Allow to pass auth token to build registry

src/main/java/land/oras/Registry.java

@@ -42,6 +42,7 @@
 import java.util.function.Supplier;
 import land.oras.auth.AuthProvider;
 import land.oras.auth.AuthStoreAuthenticationProvider;
+import land.oras.auth.BearerTokenProvider;
 import land.oras.auth.HttpClient;
 import land.oras.auth.NoAuthProvider;
 import land.oras.auth.RegistriesConf;
@@ -294,6 +295,15 @@ public Registry copy(String newRegistry) {
         return new Builder().from(this).withRegistry(newRegistry).build();
     }
 
+    /**
+     * Return a new registry with a new auth external token and same settings
+     * @param authToken The new refreshed token
+     * @return The new registry
+     */
+    public Registry withAuthToken(String authToken) {
+        return new Builder().from(this).withAuthToken(authToken).build();
+    }
+
     /**
      * Return a new registry as insecure but with same settings
      * @return The new registry
@@ -1281,6 +1291,18 @@ public Builder withAuthProvider(AuthProvider authProvider) {
             return this;
         }
 
+        /**
+         * Use given auth token for the registry.
+         * Useful when the auth token is obtained by other mean (like a token exchange).
+         * Caller are responsible to handle token expiration if any
+         * @param authToken The auth token
+         * @return The builder
+         */
+        public Builder withAuthToken(String authToken) {
+            registry.setAuthProvider(new BearerTokenProvider(authToken));
+            return this;
+        }
+
         /**
          * Set the maximum number of concurrent downloads when pulling an artifact with multiple layers. Default is 4.
          * @param parallelism The maximum number of parallel uploads/download

src/main/java/land/oras/auth/BearerTokenProvider.java

@@ -47,6 +47,14 @@ public final class BearerTokenProvider implements AuthProvider {
      */
     public BearerTokenProvider() {}
 
+    /**
+     * Create a new bearer token provider
+     * @param token The token
+     */
+    public BearerTokenProvider(String token) {
+        setToken(new HttpClient.TokenResponse(token, null, null, null, null));
+    }
+
     /**
      * Get the token
      * @return The token

src/test/java/land/oras/RegistryWireMockTest.java

@@ -83,6 +83,34 @@ class RegistryWireMockTest {
     @TempDir
     private static Path homeDir3;
 
+    @Test
+    void shouldPassBearerTokenWithExternalRequestedToken(WireMockRuntimeInfo wmRuntimeInfo) {
+        Registry registry = Registry.Builder.builder()
+                .insecure()
+                .withAuthToken("insecure-token")
+                .build();
+
+        // Ensure WireMock accept only our token
+        WireMock wireMock = wmRuntimeInfo.getWireMock();
+        wireMock.register(WireMock.get(WireMock.urlEqualTo("/v2/library/artifact-text/tags/list"))
+                .withHeader("Authorization", equalTo("Bearer insecure-token"))
+                .willReturn(WireMock.okJson(JsonUtils.toJson(new Tags("artifact-text", List.of("latest", "0.1.1"))))));
+        wireMock.register(WireMock.get(WireMock.urlEqualTo("/v2/library/artifact-text/tags/list"))
+                .withHeader("Authorization", equalTo("Bearer invalid-token"))
+                .willReturn(WireMock.unauthorized()));
+
+        registry.getTags(ContainerRef.parse("%s/library/artifact-text"
+                .formatted(wmRuntimeInfo.getHttpBaseUrl().replace("http://", ""))));
+
+        // Ensure it fail with invalid token
+        final Registry newRegistry = registry.withAuthToken("invalid-token");
+        OrasException e = assertThrows(
+                OrasException.class,
+                () -> newRegistry.getTags(ContainerRef.parse("%s/library/artifact-text"
+                        .formatted(wmRuntimeInfo.getHttpBaseUrl().replace("http://", "")))));
+        assertEquals(401, e.getStatusCode());
+    }
+
     @Test
     void shouldFailToGetManifestOn403(WireMockRuntimeInfo wmRuntimeInfo) {