Require PHP 5.5+ (#2495)

* Require PHP 5.5+

https://github.com/FreshRSS/FreshRSS/issues/2469#issuecomment-522255093
I think it would be reasonable to require PHP 5.5+ for the core of
FreshRSS after all.

As Frenzie said, WordPress currently requires PHP 5.6.20+, and it is the
most popular PHP application.

We would loose about 20% of the PHP servers according to
https://w3techs.com/technologies/details/pl-php/5/all but I expect this
number to drop fast after the release of CentOS 8 (CentOS accounts for
17% of Linux servers
https://w3techs.com/technologies/details/os-linux/all/all ).

Distributions:
* no impact on Ubuntu, Fedora, Alpine, OpenWRT, FreeBSD, OpenSuze,
Mageia, as all active versions have PHP > 7
* no impact on OpenSuze, Synology, as all active versions have PHP > 5.5
* we drop Debian 8 Jessie (-2020) - we keep supporting Debian 9 Stretch
(2017-06) - current is Debian 10 Buster
* we drop Red Hat 7 (-2024) - we keep supporting RHEL 8 (2019-05)
* we drop CentOS 7 (-2024) - we will support CentOS 8 (to be released
soonish)

When dropping older versions, I can better like when it is for a good
reason, and there is actually one with PHP 5.5, namely generators
(yield) https://php.net/language.generators.overview which I consider
using.

* Version note for JSON.php

* hex2bin

* Update .travis.yml

Co-Authored-By: Frans de Jonge <fransdejonge@gmail.com>

6 files changed, 13 insertions, 306 deletions

diff --git a/lib/Minz/Configuration.php b/lib/Minz/Configuration.php
index aae3accc6..93f6b494c 100644
--- a/lib/Minz/Configuration.php
+++ b/lib/Minz/Configuration.php
@@ -198,7 +198,7 @@ class Minz_Configuration {
 			return false;
 		}
 
-		// Clear PHP 5.5+ cache for include
+		// Clear PHP cache for include
 		if (function_exists('opcache_invalidate')) {
 			opcache_invalidate($this->config_filename);
 		}
diff --git a/lib/Minz/ModelArray.php b/lib/Minz/ModelArray.php
index 1ac2b313d..4938f4b1d 100644
--- a/lib/Minz/ModelArray.php
+++ b/lib/Minz/ModelArray.php
@@ -48,7 +48,7 @@ class Minz_ModelArray {
 			throw new Minz_PermissionDeniedException($this->filename);
 		}
 		if (function_exists('opcache_invalidate')) {
-			opcache_invalidate($this->filename);	//Clear PHP 5.5+ cache for include
+			opcache_invalidate($this->filename);	//Clear PHP cache for include
 		}
 		return true;
 	}
diff --git a/lib/Minz/ModelPdo.php b/lib/Minz/ModelPdo.php
index 733982c14..14510c983 100644
--- a/lib/Minz/ModelPdo.php
+++ b/lib/Minz/ModelPdo.php
@@ -103,7 +103,7 @@ class Minz_ModelPdo {
 		$this->bd->beginTransaction();
 	}
 	public function inTransaction() {
-		return $this->bd->inTransaction();	//requires PHP >= 5.3.3
+		return $this->bd->inTransaction();
 	}
 	public function commit() {
 		$this->bd->commit();
diff --git a/lib/lib_install.php b/lib/lib_install.php
index 6e4df4e9c..6b9b33240 100644
--- a/lib/lib_install.php
+++ b/lib/lib_install.php
@@ -6,7 +6,7 @@ Minz_Configuration::register('default_system', join_path(FRESHRSS_PATH, 'config.
 Minz_Configuration::register('default_user', join_path(FRESHRSS_PATH, 'config-user.default.php'));
 
 function checkRequirements($dbType = '') {
-	$php = version_compare(PHP_VERSION, '5.3.8') >= 0;
+	$php = version_compare(PHP_VERSION, '5.5.0') >= 0;
 	$minz = file_exists(join_path(LIB_PATH, 'Minz'));
 	$curl = extension_loaded('curl');
 	$pdo_mysql = extension_loaded('pdo_mysql');
diff --git a/lib/lib_rss.php b/lib/lib_rss.php
index c0ea23989..2706ff606 100644
--- a/lib/lib_rss.php
+++ b/lib/lib_rss.php
@@ -1,9 +1,9 @@
 <?php
-if (version_compare(PHP_VERSION, '5.3.8', '<')) {
-	die('FreshRSS error: FreshRSS requires PHP 5.3.8+!');
+if (version_compare(PHP_VERSION, '5.5.0', '<')) {
+	die('FreshRSS error: FreshRSS requires PHP 5.5.0+!');
 }
 
-if (!function_exists('json_decode')) {
+if (!function_exists('json_decode')) {	//PHP bug #63520 < PHP 7
 	require_once(__DIR__ . '/JSON.php');
 	function json_decode($var, $assoc = false) {
 		$JSON = new Services_JSON($assoc ? SERVICES_JSON_LOOSE_TYPE : 0);
@@ -19,8 +19,6 @@ if (!function_exists('json_encode')) {
 	}
 }
 
-defined('JSON_UNESCAPED_UNICODE') or define('JSON_UNESCAPED_UNICODE', 256);	//PHP 5.3
-
 if (!function_exists('mb_strcut')) {
 	function mb_strcut($str, $start, $length = null, $encoding = 'UTF-8') {
 		return substr($str, $start, $length);
@@ -68,12 +66,7 @@ function idn_to_puny($url) {
 		$parts = parse_url($url);
 		if (!empty($parts['host'])) {
 			$idn = $parts['host'];
-			// INTL_IDNA_VARIANT_UTS46 is defined starting in PHP 5.4
-			if (defined('INTL_IDNA_VARIANT_UTS46')) {
-				$puny = idn_to_ascii($idn, 0, INTL_IDNA_VARIANT_UTS46);
-			} else {
-				$puny = idn_to_ascii($idn);
-			}
+			$puny = idn_to_ascii($idn, 0, INTL_IDNA_VARIANT_UTS46);
 			$pos = strpos($url, $idn);
 			if ($pos !== false) {
 				return substr_replace($url, $puny, $pos, strlen($idn));
@@ -187,17 +180,10 @@ function timestamptodate ($t, $hour = true) {
 function html_only_entity_decode($text) {
 	static $htmlEntitiesOnly = null;
 	if ($htmlEntitiesOnly === null) {
-		if (version_compare(PHP_VERSION, '5.3.4') >= 0) {
-			$htmlEntitiesOnly = array_flip(array_diff(
-				get_html_translation_table(HTML_ENTITIES, ENT_NOQUOTES, 'UTF-8'),	//Decode HTML entities
-				get_html_translation_table(HTML_SPECIALCHARS, ENT_NOQUOTES, 'UTF-8')	//Preserve XML entities
-			));
-		} else {
-			$htmlEntitiesOnly = array_map('utf8_encode', array_flip(array_diff(
-				get_html_translation_table(HTML_ENTITIES, ENT_NOQUOTES),	//Decode HTML entities
-				get_html_translation_table(HTML_SPECIALCHARS, ENT_NOQUOTES)	//Preserve XML entities
-			)));
-		}
+		$htmlEntitiesOnly = array_flip(array_diff(
+			get_html_translation_table(HTML_ENTITIES, ENT_NOQUOTES, 'UTF-8'),	//Decode HTML entities
+			get_html_translation_table(HTML_SPECIALCHARS, ENT_NOQUOTES, 'UTF-8')	//Preserve XML entities
+		));
 	}
 	return strtr($text, $htmlEntitiesOnly);
 }
@@ -428,7 +414,7 @@ function check_install_php() {
 	$pdo_pgsql = extension_loaded('pdo_pgsql');
 	$pdo_sqlite = extension_loaded('pdo_sqlite');
 	return array(
-		'php' => version_compare(PHP_VERSION, '5.3.8') >= 0,
+		'php' => version_compare(PHP_VERSION, '5.5.0') >= 0,
 		'minz' => file_exists(LIB_PATH . '/Minz'),
 		'curl' => extension_loaded('curl'),
 		'pdo' => $pdo_mysql || $pdo_sqlite || $pdo_pgsql,
diff --git a/lib/password_compat.php b/lib/password_compat.php
deleted file mode 100644
index e8ec02885..000000000
--- a/lib/password_compat.php
+++ /dev/null
@@ -1,279 +0,0 @@
-<?php
-/**
- * A Compatibility library with PHP 5.5's simplified password hashing API.
- *
- * @author Anthony Ferrara <ircmaxell@php.net>
- * @license http://www.opensource.org/licenses/mit-license.html MIT License
- * @copyright 2012 The Authors
- */
-
-namespace {
-
-if (!defined('PASSWORD_DEFAULT')) {
-
-    define('PASSWORD_BCRYPT', 1);
-    define('PASSWORD_DEFAULT', PASSWORD_BCRYPT);
-
-    /**
-     * Hash the password using the specified algorithm
-     *
-     * @param string $password The password to hash
-     * @param int    $algo     The algorithm to use (Defined by PASSWORD_* constants)
-     * @param array  $options  The options for the algorithm to use
-     *
-     * @return string|false The hashed password, or false on error.
-     */
-    function password_hash($password, $algo, array $options = array()) {
-        if (!function_exists('crypt')) {
-            trigger_error("Crypt must be loaded for password_hash to function", E_USER_WARNING);
-            return null;
-        }
-        if (!is_string($password)) {
-            trigger_error("password_hash(): Password must be a string", E_USER_WARNING);
-            return null;
-        }
-        if (!is_int($algo)) {
-            trigger_error("password_hash() expects parameter 2 to be long, " . gettype($algo) . " given", E_USER_WARNING);
-            return null;
-        }
-        $resultLength = 0;
-        switch ($algo) {
-            case PASSWORD_BCRYPT:
-                // Note that this is a C constant, but not exposed to PHP, so we don't define it here.
-                $cost = 10;
-                if (isset($options['cost'])) {
-                    $cost = $options['cost'];
-                    if ($cost < 4 || $cost > 31) {
-                        trigger_error(sprintf("password_hash(): Invalid bcrypt cost parameter specified: %d", $cost), E_USER_WARNING);
-                        return null;
-                    }
-                }
-                // The length of salt to generate
-                $raw_salt_len = 16;
-                // The length required in the final serialization
-                $required_salt_len = 22;
-                $hash_format = sprintf("$2y$%02d$", $cost);
-                // The expected length of the final crypt() output
-                $resultLength = 60;
-                break;
-            default:
-                trigger_error(sprintf("password_hash(): Unknown password hashing algorithm: %s", $algo), E_USER_WARNING);
-                return null;
-        }
-        $salt_requires_encoding = false;
-        if (isset($options['salt'])) {
-            switch (gettype($options['salt'])) {
-                case 'NULL':
-                case 'boolean':
-                case 'integer':
-                case 'double':
-                case 'string':
-                    $salt = (string) $options['salt'];
-                    break;
-                case 'object':
-                    if (method_exists($options['salt'], '__tostring')) {
-                        $salt = (string) $options['salt'];
-                        break;
-                    }
-                case 'array':
-                case 'resource':
-                default:
-                    trigger_error('password_hash(): Non-string salt parameter supplied', E_USER_WARNING);
-                    return null;
-            }
-            if (PasswordCompat\binary\_strlen($salt) < $required_salt_len) {
-                trigger_error(sprintf("password_hash(): Provided salt is too short: %d expecting %d", PasswordCompat\binary\_strlen($salt), $required_salt_len), E_USER_WARNING);
-                return null;
-            } elseif (0 == preg_match('#^[a-zA-Z0-9./]+$#D', $salt)) {
-                $salt_requires_encoding = true;
-            }
-        } else {
-            $buffer = '';
-            $buffer_valid = false;
-            if (function_exists('mcrypt_create_iv') && !defined('PHALANGER')) {
-                $buffer = mcrypt_create_iv($raw_salt_len, MCRYPT_DEV_URANDOM);
-                if ($buffer) {
-                    $buffer_valid = true;
-                }
-            }
-            if (!$buffer_valid && function_exists('openssl_random_pseudo_bytes')) {
-                $buffer = openssl_random_pseudo_bytes($raw_salt_len);
-                if ($buffer) {
-                    $buffer_valid = true;
-                }
-            }
-            if (!$buffer_valid && @is_readable('/dev/urandom')) {
-                $f = fopen('/dev/urandom', 'r');
-                $read = PasswordCompat\binary\_strlen($buffer);
-                while ($read < $raw_salt_len) {
-                    $buffer .= fread($f, $raw_salt_len - $read);
-                    $read = PasswordCompat\binary\_strlen($buffer);
-                }
-                fclose($f);
-                if ($read >= $raw_salt_len) {
-                    $buffer_valid = true;
-                }
-            }
-            if (!$buffer_valid || PasswordCompat\binary\_strlen($buffer) < $raw_salt_len) {
-                $bl = PasswordCompat\binary\_strlen($buffer);
-                for ($i = 0; $i < $raw_salt_len; $i++) {
-                    if ($i < $bl) {
-                        $buffer[$i] = $buffer[$i] ^ chr(mt_rand(0, 255));
-                    } else {
-                        $buffer .= chr(mt_rand(0, 255));
-                    }
-                }
-            }
-            $salt = $buffer;
-            $salt_requires_encoding = true;
-        }
-        if ($salt_requires_encoding) {
-            // encode string with the Base64 variant used by crypt
-            $base64_digits =
-                'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
-            $bcrypt64_digits =
-                './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
-
-            $base64_string = base64_encode($salt);
-            $salt = strtr(rtrim($base64_string, '='), $base64_digits, $bcrypt64_digits);
-        }
-        $salt = PasswordCompat\binary\_substr($salt, 0, $required_salt_len);
-
-        $hash = $hash_format . $salt;
-
-        $ret = crypt($password, $hash);
-
-        if (!is_string($ret) || PasswordCompat\binary\_strlen($ret) != $resultLength) {
-            return false;
-        }
-
-        return $ret;
-    }
-
-    /**
-     * Get information about the password hash. Returns an array of the information
-     * that was used to generate the password hash.
-     *
-     * array(
-     *    'algo' => 1,
-     *    'algoName' => 'bcrypt',
-     *    'options' => array(
-     *        'cost' => 10,
-     *    ),
-     * )
-     *
-     * @param string $hash The password hash to extract info from
-     *
-     * @return array The array of information about the hash.
-     */
-    function password_get_info($hash) {
-        $return = array(
-            'algo' => 0,
-            'algoName' => 'unknown',
-            'options' => array(),
-        );
-        if (PasswordCompat\binary\_substr($hash, 0, 4) == '$2y$' && PasswordCompat\binary\_strlen($hash) == 60) {
-            $return['algo'] = PASSWORD_BCRYPT;
-            $return['algoName'] = 'bcrypt';
-            list($cost) = sscanf($hash, "$2y$%d$");
-            $return['options']['cost'] = $cost;
-        }
-        return $return;
-    }
-
-    /**
-     * Determine if the password hash needs to be rehashed according to the options provided
-     *
-     * If the answer is true, after validating the password using password_verify, rehash it.
-     *
-     * @param string $hash    The hash to test
-     * @param int    $algo    The algorithm used for new password hashes
-     * @param array  $options The options array passed to password_hash
-     *
-     * @return boolean True if the password needs to be rehashed.
-     */
-    function password_needs_rehash($hash, $algo, array $options = array()) {
-        $info = password_get_info($hash);
-        if ($info['algo'] != $algo) {
-            return true;
-        }
-        switch ($algo) {
-            case PASSWORD_BCRYPT:
-                $cost = isset($options['cost']) ? $options['cost'] : 10;
-                if ($cost != $info['options']['cost']) {
-                    return true;
-                }
-                break;
-        }
-        return false;
-    }
-
-    /**
-     * Verify a password against a hash using a timing attack resistant approach
-     *
-     * @param string $password The password to verify
-     * @param string $hash     The hash to verify against
-     *
-     * @return boolean If the password matches the hash
-     */
-    function password_verify($password, $hash) {
-        if (!function_exists('crypt')) {
-            trigger_error("Crypt must be loaded for password_verify to function", E_USER_WARNING);
-            return false;
-        }
-        $ret = crypt($password, $hash);
-        if (!is_string($ret) || PasswordCompat\binary\_strlen($ret) != PasswordCompat\binary\_strlen($hash) || PasswordCompat\binary\_strlen($ret) <= 13) {
-            return false;
-        }
-
-        $status = 0;
-        for ($i = 0; $i < PasswordCompat\binary\_strlen($ret); $i++) {
-            $status |= (ord($ret[$i]) ^ ord($hash[$i]));
-        }
-
-        return $status === 0;
-    }
-}
-
-}
-
-namespace PasswordCompat\binary {
-    /**
-     * Count the number of bytes in a string
-     *
-     * We cannot simply use strlen() for this, because it might be overwritten by the mbstring extension.
-     * In this case, strlen() will count the number of *characters* based on the internal encoding. A
-     * sequence of bytes might be regarded as a single multibyte character.
-     *
-     * @param string $binary_string The input string
-     *
-     * @internal
-     * @return int The number of bytes
-     */
-    function _strlen($binary_string) {
-           if (function_exists('mb_strlen')) {
-               return mb_strlen($binary_string, '8bit');
-           }
-           return strlen($binary_string);
-    }
-
-    /**
-     * Get a substring based on byte limits
-     *
-     * @see _strlen()
-     *
-     * @param string $binary_string The input string
-     * @param int    $start
-     * @param int    $length
-     *
-     * @internal
-     * @return string The substring
-     */
-    function _substr($binary_string, $start, $length) {
-       if (function_exists('mb_substr')) {
-           return mb_substr($binary_string, $start, $length, '8bit');
-       }
-       return substr($binary_string, $start, $length);
-   }
-
-}