feat(Boost/Sync for Reddit): Add Fix Redgifs patch (#5725)

extensions/shared/build.gradle.kts

@@ -1,3 +1,4 @@
 dependencies {
     implementation(project(":extensions:shared:library"))
+    compileOnly(libs.okhttp)
 }

extensions/shared/library/build.gradle.kts

@@ -18,4 +18,5 @@ android {
 
 dependencies {
     compileOnly(libs.annotation)
+    compileOnly(libs.okhttp)
 }

extensions/shared/library/src/main/java/app/revanced/extension/shared/fixes/redgifs/BaseFixRedgifsApiPatch.java

@@ -0,0 +1,71 @@
+package app.revanced.extension.shared.fixes.redgifs;
+
+import androidx.annotation.NonNull;
+
+import org.json.JSONException;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+
+import app.revanced.extension.shared.Logger;
+import okhttp3.Interceptor;
+import okhttp3.MediaType;
+import okhttp3.Protocol;
+import okhttp3.Request;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+
+
+public abstract class BaseFixRedgifsApiPatch implements Interceptor {
+    protected static BaseFixRedgifsApiPatch INSTANCE;
+    public abstract String getDefaultUserAgent();
+
+    @NonNull
+    @Override
+    public Response intercept(@NonNull Chain chain) throws IOException {
+        Request request = chain.request();
+        if (!request.url().host().equals("api.redgifs.com")) {
+            return chain.proceed(request);
+        }
+
+        String userAgent = getDefaultUserAgent();
+
+        if (request.header("Authorization") != null) {
+            Response response = chain.proceed(request.newBuilder().header("User-Agent", userAgent).build());
+            if (response.isSuccessful()) {
+                return response;
+            }
+            // It's possible that the user agent is being overwritten later down in the interceptor
+            // chain, so make sure we grab the new user agent from the request headers.
+            userAgent = response.request().header("User-Agent");
+            response.close();
+        }
+
+        try {
+            RedgifsTokenManager.RedgifsToken token = RedgifsTokenManager.refreshToken(userAgent);
+
+            // Emulate response for old OAuth endpoint
+            if (request.url().encodedPath().equals("/v2/oauth/client")) {
+                String responseBody = RedgifsTokenManager.getEmulatedOAuthResponseBody(token);
+                return new Response.Builder()
+                        .message("OK")
+                        .code(HttpURLConnection.HTTP_OK)
+                        .protocol(Protocol.HTTP_1_1)
+                        .request(request)
+                        .header("Content-Type", "application/json")
+                        .body(ResponseBody.create(
+                                responseBody, MediaType.get("application/json")))
+                        .build();
+            }
+
+            Request modifiedRequest = request.newBuilder()
+                    .header("Authorization", "Bearer " + token.getAccessToken())
+                    .header("User-Agent", userAgent)
+                    .build();
+            return chain.proceed(modifiedRequest);
+        } catch (JSONException ex) {
+            Logger.printException(() -> "Could not parse Redgifs response", ex);
+            throw new IOException(ex);
+        }
+    }
+}

extensions/shared/library/src/main/java/app/revanced/extension/shared/fixes/redgifs/RedgifsTokenManager.java

@@ -0,0 +1,94 @@
+package app.revanced.extension.shared.fixes.redgifs;
+
+import static app.revanced.extension.shared.requests.Route.Method.GET;
+
+import androidx.annotation.GuardedBy;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import app.revanced.extension.shared.requests.Requester;
+
+
+/**
+ * Manages Redgifs token lifecycle.
+ */
+public class RedgifsTokenManager {
+    public static class RedgifsToken {
+        // Expire after 23 hours to provide some breathing room
+        private static final long EXPIRY_SECONDS = 23 * 60 * 60;
+
+        private final String accessToken;
+        private final long refreshTimeInSeconds;
+
+        public RedgifsToken(String accessToken, long refreshTime) {
+            this.accessToken = accessToken;
+            this.refreshTimeInSeconds = refreshTime;
+        }
+
+        public String getAccessToken() {
+            return accessToken;
+        }
+
+        public long getExpiryTimeInSeconds() {
+            return refreshTimeInSeconds + EXPIRY_SECONDS;
+        }
+
+        public boolean isValid() {
+            if (accessToken == null) return false;
+            return getExpiryTimeInSeconds() >= System.currentTimeMillis() / 1000;
+        }
+    }
+    public static final String REDGIFS_API_HOST = "https://api.redgifs.com";
+    private static final String GET_TEMPORARY_TOKEN = REDGIFS_API_HOST + "/v2/auth/temporary";
+    @GuardedBy("itself")
+    private static final Map<String, RedgifsToken> tokenMap = new HashMap<>();
+
+    private static String getToken(String userAgent) throws IOException, JSONException {
+        HttpURLConnection connection = (HttpURLConnection) new URL(GET_TEMPORARY_TOKEN).openConnection();
+        connection.setFixedLengthStreamingMode(0);
+        connection.setRequestMethod(GET.name());
+        connection.setRequestProperty("User-Agent", userAgent);
+        connection.setRequestProperty("Content-Type", "application/json");
+        connection.setRequestProperty("Accept", "application/json");
+        connection.setUseCaches(false);
+
+        JSONObject responseObject = Requester.parseJSONObject(connection);
+        return responseObject.getString("token");
+    }
+
+    public static RedgifsToken refreshToken(String userAgent) throws IOException, JSONException {
+        synchronized(tokenMap) {
+            // Reference: https://github.com/JeffreyCA/Apollo-ImprovedCustomApi/pull/67
+            RedgifsToken token = tokenMap.get(userAgent);
+            if (token != null && token.isValid()) {
+                return token;
+            }
+
+            // Copy user agent from original request if present because Redgifs verifies
+            // that the user agent in subsequent requests matches the one in the OAuth token.
+            String accessToken = getToken(userAgent);
+            long refreshTime = System.currentTimeMillis() / 1000;
+            token = new RedgifsToken(accessToken, refreshTime);
+            tokenMap.put(userAgent, token);
+            return token;
+        }
+    }
+
+    public static String getEmulatedOAuthResponseBody(RedgifsToken token) throws JSONException {
+        // Reference: https://github.com/JeffreyCA/Apollo-ImprovedCustomApi/pull/67
+        JSONObject responseObject = new JSONObject();
+        responseObject.put("access_token", token.accessToken);
+        responseObject.put("expiry_time", token.getExpiryTimeInSeconds() - (System.currentTimeMillis() / 1000));
+        responseObject.put("scope", "read");
+        responseObject.put("token_type", "Bearer");
+        return responseObject.toString();
+    }
+}