn) {
+  if (!identity.Account || !identity.Arn) {
     throw new Error('Could not get Account ID or ARN from STS. Did you set credentials?');
   }
+  return { Account: identity.Account, Arn: identity.Arn, UserId: identity.UserId };
+}
+
+// Obtains account ID from STS Client and sets it as output
+export async function exportAccountId(credentialsClient: CredentialsClient, maskAccountId?: boolean) {
+  const identity = await getCallerIdentity(credentialsClient.stsClient);
+  const accountId = identity.Account;
+  const arn = identity.Arn;
   if (maskAccountId) {
     core.setSecret(accountId);
     core.setSecret(arn);
@@ -214,3 +218,32 @@ export async function areCredentialsValid(credentialsClient: CredentialsClient)
     return false;
   }
 }
+
+/**
+ * Like core.getBooleanInput, but respects the required option.
+ *
+ * From https://github.com/actions/toolkit/blob/6876e2a664ec02908178087905b9155e9892a437/packages/core/src/core.ts
+ *
+ * Gets the input value of the boolean type in the YAML 1.2 "core schema" specification.
+ * Support boolean input list: `true | True | TRUE | false | False | FALSE` .
+ * The return value is also in boolean type.
+ * ref: https://yaml.org/spec/1.2/spec.html#id2804923
+ *
+ * @param     name     name of the input to get
+ * @param     options  optional. See core.InputOptions. Also supports optional 'default' if the input is not set
+ * @returns   boolean
+ */
+export function getBooleanInput(name: string, options?: core.InputOptions & { default?: boolean }): boolean {
+  const trueValue = ['true', 'True', 'TRUE'];
+  const falseValue = ['false', 'False', 'FALSE'];
+  const optionsWithoutDefault = { ...options };
+  delete optionsWithoutDefault.default;
+  const val = core.getInput(name, optionsWithoutDefault);
+  if (trueValue.includes(val)) return true;
+  if (falseValue.includes(val)) return false;
+  if (val === '') return options?.default ?? false;
+  throw new TypeError(
+    `Input does not meet YAML 1.2 "Core Schema" specification: ${name}\n` +
+      `Support boolean input list: \`true | True | TRUE | false | False | FALSE\``,
+  );
+}

src/index.ts

@@ -8,6 +8,7 @@ import {
   exportAccountId,
   exportCredentials,
   exportRegion,
+  getBooleanInput,
   retryAndBackoff,
   translateEnvVariables,
   unsetCredentials,
@@ -22,68 +23,57 @@ export async function run() {
   try {
     translateEnvVariables();
     // Get inputs
+    // Undefined inputs are empty strings ( or empty arrays)
     const AccessKeyId = core.getInput('aws-access-key-id', { required: false });
-    const SecretAccessKey = core.getInput('aws-secret-access-key', {
-      required: false,
-    });
-    const sessionTokenInput = core.getInput('aws-session-token', {
-      required: false,
-    });
+    const SecretAccessKey = core.getInput('aws-secret-access-key', { required: false });
+    const sessionTokenInput = core.getInput('aws-session-token', { required: false });
     const SessionToken = sessionTokenInput === '' ? undefined : sessionTokenInput;
     const region = core.getInput('aws-region', { required: true });
     const roleToAssume = core.getInput('role-to-assume', { required: false });
     const audience = core.getInput('audience', { required: false });
-    const maskAccountIdInput = core.getInput('mask-aws-account-id', { required: false }) || 'false';
-    const maskAccountId = maskAccountIdInput.toLowerCase() === 'true';
-    const roleExternalId = core.getInput('role-external-id', {
-      required: false,
-    });
-    const webIdentityTokenFile = core.getInput('web-identity-token-file', {
-      required: false,
-    });
+    const maskAccountId = getBooleanInput('mask-aws-account-id', { required: false });
+    const roleExternalId = core.getInput('role-external-id', { required: false });
+    const webIdentityTokenFile = core.getInput('web-identity-token-file', { required: false });
     const roleDuration =
       Number.parseInt(core.getInput('role-duration-seconds', { required: false })) || DEFAULT_ROLE_DURATION;
     const roleSessionName = core.getInput('role-session-name', { required: false }) || ROLE_SESSION_NAME;
-    const roleSkipSessionTaggingInput = core.getInput('role-skip-session-tagging', { required: false }) || 'false';
-    const roleSkipSessionTagging = roleSkipSessionTaggingInput.toLowerCase() === 'true';
+    const roleSkipSessionTagging = getBooleanInput('role-skip-session-tagging', { required: false });
     const proxyServer = core.getInput('http-proxy', { required: false }) || process.env.HTTP_PROXY;
-    const inlineSessionPolicy = core.getInput('inline-session-policy', {
-      required: false,
+    const inlineSessionPolicy = core.getInput('inline-session-policy', { required: false });
+    const managedSessionPolicies = core.getMultilineInput('managed-session-policies', { required: false }).map((p) => {
+      return { arn: p };
     });
-    const managedSessionPoliciesInput = core.getMultilineInput('managed-session-policies', { required: false });
-    const managedSessionPolicies: { arn: string }[] = [];
-    const roleChainingInput = core.getInput('role-chaining', { required: false }) || 'false';
-    const roleChaining = roleChainingInput.toLowerCase() === 'true';
-    const outputCredentialsInput = core.getInput('output-credentials', { required: false }) || 'false';
-    const outputCredentials = outputCredentialsInput.toLowerCase() === 'true';
-    const outputEnvCredentialsInput = core.getInput('output-env-credentials', { required: false }) || 'true';
-    const outputEnvCredentials = outputEnvCredentialsInput.toLowerCase() === 'true';
-    const unsetCurrentCredentialsInput = core.getInput('unset-current-credentials', { required: false }) || 'false';
-    const unsetCurrentCredentials = unsetCurrentCredentialsInput.toLowerCase() === 'true';
-    const disableRetryInput = core.getInput('disable-retry', { required: false }) || 'false';
-    let disableRetry = disableRetryInput.toLowerCase() === 'true';
-    const specialCharacterWorkaroundInput =
-      core.getInput('special-characters-workaround', { required: false }) || 'false';
-    const specialCharacterWorkaround = specialCharacterWorkaroundInput.toLowerCase() === 'true';
-    const useExistingCredentialsInput = core.getInput('use-existing-credentials', { required: false }) || 'false';
-    const useExistingCredentials = useExistingCredentialsInput.toLowerCase() === 'true';
+    const roleChaining = getBooleanInput('role-chaining', { required: false });
+    const outputCredentials = getBooleanInput('output-credentials', { required: false });
+    const outputEnvCredentials = getBooleanInput('output-env-credentials', { required: false, default: true });
+    const unsetCurrentCredentials = getBooleanInput('unset-current-credentials', { required: false });
+    let disableRetry = getBooleanInput('disable-retry', { required: false });
+    const specialCharacterWorkaround = getBooleanInput('special-characters-workaround', { required: false });
+    const useExistingCredentials = core.getInput('use-existing-credentials', { required: false });
     let maxRetries = Number.parseInt(core.getInput('retry-max-attempts', { required: false })) || 12;
-    switch (true) {
-      case specialCharacterWorkaround:
-        // 😳
-        disableRetry = false;
-        maxRetries = 12;
-        break;
-      case maxRetries < 1:
-        maxRetries = 1;
-        break;
+    const expectedAccountIds = core
+      .getInput('allowed-account-ids', { required: false })
+      .split(',')
+      .map((s) => s.trim());
+    const forceSkipOidc = getBooleanInput('force-skip-oidc', { required: false });
+
+    if (forceSkipOidc && roleToAssume && !AccessKeyId && !webIdentityTokenFile) {
+      throw new Error(
+        "If 'force-skip-oidc' is true and 'role-to-assume' is set, 'aws-access-key-id' or 'web-identity-token-file' must be set",
+      );
     }
-    for (const managedSessionPolicy of managedSessionPoliciesInput) {
-      managedSessionPolicies.push({ arn: managedSessionPolicy });
+
+    if (specialCharacterWorkaround) {
+      // 😳
+      disableRetry = false;
+      maxRetries = 12;
+    } else if (maxRetries < 1) {
+      maxRetries = 1;
     }
 
     // Logic to decide whether to attempt to use OIDC or not
     const useGitHubOIDCProvider = () => {
+      if (forceSkipOidc) return false;
       // The `ACTIONS_ID_TOKEN_REQUEST_TOKEN` environment variable is set when the `id-token` permission is granted.
       // This is necessary to authenticate with OIDC, but not strictly set just for OIDC. If it is not set and all other
       // checks pass, it is likely but not guaranteed that the user needs but lacks this permission in their workflow.
@@ -158,7 +148,7 @@ export async function run() {
       exportCredentials({ AccessKeyId, SecretAccessKey, SessionToken }, outputCredentials, outputEnvCredentials);
     } else if (!webIdentityTokenFile && !roleChaining) {
       // Proceed only if credentials can be picked up
-      await credentialsClient.validateCredentials();
+      await credentialsClient.validateCredentials(undefined, roleChaining, expectedAccountIds);
       sourceAccountId = await exportAccountId(credentialsClient, maskAccountId);
     }
 
@@ -166,7 +156,7 @@ export async function run() {
       // Validate that the SDK can actually pick up credentials.
       // This validates cases where this action is using existing environment credentials,
       // and cases where the user intended to provide input credentials but the secrets inputs resolved to empty strings.
-      await credentialsClient.validateCredentials(AccessKeyId, roleChaining);
+      await credentialsClient.validateCredentials(AccessKeyId, roleChaining, expectedAccountIds);
       sourceAccountId = await exportAccountId(credentialsClient, maskAccountId);
     }
 
@@ -201,7 +191,11 @@ export async function run() {
       //  is set to `true` then we are NOT in a self-hosted runner.
       // Second: Customer provided credentials manually (IAM User keys stored in GH Secrets)
       if (!process.env.GITHUB_ACTIONS || AccessKeyId) {
-        await credentialsClient.validateCredentials(roleCredentials.Credentials?.AccessKeyId);
+        await credentialsClient.validateCredentials(
+          roleCredentials.Credentials?.AccessKeyId,
+          roleChaining,
+          expectedAccountIds,
+        );
       }
       if (outputEnvCredentials) {
         await exportAccountId(credentialsClient, maskAccountId);

test/index.test.ts

@@ -334,6 +334,288 @@ describe('Configure AWS Credentials', {}, () => {
     });
   });
 
+  describe('Force Skip OIDC', {}, () => {
+    beforeEach(() => {
+      vi.clearAllMocks();
+      mockedSTSClient.reset();
+    });
+
+    it('skips OIDC when force-skip-oidc is true with IAM credentials', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_ASSUMEROLE_INPUTS,
+        'force-skip-oidc': 'true'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials')
+        .mockResolvedValueOnce({ accessKeyId: 'MYAWSACCESSKEYID' })
+        .mockResolvedValueOnce({ accessKeyId: 'STSAWSACCESSKEYID' });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.getIDToken).not.toHaveBeenCalled();
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('skips OIDC when force-skip-oidc is true with web identity token file', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.WEBIDENTITY_TOKEN_FILE_INPUTS,
+        'force-skip-oidc': 'true'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleWithWebIdentityCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      vi.mock('node:fs');
+      vol.reset();
+      fs.mkdirSync('/home/github', { recursive: true });
+      fs.writeFileSync('/home/github/file.txt', 'test-token');
+      
+      await run();
+      expect(core.getIDToken).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Assuming role with web identity token file');
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('fails when force-skip-oidc is true but no alternative credentials provided', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        'role-to-assume': 'arn:aws:iam::111111111111:role/MY-ROLE',
+        'aws-region': 'fake-region-1',
+        'force-skip-oidc': 'true'
+      }));
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.setFailed).toHaveBeenCalledWith(
+        "If 'force-skip-oidc' is true and 'role-to-assume' is set, 'aws-access-key-id' or 'web-identity-token-file' must be set"
+      );
+    });
+
+    it('allows force-skip-oidc without role-to-assume', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'force-skip-oidc': 'true'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.getIDToken).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Proceeding with IAM user credentials');
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('uses OIDC when force-skip-oidc is false (default behavior)', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.GH_OIDC_INPUTS,
+        'force-skip-oidc': 'false'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleWithWebIdentityCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.getIDToken).toHaveBeenCalledWith('');
+      expect(core.info).toHaveBeenCalledWith('Assuming role with OIDC');
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('uses OIDC when force-skip-oidc is not set (default behavior)', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput(mocks.GH_OIDC_INPUTS));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleWithWebIdentityCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.getIDToken).toHaveBeenCalledWith('');
+      expect(core.info).toHaveBeenCalledWith('Assuming role with OIDC');
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('works with role chaining when force-skip-oidc is true', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.EXISTING_ROLE_INPUTS,
+        'force-skip-oidc': 'true',
+        'aws-access-key-id': 'MYAWSACCESSKEYID',
+        'aws-secret-access-key': 'MYAWSSECRETACCESSKEY'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials')
+        .mockResolvedValueOnce({ accessKeyId: 'MYAWSACCESSKEYID' })
+        .mockResolvedValueOnce({ accessKeyId: 'STSAWSACCESSKEYID' });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();
+      expect(core.getIDToken).not.toHaveBeenCalled();
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('Account ID Validation', {}, () => {  
+    beforeEach(() => {
+      vi.clearAllMocks();
+      mockedSTSClient.reset();
+    });
+    
+    it('succeeds when account ID matches allowed list', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': '111111111111'
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Proceeding with IAM user credentials');
+    });
+
+    it('succeeds with multiple allowed account IDs when account matches', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': '999999999999,111111111111,222222222222'
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+
+    it('fails when account ID does not match allowed list', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': '999999999999'
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).toHaveBeenCalledWith(
+        'The account ID of the provided credentials (111111111111) does not match any of the expected account IDs: 999999999999'
+      );
+    });
+
+    it('fails when account ID does not match any in multiple allowed accounts', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': '999999999999,888888888888'
+      }));    
+    
+    mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });    
+      
+      await run();
+      expect(core.setFailed).toHaveBeenCalledWith(
+        'The account ID of the provided credentials (111111111111) does not match any of the expected account IDs: 999999999999, 888888888888'
+      );
+    });
+
+    it('works with assume role when account ID matches', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_ASSUMEROLE_INPUTS,
+        'allowed-account-ids': '111111111111'
+      }));
+      mockedSTSClient.on(AssumeRoleCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials')
+        .mockResolvedValueOnce({ accessKeyId: 'MYAWSACCESSKEYID' })
+        .mockResolvedValueOnce({ accessKeyId: 'STSAWSACCESSKEYID' });
+      
+      await run();
+      expect(core.setFailed).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Authenticated as assumedRoleId AROAFAKEASSUMEDROLEID');
+    });
+
+    it('works with OIDC when account ID matches', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.GH_OIDC_INPUTS,
+        'allowed-account-ids': '111111111111'
+      }));
+      vi.spyOn(core, 'getIDToken').mockResolvedValue('testoidctoken');
+      mockedSTSClient.on(AssumeRoleWithWebIdentityCommand).resolves(mocks.outputs.STS_CREDENTIALS);
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      process.env.ACTIONS_ID_TOKEN_REQUEST_TOKEN = 'fake-token';
+      
+      await run();        
+            expect(core.setFailed).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Authenticated as assumedRoleId AROAFAKEASSUMEDROLEID');
+    });
+
+    it('handles GetCallerIdentity API failure gracefully', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': '111111111111'
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).rejects(new Error('API Error'));
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).toHaveBeenCalledWith('Could not validate account ID of credentials: API Error');
+    });
+
+    it('ignores validation when allowed-account-ids is empty', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': ''
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).not.toHaveBeenCalled();
+      expect(core.info).toHaveBeenCalledWith('Proceeding with IAM user credentials');
+    });
+
+    it('handles whitespace in allowed-account-ids input', async () => {
+      vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput({
+        ...mocks.IAM_USER_INPUTS,
+        'allowed-account-ids': ' 111111111111 , 222222222222 '
+      }));
+      mockedSTSClient.on(GetCallerIdentityCommand).resolves({ ...mocks.outputs.GET_CALLER_IDENTITY });
+      // biome-ignore lint/suspicious/noExplicitAny: any required to mock private method
+      vi.spyOn(CredentialsClient.prototype as any, 'loadCredentials').mockResolvedValue({
+        accessKeyId: 'MYAWSACCESSKEYID',
+      });
+      
+      await run();
+      expect(core.setFailed).not.toHaveBeenCalled();
+    });
+  });    
+    
   describe('HTTP Proxy Configuration', {}, () => {
     beforeEach(() => {
       vi.spyOn(core, 'getInput').mockImplementation(mocks.getInput(mocks.GH_OIDC_INPUTS));