Added auth and request storage

source/services/transport/request-headers.ts

@@ -0,0 +1,38 @@
+import type { RequestHeaders } from '../../routes/types.ts';
+import { ApplicationError } from '../../errors/index.ts';
+import { HTTP_STATUS_CODE_BAD_REQUEST } from '../../constants.ts';
+
+/** RFC 9110 field-name token grammar. */
+const HEADER_NAME_PATTERN = /^[!#$%&'*+\-.^_`|~0-9A-Za-z]+$/;
+
+/**
+ * Validate and normalize request headers at a transport boundary.
+ *
+ * Lowercase names give HTTP and WebSocket routes identical lookup semantics.
+ * Case-insensitive duplicates are rejected instead of selecting an ambiguous
+ * authentication value. Header values may not contain line breaks.
+ */
+export const normalizeRequestHeaders = (headers: Readonly<Record<string, string>>): RequestHeaders => {
+    const normalizedEntries: Array<[string, string]> = [];
+    const names = new Set<string>();
+
+    for (const [ name, value ] of Object.entries(headers)) {
+        if (!HEADER_NAME_PATTERN.test(name)) {
+            throw new ApplicationError(HTTP_STATUS_CODE_BAD_REQUEST, 'Invalid request header name');
+        }
+
+        if (value.includes('\r') || value.includes('\n')) {
+            throw new ApplicationError(HTTP_STATUS_CODE_BAD_REQUEST, 'Invalid request header value');
+        }
+
+        const normalizedName = name.toLowerCase();
+        if (names.has(normalizedName)) {
+            throw new ApplicationError(HTTP_STATUS_CODE_BAD_REQUEST, 'Duplicate request header name');
+        }
+
+        names.add(normalizedName);
+        normalizedEntries.push([ normalizedName, value ]);
+    }
+
+    return Object.freeze(Object.fromEntries(normalizedEntries));
+};