move crypto_hash_sha256 to module to uncouple wasm dependencies

crypto_hash.js

@@ -1,18 +1,11 @@
-const sha256 = require('sha256-wasm')
 const sha512 = require('sha512-wasm')
 const assert = require('nanoassert')
 
-var crypto_hash_sha256_BYTES = 32
+if (new Uint16Array([1])[0] !== 1) throw new Error('Big endian architecture is not supported.')
+
 var crypto_hash_sha512_BYTES = 64
 var crypto_hash_BYTES = crypto_hash_sha512_BYTES
 
-function crypto_hash_sha256 (out, m, n) {
-  assert(out.byteLength === crypto_hash_sha256_BYTES, "out must be 'crypto_hash_sha256_BYTES' bytes long")
-
-  sha256().update(m.subarray(0, n)).digest(out)
-  return 0
-}
-
 function crypto_hash_sha512 (out, m, n) {
   assert(out.byteLength === crypto_hash_sha512_BYTES, "out must be 'crypto_hash_sha512_BYTES' bytes long")
 
@@ -26,8 +19,6 @@ function crypto_hash (out, m, n) {
 
 module.exports = {
   crypto_hash,
-  crypto_hash_sha256,
   crypto_hash_sha512,
-  crypto_hash_BYTES,
-  crypto_hash_sha256_BYTES
+  crypto_hash_BYTES
 }

crypto_hash_256.js

@@ -0,0 +1,18 @@
+const sha256 = require('sha256-wasm')
+const assert = require('nanoassert')
+
+if (new Uint16Array([1])[0] !== 1) throw new Error('Big endian architecture is not supported.')
+
+var crypto_hash_sha256_BYTES = 32
+
+function crypto_hash_sha256 (out, m, n) {
+  assert(out.byteLength === crypto_hash_sha256_BYTES, "out must be 'crypto_hash_sha256_BYTES' bytes long")
+
+  sha256().update(m.subarray(0, n)).digest(out)
+  return 0
+}
+
+module.exports = {
+  crypto_hash_sha256,
+  crypto_hash_sha256_BYTES
+}

index.js

@@ -23,6 +23,7 @@ sodium.sodium_malloc = function (n) {
 forward(require('./crypto_box'))
 forward(require('./crypto_generichash'))
 forward(require('./crypto_hash'))
+forward(require('./crypto_hash_sha256'))
 forward(require('./crypto_kdf'))
 forward(require('./crypto_kx'))
 forward(require('./crypto_aead'))