fix refresh interval for STS profile credentials provider

Author: sbiscigl

src/aws-cpp-sdk-core/include/aws/core/auth/AWSCredentials.h

@@ -91,6 +91,14 @@ namespace Aws
 
             inline bool IsExpired() const { return m_expiration <= Aws::Utils::DateTime::Now(); }
 
+            /**
+             * Checks to see if the credentials will expire in a threshold of time
+             *
+             * @param millisecondThreshold the milliseconds of threshold we will check for expiry.
+             * @return true if the credentials will expire before the threshold
+             */
+            inline bool ExpiresSoon(int64_t millisecondThreshold = 5000) const { return (m_expiration - Aws::Utils::DateTime::Now()).count() < millisecondThreshold; }
+
             inline bool IsExpiredOrEmpty() const { return IsEmpty() || IsExpired(); }
 
             /**

src/aws-cpp-sdk-core/source/auth/AWSCredentialsProvider.cpp

@@ -274,7 +274,7 @@ bool InstanceProfileCredentialsProvider::ExpiresSoon() const
         credentials = profileIter->second.GetCredentials();
     }
 
-    return ((credentials.GetExpiration() - Aws::Utils::DateTime::Now()).count() < AWS_CREDENTIAL_PROVIDER_EXPIRATION_GRACE_PERIOD);
+    return credentials.ExpiresSoon(AWS_CREDENTIAL_PROVIDER_EXPIRATION_GRACE_PERIOD);
 }
 
 void InstanceProfileCredentialsProvider::Reload()

src/aws-cpp-sdk-identity-management/source/auth/STSProfileCredentialsProvider.cpp

@@ -45,13 +45,13 @@ AWSCredentials STSProfileCredentialsProvider::GetAWSCredentials()
 void STSProfileCredentialsProvider::RefreshIfExpired()
 {
     Utils::Threading::ReaderLockGuard guard(m_reloadLock);
-    if (!IsTimeToRefresh(static_cast<long>(m_reloadFrequency.count())) || !m_credentials.IsExpiredOrEmpty())
+    if (!IsTimeToRefresh(static_cast<long>(m_reloadFrequency.count())) && !m_credentials.IsEmpty() && !m_credentials.ExpiresSoon(m_reloadFrequency.count()))
     {
        return;
     }
 
     guard.UpgradeToWriterLock();
-    if (!IsTimeToRefresh(static_cast<long>(m_reloadFrequency.count())) || !m_credentials.IsExpiredOrEmpty()) // double-checked lock to avoid refreshing twice
+    if (!IsTimeToRefresh(static_cast<long>(m_reloadFrequency.count())) && !m_credentials.IsEmpty() && !m_credentials.ExpiresSoon(m_reloadFrequency.count())) // double-checked lock to avoid refreshing twice
     {
         return;
     }

tests/aws-cpp-sdk-identity-management-tests/auth/STSProfileCredentialsProviderTest.cpp

@@ -34,12 +34,17 @@ class MockSTSClient : public STSClient
     Model::AssumeRoleOutcome AssumeRole(const Model::AssumeRoleRequest& request) const override
     {
         m_capturedRequest = request;
-        return m_mockedOutcome;
+        if (!m_mockedOutcomes.empty()) {
+          auto outcome = m_mockedOutcomes.front();
+          m_mockedOutcomes.pop();
+          return outcome;
+        }
+        return STSError{};
     }
 
     void MockAssumeRole(const Model::AssumeRoleOutcome& outcome)
     {
-        m_mockedOutcome = outcome;
+        m_mockedOutcomes.push(outcome);
     }
 
     const Model::AssumeRoleRequest& CapturedRequest() const
@@ -54,7 +59,7 @@ class MockSTSClient : public STSClient
 
 private:
     mutable Model::AssumeRoleRequest m_capturedRequest;
-    Model::AssumeRoleOutcome m_mockedOutcome;
+    mutable Aws::Queue<Model::AssumeRoleOutcome> m_mockedOutcomes;
     AWSCredentials m_credentials;
 };
 
@@ -621,4 +626,72 @@ TEST_F(STSProfileCredentialsProviderTest, AssumeRoleRecursivelyCircularReference
 
     ASSERT_TRUE(actualCredentials.IsExpiredOrEmpty());
 }
+
+TEST_F(STSProfileCredentialsProviderTest, ShouldRefreshCredentialsNearExpiry)
+{
+    Aws::OFStream configFile {m_configFilename.c_str(), Aws::OFStream::out | Aws::OFStream::trunc};
+
+    configFile << std::endl;
+    configFile << "[default]" << std::endl;
+    configFile << "source_profile = default" << std::endl;
+    configFile << "role_arn = " << ROLE_ARN_1 << std::endl;
+    configFile << "aws_access_key_id = " << ACCESS_KEY_ID_1 << std::endl;
+    configFile << "aws_secret_access_key = " << SECRET_ACCESS_KEY_ID_1 << std::endl;
+    configFile.close();
+    Aws::Config::ReloadCachedConfigFile();
+
+    constexpr auto roleSessionDuration = std::chrono::seconds(5);
+    const DateTime expiryTime{DateTime::Now() + roleSessionDuration};
+
+    Model::Credentials stsCredentials;
+    stsCredentials.WithAccessKeyId(ACCESS_KEY_ID_2)
+        .WithSecretAccessKey(SECRET_ACCESS_KEY_ID_2)
+        .WithSessionToken(SESSION_TOKEN)
+        .WithExpiration(expiryTime);
+
+    Model::Credentials refreshedStsCredentials;
+    refreshedStsCredentials.WithAccessKeyId(ACCESS_KEY_ID_3)
+        .WithSecretAccessKey(SECRET_ACCESS_KEY_ID_3)
+        .WithSessionToken(SESSION_TOKEN)
+        .WithExpiration(expiryTime);
+
+    Model::AssumeRoleResult mockResult;
+    mockResult.SetCredentials(stsCredentials);
+    Model::AssumeRoleResult refreshedMockResult;
+    refreshedMockResult.SetCredentials(refreshedStsCredentials);
+    Aws::UniquePtr<MockSTSClient> stsClient;
+    std::once_flag stsClientInitialized;
+
+    int stsCallCounter = 0;
+    STSProfileCredentialsProvider credsProvider("default", std::chrono::minutes(60), [&](const AWSCredentials& creds)
+        {
+            ++stsCallCounter;
+            std::call_once(stsClientInitialized, [&] {
+              stsClient = Aws::MakeUnique<MockSTSClient>(CLASS_TAG, creds);
+              stsClient->MockAssumeRole(mockResult);
+              stsClient->MockAssumeRole(refreshedMockResult);
+            });
+            return stsClient.get();
+        });
+
+    auto actualCredentials = credsProvider.GetAWSCredentials();
+
+    ASSERT_STREQ(ACCESS_KEY_ID_2, actualCredentials.GetAWSAccessKeyId().c_str());
+    ASSERT_STREQ(SECRET_ACCESS_KEY_ID_2, actualCredentials.GetAWSSecretKey().c_str());
+    ASSERT_STREQ(SESSION_TOKEN, actualCredentials.GetSessionToken().c_str());
+    ASSERT_EQ(expiryTime, actualCredentials.GetExpiration());
+
+    ASSERT_EQ(1, stsCallCounter);
+    ASSERT_TRUE(stsClient);
+    ASSERT_STREQ(ACCESS_KEY_ID_1, stsClient->Credentials().GetAWSAccessKeyId().c_str());
+    ASSERT_STREQ(SECRET_ACCESS_KEY_ID_1, stsClient->Credentials().GetAWSSecretKey().c_str());
+
+    actualCredentials = credsProvider.GetAWSCredentials();
+    ASSERT_STREQ(ACCESS_KEY_ID_3, actualCredentials.GetAWSAccessKeyId().c_str());
+    ASSERT_STREQ(SECRET_ACCESS_KEY_ID_3, actualCredentials.GetAWSSecretKey().c_str());
+    ASSERT_STREQ(SESSION_TOKEN, actualCredentials.GetSessionToken().c_str());
+    ASSERT_EQ(expiryTime, actualCredentials.GetExpiration());
+    //should have called refresh
+    ASSERT_EQ(2, stsCallCounter);
+}
 } // namespace