Implement asym box

src/boxes/asymmetric.ts

@@ -1,24 +1,57 @@
 import {Result} from 'result'
+import * as misc from 'misc'
 
-export type PubKey = void
-export type PrivKey = void
+export type PubKey = CryptoKey
+export type PrivKey = CryptoKey
 
-export class PrivateBox<T> {
-    public static gen_keypair() : [PrivKey, PubKey] {
-        throw "todo"
+const algorithm: RsaOaepParams = {name: "RSA-OAEP"}
+
+export class PrivateBox<T extends ArrayBufferView> {
+    readonly cipher: Uint8Array;
+    readonly _phantom!: T;
+
+    private constructor(cipher: Uint8Array) {
+        this.cipher = cipher
     }
 
-    public static encrypt<T>(key: PubKey, data: Uint8Array) : PrivateBox<T> {
-        throw "todo"
+    public static async gen_keypair(extractable: boolean = false): Promise<[PrivKey, PubKey]> {
+        const keys = await window.crypto.subtle.generateKey(
+            {
+                name: "RSA-OAEP",
+                modulusLength: 4096,
+                publicExponent: new Uint8Array([1, 0, 1]),
+                hash: {name: "SHA-512"}
+            },
+            extractable,
+            ["encrypt", "decrypt"]
+        )
+
+        return [keys.privateKey, keys.publicKey]
     }
-    public decrypt(key: PrivKey) : Result<Uint8Array> {
-        throw "todo"
+
+    public static async encrypt<T extends ArrayBufferView>(key: PubKey, data: T): Promise<Result<PrivateBox<T>>> {
+        try {
+            const cipher = await window.crypto.subtle.encrypt(algorithm, key, data)
+            return Result.ok(new PrivateBox(new Uint8Array(cipher)))
+        } catch(_) {}
+
+        return Result.error([])
+    }
+    public async decrypt(key: PrivKey): Promise<Result<Uint8Array>> {
+        try {
+            const plain = await window.crypto.subtle.decrypt(algorithm, key, this.cipher)
+            return Result.ok(new Uint8Array(plain))
+        } catch(_) {}
+
+        return Result.error([])
     }
 
     public toString() : string {
-        throw "todo"
+        return misc.a2b64(new Uint8Array(this.cipher))
     }
-    public static fromString<T>(data: string) : Result<PrivateBox<T>> {
-        throw "todo"
+    public static fromString<T extends ArrayBufferView>(data: string) : Result<PrivateBox<T>> {
+        const res = misc.b642a(data)
+        if (res.error()) return Result.error([])
+        return Result.ok(new PrivateBox(res.unwrap()))
     }
 }