Implement auth method

Author: lm2343635

src/main/java/org/mushare/pluto/LoginType.java

@@ -0,0 +1,20 @@
+package org.mushare.pluto;
+
+public enum LoginType {
+    mail,
+    google,
+    apple;
+
+    public static LoginType fromIdentifier(String identifier) {
+        switch (identifier) {
+            case "mail":
+                return mail;
+            case "google":
+                return google;
+            case "apple":
+                return apple;
+            default:
+                return null;
+        }
+    }
+}

src/main/java/org/mushare/pluto/Pluto.java

@@ -1,5 +1,12 @@
 package org.mushare.pluto;
 
+import net.sf.json.JSONObject;
+import org.mushare.pluto.exception.PlutoErrorCode;
+import org.mushare.pluto.exception.PlutoException;
+
+import java.security.Signature;
+import java.util.Base64;
+
 public class Pluto {
 
     private PublicKeyManager keyManager;
@@ -9,35 +16,44 @@ private Pluto() {
         super();
     }
 
-    public PublicKeyManager getKeyManager() {
-        return keyManager;
-    }
-
-    public void setKeyManager(PublicKeyManager keyManager) {
-        this.keyManager = keyManager;
-    }
-
-    public String getAppId() {
-        return appId;
-    }
-
-    public void setAppId(String appId) {
-        this.appId = appId;
-    }
-
     private static Pluto shared = new Pluto();
 
     public static void setup(String server, String appId) {
-        shared.setKeyManager(new PublicKeyManager(server));
-        shared.setAppId(appId);
-    }
-
-    public static void auth(String token) {
-
-    }
-
-    public static void auth(String token, String scope) {
-
+        shared.keyManager = new PublicKeyManager(server);
+        shared.appId = appId;
+    }
+
+    public static PlutoUser auth(String token) throws PlutoException {
+        if (token == null) {
+            throw new PlutoException(PlutoErrorCode.jwtFormatError);
+        }
+        String[] parts = token.split("\\.");
+        if (parts.length != 3) {
+            throw new PlutoException(PlutoErrorCode.jwtFormatError);
+        }
+
+        try {
+            String header = new String(Base64.getDecoder().decode(parts[0]), "utf-8");
+            JSONObject payload = JSONObject.fromObject(new String(Base64.getDecoder().decode(parts[1]), "utf-8"));
+            // Verify the appId of the jwt token.
+            if (!payload.getString("appId").equals(shared.appId)) {
+                ;
+            }
+            Long expire = payload.getLong("expire_time") * 1000;
+            if (expire < System.currentTimeMillis()) {
+                throw new PlutoException(PlutoErrorCode.expired);
+            }
+            Signature signature = Signature.getInstance("SHA256withRSA");
+            signature.initVerify(shared.keyManager.getPublicKey());
+            signature.update((header + payload).getBytes());
+            if (!signature.verify(Base64.getDecoder().decode(parts[2]))) {
+                throw new PlutoException(PlutoErrorCode.notVerified);
+            }
+            return new PlutoUser(payload);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new PlutoException(PlutoErrorCode.other);
+        }
     }
 
 }

src/main/java/org/mushare/pluto/PlutoUser.java

@@ -0,0 +1,34 @@
+package org.mushare.pluto;
+
+import net.sf.json.JSONArray;
+import net.sf.json.JSONObject;
+
+public class PlutoUser {
+    private long userId;
+    private String deviceId;
+    private String [] scopes;
+    private LoginType loginType;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public String getDeviceId() {
+        return deviceId;
+    }
+
+    public LoginType getLoginType() {
+        return loginType;
+    }
+
+    public PlutoUser(JSONObject payload) {
+        userId = payload.getLong("userId");
+        deviceId = payload.getString("deviceId");
+        JSONArray scopeArray = payload.getJSONArray("scopes");
+        scopes = new String[scopeArray.size()];
+        for (int i = 0; i < scopeArray.size(); i++) {
+            scopes[i] = scopeArray.getString(i);
+        }
+        loginType = LoginType.fromIdentifier(payload.getString("login_type"));
+    }
+}

src/main/java/org/mushare/pluto/exception/PlutoErrorCode.java

@@ -1,22 +1,25 @@
 package org.mushare.pluto.exception;
 
 public enum PlutoErrorCode {
+    jwtFormatError,
     expired,
     appIdError,
-    unauthorized,
-    signatureError;
+    notVerified,
+    other;
 
     @Override
     public String toString() {
         switch (this) {
+            case jwtFormatError:
+                return "JWT must be like `header.payload.sign`";
             case expired:
                 return "JWT token is expired.";
             case appIdError:
                 return "App id is not compatiable.";
-            case unauthorized:
-                return "Unauthorized user, make sure the user contains the scopes.";
-            case signatureError:
-                return "Cannot verify signature";
+            case notVerified:
+                return "Verify failed, cannot verify signature";
+            case other:
+                return "Unhandled exception: InvalidKeyException, IOException, NoSuchAlgorithmException, SignatureException";
             default:
                 return "Unknown pluto error";
         }

src/main/java/org/mushare/pluto/exception/PlutoException.java

@@ -4,9 +4,9 @@ public class PlutoException extends RuntimeException {
 
     private final PlutoError error;
 
-    public PlutoException(PlutoError error) {
+    public PlutoException(PlutoErrorCode code) {
         super();
-        this.error = error;
+        this.error = new PlutoError(code);
     }
 
 }