feat: Update STS web identity credentials provider & add integration test

AWSSDKSwiftCLI/Sources/AWSSDKSwiftCLI/Resources/Package.Base.swift

@@ -136,6 +136,8 @@ func addIntegrationTestTarget(_ name: String) {
         ]
     case "AWSS3":
         additionalDependencies = ["AWSSSOAdmin"]
+    case "AWSSTS":
+        additionalDependencies = ["AWSIAM", "AWSCognitoIdentity"]
     default:
         break
     }

IntegrationTests/Services/AWSSTSIntegrationTests/STSWebIdentityCredentialsProviderTests.swift

@@ -0,0 +1,211 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import XCTest
+import AWSSTS
+import AWSIAM
+import AWSCognitoIdentity
+import ClientRuntime
+import AWSClientRuntime
+import Foundation
+
+/// Tests STS web identity credentials provider using STS::getCallerIdentity.
+class STSWebIdentityCredentialsProviderTests: XCTestCase {
+    private let region = "us-west-2"
+
+    // MARK: - The client used by test case
+
+    // STS client with only the STS web identity credentials provider configured.
+    private var webIdentityStsClient: STSClient!
+    private var stsConfig: STSClient.STSClientConfiguration!
+
+    // MARK: - Cognito things
+
+    // Used to create identity pools and fetch cognito ID & OIDC token from it.
+    private var cognitoIdentityClient: CognitoIdentityClient!
+    // Regular STS client used to fetch the account ID used in fetching cognito ID.
+    private var stsClient: STSClient!
+    private let identityPoolName = "aws-sts-integration-test-\(UUID().uuidString.split(separator: "-").first!.lowercased())"
+    private var identityPoolId: String!
+    private var oidcToken: String!
+    private var oidcTokenFilePath: String!
+
+    // MARK: - IAM things
+
+    // Used to create temporary role assumed by STS web identity credentials provider.
+    private var iamClient: IAMClient!
+    private let roleName = "aws-sts-integration-test-\(UUID().uuidString.split(separator: "-").first!.lowercased())"
+    private let roleSessionName = "aws-sts-integration-test-\(UUID().uuidString.split(separator: "-").first!.lowercased())"
+    private var roleArn: String!
+    // JSON assume role policy
+    private let assumeRolePolicy = """
+    {"Version": "2012-10-17","Statement": [{"Sid": "","Effect": "Allow",
+    "Principal": {"Federated": "cognito-identity.amazonaws.com"},"Action": [
+    "sts:AssumeRoleWithWebIdentity"],"Condition": {"ForAnyValue:StringLike": {
+    "cognito-identity.amazonaws.com:amr": "unauthenticated"}}}]}
+    """
+    private let identityPolicyName = "allow-STS-getCallerIdentity"
+    // JSON identity policy
+    private let roleIdentityPolicy = """
+    {"Version": "2012-10-17","Statement": [{"Sid": "","Effect": "Allow",
+    "Action": "sts:GetCallerIdentity","Resource": "*"}]}
+    """
+
+    // MARK: - SETUP & TEARDOWN
+
+    override func setUp() async throws {
+        try await super.setUp()
+
+        // Create the role to be assumed in exchange for web identity token
+        try await createRoleToBeAssumed()
+
+        // Attach identity policy to role
+        try await attachIdentityPolicyToRole()
+
+        // Create the Cognito identity pool that allows unauthenticated identities
+        try await createCognitoIdentityPool()
+
+        // Get OIDC token from Cognito
+        try await getAndCacheOIDCTokenFromCognito()
+
+        // Construct STS Client config with only STS web identity crednentials provider
+        try await constructSTSConfigWithWebIdentityCredentialsProvider()
+
+        // Construct STS client that uses STS web identity credentials provider
+        webIdentityStsClient = STSClient(config: stsConfig)
+    }
+
+    override func tearDown() async throws {
+        // Delete inline identity policy of the role
+        try await deleteInlineRolePolicy()
+
+        // Delete role
+        _ = try await iamClient.deleteRole(input: DeleteRoleInput(roleName: roleName))
+
+        // Delete Cognito identity pool
+        _ = try await cognitoIdentityClient.deleteIdentityPool(
+            input: DeleteIdentityPoolInput(identityPoolId: identityPoolId)
+        )
+
+        // Delete token file
+        try deleteTokenFile()
+    }
+
+    // MARK: - TEST CASE
+
+    // Confirm STS web identity credentials provider works by validating response.
+    func testGetCallerIdentity() async throws {
+        let response = try await webIdentityStsClient.getCallerIdentity(
+            input: GetCallerIdentityInput()
+        )
+
+        // Ensure returned caller info aren't nil
+        let account = try XCTUnwrap(response.account)
+        let userId = try XCTUnwrap(response.userId)
+        let arn = try XCTUnwrap(response.arn)
+
+        // Ensure returned caller info aren't empty strings
+        XCTAssertNotEqual(account, "")
+        XCTAssertNotEqual(userId, "")
+        XCTAssertNotEqual(arn, "")
+    }
+
+    // MARK: - SETUP HELPER FUNCTIONS
+
+    private func createRoleToBeAssumed() async throws {
+        iamClient = try IAMClient(region: region)
+        roleArn = try await iamClient.createRole(input: CreateRoleInput(
+            assumeRolePolicyDocument: assumeRolePolicy,
+            roleName: roleName
+        )).role?.arn
+        // This wait is necessary for role creation to propagate everywhere
+        let seconds = 10
+        let NSEC_PER_SEC = 1_000_000_000
+        try await Task.sleep(nanoseconds: UInt64(seconds * NSEC_PER_SEC))
+    }
+
+    private func attachIdentityPolicyToRole() async throws {
+        _ = try await iamClient.putRolePolicy(input: PutRolePolicyInput(
+            policyDocument: roleIdentityPolicy,
+            policyName: identityPolicyName,
+            roleName: roleName
+        ))
+    }
+
+    private func createCognitoIdentityPool() async throws {
+        cognitoIdentityClient = try CognitoIdentityClient(region: region)
+        let identityPool = try await cognitoIdentityClient.createIdentityPool(
+            input: CreateIdentityPoolInput(
+                allowUnauthenticatedIdentities: true,
+                identityPoolName: identityPoolName
+        ))
+        identityPoolId = identityPool.identityPoolId
+    }
+
+    private func saveTokenIntoFile() throws {
+        oidcTokenFilePath = FileManager.default.temporaryDirectory.appendingPathComponent("token.txt").pathExtension
+        let tokenData = oidcToken.data(using: String.Encoding.utf8)
+        let fileCreated = FileManager.default.createFile(
+            atPath: oidcTokenFilePath, contents: tokenData, attributes: nil
+        )
+        if !fileCreated {
+            throw TokenFileError.tokenFileCreationFailed("Failed to create token text file.")
+        }
+    }
+
+    private func getAndCacheOIDCTokenFromCognito() async throws {
+        // Get Cognito ID from Cognito identity pool
+        stsClient = try STSClient(region: region)
+        let accountId = try await stsClient.getCallerIdentity(input: GetCallerIdentityInput()).account
+        let cognitoId = try await cognitoIdentityClient.getId(input: GetIdInput(
+            accountId: accountId, identityPoolId: identityPoolId
+        ))
+        // Get OIDC token from Cognito identity pool using Cognito ID
+        oidcToken  = try await cognitoIdentityClient.getOpenIdToken(
+            input: GetOpenIdTokenInput(identityId: cognitoId.identityId)
+        ).token
+        // Save OIDC token to a file then save filepath
+        try saveTokenIntoFile()
+    }
+
+    private func constructSTSConfigWithWebIdentityCredentialsProvider() async throws {
+        let webIdentityCredentialsProvider = try STSWebIdentityCredentialsProvider(
+            region: region,
+            roleArn: roleArn,
+            roleSessionName: roleSessionName,
+            tokenFilePath: oidcTokenFilePath
+        )
+        stsConfig = try await STSClient.STSClientConfiguration(
+            credentialsProvider: webIdentityCredentialsProvider,
+            region: region
+        )
+    }
+
+    // MARK: - TEARDOWN HELPER FUNCTIONS
+
+    private func deleteInlineRolePolicy() async throws {
+        let policyName = try await iamClient.listRolePolicies(input: ListRolePoliciesInput(roleName: roleName)).policyNames
+        _ = try await iamClient.deleteRolePolicy(input: DeleteRolePolicyInput(
+            policyName: policyName?[0], roleName: roleName
+        ))
+    }
+
+    private func deleteTokenFile() throws {
+        do {
+            try FileManager.default.removeItem(atPath: oidcTokenFilePath)
+        } catch {
+            throw TokenFileError.tokenFileDeletionFailed("Failed to delete token text file.")
+        }
+    }
+
+    // MARK: - ERROR USED IN SETUP & TEARDOWN
+
+    enum TokenFileError: Error {
+        case tokenFileCreationFailed(String)
+        case tokenFileDeletionFailed(String)
+    }
+}

Sources/Core/AWSClientRuntime/Auth/CredentialsProviders/STSWebIdentityCredentialsProvider.swift

@@ -26,9 +26,17 @@ public struct STSWebIdentityCredentialsProvider: CredentialsSourcedByCRT {
     /// - Parameters:
     ///   - configFilePath: The path to the configuration file to use. If not provided it will be resolved internally via the `AWS_CONFIG_FILE` environment variable or defaulted  to `~/.aws/config` if not configured.
     ///   - credentialsFilePath: The path to the shared credentials file to use. If not provided it will be resolved internally via the `AWS_SHARED_CREDENTIALS_FILE` environment variable or defaulted `~/.aws/credentials` if not configured.
+    ///   - region: (Optional) region override.
+    ///   - roleArn: (Optional) roleArn override.
+    ///   - roleSessionName: (Optional) roleSessionName override.
+    ///   - tokenFilePath: (Optional) tokenFilePath override.
     public init(
         configFilePath: String? = nil,
-        credentialsFilePath: String? = nil
+        credentialsFilePath: String? = nil,
+        region: String? = nil,
+        roleArn: String? = nil,
+        roleSessionName: String? = nil,
+        tokenFilePath: String? = nil
     ) throws {
         let fileBasedConfig = try CRTFileBasedConfiguration(
             configFilePath: configFilePath,
@@ -38,6 +46,10 @@ public struct STSWebIdentityCredentialsProvider: CredentialsSourcedByCRT {
             bootstrap: SDKDefaultIO.shared.clientBootstrap,
             tlsContext: SDKDefaultIO.shared.tlsContext,
             fileBasedConfiguration: fileBasedConfig,
+            region: region,
+            roleArn: roleArn,
+            roleSessionName: roleSessionName,
+            tokenFilePath: tokenFilePath,
             shutdownCallback: nil
         ))
     }

scripts/integration-test-sdk.properties

@@ -1,2 +1,2 @@
 # Only include services needed for running integration tests
-onlyIncludeModels=kinesis.2013-12-02,s3.2006-03-01,sso-admin.2020-07-20,translate.2017-07-01,sqs.2012-11-05,mediaconvert.2017-08-29,sts.2011-06-15
+onlyIncludeModels=kinesis.2013-12-02,s3.2006-03-01,sso-admin.2020-07-20,translate.2017-07-01,sqs.2012-11-05,mediaconvert.2017-08-29,sts.2011-06-15,cognito-identity.2014-06-30,iam.2010-05-08