first commit

2025-11-28 10:08:12 +08:00
commit 09a14bf0a3
1088 changed files with 145132 additions and 0 deletions
@@ -0,0 +1,77 @@
+<?php
+declare(strict_types=1);
+
+namespace Mdanter\Ecc\Serializer\Point;
+
+use Mdanter\Ecc\Math\GmpMathInterface;
+use Mdanter\Ecc\Primitives\CurveFpInterface;
+use Mdanter\Ecc\Primitives\PointInterface;
+use Mdanter\Ecc\Serializer\Util\CurveOidMapper;
+
+class CompressedPointSerializer implements PointSerializerInterface
+{
+    /**
+     * @var GmpMathInterface
+     */
+    private $adapter;
+
+    /**
+     * @var \Mdanter\Ecc\Math\NumberTheory
+     */
+    private $theory;
+
+    /**
+     * CompressedPointSerializer constructor.
+     * @param GmpMathInterface $adapter
+     */
+    public function __construct(GmpMathInterface $adapter)
+    {
+        $this->adapter = $adapter;
+        $this->theory = $adapter->getNumberTheory();
+    }
+
+    /**
+     * @param PointInterface $point
+     * @return string
+     */
+    public function getPrefix(PointInterface $point): string
+    {
+        if ($this->adapter->equals($this->adapter->mod($point->getY(), gmp_init(2, 10)), gmp_init(0))) {
+            return '02';
+        } else {
+            return '03';
+        }
+    }
+
+    /**
+     * @param PointInterface $point
+     * @return string
+     */
+    public function serialize(PointInterface $point): string
+    {
+        $length = CurveOidMapper::getByteSize($point->getCurve()) * 2;
+
+        $hexString = $this->getPrefix($point);
+        $hexString .= str_pad(gmp_strval($point->getX(), 16), $length, '0', STR_PAD_LEFT);
+
+        return $hexString;
+    }
+
+    /**
+     * @param CurveFpInterface $curve
+     * @param string $data - hex serialized compressed point
+     * @return PointInterface
+     */
+    public function unserialize(CurveFpInterface $curve, string $data): PointInterface
+    {
+        $prefix = substr($data, 0, 2);
+        if ($prefix !== '03' && $prefix !== '02') {
+            throw new \InvalidArgumentException('Invalid data: only compressed keys are supported.');
+        }
+
+        $x = gmp_init(substr($data, 2), 16);
+        $y = $curve->recoverYfromX($prefix === '03', $x);
+
+        return $curve->getPoint($x, $y);
+    }
+}