Added OIDC client functionality in core package

packages/core/README.md

@@ -257,3 +257,51 @@ var pid = core.getState("pidToKill");
 
 process.kill(pid);
 ```
+
+#### OIDC Token
+
+You can use these methods to interact with the GitHub OIDC provider and get a JWT ID token which would help to get access token from third party cloud providers.
+
+**Method Name**: getIDToken()
+
+**Inputs**
+
+audience : optional
+
+**Outputs**
+
+A [JWT](https://jwt.io/) ID Token
+
+In action's `main.ts`:
+```js
+const core = require('@actions/core');
+async function getIDTokenAction(): Promise<void> {
+
+   const audience = core.getInput('audience', {required: false})
+
+   const id_token1 = await core.getIDToken()            // ID Token with default audience
+   const id_token2 = await core.getIDToken(audience)    // ID token with custom audience
+
+   // this id_token can be used to get access token from third party cloud providers
+}
+getIDTokenAction()
+```
+
+In action's `actions.yml`:
+
+```yaml
+name: 'GetIDToken'
+description: 'Get ID token from Github OIDC provider'
+inputs:
+  audience:  
+    description: 'Audience for which the ID token is intended for'
+    required: false
+outputs:
+  id_token1: 
+    description: 'ID token obtained from OIDC provider'
+  id_token2: 
+    description: 'ID token obtained from OIDC provider'
+runs:
+  using: 'node12'
+  main: 'dist/index.js'
+```

packages/core/RELEASES.md

@@ -1,5 +1,8 @@
 # @actions/core Releases
 
+### 1.6.0
+- [Added OIDC Client function `getIDToken`](https://github.com/actions/toolkit/pull/887)
+
 ### 1.5.0
 - [Added support for notice annotations and more annotation fields](https://github.com/actions/toolkit/pull/855)
 

packages/core/__tests__/core.test.ts

@@ -2,6 +2,7 @@ import * as fs from 'fs'
 import * as os from 'os'
 import * as path from 'path'
 import * as core from '../src/core'
+import {HttpClient} from '@actions/http-client'
 import {toCommandProperties} from '../src/utils'
 
 /* eslint-disable @typescript-eslint/unbound-method */
@@ -434,3 +435,20 @@ function verifyFileCommand(command: string, expectedContents: string): void {
     fs.unlinkSync(filePath)
   }
 }
+
+function getTokenEndPoint(): string {
+  return 'https://vstoken.actions.githubusercontent.com/.well-known/openid-configuration'
+}
+
+describe('oidc-client-tests', () => {
+  it('Get Http Client', async () => {
+    const http = new HttpClient('actions/oidc-client')
+    expect(http).toBeDefined()
+  })
+
+  it('HTTP get request to get token endpoint', async () => {
+    const http = new HttpClient('actions/oidc-client')
+    const res = await http.get(getTokenEndPoint())
+    expect(res.message.statusCode).toBe(200)
+  })
+})

packages/core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/core",
-  "version": "1.5.0",
+  "version": "1.6.0",
   "description": "Actions core lib",
   "keywords": [
     "github",
@@ -35,6 +35,9 @@
   "bugs": {
     "url": "https://github.com/actions/toolkit/issues"
   },
+  "dependencies": {
+    "@actions/http-client": "^1.0.11"
+  },
   "devDependencies": {
     "@types/node": "^12.0.2"
   }

packages/core/src/core.ts

@@ -5,6 +5,8 @@ import {toCommandProperties, toCommandValue} from './utils'
 import * as os from 'os'
 import * as path from 'path'
 
+import {OidcClient} from './oidc-utils'
+
 /**
  * Interface for getInput options
  */
@@ -348,3 +350,7 @@ export function saveState(name: string, value: any): void {
 export function getState(name: string): string {
   return process.env[`STATE_${name}`] || ''
 }
+
+export async function getIDToken(aud?: string): Promise<string> {
+  return await OidcClient.getIDToken(aud)
+}

packages/core/src/oidc-utils.ts

@@ -0,0 +1,94 @@
+/* eslint-disable @typescript-eslint/no-extraneous-class */
+import * as actions_http_client from '@actions/http-client'
+import {IRequestOptions} from '@actions/http-client/interfaces'
+import {HttpClient} from '@actions/http-client'
+import {BearerCredentialHandler} from '@actions/http-client/auth'
+import {debug, setSecret} from './core'
+
+interface TokenRequest {
+  aud?: string
+}
+
+interface TokenResponse {
+  value?: string
+}
+
+export class OidcClient {
+  private static createHttpClient(
+    allowRetry = true,
+    maxRetry = 10
+  ): actions_http_client.HttpClient {
+    const requestOptions: IRequestOptions = {
+      allowRetries: allowRetry,
+      maxRetries: maxRetry
+    }
+
+    return new HttpClient(
+      'actions/oidc-client',
+      [new BearerCredentialHandler(OidcClient.getRuntimeToken())],
+      requestOptions
+    )
+  }
+
+  private static getApiVersion(): string {
+    return '2.0'
+  }
+
+  private static getRuntimeToken(): string {
+    const token = process.env['ACTIONS_RUNTIME_TOKEN']
+    if (!token) {
+      throw new Error('Unable to get ACTIONS_RUNTIME_TOKEN env variable')
+    }
+    return token
+  }
+
+  private static getIDTokenUrl(): string {
+    const runtimeUrl = process.env['ACTIONS_ID_TOKEN_REQUEST_URL']
+    if (!runtimeUrl) {
+      throw new Error('Unable to get ACTIONS_ID_TOKEN_REQUEST_URL env variable')
+    }
+    return `${runtimeUrl}?api-version=${OidcClient.getApiVersion()}`
+  }
+
+  private static async postCall(
+    id_token_url: string,
+    data: TokenRequest
+  ): Promise<string> {
+    const httpclient = OidcClient.createHttpClient()
+
+    const res = await httpclient
+      .postJson<TokenResponse>(id_token_url, data)
+      .catch(error => {
+        throw new Error(
+          `Failed to get ID Token. \n 
+        Error Code : ${error.statusCode}\n 
+        Error Message: ${error.result.message}`
+        )
+      })
+
+    const id_token = res.result?.value
+    if (!id_token) {
+      throw new Error('Response json body do not have ID Token field')
+    }
+    return id_token
+  }
+
+  static async getIDToken(audience?: string): Promise<string> {
+    try {
+      // New ID Token is requested from action service
+      const id_token_url: string = OidcClient.getIDTokenUrl()
+
+      debug(`ID token url is ${id_token_url}`)
+
+      const data: TokenRequest = {aud: audience}
+
+      debug(`audience is ${audience ? audience : 'not defined'}`)
+
+      const id_token = await OidcClient.postCall(id_token_url, data)
+      setSecret(id_token)
+      return id_token
+    } catch (error) {
+      throw new Error(`Error message: ${error.message}`)
+    }
+  }
+}