Add aws credential provider

2 files changed, 83 insertions, 1 deletions

diff --git a/vespa-athenz/pom.xml b/vespa-athenz/pom.xml
index 27b68fbf360..f30aed1af5f 100644
--- a/vespa-athenz/pom.xml
+++ b/vespa-athenz/pom.xml
@@ -114,7 +114,10 @@
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
         </dependency>
-
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk-core</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/vespa-athenz/src/main/java/com/yahoo/vespa/athenz/client/aws/AwsCredentialsProvider.java b/vespa-athenz/src/main/java/com/yahoo/vespa/athenz/client/aws/AwsCredentialsProvider.java
new file mode 100644
index 00000000000..28f028832b4
--- /dev/null
+++ b/vespa-athenz/src/main/java/com/yahoo/vespa/athenz/client/aws/AwsCredentialsProvider.java
@@ -0,0 +1,79 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.athenz.client.aws;
+
+import com.amazonaws.auth.AWSCredentials;
+import com.amazonaws.auth.AWSCredentialsProvider;
+import com.amazonaws.auth.BasicSessionCredentials;
+import com.yahoo.vespa.athenz.api.AthenzDomain;
+import com.yahoo.vespa.athenz.api.AwsRole;
+import com.yahoo.vespa.athenz.api.AwsTemporaryCredentials;
+import com.yahoo.vespa.athenz.client.zts.DefaultZtsClient;
+import com.yahoo.vespa.athenz.client.zts.ZtsClient;
+import com.yahoo.vespa.athenz.identity.ServiceIdentityProvider;
+
+import javax.net.ssl.SSLContext;
+import java.net.URI;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Objects;
+import java.util.logging.Logger;
+
+/**
+ * Implementation of AWSCredentialsProvider using com.yahoo.vespa.athenz.client.zts.ZtsClient
+ *
+ * @author mortent
+ */
+public class AwsCredentialsProvider implements AWSCredentialsProvider {
+
+    private static final Logger logger = Logger.getLogger(AwsCredentialsProvider.class.getName());
+
+    private final static Duration MIN_EXPIRY = Duration.ofMinutes(5);
+    private final AthenzDomain athenzDomain;
+    private final AwsRole awsRole;
+    private final ZtsClient ztsClient;
+    private volatile AwsTemporaryCredentials credentials;
+
+    public AwsCredentialsProvider(ZtsClient ztsClient, AthenzDomain athenzDomain, AwsRole awsRole) {
+        this.ztsClient = ztsClient;
+        this.athenzDomain = athenzDomain;
+        this.awsRole = awsRole;
+        this.credentials = getAthenzTempCredentials();
+    }
+
+    public AwsCredentialsProvider(URI ztsUrl, ServiceIdentityProvider identityProvider, AthenzDomain athenzDomain, AwsRole awsRole) {
+        this(new DefaultZtsClient(ztsUrl, identityProvider), athenzDomain, awsRole);
+    }
+
+    public AwsCredentialsProvider(URI ztsUrl, SSLContext sslContext, AthenzDomain athenzDomain, AwsRole awsRole) {
+        this(new DefaultZtsClient(ztsUrl, null, sslContext), athenzDomain, awsRole);
+    }
+
+    /**
+     * Requests temporary credentials from ZTS or return cached credentials
+     */
+    private AwsTemporaryCredentials getAthenzTempCredentials() {
+        if(shouldRefresh(credentials)) {
+            this.credentials = ztsClient.getAwsTemporaryCredentials(athenzDomain, awsRole);
+        }
+        return credentials;
+    }
+
+    @Override
+    public AWSCredentials getCredentials() {
+        AwsTemporaryCredentials creds = getAthenzTempCredentials();
+        return new BasicSessionCredentials(creds.accessKeyId(), creds.secretAccessKey(), creds.sessionToken());
+    }
+
+    @Override
+    public void refresh() {
+        getAthenzTempCredentials();
+    }
+
+    /*
+     * Checks credential expiration, returns true if it will expipre in the next MIN_EXPIRY minutes
+     */
+    private static boolean shouldRefresh(AwsTemporaryCredentials credentials) {
+        Instant expiration = credentials.expiration();
+        return Objects.isNull(expiration) || expiration.minus(MIN_EXPIRY).isAfter(Instant.now());
+    }
+}