feat(std/http): Add Cookie value validation

std/http/cookie.ts

@@ -40,6 +40,7 @@ function toString(cookie: Cookie): string {
   }
   const out: string[] = [];
   validateCookieName(cookie.name);
+  validateCookieValue(cookie.value);
   out.push(`${cookie.name}=${cookie.value}`);
 
   // Fallback for invalid Set-Cookie
@@ -114,6 +115,31 @@ function validatePath(path: string | null): void {
   }
 }
 
+/**
+ *Validate Cookie Value.
+ * @see https://tools.ietf.org/html/rfc6265#section-4.1
+ * @param value Cookie value.
+ */
+function validateCookieValue(value: string | null): void {
+  if (value == null) return;
+  for (let i = 0; i < value.length; i++) {
+    const c = value.charAt(i);
+    if (
+      c < String.fromCharCode(0x21) || c == String.fromCharCode(0x22) ||
+      c == String.fromCharCode(0x2c) || c == String.fromCharCode(0x3b) ||
+      c == String.fromCharCode(0x5c) || c == String.fromCharCode(0x7f)
+    ) {
+      throw new Error("RFC2616 cookie value cannot have '" + c + "'");
+    }
+    if (c > String.fromCharCode(0x80)) {
+      throw new Error(
+        "RFC2616 cookie value can only have US-ASCII chars" +
+          c.charCodeAt(0).toString(16),
+      );
+    }
+  }
+}
+
 /**
  * Parse the cookies of the Server Request
  * @param req An object which has a `headers` property

std/http/cookie_test.ts

@@ -65,6 +65,44 @@ Deno.test({
   },
 });
 
+Deno.test({
+  name: "Cookie Value Validation",
+  fn(): void {
+    const res: Response = {};
+    const tokens = [
+      "1f\tWa",
+      "\t",
+      "1f Wa",
+      "1f;Wa",
+      '"1fWa',
+      "1f\\Wa",
+      '1f"Wa',
+      '"',
+      "1fWa\u0005",
+      "1f\u0091Wa",
+    ];
+    res.headers = new Headers();
+    tokens.forEach((value) => {
+      assertThrows(
+        (): void => {
+          setCookie(
+            res,
+            {
+              name: "Space",
+              value,
+              httpOnly: true,
+              secure: true,
+              maxAge: 3,
+            },
+          );
+        },
+        Error,
+        "RFC2616 cookie value",
+      );
+    });
+  },
+});
+
 Deno.test({
   name: "Cookie Path Validation",
   fn(): void {