From 0fba70b6fa0347d903e3c7248883a6ec6b601c76 Mon Sep 17 00:00:00 2001
From: Christophe Diederichs <chris.d.itunes@gmail.com>
Date: Thu, 3 Sep 2020 12:49:05 +0200
Subject: [PATCH] add crypto_auth_hmac methods

---
 crypto_auth.js   | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 crypto_verify.js |  4 +++
 index.js         |  1 +
 package.json     |  4 +--
 4 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 crypto_auth.js

diff --git a/crypto_auth.js b/crypto_auth.js
new file mode 100644
index 0000000..3b8099f
--- /dev/null
+++ b/crypto_auth.js
@@ -0,0 +1,72 @@
+/* eslint-disable camelcase */
+const { crypto_verify_32, crypto_verify_64 } = require('./crypto_verify')
+const Sha256 = require('sha256-universal')
+const Sha512 = require('sha512-universal')
+const assert = require('nanoassert')
+
+const crypto_auth_hmacsha256_BYTES = 32
+const crypto_auth_hmacsha256_KEYBYTES = 32
+const crypto_auth_hmacsha512_BYTES = 64
+const crypto_auth_hmacsha512_KEYBYTES = 32
+const crypto_auth_hmacsha512256_BYTES = 32
+const crypto_auth_hmacsha512256_KEYBYTES = 32
+
+function crypto_auth_hmacsha256 (out, input, k) {
+  assert(out.byteLength === crypto_auth_hmacsha256_BYTES, "out should be 'crypto_auth_hmacsha256_BYTES' in length")
+
+  const hmac = Sha256.HMAC(key)
+  hmac.update(input)
+  return hmac.digest(out)
+}
+
+function crypto_auth_hmacsha256_verify (h, input, k) {
+  const correct = Sha256.HMAC(k).update(input).digest()
+
+  return crypto_verify_32(h, 0, correct, 0) | sodium_memcmp(correct, h, 32)
+}
+
+function crypto_auth_hmacsha512 (out, input, k) {
+  assert(out.byteLength === crypto_auth_hmacsha512_BYTES, "out should be 'crypto_auth_hmacsha512_BYTES' in length")
+
+  const hmac = Sha512.HMAC(key)
+  hmac.update(input)
+  return hmac.digest(out)
+}
+
+function crypto_auth_hmacsha512_verify (h, input, k) {
+  const correct = Sha512.HMAC(k).update(input).digest()
+
+  return crypto_verify_64(h, 0, correct, 0) | sodium_memcmp(correct, h, 64)
+}
+
+function crypto_auth_hmacsha512256 (out, input, k) {
+  assert(out.byteLength === crypto_auth_hmacsha512_BYTES, "out should be 'crypto_auth_hmacsha512256_BYTES' in length")
+  
+  const out0 = Buffer.alloc(64)
+  const hmac = Sha512.HMAC(key)
+  hmac.update(input)
+  hmac.digest(out)
+
+  out.set(out0.subarray(0, 32))
+}
+
+function crypto_auth_hmacsha512256_verify (h, input, k) {
+  const correct = Sha512.HMAC(k).update(input).digest()
+
+  return crypto_verify_32(h, 0, correct, 0) | sodium_memcmp(correct, h, 32)
+}
+
+module.exports = {
+  crypto_auth_hmacsha256_BYTES,
+  crypto_auth_hmacsha256_KEYBYTES,
+  crypto_auth_hmacsha512_BYTES,
+  crypto_auth_hmacsha512_KEYBYTES,
+  crypto_auth_hmacsha512256_BYTES,
+  crypto_auth_hmacsha512256_KEYBYTES,
+  crypto_auth_hmacsha256,
+  crypto_auth_hmacsha256_verify,
+  crypto_auth_hmacsha512,
+  crypto_auth_hmacsha512_verify,
+  crypto_auth_hmacsha512256,
+  crypto_auth_hmacsha512256_verify
+}
diff --git a/crypto_verify.js b/crypto_verify.js
index f23ff3d..9b7e0c1 100644
--- a/crypto_verify.js
+++ b/crypto_verify.js
@@ -22,3 +22,7 @@ function crypto_verify_16 (x, xi, y, yi) {
 function crypto_verify_32 (x, xi, y, yi) {
   return vn(x, xi, y, yi, 32)
 }
+
+function crypto_verify_64 (x, xi, y, yi) {
+  return vn(x, xi, y, yi, 64)
+}
diff --git a/index.js b/index.js
index 48a88bb..980fdd6 100644
--- a/index.js
+++ b/index.js
@@ -12,6 +12,7 @@ forward(require('./randombytes'))
 forward(require('./memory'))
 forward(require('./helpers'))
 forward(require('./crypto_verify'))
+forward(require('./crypto_auth'))
 forward(require('./crypto_box'))
 forward(require('./crypto_generichash'))
 forward(require('./crypto_hash'))
diff --git a/package.json b/package.json
index e811952..dc91eab 100644
--- a/package.json
+++ b/package.json
@@ -7,8 +7,8 @@
     "blake2b": "^2.1.1",
     "chacha20-universal": "^1.0.4",
     "nanoassert": "^2.0.0",
-    "sha256-universal": "^1.0.1",
-    "sha512-universal": "^1.0.1",
+    "sha256-universal": "^1.1.0",
+    "sha512-universal": "^1.1.0",
     "siphash24": "^1.0.1",
     "xsalsa20": "^1.0.0"
   },