EC/Signature/Format: add new IEEE format

phpseclib/Crypt/EC/Formats/Signature/IEEE.php

@@ -0,0 +1,66 @@
+<?php
+
+/**
+ * IEEE P1363 Signature Handler
+ *
+ * PHP version 5
+ *
+ * Handles signatures in the format described in
+ * https://standards.ieee.org/ieee/1363/2049/ and
+ * https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/sign#ecdsa
+ *
+ * @author    Jim Wigginton <terrafrost@php.net>
+ * @copyright 2016 Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @link      http://phpseclib.sourceforge.net
+ */
+
+namespace phpseclib3\Crypt\EC\Formats\Signature;
+
+use phpseclib3\Math\BigInteger;
+
+/**
+ * ASN1 Signature Handler
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ */
+abstract class IEEE
+{
+    /**
+     * Loads a signature
+     *
+     * @param string $sig
+     * @return array
+     */
+    public static function load($sig)
+    {
+        if (!is_string($sig)) {
+            return false;
+        }
+
+        $len = strlen($sig);
+        if ($len & 1) {
+            return false;
+        }
+
+        $r = new BigInteger(substr($sig, 0, $len >> 1), 256);
+        $s = new BigInteger(substr($sig, $len >> 1), 256);
+
+        return compact('r', 's');
+    }
+
+    /**
+     * Returns a signature in the appropriate format
+     *
+     * @param \phpseclib3\Math\BigInteger $r
+     * @param \phpseclib3\Math\BigInteger $s
+     * @return string
+     */
+    public static function save(BigInteger $r, BigInteger $s)
+    {
+        $r = $r->toBytes();
+        $s = $s->toBytes();
+        $len = max(strlen($r), strlen($s));
+        return str_pad($r, $len, "\0", STR_PAD_LEFT) . str_pad($s, $len, "\0", STR_PAD_LEFT);
+    }
+}

tests/Unit/Crypt/EC/KeyTest.php

@@ -690,4 +690,18 @@ cN6W+k8UvGf+Y/lDWNbFitQocabsDUvSN0edHH3UKP5QPTz4cOlyIPMrXQ==
         $key = PublicKeyLoader::load($key);
         $this->assertInstanceOf(PublicKey::class, $key);
     }
+
+    /**
+     * @group github1956
+     */
+    public function testIEEESignature()
+    {
+        $key = '{"alg":"ES256","crv":"P-256","ext":true,"key_ops":["verify"],"kty":"EC","x":"FKwqyGd4i2NAl8RUXCCBRCAIbcpeGyfyXwgA_AWHb8Y","y":"njxhw5O6zGVkBlcPDKYj0E-6VO1giHTUkJWBhgKNqd8"}';
+        $key = PublicKeyLoader::load($key)->withSignatureFormat('IEEE')->withHash('sha384');
+
+        $signature = 'a4f61518323bac50b4f87a0f766ebb10d1db25358a0a20a98dab20be4e9c3be2d77ff5a8415cfce2967999c73d2a49b2d8c01990f72c04d99ebe3c4ebf75b4e9';
+        $signature = pack('H*', $signature);
+
+        $this->assertTrue($key->verify('hello world!', $signature));
+    }
 }