add hashLength and keyLength property to Cipher

Author: Srabutdotcom

deno.json

@@ -1,6 +1,6 @@
 {
   "name": "@tls/enum",
-  "version": "0.5.5",
+  "version": "0.5.6",
   "exports": "./src/mod.ts",
   "publish": {
     "exclude": ["dist/"]

src/cipher.js

@@ -6,13 +6,21 @@ export class Cipher extends Enum {
    static AES_128_GCM_SHA256 = new Cipher('AES_128_GCM_SHA256', 0x01);
    static AES_256_GCM_SHA384 = new Cipher('AES_256_GCM_SHA384', 0x02);
    static CHACHA20_POLY1305_SHA256 = new Cipher('CHACHA20_POLY1305_SHA256', 0x03);
-   
-   static from(array){
+
+   static from(array) {
       const copy = Uint8Array.from(array);
-      if(copy.at(0)!==0x13)throw TypeError(`Expected 0x13 at index 0`)
+      if (copy.at(0) !== 0x13) throw TypeError(`Expected 0x13 at index 0`)
       return Cipher.fromValue(copy.at(1))
    }
 
-   get Uint16(){return Uint8Array.of(0x13, +this)}
+   get Uint16() { return Uint8Array.of(0x13, +this) }
+
+   get hashLength() {
+      return this.name.slice(-3) / 8;
+   }
+
+   get keyLength() {
+      return this.name.startsWith('AES_128') ? 16 : 32
+   }
 }
 

test/cipher_test.js

@@ -5,4 +5,8 @@ Deno.test("Cipher", () => {
    const test = Cipher.AES_128_GCM_SHA256.Uint16;
    const back = Cipher.from(test).Uint16;
    assertEquals(test, back)
-})
+})
+
+console.log(Cipher.AES_128_GCM_SHA256.keyLength);
+console.log(Cipher.AES_256_GCM_SHA384.hashLength);
+console.log(Cipher.CHACHA20_POLY1305_SHA256.keyLength);

type/cipher.d.ts

@@ -33,4 +33,16 @@ export class Cipher extends Enum {
      * @returns A `Uint8Array` containing the cipher suite identifier.
      */
     get Uint16(): Uint8Array;
+  
+    /**
+     * Get hash length for respective cipher
+     * @returns hash length either 32 or 48 
+     */
+    get hashLength(): number;
+
+    /**
+     * Get key length for respective cipher
+     * @returns key length either 16 or 32 
+     */
+    get keyLength(): number;
 }