acm19 · acm19 · Jan 6, 2023 · dblock · Jan 6, 2023 · acm19
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ### 2.2.1 (Next)
 
+* [#90](https://github.com/acm19/aws-request-signing-apache-interceptor/pull/90): Add support for OpenSearch Serverless - [@acm19](https://github.com/acm19).
+
 ### 2.2.0 (2022/10/02)
 
 * [#80](https://github.com/acm19/aws-request-signing-apache-interceptor/pull/80): Add support for Apache client v5 - [@acm19](https://github.com/acm19).

diff --git a/Makefile b/Makefile
@@ -14,6 +14,14 @@ run_sample:
 		-Dexec.mainClass="io.github.acm19.aws.interceptor.test.AmazonOpenSearchServiceSample" \
 		-Dexec.args="--endpoint=$(ENDPOINT) --region=$(REGION)"
 
+.PHONY: run_serverless_sample
+.SILENT: run_serverless_sample
+run_serverless_sample:
+	mvn test-compile exec:java \
+		-Dexec.classpathScope=test \
+		-Dexec.mainClass="io.github.acm19.aws.interceptor.test.AmazonOpenSearchServerlessSample" \
+		-Dexec.args="--endpoint=$(ENDPOINT) --region=$(REGION)"
+
 .PHONY: run_v5_sample
 .SILENT: run_v5_sample
 run_v5_sample:
@@ -22,6 +30,14 @@ run_v5_sample:
 		-Dexec.mainClass="io.github.acm19.aws.interceptorv5.test.AmazonOpenSearchServiceSample" \
 		-Dexec.args="--endpoint=$(ENDPOINT) --region=$(REGION)"
 
+.PHONY: run_v5_serverless_sample
+.SILENT: run_v5_serverless_sample
+run_v5_serverless_sample:
+	mvn test-compile exec:java \
+		-Dexec.classpathScope=test \
+		-Dexec.mainClass="io.github.acm19.aws.interceptorv5.test.AmazonOpenSearchServerlessSample" \
+		-Dexec.args="--endpoint=$(ENDPOINT) --region=$(REGION)"
+
 debug_v5_sample:
 	mvn exec:exec -Dexec.executable="java" -Dexec.classpathScope=test \
 		-Dexec.args="-classpath %classpath -Xdebug \

diff --git a/checkstyle.xml b/checkstyle.xml
@@ -159,7 +159,6 @@
 
     <!-- See https://checkstyle.org/config_misc.html -->
     <module name="ArrayTypeStyle"/>
-    <module name="FinalParameters"/>
     <module name="TodoComment"/>
     <module name="UpperEll"/>
 

diff --git a/src/main/java/io/github/acm19/aws/interceptor/http/AwsRequestSigningApacheInterceptor.java b/src/main/java/io/github/acm19/aws/interceptor/http/AwsRequestSigningApacheInterceptor.java
@@ -40,6 +40,7 @@
  */
 public final class AwsRequestSigningApacheInterceptor implements HttpRequestInterceptor {
     private final RequestSigner signer;
+    private final boolean isServerlessOpenSearch;
 
     /**
      * Creates an {@code AwsRequestSigningApacheInterceptor} with the
@@ -51,12 +52,12 @@ public final class AwsRequestSigningApacheInterceptor implements HttpRequestInte
      * @param awsCredentialsProvider source of AWS credentials for signing
      * @param region                 signing region
      */
-    public AwsRequestSigningApacheInterceptor(
-            final String service,
-            final Signer signer,
-            final AwsCredentialsProvider awsCredentialsProvider,
-            final Region region) {
+    public AwsRequestSigningApacheInterceptor(String service,
+                                              Signer signer,
+                                              AwsCredentialsProvider awsCredentialsProvider,
+                                              Region region) {
         this.signer = new RequestSigner(service, signer, awsCredentialsProvider, region);
+        this.isServerlessOpenSearch = "aoss".equals(service);
     }
 
     /**
@@ -69,19 +70,18 @@ public AwsRequestSigningApacheInterceptor(
      * @param awsCredentialsProvider source of AWS credentials for signing
      * @param region                 signing region
      */
-    public AwsRequestSigningApacheInterceptor(
-            final String service,
-            final Signer signer,
-            final AwsCredentialsProvider awsCredentialsProvider,
-            final String region) {
+    public AwsRequestSigningApacheInterceptor(String service,
+                                              Signer signer,
+                                              AwsCredentialsProvider awsCredentialsProvider,
+                                              String region) {
         this(service, signer, awsCredentialsProvider, Region.of(region));
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void process(final HttpRequest request, final HttpContext context)
+    public void process(HttpRequest request, HttpContext context)
             throws HttpException, IOException {
         URI requestUri = RequestSigner.buildUri(context, request.getRequestLine().getUri());
 
@@ -101,8 +101,15 @@ public void process(final HttpRequest request, final HttpContext context)
         requestBuilder.headers(headerArrayToMap(request.getAllHeaders()));
         SdkHttpFullRequest signedRequest = signer.signRequest(requestBuilder.build());
 
-        // copy everything back
-        request.setHeaders(mapToHeaderArray(signedRequest.headers()));
+        if (!isServerlessOpenSearch) {
+            // copy everything back
+            request.setHeaders(mapToHeaderArray(signedRequest.headers()));
+        } else {
+            // copy everything back, don't override headers as not all of them were used for signing the request
+            for (Header header : mapToHeaderArray(signedRequest.headers())) {
+                request.setHeader(header);
+            }
+        }
 
         if (request instanceof HttpEntityEnclosingRequest) {
             HttpEntityEnclosingRequest httpEntityEnclosingRequest = (HttpEntityEnclosingRequest) request;
@@ -117,7 +124,7 @@ public void process(final HttpRequest request, final HttpContext context)
         }
     }
 
-    private static Map<String, List<String>> headerArrayToMap(final Header[] headers) {
+    private Map<String, List<String>> headerArrayToMap(Header[] headers) {
         Map<String, List<String>> headersMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
         for (Header header : headers) {
             if (!skipHeader(header)) {
@@ -129,13 +136,28 @@ private static Map<String, List<String>> headerArrayToMap(final Header[] headers
         return headersMap;
     }
 
-    private static boolean skipHeader(final Header header) {
+    /**
+     * Ignores {@code Host} headers and {@code Content-Length} as long as it either
+     * contains the value {@code 0} or the service to be signed is Serverless
+     * OpenSearch. Details in AWS documentation below.
+     *
+     * AWS documentation:
+     * <pre><a href="https://docs.aws.amazon.com/opensearch-service/latest/developerguide/serverless-clients.html
+     * #serverless-signing">
+     *   Signing requests to OpenSearch Serverless
+     * </a></pre>
+     *
+     * @param header the header to evaluate
+     * @return {@code true} if header must be ignored {@code false} otherwise
+     */
+    private boolean skipHeader(Header header) {
+               // Strip for Content-Length: 0 and Serverless
         return (HTTP.CONTENT_LEN.equalsIgnoreCase(header.getName())
-                && "0".equals(header.getValue())) // Strip Content-Length: 0
+                && (("0".equals(header.getValue())) || isServerlessOpenSearch))
                 || HTTP.TARGET_HOST.equalsIgnoreCase(header.getName()); // Host comes from endpoint
     }
 
-    private static Header[] mapToHeaderArray(final Map<String, List<String>> mapHeaders) {
+    private static Header[] mapToHeaderArray(Map<String, List<String>> mapHeaders) {
         Header[] headers = new Header[mapHeaders.size()];
         int i = 0;
         for (Map.Entry<String, List<String>> headerEntry : mapHeaders.entrySet()) {

diff --git a/src/main/java/io/github/acm19/aws/interceptor/http/AwsRequestSigningApacheV5Interceptor.java b/src/main/java/io/github/acm19/aws/interceptor/http/AwsRequestSigningApacheV5Interceptor.java
@@ -43,6 +43,7 @@
  */
 public final class AwsRequestSigningApacheV5Interceptor implements HttpRequestInterceptor {
     private final RequestSigner signer;
+    private final boolean isServerlessOpenSearch;
 
     /**
      * Creates an {@code AwsRequestSigningApacheInterceptor} with the
@@ -54,19 +55,19 @@ public final class AwsRequestSigningApacheV5Interceptor implements HttpRequestIn
      * @param awsCredentialsProvider source of AWS credentials for signing
      * @param region                 signing region
      */
-    public AwsRequestSigningApacheV5Interceptor(
-            final String service,
-            final Signer signer,
-            final AwsCredentialsProvider awsCredentialsProvider,
-            final Region region) {
+    public AwsRequestSigningApacheV5Interceptor(String service,
+                                                Signer signer,
+                                                AwsCredentialsProvider awsCredentialsProvider,
+                                                Region region) {
         this.signer = new RequestSigner(service, signer, awsCredentialsProvider, region);
+        this.isServerlessOpenSearch = "aoss".equals(service);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void process(final HttpRequest request, final EntityDetails entityDetails, final HttpContext context)
+    public void process(HttpRequest request, EntityDetails entityDetails, HttpContext context)
             throws HttpException, IOException {
         // copy Apache HttpRequest to AWS request
         SdkHttpFullRequest.Builder requestBuilder = SdkHttpFullRequest.builder()
@@ -85,8 +86,15 @@ public void process(final HttpRequest request, final EntityDetails entityDetails
         requestBuilder.headers(headerArrayToMap(request.getHeaders()));
         SdkHttpFullRequest signedRequest = signer.signRequest(requestBuilder.build());
 
-        // copy everything back
-        request.setHeaders(mapToHeaderArray(signedRequest.headers()));
+        if (!isServerlessOpenSearch) {
+            // copy everything back
+            request.setHeaders(mapToHeaderArray(signedRequest.headers()));
+        } else {
+            // copy everything back, don't override headers as not all of them were used for signing the request
+            for (Header header : mapToHeaderArray(signedRequest.headers())) {
+                request.setHeader(header);
+            }
+        }
 
         if (request instanceof ClassicHttpRequest) {
             ClassicHttpRequest httpEntityEnclosingRequest = (ClassicHttpRequest) request;
@@ -100,15 +108,15 @@ public void process(final HttpRequest request, final EntityDetails entityDetails
         }
     }
 
-    private static URI buildUri(final HttpRequest request) throws IOException {
+    private static URI buildUri(HttpRequest request) throws IOException {
         try {
             return request.getUri();
         } catch (URISyntaxException ex) {
             throw new IOException("Invalid URI", ex);
         }
     }
 
-    private static Map<String, List<String>> headerArrayToMap(final Header[] headers) {
+    private Map<String, List<String>> headerArrayToMap(Header[] headers) {
         Map<String, List<String>> headersMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
         for (Header header : headers) {
             if (!skipHeader(header)) {
@@ -120,9 +128,24 @@ private static Map<String, List<String>> headerArrayToMap(final Header[] headers
         return headersMap;
     }
 
-    private static boolean skipHeader(final Header header) {
+    /**
+     * Ignores {@code Host} headers and {@code Content-Length} as long as it either
+     * contains the value {@code 0} or the service to be signed is Serverless
+     * OpenSearch. Details in AWS documentation below.
+     *
+     * AWS documentation:
+     * <pre><a href="https://docs.aws.amazon.com/opensearch-service/latest/developerguide/serverless-clients.html
+     * #serverless-signing">
+     *   Signing requests to OpenSearch Serverless
+     * </a></pre>
+     *
+     * @param header the header to evaluate
+     * @return {@code true} if header must be ignored {@code false} otherwise
+     */
+    private boolean skipHeader(Header header) {
+               // Strip for Content-Length: 0 and Serverless
         return (HttpHeaders.CONTENT_LENGTH.equalsIgnoreCase(header.getName())
-                && "0".equals(header.getValue())) // Strip Content-Length: 0
+                && (("0".equals(header.getValue())) || isServerlessOpenSearch))
                 || HttpHeaders.HOST.equalsIgnoreCase(header.getName()); // Host comes from endpoint
     }
 

diff --git a/src/main/java/io/github/acm19/aws/interceptor/http/RequestSigner.java b/src/main/java/io/github/acm19/aws/interceptor/http/RequestSigner.java
@@ -48,10 +48,10 @@ class RequestSigner {
      * @param awsCredentialsProvider
      * @param region
      */
-    RequestSigner(final String service,
-                         final Signer signer,
-                         final AwsCredentialsProvider awsCredentialsProvider,
-                         final Region region) {
+    RequestSigner(String service,
+                  Signer signer,
+                  AwsCredentialsProvider awsCredentialsProvider,
+                  Region region) {
         this.service = service;
         this.signer = signer;
         this.awsCredentialsProvider = awsCredentialsProvider;
@@ -67,7 +67,7 @@ class RequestSigner {
      * @return signed request
      * @see Signer#sign
      */
-    SdkHttpFullRequest signRequest(final SdkHttpFullRequest request) {
+    SdkHttpFullRequest signRequest(SdkHttpFullRequest request) {
         ExecutionAttributes attributes = new ExecutionAttributes();
         attributes.putAttribute(AwsSignerExecutionAttribute.AWS_CREDENTIALS,
                                 awsCredentialsProvider.resolveCredentials());
@@ -86,7 +86,7 @@ SdkHttpFullRequest signRequest(final SdkHttpFullRequest request) {
      * @return an {@link URI} from an HTTP context
      * @throws IOException if the {@code uri} syntax is invalid
      */
-    static URI buildUri(final HttpContext context, final String uri) throws IOException {
+    static URI buildUri(HttpContext context, String uri) throws IOException {
         try {
             URIBuilder uriBuilder = new URIBuilder(uri);