code:
<?php
require_once 'Net/IDNA2.php';

// Test cases from https://www.gnu.org/software/libidn/draft-josefsson-idn-test-vectors.html

define('IDNA_ACE_PREFIX', 'xn--');

class IDNATest extends PHPUnit_Framework_TestCase
{
    public function setUp()
    {
        $this->idn = new Net_IDNA2();
    }

    public static function unichr($chr)
    {
        return mb_convert_encoding('&#' . intval($chr) . ';', 'UTF-8', 'HTML-ENTITIES');
    }

    private function hexarray2string($arr)
    {
        return implode('', array_map(array('self', 'unichr'), $arr));
    }

    public function testDecode1()
    {
        // Arabic (Egyptian)
        $expected = $this->hexarray2string(array(
            0x0644, 0x064A, 0x0647, 0x0645, 0x0627, 0x0628, 0x062A, 0x0643,
            0x0644, 0x0645, 0x0648, 0x0634, 0x0639, 0x0631, 0x0628, 0x064A,
            0x061F
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "egbpdaj6bu4bxfgehfvwxn");
        $this->assertSame($expected, $result);
    }

    public function testDecode2()
    {
        // Chinese (simplified)
        $expected = $this->hexarray2string(array(
            0x4ED6, 0x4EEC, 0x4E3A, 0x4EC0, 0x4E48, 0x4E0D, 0x8BF4, 0x4E2D, 0x6587
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "ihqwcrb4cv8a8dqg056pqjye");
        $this->assertSame($expected, $result);
    }

    public function testDecode3()
    {
        // Chinese (traditional)
        $expected = $this->hexarray2string(array(
            0x4ED6, 0x5011, 0x7232, 0x4EC0, 0x9EBD, 0x4E0D, 0x8AAA, 0x4E2D, 0x6587
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "ihqwctvzc91f659drss3x8bo0yb");
        $this->assertSame($expected, $result);
    }

    public function testDecode4()
    {
        // Czech
        $expected = $this->hexarray2string(array(
            0x0050, 0x0072, 0x006F, 0x010D, 0x0070, 0x0072, 0x006F, 0x0073,
            0x0074, 0x011B, 0x006E, 0x0065, 0x006D, 0x006C, 0x0075, 0x0076,
            0x00ED, 0x010D, 0x0065, 0x0073, 0x006B, 0x0079
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "Proprostnemluvesky-uyb24dma41a");
        $this->assertSame($expected, $result);
    }

    public function testDecode5()
    {
        // Hebrew
        $expected = $this->hexarray2string(array(
            0x05DC, 0x05DE, 0x05D4, 0x05D4, 0x05DD, 0x05E4, 0x05E9, 0x05D5,
            0x05D8, 0x05DC, 0x05D0, 0x05DE, 0x05D3, 0x05D1, 0x05E8, 0x05D9,
            0x05DD, 0x05E2, 0x05D1, 0x05E8, 0x05D9, 0x05EA
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "4dbcagdahymbxekheh6e0a7fei0b");
        $this->assertSame($expected, $result);
    }

    public function testDecode6()
    {
        // Hindi (Devanagari)
        $expected = $this->hexarray2string(array(
            0x092F, 0x0939, 0x0932, 0x094B, 0x0917, 0x0939, 0x093F, 0x0928,
            0x094D, 0x0926, 0x0940, 0x0915, 0x094D, 0x092F, 0x094B, 0x0902,
            0x0928, 0x0939, 0x0940, 0x0902, 0x092C, 0x094B, 0x0932, 0x0938,
            0x0915, 0x0924, 0x0947, 0x0939, 0x0948, 0x0902
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd");
        $this->assertSame($expected, $result);
    }

    public function testDecode7()
    {
        // Japanese (kanji and hiragana)
        $expected = $this->hexarray2string(array(
            0x306A, 0x305C, 0x307F, 0x3093, 0x306A, 0x65E5, 0x672C, 0x8A9E,
            0x3092, 0x8A71, 0x3057, 0x3066, 0x304F, 0x308C, 0x306A, 0x3044,
            0x306E, 0x304B
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa");
        $this->assertSame($expected, $result);
    }

    public function testDecode8()
    {
        // Russian (Cyrillic)
        $expected = $this->hexarray2string(array(
            0x043F, 0x043E, 0x0447, 0x0435, 0x043C, 0x0443, 0x0436, 0x0435,
            0x043E, 0x043D, 0x0438, 0x043D, 0x0435, 0x0433, 0x043E, 0x0432,
            0x043E, 0x0440, 0x044F, 0x0442, 0x043F, 0x043E, 0x0440, 0x0443,
            0x0441, 0x0441, 0x043A, 0x0438
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "b1abfaaepdrnnbgefbadotcwatmq2g4l");
        $this->assertSame($expected, $result);
    }

    public function testDecode9()
    {
        // Spanish
        $expected = $this->hexarray2string(array(
            0x0050, 0x006F, 0x0072, 0x0071, 0x0075, 0x00E9, 0x006E, 0x006F,
            0x0070, 0x0075, 0x0065, 0x0064, 0x0065, 0x006E, 0x0073, 0x0069,
            0x006D, 0x0070, 0x006C, 0x0065, 0x006D, 0x0065, 0x006E, 0x0074,
            0x0065, 0x0068, 0x0061, 0x0062, 0x006C, 0x0061, 0x0072, 0x0065,
            0x006E, 0x0045, 0x0073, 0x0070, 0x0061, 0x00F1, 0x006F, 0x006C
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "PorqunopuedensimplementehablarenEspaol-fmd56a");
        $this->assertSame($expected, $result);
    }

    public function testDecode10()
    {
        // Vietnamese
        $expected = $this->hexarray2string(array(
            0x0054, 0x1EA1, 0x0069, 0x0073, 0x0061, 0x006F, 0x0068, 0x1ECD,
            0x006B, 0x0068, 0x00F4, 0x006E, 0x0067, 0x0074, 0x0068, 0x1EC3,
            0x0063, 0x0068, 0x1EC9, 0x006E, 0x00F3, 0x0069, 0x0074, 0x0069,
            0x1EBF, 0x006E, 0x0067, 0x0056, 0x0069, 0x1EC7, 0x0074
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "TisaohkhngthchnitingVit-kjcr8268qyxafd2f1b9g");
        $this->assertSame($expected, $result);
    }

    public function testDecode11()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x0033, 0x5E74, 0x0042, 0x7D44, 0x91D1, 0x516B, 0x5148, 0x751F
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "3B-ww4c5e180e575a65lsy2b");
        $this->assertSame($expected, $result);
    }

    public function testDecode12()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x5B89, 0x5BA4, 0x5948, 0x7F8E, 0x6075, 0x002D, 0x0077, 0x0069,
            0x0074, 0x0068, 0x002D, 0x0053, 0x0055, 0x0050, 0x0045, 0x0052,
            0x002D, 0x004D, 0x004F, 0x004E, 0x004B, 0x0045, 0x0059, 0x0053
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "-with-SUPER-MONKEYS-pc58ag80a8qai00g7n9n");
        $this->assertSame($expected, $result);
    }

    public function testDecode13()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x0048, 0x0065, 0x006C, 0x006C, 0x006F, 0x002D, 0x0041, 0x006E,
            0x006F, 0x0074, 0x0068, 0x0065, 0x0072, 0x002D, 0x0057, 0x0061,
            0x0079, 0x002D, 0x305D, 0x308C, 0x305E, 0x308C, 0x306E, 0x5834,
            0x6240
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "Hello-Another-Way--fc4qua05auwb3674vfr0b");
        $this->assertSame($expected, $result);
    }

    public function testDecode14()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x3072, 0x3068, 0x3064, 0x5C4B, 0x6839, 0x306E, 0x4E0B, 0x0032
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "2-u9tlzr9756bt3uc0v");
        $this->assertSame($expected, $result);
    }

    public function testDecode15()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x004D, 0x0061, 0x006A, 0x0069, 0x3067, 0x004B, 0x006F, 0x0069,
            0x3059, 0x308B, 0x0035, 0x79D2, 0x524D
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "MajiKoi5-783gue6qz075azm5e");
        $this->assertSame($expected, $result);
    }

    public function testDecode16()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x30D1, 0x30D5, 0x30A3, 0x30FC, 0x0064, 0x0065, 0x30EB, 0x30F3, 0x30D0
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "de-jg4avhby1noc0d");
        $this->assertSame($expected, $result);
    }

    public function testDecode17()
    {
        // Japanese
        $expected = $this->hexarray2string(array(
            0x305D, 0x306E, 0x30B9, 0x30D4, 0x30FC, 0x30C9, 0x3067
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "d9juau41awczczp");
        $this->assertSame($expected, $result);
    }

    public function testDecode18()
    {
        // Greek
        $expected = $this->hexarray2string(array(
            0x03b5, 0x03bb, 0x03bb, 0x03b7, 0x03bd, 0x03b9, 0x03ba, 0x03ac
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "hxargifdar");
        $this->assertSame($expected, $result);
    }

    public function testDecode19()
    {
        // Maltese (Malti)
        $expected = $this->hexarray2string(array(
            0x0062, 0x006f, 0x006e, 0x0121, 0x0075, 0x0073, 0x0061, 0x0127,
            0x0127, 0x0061
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "bonusaa-5bb1da");
        $this->assertSame($expected, $result);
    }

    public function testDecode20()
    {
        // Russian (Cyrillic)
        $expected = $this->hexarray2string(array(
            0x043f, 0x043e, 0x0447, 0x0435, 0x043c, 0x0443, 0x0436, 0x0435,
            0x043e, 0x043d, 0x0438, 0x043d, 0x0435, 0x0433, 0x043e, 0x0432,
            0x043e, 0x0440, 0x044f, 0x0442, 0x043f, 0x043e, 0x0440, 0x0443,
            0x0441, 0x0441, 0x043a, 0x0438
        ));
        $result = $this->idn->decode(IDNA_ACE_PREFIX . "b1abfaaepdrnnbgefbadotcwatmq2g4l");
        $this->assertSame($expected, $result);
    }

    public function testEncode1()
    {
        // Arabic (Egyptian)
        $idna = $this->hexarray2string(array(
            0x0644, 0x064A, 0x0647, 0x0645, 0x0627, 0x0628, 0x062A, 0x0643,
            0x0644, 0x0645, 0x0648, 0x0634, 0x0639, 0x0631, 0x0628, 0x064A,
            0x061F
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "egbpdaj6bu4bxfgehfvwxn", $result);
    }

    public function testEncode2()
    {
        // Chinese (simplified)
        $idna = $this->hexarray2string(array(
            0x4ED6, 0x4EEC, 0x4E3A, 0x4EC0, 0x4E48, 0x4E0D, 0x8BF4, 0x4E2D, 0x6587
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "ihqwcrb4cv8a8dqg056pqjye", $result);
    }

    public function testEncode3()
    {
        // Chinese (traditional)
        $idna = $this->hexarray2string(array(
            0x4ED6, 0x5011, 0x7232, 0x4EC0, 0x9EBD, 0x4E0D, 0x8AAA, 0x4E2D, 0x6587
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "ihqwctvzc91f659drss3x8bo0yb", $result);
    }

    public function testEncode4()
    {
        // Czech
        $idna = $this->hexarray2string(array(
            0x0050, 0x0072, 0x006F, 0x010D, 0x0070, 0x0072, 0x006F, 0x0073,
            0x0074, 0x011B, 0x006E, 0x0065, 0x006D, 0x006C, 0x0075, 0x0076,
            0x00ED, 0x010D, 0x0065, 0x0073, 0x006B, 0x0079
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "proprostnemluvesky-uyb24dma41a", $result);
    }

    public function testEncode5()
    {
        // Hebrew
        $idna = $this->hexarray2string(array(
            0x05DC, 0x05DE, 0x05D4, 0x05D4, 0x05DD, 0x05E4, 0x05E9, 0x05D5,
            0x05D8, 0x05DC, 0x05D0, 0x05DE, 0x05D3, 0x05D1, 0x05E8, 0x05D9,
            0x05DD, 0x05E2, 0x05D1, 0x05E8, 0x05D9, 0x05EA
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "4dbcagdahymbxekheh6e0a7fei0b", $result);
    }

    public function testEncode6()
    {
        // Hindi (Devanagari)
        $idna = $this->hexarray2string(array(
            0x092F, 0x0939, 0x0932, 0x094B, 0x0917, 0x0939, 0x093F, 0x0928,
            0x094D, 0x0926, 0x0940, 0x0915, 0x094D, 0x092F, 0x094B, 0x0902,
            0x0928, 0x0939, 0x0940, 0x0902, 0x092C, 0x094B, 0x0932, 0x0938,
            0x0915, 0x0924, 0x0947, 0x0939, 0x0948, 0x0902
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd", $result);
    }

    public function testEncode7()
    {
        // Japanese (kanji and hiragana)
        $idna = $this->hexarray2string(array(
            0x306A, 0x305C, 0x307F, 0x3093, 0x306A, 0x65E5, 0x672C, 0x8A9E,
            0x3092, 0x8A71, 0x3057, 0x3066, 0x304F, 0x308C, 0x306A, 0x3044,
            0x306E, 0x304B
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa", $result);
    }

    public function testEncode8()
    {
        // Russian (Cyrillic)
        $idna = $this->hexarray2string(array(
            0x043F, 0x043E, 0x0447, 0x0435, 0x043C, 0x0443, 0x0436, 0x0435,
            0x043E, 0x043D, 0x0438, 0x043D, 0x0435, 0x0433, 0x043E, 0x0432,
            0x043E, 0x0440, 0x044F, 0x0442, 0x043F, 0x043E, 0x0440, 0x0443,
            0x0441, 0x0441, 0x043A, 0x0438
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "b1abfaaepdrnnbgefbadotcwatmq2g4l", $result);
    }

    public function testEncode9()
    {
        // Spanish
        $idna = $this->hexarray2string(array(
            0x0050, 0x006F, 0x0072, 0x0071, 0x0075, 0x00E9, 0x006E, 0x006F,
            0x0070, 0x0075, 0x0065, 0x0064, 0x0065, 0x006E, 0x0073, 0x0069,
            0x006D, 0x0070, 0x006C, 0x0065, 0x006D, 0x0065, 0x006E, 0x0074,
            0x0065, 0x0068, 0x0061, 0x0062, 0x006C, 0x0061, 0x0072, 0x0065,
            0x006E, 0x0045, 0x0073, 0x0070, 0x0061, 0x00F1, 0x006F, 0x006C
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "porqunopuedensimplementehablarenespaol-fmd56a", $result);
    }

    public function testEncode10()
    {
        // Vietnamese
        $idna = $this->hexarray2string(array(
            0x0054, 0x1EA1, 0x0069, 0x0073, 0x0061, 0x006F, 0x0068, 0x1ECD,
            0x006B, 0x0068, 0x00F4, 0x006E, 0x0067, 0x0074, 0x0068, 0x1EC3,
            0x0063, 0x0068, 0x1EC9, 0x006E, 0x00F3, 0x0069, 0x0074, 0x0069,
            0x1EBF, 0x006E, 0x0067, 0x0056, 0x0069, 0x1EC7, 0x0074
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "tisaohkhngthchnitingvit-kjcr8268qyxafd2f1b9g", $result);
    }

    public function testEncode11()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x0033, 0x5E74, 0x0042, 0x7D44, 0x91D1, 0x516B, 0x5148, 0x751F
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "3b-ww4c5e180e575a65lsy2b", $result);
    }

    public function testEncode12()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x5B89, 0x5BA4, 0x5948, 0x7F8E, 0x6075, 0x002D, 0x0077, 0x0069,
            0x0074, 0x0068, 0x002D, 0x0053, 0x0055, 0x0050, 0x0045, 0x0052,
            0x002D, 0x004D, 0x004F, 0x004E, 0x004B, 0x0045, 0x0059, 0x0053
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "-with-super-monkeys-pc58ag80a8qai00g7n9n", $result);
    }

    public function testEncode13()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x0048, 0x0065, 0x006C, 0x006C, 0x006F, 0x002D, 0x0041, 0x006E,
            0x006F, 0x0074, 0x0068, 0x0065, 0x0072, 0x002D, 0x0057, 0x0061,
            0x0079, 0x002D, 0x305D, 0x308C, 0x305E, 0x308C, 0x306E, 0x5834,
            0x6240
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "hello-another-way--fc4qua05auwb3674vfr0b", $result);
    }

    public function testEncode14()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x3072, 0x3068, 0x3064, 0x5C4B, 0x6839, 0x306E, 0x4E0B, 0x0032
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "2-u9tlzr9756bt3uc0v", $result);
    }

    public function testEncode15()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x004D, 0x0061, 0x006A, 0x0069, 0x3067, 0x004B, 0x006F, 0x0069,
            0x3059, 0x308B, 0x0035, 0x79D2, 0x524D
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "majikoi5-783gue6qz075azm5e", $result);
    }

    public function testEncode16()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x30D1, 0x30D5, 0x30A3, 0x30FC, 0x0064, 0x0065, 0x30EB, 0x30F3, 0x30D0
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "de-jg4avhby1noc0d", $result);
    }

    public function testEncode17()
    {
        // Japanese
        $idna = $this->hexarray2string(array(
            0x305D, 0x306E, 0x30B9, 0x30D4, 0x30FC, 0x30C9, 0x3067
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "d9juau41awczczp", $result);
    }

    public function testEncode18()
    {
        // Greek
        $idna = $this->hexarray2string(array(
            0x03b5, 0x03bb, 0x03bb, 0x03b7, 0x03bd, 0x03b9, 0x03ba, 0x03ac
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "hxargifdar", $result);
    }

    public function testEncode19()
    {
        // Maltese (Malti)
        $idna = $this->hexarray2string(array(
            0x0062, 0x006f, 0x006e, 0x0121, 0x0075, 0x0073, 0x0061, 0x0127,
            0x0127, 0x0061
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "bonusaa-5bb1da", $result);
    }

    public function testEncode20()
    {
        // Russian (Cyrillic)
        $idna = $this->hexarray2string(array(
            0x043f, 0x043e, 0x0447, 0x0435, 0x043c, 0x0443, 0x0436, 0x0435,
            0x043e, 0x043d, 0x0438, 0x043d, 0x0435, 0x0433, 0x043e, 0x0432,
            0x043e, 0x0440, 0x044f, 0x0442, 0x043f, 0x043e, 0x0440, 0x0443,
            0x0441, 0x0441, 0x043a, 0x0438
        ));
        $result = $this->idn->encode($idna);
        $this->assertSame(IDNA_ACE_PREFIX . "b1abfaaepdrnnbgefbadotcwatmq2g4l", $result);
    }
}


code:
Copyright (c) 2002-2003, Richard Heyes
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1) Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2) Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3) Neither the name of the Richard Heyes nor the names of his
   contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

license: mit


code:
<?php
/** vim: set expandtab softtabstop=4 tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP Version 5 and 7                                                  |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2017 Jon Parise and Chuck Hagenbuch               |
// | All rights reserved.                                                 |
// |                                                                      |
// | Redistribution and use in source and binary forms, with or without   |
// | modification, are permitted provided that the following conditions   |
// | are met:                                                             |
// |                                                                      |
// | 1. Redistributions of source code must retain the above copyright    |
// |    notice, this list of conditions and the following disclaimer.     |
// |                                                                      |
// | 2. Redistributions in binary form must reproduce the above copyright |
// |    notice, this list of conditions and the following disclaimer in   |
// |    the documentation and/or other materials provided with the        |
// |    distribution.                                                     |
// |                                                                      |
// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE       |
// | COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;     |
// | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER     |
// | CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT   |
// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN    |
// | ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE      |
// | POSSIBILITY OF SUCH DAMAGE.                                          |
// +----------------------------------------------------------------------+
// | Authors: Chuck Hagenbuch <chuck@horde.org>                           |
// |          Jon Parise <jon@php.net>                                    |
// |          Damian Alejandro Fernandez Sosa <damlists@cnba.uba.ar>      |
// +----------------------------------------------------------------------+

require_once 'PEAR.php';
require_once 'Net/Socket.php';

/**
 * Provides an implementation of the SMTP protocol using PEAR's
 * Net_Socket class.
 *
 * @package Net_SMTP
 * @author  Chuck Hagenbuch <chuck@horde.org>
 * @author  Jon Parise <jon@php.net>
 * @author  Damian Alejandro Fernandez Sosa <damlists@cnba.uba.ar>
 * @license http://opensource.org/licenses/bsd-license.php BSD-2-Clause
 *
 * @example basic.php A basic implementation of the Net_SMTP package.
 */
class Net_SMTP
{
    /**
     * The server to connect to.
     * @var string
     */
    public $host = 'localhost';

    /**
     * The port to connect to.
     * @var int
     */
    public $port = 25;

    /**
     * The value to give when sending EHLO or HELO.
     * @var string
     */
    public $localhost = 'localhost';

    /**
     * List of supported authentication methods, in preferential order.
     * @var array
     */
    public $auth_methods = array();

    /**
     * Use SMTP command pipelining (specified in RFC 2920) if the SMTP
     * server supports it.
     *
     * When pipeling is enabled, rcptTo(), mailFrom(), sendFrom(),
     * somlFrom() and samlFrom() do not wait for a response from the
     * SMTP server but return immediately.
     *
     * @var bool
     */
    public $pipelining = false;

    /**
     * Number of pipelined commands.
     * @var int
     */
    protected $pipelined_commands = 0;

    /**
     * Should debugging output be enabled?
     * @var boolean
     */
    protected $debug = false;

    /**
     * Debug output handler.
     * @var callback
     */
    protected $debug_handler = null;

    /**
     * The socket resource being used to connect to the SMTP server.
     * @var resource
     */
    protected $socket = null;

    /**
     * Array of socket options that will be passed to Net_Socket::connect().
     * @see stream_context_create()
     * @var array
     */
    protected $socket_options = null;

    /**
     * The socket I/O timeout value in seconds.
     * @var int
     */
    protected $timeout = 0;

    /**
     * The most recent server response code.
     * @var int
     */
    protected $code = -1;

    /**
     * The most recent server response arguments.
     * @var array
     */
    protected $arguments = array();

    /**
     * Stores the SMTP server's greeting string.
     * @var string
     */
    protected $greeting = null;

    /**
     * Stores detected features of the SMTP server.
     * @var array
     */
    protected $esmtp = array();

    /**
     * Instantiates a new Net_SMTP object, overriding any defaults
     * with parameters that are passed in.
     *
     * If you have SSL support in PHP, you can connect to a server
     * over SSL using an 'ssl://' prefix:
     *
     *   // 465 is a common smtps port.
     *   $smtp = new Net_SMTP('ssl://mail.host.com', 465);
     *   $smtp->connect();
     *
     * @param string  $host           The server to connect to.
     * @param integer $port           The port to connect to.
     * @param string  $localhost      The value to give when sending EHLO or HELO.
     * @param boolean $pipelining     Use SMTP command pipelining
     * @param integer $timeout        Socket I/O timeout in seconds.
     * @param array   $socket_options Socket stream_context_create() options.
     *
     * @since 1.0
     */
    public function __construct($host = null, $port = null, $localhost = null,
        $pipelining = false, $timeout = 0, $socket_options = null
    ) {
        if (isset($host)) {
            $this->host = $host;
        }
        if (isset($port)) {
            $this->port = $port;
        }
        if (isset($localhost)) {
            $this->localhost = $localhost;
        }

        $this->pipelining      = $pipelining;
        $this->socket         = new Net_Socket();
        $this->socket_options = $socket_options;
        $this->timeout        = $timeout;

        /* Include the Auth_SASL package.  If the package is available, we
         * enable the authentication methods that depend upon it. */
        if (@include_once 'Auth/SASL.php') {
            $this->setAuthMethod('CRAM-MD5', array($this, 'authCramMD5'));
            $this->setAuthMethod('DIGEST-MD5', array($this, 'authDigestMD5'));
        }

        /* These standard authentication methods are always available. */
        $this->setAuthMethod('LOGIN', array($this, 'authLogin'), false);
        $this->setAuthMethod('PLAIN', array($this, 'authPlain'), false);
    }

    /**
     * Set the socket I/O timeout value in seconds plus microseconds.
     *
     * @param integer $seconds      Timeout value in seconds.
     * @param integer $microseconds Additional value in microseconds.
     *
     * @since 1.5.0
     */
    public function setTimeout($seconds, $microseconds = 0)
    {
        return $this->socket->setTimeout($seconds, $microseconds);
    }

    /**
     * Set the value of the debugging flag.
     *
     * @param boolean  $debug   New value for the debugging flag.
     * @param callback $handler Debug handler callback
     *
     * @since 1.1.0
     */
    public function setDebug($debug, $handler = null)
    {
        $this->debug         = $debug;
        $this->debug_handler = $handler;
    }

    /**
     * Write the given debug text to the current debug output handler.
     *
     * @param string $message Debug mesage text.
     *
     * @since 1.3.3
     */
    protected function debug($message)
    {
        if ($this->debug) {
            if ($this->debug_handler) {
                call_user_func_array(
                    $this->debug_handler, array(&$this, $message)
                );
            } else {
                echo "DEBUG: $message\n";
            }
        }
    }

    /**
     * Send the given string of data to the server.
     *
     * @param string $data The string of data to send.
     *
     * @return mixed The number of bytes that were actually written,
     *               or a PEAR_Error object on failure.
     *
     * @since 1.1.0
     */
    protected function send($data)
    {
        $this->debug("Send: $data");

        $result = $this->socket->write($data);
        if (!$result || PEAR::isError($result)) {
            $msg = $result ? $result->getMessage() : "unknown error";
            return PEAR::raiseError("Failed to write to socket: $msg");
        }

        return $result;
    }

    /**
     * Send a command to the server with an optional string of
     * arguments.  A carriage return / linefeed (CRLF) sequence will
     * be appended to each command string before it is sent to the
     * SMTP server - an error will be thrown if the command string
     * already contains any newline characters. Use send() for
     * commands that must contain newlines.
     *
     * @param string $command The SMTP command to send to the server.
     * @param string $args    A string of optional arguments to append
     *                        to the command.
     *
     * @return mixed The result of the send() call.
     *
     * @since 1.1.0
     */
    protected function put($command, $args = '')
    {
        if (!empty($args)) {
            $command .= ' ' . $args;
        }

        if (strcspn($command, "\r\n") !== strlen($command)) {
            return PEAR::raiseError('Commands cannot contain newlines');
        }

        return $this->send($command . "\r\n");
    }

    /**
     * Read a reply from the SMTP server.  The reply consists of a response
     * code and a response message.
     *
     * @param mixed $valid The set of valid response codes.  These
     *                     may be specified as an array of integer
     *                     values or as a single integer value.
     * @param bool  $later Do not parse the response now, but wait
     *                     until the last command in the pipelined
     *                     command group
     *
     * @return mixed True if the server returned a valid response code or
     *               a PEAR_Error object is an error condition is reached.
     *
     * @since 1.1.0
     *
     * @see getResponse
     */
    protected function parseResponse($valid, $later = false)
    {
        $this->code      = -1;
        $this->arguments = array();

        if ($later) {
            $this->pipelined_commands++;
            return true;
        }

        for ($i = 0; $i <= $this->pipelined_commands; $i++) {
            while ($line = $this->socket->readLine()) {
                $this->debug("Recv: $line");

                /* If we receive an empty line, the connection was closed. */
                if (empty($line)) {
                    $this->disconnect();
                    return PEAR::raiseError('Connection was closed');
                }

                /* Read the code and store the rest in the arguments array. */
                $code = substr($line, 0, 3);
                $this->arguments[] = trim(substr($line, 4));

                /* Check the syntax of the response code. */
                if (is_numeric($code)) {
                    $this->code = (int)$code;
                } else {
                    $this->code = -1;
                    break;
                }

                /* If this is not a multiline response, we're done. */
                if (substr($line, 3, 1) != '-') {
                    break;
                }
            }
        }

        $this->pipelined_commands = 0;

        /* Compare the server's response code with the valid code/codes. */
        if (is_int($valid) && ($this->code === $valid)) {
            return true;
        } elseif (is_array($valid) && in_array($this->code, $valid, true)) {
            return true;
        }

        return PEAR::raiseError('Invalid response code received from server', $this->code);
    }

    /**
     * Issue an SMTP command and verify its response.
     *
     * @param string $command The SMTP command string or data.
     * @param mixed  $valid   The set of valid response codes. These
     *                        may be specified as an array of integer
     *                        values or as a single integer value.
     *
     * @return mixed True on success or a PEAR_Error object on failure.
     *
     * @since 1.6.0
     */
    public function command($command, $valid)
    {
        if (PEAR::isError($error = $this->put($command))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse($valid))) {
            return $error;
        }

        return true;
    }

    /**
     * Return a 2-tuple containing the last response from the SMTP server.
     *
     * @return array A two-element array: the first element contains the
     *               response code as an integer and the second element
     *               contains the response's arguments as a string.
     *
     * @since 1.1.0
     */
    public function getResponse()
    {
        return array($this->code, join("\n", $this->arguments));
    }

    /**
     * Return the SMTP server's greeting string.
     *
     * @return string A string containing the greeting string, or null if
     *                a greeting has not been received.
     *
     * @since 1.3.3
     */
    public function getGreeting()
    {
        return $this->greeting;
    }

    /**
     * Attempt to connect to the SMTP server.
     *
     * @param int  $timeout    The timeout value (in seconds) for the
     *                         socket connection attempt.
     * @param bool $persistent Should a persistent socket connection
     *                         be used?
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function connect($timeout = null, $persistent = false)
    {
        $this->greeting = null;

        $result = $this->socket->connect(
            $this->host, $this->port, $persistent, $timeout, $this->socket_options
        );

        if (PEAR::isError($result)) {
            return PEAR::raiseError(
                'Failed to connect socket: ' . $result->getMessage()
            );
        }

        /*
         * Now that we're connected, reset the socket's timeout value for
         * future I/O operations.  This allows us to have different socket
         * timeout values for the initial connection (our $timeout parameter)
         * and all other socket operations.
         */
        if ($this->timeout > 0) {
            if (PEAR::isError($error = $this->setTimeout($this->timeout))) {
                return $error;
            }
        }

        if (PEAR::isError($error = $this->parseResponse(220))) {
            return $error;
        }

        /* Extract and store a copy of the server's greeting string. */
        list(, $this->greeting) = $this->getResponse();

        if (PEAR::isError($error = $this->negotiate())) {
            return $error;
        }

        return true;
    }

    /**
     * Attempt to disconnect from the SMTP server.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function disconnect()
    {
        if (PEAR::isError($error = $this->put('QUIT'))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(221))) {
            return $error;
        }
        if (PEAR::isError($error = $this->socket->disconnect())) {
            return PEAR::raiseError(
                'Failed to disconnect socket: ' . $error->getMessage()
            );
        }

        return true;
    }

    /**
     * Attempt to send the EHLO command and obtain a list of ESMTP
     * extensions available, and failing that just send HELO.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     *
     * @since 1.1.0
     */
    protected function negotiate()
    {
        if (PEAR::isError($error = $this->put('EHLO', $this->localhost))) {
            return $error;
        }

        if (PEAR::isError($this->parseResponse(250))) {
            /* If the EHLO failed, try the simpler HELO command. */
            if (PEAR::isError($error = $this->put('HELO', $this->localhost))) {
                return $error;
            }
            if (PEAR::isError($this->parseResponse(250))) {
                return PEAR::raiseError('HELO was not accepted', $this->code);
            }

            return true;
        }

        foreach ($this->arguments as $argument) {
            $verb      = strtok($argument, ' ');
            $len       = strlen($verb);
            $arguments = substr($argument, $len + 1, strlen($argument) - $len - 1);
            $this->esmtp[$verb] = $arguments;
        }

        if (!isset($this->esmtp['PIPELINING'])) {
            $this->pipelining = false;
        }

        return true;
    }

    /**
     * Returns the name of the best authentication method that the server
     * has advertised.
     *
     * @return mixed Returns a string containing the name of the best
     *               supported authentication method or a PEAR_Error object
     *               if a failure condition is encountered.
     * @since 1.1.0
     */
    protected function getBestAuthMethod()
    {
        $available_methods = explode(' ', $this->esmtp['AUTH']);

        foreach ($this->auth_methods as $method => $callback) {
            if (in_array($method, $available_methods)) {
                return $method;
            }
        }

        return PEAR::raiseError('No supported authentication methods');
    }

    /**
     * Attempt to do SMTP authentication.
     *
     * @param string $uid    The userid to authenticate as.
     * @param string $pwd    The password to authenticate with.
     * @param string $method The requested authentication method.  If none is
     *                       specified, the best supported method will be used.
     * @param bool   $tls    Flag indicating whether or not TLS should be attempted.
     * @param string $authz  An optional authorization identifier.  If specified, this
     *                       identifier will be used as the authorization proxy.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function auth($uid, $pwd , $method = '', $tls = true, $authz = '')
    {
        /* We can only attempt a TLS connection if one has been requested,
         * we're running PHP 5.1.0 or later, have access to the OpenSSL
         * extension, are connected to an SMTP server which supports the
         * STARTTLS extension, and aren't already connected over a secure
         * (SSL) socket connection. */
        if ($tls && version_compare(PHP_VERSION, '5.1.0', '>=')
            && extension_loaded('openssl') && isset($this->esmtp['STARTTLS'])
            && strncasecmp($this->host, 'ssl://', 6) !== 0
        ) {
            /* Start the TLS connection attempt. */
            if (PEAR::isError($result = $this->put('STARTTLS'))) {
                return $result;
            }
            if (PEAR::isError($result = $this->parseResponse(220))) {
                return $result;
            }
            if (isset($this->socket_options['ssl']['crypto_method'])) {
                $crypto_method = $this->socket_options['ssl']['crypto_method'];
            } else {
                /* STREAM_CRYPTO_METHOD_TLS_ANY_CLIENT constant does not exist
                 * and STREAM_CRYPTO_METHOD_SSLv23_CLIENT constant is
                 * inconsistent across PHP versions. */
                $crypto_method = STREAM_CRYPTO_METHOD_TLS_CLIENT
                                 | @STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT
                                 | @STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT;
            }
            if (PEAR::isError($result = $this->socket->enableCrypto(true, $crypto_method))) {
                return $result;
            } elseif ($result !== true) {
                return PEAR::raiseError('STARTTLS failed');
            }

            /* Send EHLO again to recieve the AUTH string from the
             * SMTP server. */
            $this->negotiate();
        }

        if (empty($this->esmtp['AUTH'])) {
            return PEAR::raiseError('SMTP server does not support authentication');
        }

        /* If no method has been specified, get the name of the best
         * supported method advertised by the SMTP server. */
        if (empty($method)) {
            if (PEAR::isError($method = $this->getBestAuthMethod())) {
                /* Return the PEAR_Error object from _getBestAuthMethod(). */
                return $method;
            }
        } else {
            $method = strtoupper($method);
            if (!array_key_exists($method, $this->auth_methods)) {
                return PEAR::raiseError("$method is not a supported authentication method");
            }
        }

        if (!isset($this->auth_methods[$method])) {
            return PEAR::raiseError("$method is not a supported authentication method");
        }

        if (!is_callable($this->auth_methods[$method], false)) {
            return PEAR::raiseError("$method authentication method cannot be called");
        }

        if (is_array($this->auth_methods[$method])) {
            list($object, $method) = $this->auth_methods[$method];
            $result = $object->{$method}($uid, $pwd, $authz, $this);
        } else {
            $func   = $this->auth_methods[$method];
            $result = $func($uid, $pwd, $authz, $this);
        }

        /* If an error was encountered, return the PEAR_Error object. */
        if (PEAR::isError($result)) {
            return $result;
        }

        return true;
    }

    /**
     * Add a new authentication method.
     *
     * @param string $name     The authentication method name (e.g. 'PLAIN')
     * @param mixed  $callback The authentication callback (given as the name of a
     *                         function or as an (object, method name) array).
     * @param bool   $prepend  Should the new method be prepended to the list of
     *                         available methods?  This is the default behavior,
     *                         giving the new method the highest priority.
     *
     * @return mixed True on success or a PEAR_Error object on failure.
     *
     * @since 1.6.0
     */
    public function setAuthMethod($name, $callback, $prepend = true)
    {
        if (!is_string($name)) {
            return PEAR::raiseError('Method name is not a string');
        }

        if (!is_string($callback) && !is_array($callback)) {
            return PEAR::raiseError('Method callback must be string or array');
        }

        if (is_array($callback)) {
            if (!is_object($callback[0]) || !is_string($callback[1])) {
                return PEAR::raiseError('Bad mMethod callback array');
            }
        }

        if ($prepend) {
            $this->auth_methods = array_merge(
                array($name => $callback), $this->auth_methods
            );
        } else {
            $this->auth_methods[$name] = $callback;
        }

        return true;
    }

    /**
     * Authenticates the user using the DIGEST-MD5 method.
     *
     * @param string $uid   The userid to authenticate as.
     * @param string $pwd   The password to authenticate with.
     * @param string $authz The optional authorization proxy identifier.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.1.0
     */
    protected function authDigestMD5($uid, $pwd, $authz = '')
    {
        if (PEAR::isError($error = $this->put('AUTH', 'DIGEST-MD5'))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            /* 503: Error: already authenticated */
            if ($this->code === 503) {
                return true;
            }
            return $error;
        }

        $auth_sasl = new Auth_SASL;
        $digest    = $auth_sasl->factory('digest-md5');
        $challenge = base64_decode($this->arguments[0]);
        $auth_str  = base64_encode(
            $digest->getResponse($uid, $pwd, $challenge, $this->host, "smtp", $authz)
        );

        if (PEAR::isError($error = $this->put($auth_str))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            return $error;
        }

        /* We don't use the protocol's third step because SMTP doesn't
         * allow subsequent authentication, so we just silently ignore
         * it. */
        if (PEAR::isError($error = $this->put(''))) {
            return $error;
        }
        /* 235: Authentication successful */
        if (PEAR::isError($error = $this->parseResponse(235))) {
            return $error;
        }
    }

    /**
     * Authenticates the user using the CRAM-MD5 method.
     *
     * @param string $uid   The userid to authenticate as.
     * @param string $pwd   The password to authenticate with.
     * @param string $authz The optional authorization proxy identifier.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.1.0
     */
    protected function authCRAMMD5($uid, $pwd, $authz = '')
    {
        if (PEAR::isError($error = $this->put('AUTH', 'CRAM-MD5'))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            /* 503: Error: already authenticated */
            if ($this->code === 503) {
                return true;
            }
            return $error;
        }

        $auth_sasl = new Auth_SASL;
        $challenge = base64_decode($this->arguments[0]);
        $cram      = $auth_sasl->factory('cram-md5');
        $auth_str  = base64_encode($cram->getResponse($uid, $pwd, $challenge));

        if (PEAR::isError($error = $this->put($auth_str))) {
            return $error;
        }

        /* 235: Authentication successful */
        if (PEAR::isError($error = $this->parseResponse(235))) {
            return $error;
        }
    }

    /**
     * Authenticates the user using the LOGIN method.
     *
     * @param string $uid   The userid to authenticate as.
     * @param string $pwd   The password to authenticate with.
     * @param string $authz The optional authorization proxy identifier.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.1.0
     */
    protected function authLogin($uid, $pwd, $authz = '')
    {
        if (PEAR::isError($error = $this->put('AUTH', 'LOGIN'))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            /* 503: Error: already authenticated */
            if ($this->code === 503) {
                return true;
            }
            return $error;
        }

        if (PEAR::isError($error = $this->put(base64_encode($uid)))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            return $error;
        }

        if (PEAR::isError($error = $this->put(base64_encode($pwd)))) {
            return $error;
        }

        /* 235: Authentication successful */
        if (PEAR::isError($error = $this->parseResponse(235))) {
            return $error;
        }

        return true;
    }

    /**
     * Authenticates the user using the PLAIN method.
     *
     * @param string $uid   The userid to authenticate as.
     * @param string $pwd   The password to authenticate with.
     * @param string $authz The optional authorization proxy identifier.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.1.0
     */
    protected function authPlain($uid, $pwd, $authz = '')
    {
        if (PEAR::isError($error = $this->put('AUTH', 'PLAIN'))) {
            return $error;
        }
        /* 334: Continue authentication request */
        if (PEAR::isError($error = $this->parseResponse(334))) {
            /* 503: Error: already authenticated */
            if ($this->code === 503) {
                return true;
            }
            return $error;
        }

        $auth_str = base64_encode($authz . chr(0) . $uid . chr(0) . $pwd);

        if (PEAR::isError($error = $this->put($auth_str))) {
            return $error;
        }

        /* 235: Authentication successful */
        if (PEAR::isError($error = $this->parseResponse(235))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the HELO command.
     *
     * @param string $domain The domain name to say we are.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function helo($domain)
    {
        if (PEAR::isError($error = $this->put('HELO', $domain))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250))) {
            return $error;
        }

        return true;
    }

    /**
     * Return the list of SMTP service extensions advertised by the server.
     *
     * @return array The list of SMTP service extensions.
     * @since 1.3
     */
    public function getServiceExtensions()
    {
        return $this->esmtp;
    }

    /**
     * Send the MAIL FROM: command.
     *
     * @param string $sender The sender (reverse path) to set.
     * @param string $params String containing additional MAIL parameters,
     *                       such as the NOTIFY flags defined by RFC 1891
     *                       or the VERP protocol.
     *
     *                       If $params is an array, only the 'verp' option
     *                       is supported.  If 'verp' is true, the XVERP
     *                       parameter is appended to the MAIL command.
     *                       If the 'verp' value is a string, the full
     *                       XVERP=value parameter is appended.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function mailFrom($sender, $params = null)
    {
        $args = "FROM:<$sender>";

        /* Support the deprecated array form of $params. */
        if (is_array($params) && isset($params['verp'])) {
            if ($params['verp'] === true) {
                $args .= ' XVERP';
            } elseif (trim($params['verp'])) {
                $args .= ' XVERP=' . $params['verp'];
            }
        } elseif (is_string($params) && !empty($params)) {
            $args .= ' ' . $params;
        }

        if (PEAR::isError($error = $this->put('MAIL', $args))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the RCPT TO: command.
     *
     * @param string $recipient The recipient (forward path) to add.
     * @param string $params    String containing additional RCPT parameters,
     *                          such as the NOTIFY flags defined by RFC 1891.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     *
     * @since 1.0
     */
    public function rcptTo($recipient, $params = null)
    {
        $args = "TO:<$recipient>";
        if (is_string($params)) {
            $args .= ' ' . $params;
        }

        if (PEAR::isError($error = $this->put('RCPT', $args))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(array(250, 251), $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Quote the data so that it meets SMTP standards.
     *
     * This is provided as a separate public function to facilitate
     * easier overloading for the cases where it is desirable to
     * customize the quoting behavior.
     *
     * @param string &$data The message text to quote. The string must be passed
     *                      by reference, and the text will be modified in place.
     *
     * @since 1.2
     */
    public function quotedata(&$data)
    {
        /* Because a single leading period (.) signifies an end to the
         * data, legitimate leading periods need to be "doubled" ('..'). */
        $data = preg_replace('/^\./m', '..', $data);

        /* Change Unix (\n) and Mac (\r) linefeeds into CRLF's (\r\n). */
        $data = preg_replace('/(?:\r\n|\n|\r(?!\n))/', "\r\n", $data);
    }

    /**
     * Send the DATA command.
     *
     * @param mixed  $data    The message data, either as a string or an open
     *                        file resource.
     * @param string $headers The message headers.  If $headers is provided,
     *                        $data is assumed to contain only body data.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function data($data, $headers = null)
    {
        /* Verify that $data is a supported type. */
        if (!is_string($data) && !is_resource($data)) {
            return PEAR::raiseError('Expected a string or file resource');
        }

        /* Start by considering the size of the optional headers string.  We
         * also account for the addition 4 character "\r\n\r\n" separator
         * sequence. */
        $size = $headers_size = (is_null($headers)) ? 0 : strlen($headers) + 4;

        if (is_resource($data)) {
            $stat = fstat($data);
            if ($stat === false) {
                return PEAR::raiseError('Failed to get file size');
            }
            $size += $stat['size'];
        } else {
            $size += strlen($data);
        }

        /* RFC 1870, section 3, subsection 3 states "a value of zero indicates
         * that no fixed maximum message size is in force".  Furthermore, it
         * says that if "the parameter is omitted no information is conveyed
         * about the server's fixed maximum message size". */
        $limit = (isset($this->esmtp['SIZE'])) ? $this->esmtp['SIZE'] : 0;
        if ($limit > 0 && $size >= $limit) {
            $this->disconnect();
            return PEAR::raiseError('Message size exceeds server limit');
        }

        /* Initiate the DATA command. */
        if (PEAR::isError($error = $this->put('DATA'))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(354))) {
            return $error;
        }

        /* If we have a separate headers string, send it first. */
        if (!is_null($headers)) {
            $this->quotedata($headers);
            if (PEAR::isError($result = $this->send($headers . "\r\n\r\n"))) {
                return $result;
            }

            /* Subtract the headers size now that they've been sent. */
            $size -= $headers_size;
        }

        /* Now we can send the message body data. */
        if (is_resource($data)) {
            /* Stream the contents of the file resource out over our socket
             * connection, line by line.  Each line must be run through the
             * quoting routine. */
            while (strlen($line = fread($data, 8192)) > 0) {
                /* If the last character is an newline, we need to grab the
                 * next character to check to see if it is a period. */
                while (!feof($data)) {
                    $char = fread($data, 1);
                    $line .= $char;
                    if ($char != "\n") {
                        break;
                    }
                }
                $this->quotedata($line);
                if (PEAR::isError($result = $this->send($line))) {
                    return $result;
                }
            }

             $last = $line;
        } else {
            /*
             * Break up the data by sending one chunk (up to 512k) at a time.
             * This approach reduces our peak memory usage.
             */
            for ($offset = 0; $offset < $size;) {
                $end = $offset + 512000;

                /*
                 * Ensure we don't read beyond our data size or span multiple
                 * lines.  quotedata() can't properly handle character data
                 * that's split across two line break boundaries.
                 */
                if ($end >= $size) {
                    $end = $size;
                } else {
                    for (; $end < $size; $end++) {
                        if ($data[$end] != "\n") {
                            break;
                        }
                    }
                }

                /* Extract our chunk and run it through the quoting routine. */
                $chunk = substr($data, $offset, $end - $offset);
                $this->quotedata($chunk);

                /* If we run into a problem along the way, abort. */
                if (PEAR::isError($result = $this->send($chunk))) {
                    return $result;
                }

                /* Advance the offset to the end of this chunk. */
                $offset = $end;
            }

            $last = $chunk;
        }

        /* Don't add another CRLF sequence if it's already in the data */
        $terminator = (substr($last, -2) == "\r\n" ? '' : "\r\n") . ".\r\n";

        /* Finally, send the DATA terminator sequence. */
        if (PEAR::isError($result = $this->send($terminator))) {
            return $result;
        }

        /* Verify that the data was successfully received by the server. */
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the SEND FROM: command.
     *
     * @param string $path The reverse path to send.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.2.6
     */
    public function sendFrom($path)
    {
        if (PEAR::isError($error = $this->put('SEND', "FROM:<$path>"))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the SOML FROM: command.
     *
     * @param string $path The reverse path to send.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.2.6
     */
    public function somlFrom($path)
    {
        if (PEAR::isError($error = $this->put('SOML', "FROM:<$path>"))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the SAML FROM: command.
     *
     * @param string $path The reverse path to send.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.2.6
     */
    public function samlFrom($path)
    {
        if (PEAR::isError($error = $this->put('SAML', "FROM:<$path>"))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the RSET command.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since  1.0
     */
    public function rset()
    {
        if (PEAR::isError($error = $this->put('RSET'))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250, $this->pipelining))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the VRFY command.
     *
     * @param string $string The string to verify
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function vrfy($string)
    {
        /* Note: 251 is also a valid response code */
        if (PEAR::isError($error = $this->put('VRFY', $string))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(array(250, 252)))) {
            return $error;
        }

        return true;
    }

    /**
     * Send the NOOP command.
     *
     * @return mixed Returns a PEAR_Error with an error message on any
     *               kind of failure, or true on success.
     * @since 1.0
     */
    public function noop()
    {
        if (PEAR::isError($error = $this->put('NOOP'))) {
            return $error;
        }
        if (PEAR::isError($error = $this->parseResponse(250))) {
            return $error;
        }

        return true;
    }

    /**
     * Backwards-compatibility method.  identifySender()'s functionality is
     * now handled internally.
     *
     * @return boolean This method always return true.
     *
     * @since 1.0
     */
    public function identifySender()
    {
        return true;
    }
}


code:
<?php
/**
 * Net_Socket
 *
 * PHP Version 5
 *
 * LICENSE:
 *
 * Copyright (c) 1997-2017 The PHP Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * o Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * o Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @category  Net
 * @package   Net_Socket
 * @author    Stig Bakken <ssb@php.net>
 * @author    Chuck Hagenbuch <chuck@horde.org>
 * @copyright 1997-2017 The PHP Group
 * @license   http://opensource.org/licenses/bsd-license.php BSD-2-Clause
 * @link      http://pear.php.net/packages/Net_Socket
 */

require_once 'PEAR.php';

define('NET_SOCKET_READ', 1);
define('NET_SOCKET_WRITE', 2);
define('NET_SOCKET_ERROR', 4);

/**
 * Generalized Socket class.
 *
 * @category  Net
 * @package   Net_Socket
 * @author    Stig Bakken <ssb@php.net>
 * @author    Chuck Hagenbuch <chuck@horde.org>
 * @copyright 1997-2017 The PHP Group
 * @license   http://opensource.org/licenses/bsd-license.php BSD-2-Clause
 * @link      http://pear.php.net/packages/Net_Socket
 */
class Net_Socket extends PEAR
{
    /**
     * Socket file pointer.
     * @var resource $fp
     */
    public $fp = null;

    /**
     * Whether the socket is blocking. Defaults to true.
     * @var boolean $blocking
     */
    public $blocking = true;

    /**
     * Whether the socket is persistent. Defaults to false.
     * @var boolean $persistent
     */
    public $persistent = false;

    /**
     * The IP address to connect to.
     * @var string $addr
     */
    public $addr = '';

    /**
     * The port number to connect to.
     * @var integer $port
     */
    public $port = 0;

    /**
     * Number of seconds to wait on socket operations before assuming
     * there's no more data. Defaults to no timeout.
     * @var integer|float $timeout
     */
    public $timeout = null;

    /**
     * Number of bytes to read at a time in readLine() and
     * readAll(). Defaults to 2048.
     * @var integer $lineLength
     */
    public $lineLength = 2048;

    /**
     * The string to use as a newline terminator. Usually "\r\n" or "\n".
     * @var string $newline
     */
    public $newline = "\r\n";

    /**
     * Connect to the specified port. If called when the socket is
     * already connected, it disconnects and connects again.
     *
     * @param string $addr IP address or host name (may be with protocol prefix).
     * @param integer $port TCP port number.
     * @param boolean $persistent (optional) Whether the connection is
     *                            persistent (kept open between requests
     *                            by the web server).
     * @param integer $timeout (optional) Connection socket timeout.
     * @param array $options See options for stream_context_create.
     *
     * @access public
     *
     * @return boolean|PEAR_Error  True on success or a PEAR_Error on failure.
     */
    public function connect(
        $addr,
        $port = 0,
        $persistent = null,
        $timeout = null,
        $options = null
    ) {
        if (is_resource($this->fp)) {
            @fclose($this->fp);
            $this->fp = null;
        }

        if (!$addr) {
            return $this->raiseError('$addr cannot be empty');
        } else {
            if (strspn($addr, ':.0123456789') === strlen($addr)) {
                $this->addr = strpos($addr, ':') !== false ? '[' . $addr . ']' : $addr;
            } else {
                $this->addr = $addr;
            }
        }

        $this->port = $port % 65536;

        if ($persistent !== null) {
            $this->persistent = $persistent;
        }

        $openfunc = $this->persistent ? 'pfsockopen' : 'fsockopen';
        $errno = 0;
        $errstr = '';

        if (function_exists('error_clear_last')) {
            error_clear_last();
        } else {
            $old_track_errors = @ini_set('track_errors', 1);
        }

        if ($timeout <= 0) {
            $timeout = @ini_get('default_socket_timeout');
        }

        if ($options && function_exists('stream_context_create')) {
            $context = stream_context_create($options);

            // Since PHP 5 fsockopen doesn't allow context specification
            if (function_exists('stream_socket_client')) {
                $flags = STREAM_CLIENT_CONNECT;

                if ($this->persistent) {
                    $flags = STREAM_CLIENT_PERSISTENT;
                }

                $addr = $this->addr . ':' . $this->port;
                $fp = @stream_socket_client($addr, $errno, $errstr,
                    $timeout, $flags, $context);
            } else {
                $fp = @$openfunc($this->addr, $this->port, $errno,
                    $errstr, $timeout, $context);
            }
        } else {
            $fp = @$openfunc($this->addr, $this->port, $errno, $errstr, $timeout);
        }

        if (!$fp) {
            if ($errno === 0 && !strlen($errstr)) {
                $errstr = '';
                if (isset($old_track_errors)) {
                    $errstr = $php_errormsg ?: '';
                    @ini_set('track_errors', $old_track_errors);
                } else {
                    $lastError = error_get_last();
                    if (isset($lastError['message'])) {
                        $errstr = $lastError['message'];
                    }
                }
            }

            return $this->raiseError($errstr, $errno);
        }

        if (isset($old_track_errors)) {
            @ini_set('track_errors', $old_track_errors);
        }

        $this->fp = $fp;
        $this->setTimeout();

        return $this->setBlocking($this->blocking);
    }

    /**
     * Disconnects from the peer, closes the socket.
     *
     * @access public
     * @return mixed true on success or a PEAR_Error instance otherwise
     */
    public function disconnect()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        @fclose($this->fp);
        $this->fp = null;

        return true;
    }

    /**
     * Set the newline character/sequence to use.
     *
     * @param string $newline Newline character(s)
     * @return boolean True
     */
    public function setNewline($newline)
    {
        $this->newline = $newline;

        return true;
    }

    /**
     * Find out if the socket is in blocking mode.
     *
     * @access public
     * @return boolean  The current blocking mode.
     */
    public function isBlocking()
    {
        return $this->blocking;
    }

    /**
     * Sets whether the socket connection should be blocking or
     * not. A read call to a non-blocking socket will return immediately
     * if there is no data available, whereas it will block until there
     * is data for blocking sockets.
     *
     * @param boolean $mode True for blocking sockets, false for nonblocking.
     *
     * @access public
     * @return mixed true on success or a PEAR_Error instance otherwise
     */
    public function setBlocking($mode)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $this->blocking = $mode;
        stream_set_blocking($this->fp, (int)$this->blocking);

        return true;
    }

    /**
     * Sets the timeout value on socket descriptor,
     * expressed in the sum of seconds and microseconds
     *
     * @param integer $seconds Seconds.
     * @param integer $microseconds Microseconds, optional.
     *
     * @access public
     * @return mixed True on success or false on failure or
     *               a PEAR_Error instance when not connected
     */
    public function setTimeout($seconds = null, $microseconds = null)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        if ($seconds === null && $microseconds === null) {
            $seconds = (int)$this->timeout;
            $microseconds = (int)(($this->timeout - $seconds) * 1000000);
        } else {
            $this->timeout = $seconds + $microseconds / 1000000;
        }

        if ($this->timeout > 0) {
            return stream_set_timeout($this->fp, (int)$seconds, (int)$microseconds);
        } else {
            return false;
        }
    }

    /**
     * Sets the file buffering size on the stream.
     * See php's stream_set_write_buffer for more information.
     *
     * @param integer $size Write buffer size.
     *
     * @access public
     * @return mixed on success or an PEAR_Error object otherwise
     */
    public function setWriteBuffer($size)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $returned = stream_set_write_buffer($this->fp, $size);
        if ($returned === 0) {
            return true;
        }

        return $this->raiseError('Cannot set write buffer.');
    }

    /**
     * Returns information about an existing socket resource.
     * Currently returns four entries in the result array:
     *
     *

     * timed_out (bool) - The socket timed out waiting for data

     * blocked (bool) - The socket was blocked

     * eof (bool) - Indicates EOF event

     * unread_bytes (int) - Number of bytes left in the socket buffer

     *

     *
     * @access public
     * @return mixed Array containing information about existing socket
     *               resource or a PEAR_Error instance otherwise
     */
    public function getStatus()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        return stream_get_meta_data($this->fp);
    }

    /**
     * Get a specified line of data
     *
     * @param int $size Reading ends when size - 1 bytes have been read,
     *                  or a newline or an EOF (whichever comes first).
     *                  If no size is specified, it will keep reading from
     *                  the stream until it reaches the end of the line.
     *
     * @access public
     * @return mixed $size bytes of data from the socket, or a PEAR_Error if
     *         not connected. If an error occurs, FALSE is returned.
     */
    public function gets($size = null)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        if (null === $size) {
            return @fgets($this->fp);
        } else {
            return @fgets($this->fp, $size);
        }
    }

    /**
     * Read a specified amount of data. This is guaranteed to return,
     * and has the added benefit of getting everything in one fread()
     * chunk; if you know the size of the data you're getting
     * beforehand, this is definitely the way to go.
     *
     * @param integer $size The number of bytes to read from the socket.
     *
     * @access public
     * @return string $size bytes of data from the socket, or a PEAR_Error if
     *         not connected.
     */
    public function read($size)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        return @fread($this->fp, $size);
    }

    /**
     * Write a specified amount of data.
     *
     * @param string $data Data to write.
     * @param integer $blocksize Amount of data to write at once.
     *                           NULL means all at once.
     *
     * @access public
     * @return mixed If the socket is not connected, returns an instance of
     *               PEAR_Error.
     *               If the write succeeds, returns the number of bytes written.
     *               If the write fails, returns false.
     *               If the socket times out, returns an instance of PEAR_Error.
     */
    public function write($data, $blocksize = null)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        if (null === $blocksize && !OS_WINDOWS) {
            $written = @fwrite($this->fp, $data);

            // Check for timeout or lost connection
            if ($written === false) {
                $meta_data = $this->getStatus();

                if (!is_array($meta_data)) {
                    return $meta_data; // PEAR_Error
                }

                if (!empty($meta_data['timed_out'])) {
                    return $this->raiseError('timed out');
                }
            }

            return $written;
        } else {
            if (null === $blocksize) {
                $blocksize = 1024;
            }

            $pos = 0;
            $size = strlen($data);
            while ($pos < $size) {
                $written = @fwrite($this->fp, substr($data, $pos, $blocksize));

                // Check for timeout or lost connection
                if ($written === false) {
                    $meta_data = $this->getStatus();

                    if (!is_array($meta_data)) {
                        return $meta_data; // PEAR_Error
                    }

                    if (!empty($meta_data['timed_out'])) {
                        return $this->raiseError('timed out');
                    }

                    return $written;
                }

                $pos += $written;
            }

            return $pos;
        }
    }

    /**
     * Write a line of data to the socket, followed by a trailing newline.
     *
     * @param string $data Data to write
     *
     * @access public
     * @return mixed fwrite() result, or PEAR_Error when not connected
     */
    public function writeLine($data)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        return fwrite($this->fp, $data . $this->newline);
    }

    /**
     * Tests for end-of-file on a socket descriptor.
     *
     * Also returns true if the socket is disconnected.
     *
     * @access public
     * @return bool
     */
    public function eof()
    {
        return (!is_resource($this->fp) || feof($this->fp));
    }

    /**
     * Reads a byte of data
     *
     * @access public
     * @return integer 1 byte of data from the socket, or a PEAR_Error if
     *         not connected.
     */
    public function readByte()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        return ord(@fread($this->fp, 1));
    }

    /**
     * Reads a word of data
     *
     * @access public
     * @return integer 1 word of data from the socket, or a PEAR_Error if
     *         not connected.
     */
    public function readWord()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $buf = @fread($this->fp, 2);

        return (ord($buf[0]) + (ord($buf[1]) << 8));
    }

    /**
     * Reads an int of data
     *
     * @access public
     * @return integer  1 int of data from the socket, or a PEAR_Error if
     *                  not connected.
     */
    public function readInt()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $buf = @fread($this->fp, 4);

        return (ord($buf[0]) + (ord($buf[1]) << 8) +
            (ord($buf[2]) << 16) + (ord($buf[3]) << 24));
    }

    /**
     * Reads a zero-terminated string of data
     *
     * @access public
     * @return string, or a PEAR_Error if
     *         not connected.
     */
    public function readString()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $string = '';
        while (($char = @fread($this->fp, 1)) !== "\x00") {
            $string .= $char;
        }

        return $string;
    }

    /**
     * Reads an IP Address and returns it in a dot formatted string
     *
     * @access public
     * @return string Dot formatted string, or a PEAR_Error if
     *         not connected.
     */
    public function readIPAddress()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $buf = @fread($this->fp, 4);

        return sprintf('%d.%d.%d.%d', ord($buf[0]), ord($buf[1]),
            ord($buf[2]), ord($buf[3]));
    }

    /**
     * Read until either the end of the socket or a newline, whichever
     * comes first. Strips the trailing newline from the returned data.
     *
     * @access public
     * @return string All available data up to a newline, without that
     *         newline, or until the end of the socket, or a PEAR_Error if
     *         not connected.
     */
    public function readLine()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $line = '';

        $timeout = time() + $this->timeout;

        while (!feof($this->fp) && (!$this->timeout || time() < $timeout)) {
            $line .= @fgets($this->fp, $this->lineLength);
            if (substr($line, -1) == "\n") {
                return rtrim($line, $this->newline);
            }
        }

        return $line;
    }

    /**
     * Read until the socket closes, or until there is no more data in
     * the inner PHP buffer. If the inner buffer is empty, in blocking
     * mode we wait for at least 1 byte of data. Therefore, in
     * blocking mode, if there is no data at all to be read, this
     * function will never exit (unless the socket is closed on the
     * remote end).
     *
     * @access public
     *
     * @return string  All data until the socket closes, or a PEAR_Error if
     *                 not connected.
     */
    public function readAll()
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $data = '';
        $timeout = time() + $this->timeout;

        while (!feof($this->fp) && (!$this->timeout || time() < $timeout)) {
            $data .= @fread($this->fp, $this->lineLength);
        }

        return $data;
    }

    /**
     * Runs the equivalent of the select() system call on the socket
     * with a timeout specified by tv_sec and tv_usec.
     *
     * @param integer $state Which of read/write/error to check for.
     * @param integer $tv_sec Number of seconds for timeout.
     * @param integer $tv_usec Number of microseconds for timeout.
     *
     * @access public
     * @return False if select fails, integer describing which of read/write/error
     *         are ready, or PEAR_Error if not connected.
     */
    public function select($state, $tv_sec, $tv_usec = 0)
    {
        if (!is_resource($this->fp)) {
            return $this->raiseError('not connected');
        }

        $read = null;
        $write = null;
        $except = null;
        if ($state & NET_SOCKET_READ) {
            $read[] = $this->fp;
        }
        if ($state & NET_SOCKET_WRITE) {
            $write[] = $this->fp;
        }
        if ($state & NET_SOCKET_ERROR) {
            $except[] = $this->fp;
        }
        if (false === ($sr = stream_select($read, $write, $except,
                $tv_sec, $tv_usec))
        ) {
            return false;
        }

        $result = 0;
        if (count($read)) {
            $result |= NET_SOCKET_READ;
        }
        if (count($write)) {
            $result |= NET_SOCKET_WRITE;
        }
        if (count($except)) {
            $result |= NET_SOCKET_ERROR;
        }

        return $result;
    }

    /**
     * Turns encryption on/off on a connected socket.
     *
     * @param bool $enabled Set this parameter to true to enable encryption
     *                         and false to disable encryption.
     * @param integer $type Type of encryption. See stream_socket_enable_crypto()
     *                         for values.
     *
     * @see    http://se.php.net/manual/en/function.stream-socket-enable-crypto.php
     * @access public
     * @return false on error, true on success and 0 if there isn't enough data
     *         and the user should try again (non-blocking sockets only).
     *         A PEAR_Error object is returned if the socket is not
     *         connected
     */
    public function enableCrypto($enabled, $type)
    {
        if (version_compare(phpversion(), '5.1.0', '>=')) {
            if (!is_resource($this->fp)) {
                return $this->raiseError('not connected');
            }

            return @stream_socket_enable_crypto($this->fp, $enabled, $type);
        } else {
            $msg = 'Net_Socket::enableCrypto() requires php version >= 5.1.0';

            return $this->raiseError($msg);
        }
    }

}