WinZipAesDecryptionStreamFilter::filter() - Code Metrics - Inspection of "Merge branch 'release/3.2.0'" - Ne-Lexa/php-zip - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 3b7697...25d5dd )

by Alexey

created 2020-01-09 14:46 UTC

WinZipAesDecryptionStreamFilter::filter() C

↳ Parent: WinZipAesDecryptionStreamFilter

Complexity

Conditions	15
Paths	45

Size

Total Lines	87
Code Lines	51

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
cc	15
eloc	51
c	1
b	0
f	1
nc	45
nop	4
dl	0
loc	87
rs	5.9166

How to fix Long Method Complexity

<?php

namespace PhpZip\IO\Filter\Cipher\WinZipAes;

use PhpZip\Exception\RuntimeException;
use PhpZip\Exception\ZipAuthenticationException;
use PhpZip\Model\Extra\Fields\WinZipAesExtraField;
use PhpZip\Model\ZipEntry;

/**
 * Decrypt WinZip AES stream.
 */
class WinZipAesDecryptionStreamFilter extends \php_user_filter
{
    const FILTER_NAME = 'phpzip.decryption.winzipaes';

    /** @var string */
    private $buffer;

    /** @var string */
    private $authenticationCode;

    /** @var int */
    private $encBlockPosition = 0;

    /** @var int */
    private $encBlockLength = 0;

    /** @var int */
    private $readLength = 0;

    /** @var ZipEntry */
    private $entry;

    /** @var WinZipAesContext|null */
    private $context;

    /**
     * @return bool
     */
    public static function register()
    {
        return stream_filter_register(self::FILTER_NAME, __CLASS__);
    }

    /**
     * @return bool
     *
     * @noinspection DuplicatedCode
     */
    public function onCreate()
    {
        if (!isset($this->params['entry'])) {
            return false;
        }

        if (!($this->params['entry'] instanceof ZipEntry)) {
            throw new \RuntimeException('ZipEntry expected');
        }
        $this->entry = $this->params['entry'];

        if (
            $this->entry->getPassword() === null ||
            !$this->entry->isEncrypted() ||
            !$this->entry->hasExtraField(WinZipAesExtraField::HEADER_ID)
        ) {
            return false;
        }

        $this->buffer = '';

        return true;
    }

    /**
     * @param resource $in
     * @param resource $out
     * @param int      $consumed
     * @param bool     $closing
     *
     * @throws ZipAuthenticationException
     *
     * @return int
     */
    public function filter($in, $out, &$consumed, $closing)
    {
        while ($bucket = stream_bucket_make_writeable($in)) {
            $this->buffer .= $bucket->data;
            $this->readLength += $bucket->datalen;

            if ($this->readLength > $this->entry->getCompressedSize()) {
                $this->buffer = substr($this->buffer, 0, $this->entry->getCompressedSize() - $this->readLength);
            }

            // read header
            if ($this->context === null) {
                /**
                 * @var WinZipAesExtraField|null $winZipExtra
                 */
                $winZipExtra = $this->entry->getExtraField(WinZipAesExtraField::HEADER_ID);

                if ($winZipExtra === null) {
                    throw new RuntimeException('$winZipExtra is null');
                }
                $saltSize = $winZipExtra->getSaltSize();
                $headerSize = $saltSize + WinZipAesContext::PASSWORD_VERIFIER_SIZE;

                if (\strlen($this->buffer) < $headerSize) {
                    return \PSFS_FEED_ME;
                }

                $salt = substr($this->buffer, 0, $saltSize);
                $passwordVerifier = substr($this->buffer, $saltSize, WinZipAesContext::PASSWORD_VERIFIER_SIZE);
                $password = $this->entry->getPassword();

                if ($password === null) {
                    throw new RuntimeException('$password is null');
                }
                $this->context = new WinZipAesContext($winZipExtra->getEncryptionStrength(), $password, $salt);
                unset($password);

                // Verify password.
                if ($passwordVerifier !== $this->context->getPasswordVerifier()) {
                    throw new ZipAuthenticationException('Invalid password');
                }

                $this->encBlockPosition = 0;
                $this->encBlockLength = $this->entry->getCompressedSize() - $headerSize - WinZipAesContext::FOOTER_SIZE;

                $this->buffer = substr($this->buffer, $headerSize);
            }

            // encrypt data
            $plainText = '';
            $offset = 0;
            $len = \strlen($this->buffer);
            $remaining = $this->encBlockLength - $this->encBlockPosition;

            if ($remaining >= WinZipAesContext::BLOCK_SIZE && $len < WinZipAesContext::BLOCK_SIZE) {
                return \PSFS_FEED_ME;
            }
            $limit = min($len, $remaining);

            if ($remaining > $limit && ($limit % WinZipAesContext::BLOCK_SIZE) !== 0) {
                $limit -= ($limit % WinZipAesContext::BLOCK_SIZE);
            }

            while ($offset < $limit) {
                $this->context->updateIv();
                $length = min(WinZipAesContext::BLOCK_SIZE, $limit - $offset);
                $data = substr($this->buffer, 0, $length);
                $plainText .= $this->context->decryption($data);
                $offset += $length;
                $this->buffer = substr($this->buffer, $length);
            }
            $this->encBlockPosition += $offset;

            if (
                $this->encBlockPosition === $this->encBlockLength &&
                \strlen($this->buffer) === WinZipAesContext::FOOTER_SIZE
            ) {
                $this->authenticationCode = $this->buffer;
                $this->buffer = '';
            }

            $bucket->data = $plainText;
            $consumed += $bucket->datalen;
            stream_bucket_append($out, $bucket);
        }

        return \PSFS_PASS_ON;
    }

    /**
     * @see http://php.net/manual/en/php-user-filter.onclose.php
     *
     * @throws ZipAuthenticationException
     */
    public function onClose()
    {
        $this->buffer = '';

        if ($this->context !== null) {
            $this->context->checkAuthCode($this->authenticationCode);
        }
    }
}


1			<?php
2
3			namespace PhpZip\IO\Filter\Cipher\WinZipAes;
4
5			use PhpZip\Exception\RuntimeException;
6			use PhpZip\Exception\ZipAuthenticationException;
7			use PhpZip\Model\Extra\Fields\WinZipAesExtraField;
8			use PhpZip\Model\ZipEntry;
9
10			/**
11			* Decrypt WinZip AES stream.
12			*/
13			class WinZipAesDecryptionStreamFilter extends \php_user_filter
14			{
15			const FILTER_NAME = 'phpzip.decryption.winzipaes';
16
17			/** @var string */
18			private $buffer;
19
20			/** @var string */
21			private $authenticationCode;
22
23			/** @var int */
24			private $encBlockPosition = 0;
25
26			/** @var int */
27			private $encBlockLength = 0;
28
29			/** @var int */
30			private $readLength = 0;
31
32			/** @var ZipEntry */
33			private $entry;
34
35			/** @var WinZipAesContext\|null */
36			private $context;
37
38			/**
39			* @return bool
40			*/
41			public static function register()
42			{
43			return stream_filter_register(self::FILTER_NAME, __CLASS__);
44			}
45
46			/**
47			* @return bool
48			*
49			* @noinspection DuplicatedCode
50			*/
51			public function onCreate()
52			{
53			if (!isset($this->params['entry'])) {
54			return false;
55			}
56
57			if (!($this->params['entry'] instanceof ZipEntry)) {
58			throw new \RuntimeException('ZipEntry expected');
59			}
60			$this->entry = $this->params['entry'];
61
62			if (
63			$this->entry->getPassword() === null \|\|
64			!$this->entry->isEncrypted() \|\|
65			!$this->entry->hasExtraField(WinZipAesExtraField::HEADER_ID)
66			) {
67			return false;
68			}
69
70			$this->buffer = '';
71
72			return true;
73			}
74
75			/**
76			* @param resource $in
77			* @param resource $out
78			* @param int $consumed
79			* @param bool $closing
80			*
81			* @throws ZipAuthenticationException
82			*
83			* @return int
84			*/
85			public function filter($in, $out, &$consumed, $closing)
86			{
87			while ($bucket = stream_bucket_make_writeable($in)) {
88			$this->buffer .= $bucket->data;
89			$this->readLength += $bucket->datalen;
90
91			if ($this->readLength > $this->entry->getCompressedSize()) {
92			$this->buffer = substr($this->buffer, 0, $this->entry->getCompressedSize() - $this->readLength);
93			}
94
95			// read header
96			if ($this->context === null) {
97			/**
98			* @var WinZipAesExtraField\|null $winZipExtra
99			*/
100			$winZipExtra = $this->entry->getExtraField(WinZipAesExtraField::HEADER_ID);
101
102			if ($winZipExtra === null) {
103			throw new RuntimeException('$winZipExtra is null');
104			}
105			$saltSize = $winZipExtra->getSaltSize();
106			$headerSize = $saltSize + WinZipAesContext::PASSWORD_VERIFIER_SIZE;
107
108			if (\strlen($this->buffer) < $headerSize) {
109			return \PSFS_FEED_ME;
110			}
111
112			$salt = substr($this->buffer, 0, $saltSize);
113			$passwordVerifier = substr($this->buffer, $saltSize, WinZipAesContext::PASSWORD_VERIFIER_SIZE);
114			$password = $this->entry->getPassword();
115
116			if ($password === null) {
117			throw new RuntimeException('$password is null');
118			}
119			$this->context = new WinZipAesContext($winZipExtra->getEncryptionStrength(), $password, $salt);
120			unset($password);
121
122			// Verify password.
123			if ($passwordVerifier !== $this->context->getPasswordVerifier()) {
124			throw new ZipAuthenticationException('Invalid password');
125			}
126
127			$this->encBlockPosition = 0;
128			$this->encBlockLength = $this->entry->getCompressedSize() - $headerSize - WinZipAesContext::FOOTER_SIZE;
129
130			$this->buffer = substr($this->buffer, $headerSize);
131			}
132
133			// encrypt data
134			$plainText = '';
135			$offset = 0;
136			$len = \strlen($this->buffer);
137			$remaining = $this->encBlockLength - $this->encBlockPosition;
138
139			if ($remaining >= WinZipAesContext::BLOCK_SIZE && $len < WinZipAesContext::BLOCK_SIZE) {
140			return \PSFS_FEED_ME;
141			}
142			$limit = min($len, $remaining);
143
144			if ($remaining > $limit && ($limit % WinZipAesContext::BLOCK_SIZE) !== 0) {
145			$limit -= ($limit % WinZipAesContext::BLOCK_SIZE);
146			}
147
148			while ($offset < $limit) {
149			$this->context->updateIv();
150			$length = min(WinZipAesContext::BLOCK_SIZE, $limit - $offset);
151			$data = substr($this->buffer, 0, $length);
152			$plainText .= $this->context->decryption($data);
153			$offset += $length;
154			$this->buffer = substr($this->buffer, $length);
155			}
156			$this->encBlockPosition += $offset;
157
158			if (
159			$this->encBlockPosition === $this->encBlockLength &&
160			\strlen($this->buffer) === WinZipAesContext::FOOTER_SIZE
161			) {
162			$this->authenticationCode = $this->buffer;
163			$this->buffer = '';
164			}
165
166			$bucket->data = $plainText;
167			$consumed += $bucket->datalen;
168			stream_bucket_append($out, $bucket);
169			}
170
171			return \PSFS_PASS_ON;
172			}
173
174			/**
175			* @see http://php.net/manual/en/php-user-filter.onclose.php
176			*
177			* @throws ZipAuthenticationException
178			*/
179			public function onClose()
180			{
181			$this->buffer = '';
182
183			if ($this->context !== null) {
184			$this->context->checkAuthCode($this->authenticationCode);
185			}
186			}
187			}
188

Ne-Lexa / php-zip

Push — master ( 3b7697...25d5dd )

WinZipAesDecryptionStreamFilter::filter() C

Complexity

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Duplication

Importance

How to fix Long Method Complexity

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