feat: add steam_guard examples

examples/deno/mod.ts

@@ -1,4 +1,4 @@
-import { init, wasm_data, totp, hotp } from 'totp-wasm'
+import { init, wasm_data, totp, hotp, steam_guard } from 'totp-wasm'
 import { assertEquals, base64Decode } from './deps.ts'
 
 await init(base64Decode(wasm_data))
@@ -25,3 +25,13 @@ Deno.test({
     assertEquals(code, 473526)
   },
 })
+
+Deno.test({
+  name: 'Steam Guard test',
+  fn() {
+    const secret = 'GM4VC2CQN5UGS33ZJJVWYUSFMQ4HOQJW'
+    const t = BigInt(1662681600)
+    const code = steam_guard(secret, t)
+    assertEquals(code, '4PRPM')
+  },
+})

examples/node/index.ts

@@ -1,4 +1,4 @@
-import { init, totp, hotp } from '../../packages/totp-wasm/index'
+import { init, totp, hotp, steam_guard } from '../../packages/totp-wasm/index'
 import { wasm_data } from '../../packages/totp-wasm/dist/wasm_data'
 
 test()
@@ -21,4 +21,10 @@ async function test() {
     const code = totp(secret, t, digit, period)
     console.log(code === 473526)
   }
+  {
+    const secret = 'GM4VC2CQN5UGS33ZJJVWYUSFMQ4HOQJW'
+    const t = BigInt(1662681600)
+    const code = steam_guard(secret, t)
+    console.log(code === '4PRPM')
+  }
 }

packages/totp-wasm/index.ts

@@ -32,9 +32,24 @@ export function totp(secret: string, t: bigint, digit: number, period: number):
   return code
 }
 
+export function steam_guard(secret: string, t: bigint): string {
+  if (!instance) return ''
+  const str = to_cstr(instance, memory, secret)
+  const steam_guard = instance.exports.steam_guard as steam_guard_func
+  const output_ptr = steam_guard(str.ptr, str.len, t)
+  const code = new TextDecoder().decode(new Uint8Array(memory.buffer, output_ptr, 5))
+  free(instance, str.ptr)
+  free(instance, output_ptr)
+  return code
+}
+
 interface hotp_func {
   (ptr: number, len: number, counter: bigint, digit: number): number
 }
 interface totp_func {
   (ptr: number, len: number, t: bigint, digit: number, period: number): number
 }
+
+interface steam_guard_func {
+  (ptr: number, len: number, t: bigint): number
+}

packages/totp-wasm/mod.ts

@@ -1,3 +1,3 @@
 //@ts-nocheck
-export { hotp, totp, init } from './index.js'
+export * from './index.js'
 export { wasm_data } from './dist/wasm_data.js'

src/main.zig

@@ -11,9 +11,11 @@ export fn totp(secret_ptr: [*]const u8, secret_len: usize, t: i64, digit: u32, p
     return otp.totp(secret_ptr[0..secret_len], t, digit, period) catch return 0;
 }
 
-export fn steam_guard(secret_ptr: [*]const u8, secret_len: usize, t: i64) u32 {
-    _ = otp.steam_guard(secret_ptr[0..secret_len], t) catch return 0;
-    return 0;
+export fn steam_guard(secret_ptr: [*]const u8, secret_len: usize, t: i64) [*]u8 {
+    var code = otp.steam_guard(secret_ptr[0..secret_len], t) catch @panic("steam_guard: steam_guard");
+    const output: []u8 = allocator.alloc(u8, 5) catch @panic("steam_guard: allocator.alloc");
+    @memcpy(output[0..5], code[0..5]);
+    return output[0..5 :0].ptr;
 }
 
 export fn malloc(size: usize) ?[*]const u8 {

src/otp.zig

@@ -61,7 +61,7 @@ test "totp test" {
 
 const STEAM_CHARS: *const [26:0]u8 = "23456789BCDFGHJKMNPQRTVWXY";
 
-pub fn steam_guard(secret: []const u8, t: i64) ![]u8 {
+pub fn steam_guard(secret: []const u8, t: i64) ![5]u8 {
     const alloc = std.heap.page_allocator;
     var counter = @intCast(u64, @divFloor(t, 30));
     var key = try base32.decode(alloc, secret);
@@ -96,13 +96,13 @@ pub fn steam_guard(secret: []const u8, t: i64) ![]u8 {
         bin_code[i] = STEAM_CHARS[(fc % STEAM_CHARS.len)];
         fc /= @intCast(u32, STEAM_CHARS.len);
     }
-    return bin_code[0..];
+    return bin_code;
 }
 
 test "Steam Guard test" {
     const secret: []const u8 = "GM4VC2CQN5UGS33ZJJVWYUSFMQ4HOQJW";
     const t: i64 = 1662681600;
     const code = "4PRPM";
 
-    try testing.expectEqualSlices(u8, code[0..], try steam_guard(secret, t));
+    try testing.expectEqualSlices(u8, code[0..], (try steam_guard(secret, t))[0..]);
 }