chore: calculate encoded length in js

build.sh

@@ -19,7 +19,7 @@ set -eu
     -sNO_FILESYSTEM \
     -sMALLOC=emmalloc \
     -sALLOW_MEMORY_GROWTH \
-    -sEXPORTED_FUNCTIONS=_malloc,_free,_argon2_hash,_argon2_verify,_argon2_error_message,_argon2_encodedlen \
+    -sEXPORTED_FUNCTIONS=_malloc,_free,_argon2_hash,_argon2_verify,_argon2_error_message \
     -DARGON2_NO_THREADS \
     --cache=../.emscripten \
     -Iinclude \

src/index.ts

@@ -14,7 +14,7 @@ export enum Argon2Version {
 }
 
 export interface Argon2HashOptions {
-  salt?: Uint8Array;
+  salt: Uint8Array;
   hashLength: number;
   timeCost: number;
   memoryCost: number;
@@ -54,14 +54,24 @@ export interface Argon2TryVerifyError {
 
 export type Argon2TryVerifyResult = Argon2TryVerifySuccess | Argon2TryVerifyError;
 
+export const typeStringLength = (type: Argon2Type): number => {
+  switch (type) {
+    case Argon2Type.Argon2d:
+    case Argon2Type.Argon2i:
+      return 7;
+    case Argon2Type.Argon2id:
+      return 8;
+  }
+};
+
 export const typeFromEncoded = (encoded: string): Argon2Type | undefined => {
   if (!encoded?.length) return;
   if (encoded.startsWith("$argon2d$")) return Argon2Type.Argon2d;
   if (encoded.startsWith("$argon2i$")) return Argon2Type.Argon2i;
   if (encoded.startsWith("$argon2id$")) return Argon2Type.Argon2id;
 };
 
-export const defaultHashOptions: Argon2HashOptions = {
+export const defaultHashOptions: Partial<Argon2HashOptions> = {
   hashLength: 32,
   timeCost: 3,
   memoryCost: 65_536,
@@ -70,6 +80,13 @@ export const defaultHashOptions: Argon2HashOptions = {
   version: Argon2Version.Version13
 };
 
+const mergeOptions = (options?: Partial<Argon2HashOptions>): Argon2HashOptions =>
+  ({
+    ...defaultHashOptions,
+    ...options,
+    salt: options?.salt ?? generateSalt(16)
+  }) as Argon2HashOptions;
+
 const validateHashOptions = (opts: Argon2HashOptions): string | undefined => {
   if (!Number.isInteger(opts.hashLength)) return "Hash length must be an integer";
   if (!Number.isInteger(opts.timeCost)) return "Time cost must be an integer";
@@ -145,6 +162,23 @@ export const generateSalt = (length: number): Uint8Array => {
 // eslint-disable-next-line @typescript-eslint/no-empty-function
 const noop = () => {};
 
+const numberLength = (value: number) => Math.ceil(Math.log10(value + 1));
+
+const base64Length = (len: number) => Math.trunc((len * 4 + 3 - 1) / 3);
+
+const encodedConstant = "$$v=$m=,t=,p=$$".length;
+
+const getEncodedLength = (opts: Argon2HashOptions) =>
+  encodedConstant +
+  typeStringLength(opts.type) +
+  numberLength(opts.timeCost) +
+  numberLength(opts.memoryCost) +
+  numberLength(opts.parallelism) +
+  base64Length(opts.salt.length) +
+  base64Length(opts.hashLength) +
+  numberLength(opts.version) +
+  1;
+
 class Argon2 {
   readonly #exports: Argon2Exports;
   readonly #encoder = new TextEncoder();
@@ -209,29 +243,18 @@ class Argon2 {
     password: string,
     options?: Partial<Argon2HashOptions>
   ): Argon2TryHashResult => {
-    const opts = {
-      ...defaultHashOptions,
-      ...options
-    };
+    const opts = mergeOptions(options);
 
     const error = validateHashOptions(opts);
     if (error) return { success: false, error };
 
-    const salt = opts.salt ?? generateSalt(16);
-
-    const encodedLength = this.#exports.argon2_encodedlen(
-      opts.timeCost,
-      opts.memoryCost,
-      opts.parallelism,
-      salt.length,
-      opts.hashLength,
-      opts.type
-    );
+    const encodedLength = getEncodedLength(opts);
+    console.log(encodedLength);
 
     using passwordPtr = this.#copyStringToHeap(password);
-    using saltPtr = this.#copyToHeap(salt);
+    using saltPtr = this.#copyToHeap(opts.salt);
 
-    using hashPtr = this.#malloc(opts.hashLength + 1);
+    using hashPtr = this.#malloc(opts.hashLength);
     using encodedPtr = this.#malloc(encodedLength);
 
     const result = this.#exports.argon2_hash(
@@ -241,7 +264,7 @@ class Argon2 {
       passwordPtr.ptr,
       password.length,
       saltPtr.ptr,
-      salt.length,
+      opts.salt.length,
       hashPtr.ptr,
       opts.hashLength,
       encodedPtr.ptr,