Merge pull request #32 from recolic/master

Allow modifying cookies, just like modifying headers

background.js

@@ -97,6 +97,60 @@ function storeInBrowserStorage(item, callback_function) {
   chrome.storage.local.set(item, callback_function);
 }
 
+/*
+ * This function set a key-value pair in HTTP header "Cookie", 
+ *   and returns the value of HTTP header after modification. 
+ * If key already exists, it modify the value. 
+ * If key doesn't exist, it add the key-value pair. 
+ * If value is undefined, it delete the key-value pair from cookies. 
+ *
+ * Assuming that, the same key SHOULD NOT appear twice in cookies. 
+ * Also assuming that, all cookies doesn't contains semicolon. 
+ *   (99.9% websites are following these rules)
+ *
+ * Example: 
+ *   cookie_keyvalues_set("msg=good; user=recolic; password=test", "user", "p")
+ *     => "msg=good; user=p; password=test"
+ *   cookie_keyvalues_set("msg=good; user=recolic; password=test", "time", "night")
+ *     => "msg=good; user=recolic; password=test;time=night"
+ *
+ * Recolic K <root@recolic.net>
+ */
+function cookie_keyvalues_set(original_cookies, key, value) {
+    let new_element = key + "=" + value; // not used if value is undefined. 
+    let cookies_ar = original_cookies.split(";").filter(e => e.trim().length > 0);
+    let selected_cookie_index = cookies_ar.findIndex(kv => kv.trim().startsWith(key+"="));
+    if (selected_cookie_index == -1)
+        cookies_ar.push(new_element);
+    else {
+        if (value === undefined)
+            cookies_ar.splice(selected_cookie_index, 1);
+        else
+            cookies_ar.splice(selected_cookie_index, 1, new_element);
+    }
+    return cookies_ar.join(";");
+}
+/* 
+ * This function modify the HTTP response header "Set-Cookie", 
+ *   and replace the value of its cookie, to some new_value. 
+ * If key doesn't match original_set_cookie_header_content, new key is used in result. 
+ *
+ * Example: 
+ *   set_cookie_modify_cookie_value("token=123; path=/; expires=Sat, 30 Oct 2021 17:57:32 GMT; secure; HttpOnly", "token", "bar")
+ *     => "token=bar; path=/; expires=Sat, 30 Oct 2021 17:57:32 GMT; secure; HttpOnly"
+ *   set_cookie_modify_cookie_value("  user=recolic", "user", "hacker")
+ *     => "user=hacker"
+ *   set_cookie_modify_cookie_value("user=recolic; path=/; HttpOnly", "token", "bar")
+ *     => "token=bar; path=/; HttpOnly"
+ *
+ * Recolic K <root@recolic.net>
+ */
+function set_cookie_modify_cookie_value(original_set_cookie_header_content, key, new_value) {
+    let trimmed = original_set_cookie_header_content.trimStart();
+    let original_attributes = trimmed.indexOf(";") === -1 ? "" : trimmed.substring(trimmed.indexOf(";"))
+    return key + "=" + new_value + original_attributes;
+}
+
 
 /*
 * Standard function to log messages
@@ -142,6 +196,29 @@ function rewriteRequestHeader(e) {
             " for url " + e.url);
         }
       }
+      else if (to_modify.action === "cookie_add_or_modify") {
+        let header_cookie = e.requestHeaders.find(header => header.name.toLowerCase() === "cookie");
+        let new_cookie = cookie_keyvalues_set(header_cookie === undefined ? "" : header_cookie.value, to_modify.header_name, to_modify.header_value);
+        if (header_cookie === undefined) {
+          e.requestHeaders.push({"name": "Cookie", "value": new_cookie});
+          if (config.debug_mode) log("cookie_add_or_modify.req new_header : name=Cookie,value=" + new_cookie + " for url " + e.url);
+        }
+        else {
+          header_cookie.value = new_cookie;
+          if (config.debug_mode) log("cookie_add_or_modify.req modify_header : name=Cookie,value=" + new_cookie + " for url " + e.url);
+        }
+      }
+      else if (to_modify.action === "cookie_delete") {
+        let header_cookie = e.requestHeaders.find(header => header.name.toLowerCase() === "cookie");
+        let new_cookie = cookie_keyvalues_set(header_cookie === undefined ? "" : header_cookie.value, to_modify.header_name, undefined);
+        if (header_cookie === undefined) {
+          if (config.debug_mode) log("cookie_delete.req: no cookie header found. doing nothing for url " + e.url);
+        }
+        else {
+          header_cookie.value = new_cookie;
+          if (config.debug_mode) log("cookie_delete.req modify_header : name=Cookie,value=" + new_cookie + " for url " + e.url);
+        }
+      }
     }
   }
   if (config.debug_mode) log("End modify request headers for url " + e.url);
@@ -183,6 +260,35 @@ function rewriteResponseHeader(e) {
             + " for url " + e.url);
         }
       }
+      else if (to_modify.action === "cookie_add_or_modify") {
+        let header_cookie = e.responseHeaders.find(header => 
+            header.name.toLowerCase() === "set-cookie" && 
+            header.value.toLowerCase().trim().startsWith(to_modify.header_name.toLowerCase()+"=")
+        );
+        let new_header_value = set_cookie_modify_cookie_value(header_cookie === undefined ? "" : header_cookie.value, to_modify.header_name, to_modify.header_value);
+        if (header_cookie === undefined) {
+          log("SimpleModifyHeaders.Warning: you're using cookie_add_or_modify in Response. While adding new cookie in response, this plugin only generates `Set-Cookie: cookie-name=cookie-value `, without ANY additional attributes. Add a `Set-Cookie` header if you need them. ");
+          e.responseHeaders.push({"name": "Set-Cookie", "value": new_header_value});
+          if (config.debug_mode) log("cookie_add_or_modify.resp new_header : name=Cookie,value=" + new_header_value + " for url " + e.url);
+        }
+        else {
+          header_cookie.value = new_header_value;
+          if (config.debug_mode) log("cookie_add_or_modify.resp modify_header : name=Cookie,value=" + new_header_value + " for url " + e.url);
+        }
+      }
+      else if (to_modify.action === "cookie_delete") {
+        let index = e.responseHeaders.findIndex(header => 
+            header.name.toLowerCase() === "set-cookie" && 
+            header.value.toLowerCase().trim().startsWith(to_modify.header_name.toLowerCase()+"=")
+        );
+        if (index === -1) {
+          if (config.debug_mode) log("cookie_delete.resp: no matching set-cookie header. doing nothing for url " + e.url);
+        }
+        else {
+          e.responseHeaders.splice(index, 1);
+          if (config.debug_mode) log("cookie_delete.resp delete_header : name=" + to_modify.header_name + " for url " + e.url);
+        }
+      }
     }
   }
   if (config.debug_mode) log("End modify response headers for url " + e.url);

popup/config.js

@@ -118,6 +118,8 @@ function appendLine(url_contains,action,header_name,header_value,comment,apply_o
         <option value="add">Add</option>
         <option value="modify">Modify</option>
         <option value="delete">Delete</option>
+        <option value="cookie_add_or_modify">Cookie Add/Modify</option>
+        <option value="cookie_delete">Cookie Delete</option>
       </select>
     </td>
     <td>