Structure::withPrepended() - Code Metrics - sop/asn1 - Measure and Improve Code Quality continuously with Scrutinizer

Structure::withPrepended() A
last analyzed 2025-01-08 14:01 UTC

↳ Parent: Structure

Complexity

Conditions	1
Paths	1

Size

Total Lines	5
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	4
CRAP Score	1

Importance

Changes

Metric	Value
cc	1
eloc	3
nc	1
nop	1
dl	0
loc	5
ccs	4
cts	4
cp	1
crap	1
rs	10
c	0
b	0
f	0

<?php

declare(strict_types = 1);

namespace Sop\ASN1\Type;

use Sop\ASN1\Component\Identifier;
use Sop\ASN1\Component\Length;
use Sop\ASN1\Element;
use Sop\ASN1\Exception\DecodeException;
use Sop\ASN1\Feature\ElementBase;

/**
 * Base class for the constructed types.
 */
abstract class Structure extends Element implements \Countable, \IteratorAggregate
{
    use UniversalClass;

    /**
     * Array of elements in the structure.
     *
     * @var Element[]
     */
    protected $_elements;

    /**
     * Lookup table for the tagged elements.
     *
     * @var null|TaggedType[]
     */
    private $_taggedMap;

    /**
     * Cache variable of elements wrapped into `UnspecifiedType` objects.
     *
     * @var null|UnspecifiedType[]
     */
    private $_unspecifiedTypes;

    /**
     * Constructor.
     *
     * @param ElementBase ...$elements Any number of elements
     */
    public function __construct(ElementBase ...$elements)
    {
        $this->_elements = array_map(
            function (ElementBase $el) {
                return $el->asElement();
            }, $elements);
    }

    /**
     * Clone magic method.
     */
    public function __clone()
    {
        // clear cache-variables
        $this->_taggedMap = null;
        $this->_unspecifiedTypes = null;
    }

    /**
     * {@inheritdoc}
     */
    public function isConstructed(): bool
    {
        return true;
    }

    /**
     * Explode DER structure to DER encoded components that it contains.
     *
     * @throws DecodeException
     *
     * @return string[]
     */
    public static function explodeDER(string $data): array
    {
        $offset = 0;
        $identifier = Identifier::fromDER($data, $offset);
        if (!$identifier->isConstructed()) {
            throw new DecodeException('Element is not constructed.');
        }
        $length = Length::expectFromDER($data, $offset);
        if ($length->isIndefinite()) {
            throw new DecodeException(
                'Explode not implemented for indefinite length encoding.');
        }
        $end = $offset + $length->intLength();
        $parts = [];
        while ($offset < $end) {
            // start of the element
            $idx = $offset;
            // skip identifier
            Identifier::fromDER($data, $offset);
            // decode element length
            $length = Length::expectFromDER($data, $offset)->intLength();
            // extract der encoding of the element
            $parts[] = substr($data, $idx, $offset - $idx + $length);
            // update offset over content
            $offset += $length;
        }
        return $parts;
    }

    /**
     * Get self with an element at the given index replaced by another.
     *
     * @param int     $idx Element index
     * @param Element $el  New element to insert into the structure
     *
     * @throws \OutOfBoundsException
     */
    public function withReplaced(int $idx, Element $el): self
    {
        if (!isset($this->_elements[$idx])) {
            throw new \OutOfBoundsException(
                "Structure doesn't have element at index {$idx}.");
        }
        $obj = clone $this;
        $obj->_elements[$idx] = $el;
        return $obj;
    }

    /**
     * Get self with an element inserted before the given index.
     *
     * @param int     $idx Element index
     * @param Element $el  New element to insert into the structure
     *
     * @throws \OutOfBoundsException
     */
    public function withInserted(int $idx, Element $el): self
    {
        if (count($this->_elements) < $idx || $idx < 0) {
            throw new \OutOfBoundsException("Index {$idx} is out of bounds.");
        }
        $obj = clone $this;
        array_splice($obj->_elements, $idx, 0, [$el]);
        return $obj;
    }

    /**
     * Get self with an element appended to the end.
     *
     * @param Element $el Element to insert into the structure
     */
    public function withAppended(Element $el): self
    {
        $obj = clone $this;
        array_push($obj->_elements, $el);
        return $obj;
    }

    /**
     * Get self with an element prepended in the beginning.
     *
     * @param Element $el Element to insert into the structure
     */
    public function withPrepended(Element $el): self
    {
        $obj = clone $this;
        array_unshift($obj->_elements, $el);
        return $obj;
    }

    /**
     * Get self with an element at the given index removed.
     *
     * @param int $idx Element index
     *
     * @throws \OutOfBoundsException
     */
    public function withoutElement(int $idx): self
    {
        if (!isset($this->_elements[$idx])) {
            throw new \OutOfBoundsException(
                "Structure doesn't have element at index {$idx}.");
        }
        $obj = clone $this;
        array_splice($obj->_elements, $idx, 1);
        return $obj;
    }

    /**
     * Get elements in the structure.
     *
     * @return UnspecifiedType[]
     */
    public function elements(): array
    {
        if (!isset($this->_unspecifiedTypes)) {
            $this->_unspecifiedTypes = array_map(
                function (Element $el) {
                    return new UnspecifiedType($el);
                }, $this->_elements);
        }
        return $this->_unspecifiedTypes;
    }

    /**
     * Check whether the structure has an element at the given index, optionally
     * satisfying given tag expectation.
     *
     * @param int      $idx         Index 0..n
     * @param null|int $expectedTag Optional type tag expectation
     */
    public function has(int $idx, ?int $expectedTag = null): bool
    {
        if (!isset($this->_elements[$idx])) {
            return false;
        }
        if (isset($expectedTag)) {
            if (!$this->_elements[$idx]->isType($expectedTag)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Get the element at the given index, optionally checking that the element
     * has a given tag.
     *
     * @param int $idx Index 0..n
     *
     * @throws \OutOfBoundsException     If element doesn't exists
     * @throws \UnexpectedValueException If expectation fails
     */
    public function at(int $idx): UnspecifiedType
    {
        if (!isset($this->_elements[$idx])) {
            throw new \OutOfBoundsException(
                "Structure doesn't have an element at index {$idx}.");
        }
        return new UnspecifiedType($this->_elements[$idx]);
    }

    /**
     * Check whether the structure contains a context specific element with a
     * given tag.
     *
     * @param int $tag Tag number
     */
    public function hasTagged(int $tag): bool
    {
        // lazily build lookup map
        if (!isset($this->_taggedMap)) {
            $this->_taggedMap = [];
            foreach ($this->_elements as $element) {
                if ($element->isTagged()) {
                    $this->_taggedMap[$element->tag()] = $element;
                }
            }
        }
        return isset($this->_taggedMap[$tag]);
    }

    /**
     * Get a context specific element tagged with a given tag.
     *
     * @throws \LogicException If tag doesn't exists
     */
    public function getTagged(int $tag): TaggedType
    {
        if (!$this->hasTagged($tag)) {
            throw new \LogicException("No tagged element for tag {$tag}.");
        }
        return $this->_taggedMap[$tag];
    }

    /**
     * @see \Countable::count()
     */
    public function count(): int
    {
        return count($this->_elements);
    }

    /**
     * Get an iterator for the `UnspecifiedElement` objects.
     *
     * @see \IteratorAggregate::getIterator()
     */
    public function getIterator(): \ArrayIterator
    {
        return new \ArrayIterator($this->elements());
    }

    /**
     * {@inheritdoc}
     */
    protected function _encodedContentDER(): string
    {
        $data = '';
        foreach ($this->_elements as $element) {
            $data .= $element->toDER();
        }
        return $data;
    }

    /**
     * {@inheritdoc}
     *
     * @return self
     */
    protected static function _decodeFromDER(Identifier $identifier,
        string $data, int &$offset): ElementBase
    {
        if (!$identifier->isConstructed()) {
            throw new DecodeException(
                'Structured element must have constructed bit set.');
        }
        $idx = $offset;
        $length = Length::expectFromDER($data, $idx);
        if ($length->isIndefinite()) {
            $type = self::_decodeIndefiniteLength($data, $idx);
        } else {
            $type = self::_decodeDefiniteLength($data, $idx,
                $length->intLength());
        }
        $offset = $idx;
        return $type;
    }

    /**
     * Decode elements for a definite length.
     *
     * @param string $data   DER data
     * @param int    $offset Offset to data
     * @param int    $length Number of bytes to decode
     *
     * @throws DecodeException
     */
    private static function _decodeDefiniteLength(string $data, int &$offset,
        int $length): ElementBase
    {
        $idx = $offset;
        $end = $idx + $length;
        $elements = [];
        while ($idx < $end) {
            $elements[] = Element::fromDER($data, $idx);
            // check that element didn't overflow length
            if ($idx > $end) {
                throw new DecodeException("Structure's content overflows length.");
            }
        }
        $offset = $idx;
        // return instance by static late binding
        return new static(...$elements);
    }

    /**
     * Decode elements for an indefinite length.
     *
     * @param string $data   DER data
     * @param int    $offset Offset to data
     *
     * @throws DecodeException
     */
    private static function _decodeIndefiniteLength(string $data, int &$offset): ElementBase
    {
        $idx = $offset;
        $elements = [];
        $end = strlen($data);
        while (true) {
            if ($idx >= $end) {
                throw new DecodeException(
                    'Unexpected end of data while decoding indefinite length structure.');
            }
            $el = Element::fromDER($data, $idx);
            if ($el->isType(self::TYPE_EOC)) {
                break;
            }
            $elements[] = $el;
        }
        $offset = $idx;
        $type = new static(...$elements);
        $type->_indefiniteLength = true;
        return $type;
    }
}


1		<?php
2
3		declare(strict_types = 1);
4
5		namespace Sop\ASN1\Type;
6
7		use Sop\ASN1\Component\Identifier;
8		use Sop\ASN1\Component\Length;
9		use Sop\ASN1\Element;
10		use Sop\ASN1\Exception\DecodeException;
11		use Sop\ASN1\Feature\ElementBase;
12
13		/**
14		* Base class for the constructed types.
15		*/
16		abstract class Structure extends Element implements \Countable, \IteratorAggregate
17		{
18		use UniversalClass;
19
20		/**
21		* Array of elements in the structure.
22		*
23		* @var Element[]
24		*/
25		protected $_elements;
26
27		/**
28		* Lookup table for the tagged elements.
29		*
30		* @var null\|TaggedType[]
31		*/
32		private $_taggedMap;
33
34		/**
35		* Cache variable of elements wrapped into `UnspecifiedType` objects.
36		*
37		* @var null\|UnspecifiedType[]
38		*/
39		private $_unspecifiedTypes;
40
41		/**
42		* Constructor.
43		*
44		* @param ElementBase ...$elements Any number of elements
45		*/
46	78	public function __construct(ElementBase ...$elements)
47		{
48	78	$this->_elements = array_map(
49		function (ElementBase $el) {
50	69	return $el->asElement();
51	78	}, $elements);
52	78	}
53
54		/**
55		* Clone magic method.
56		*/
57	35	public function __clone()
58		{
59		// clear cache-variables
60	35	$this->_taggedMap = null;
61	35	$this->_unspecifiedTypes = null;
62	35	}
63
64		/**
65		* {@inheritdoc}
66		*/
67	36	public function isConstructed(): bool
68		{
69	36	return true;
70		}
71
72		/**
73		* Explode DER structure to DER encoded components that it contains.
74		*
75		* @throws DecodeException
76		*
77		* @return string[]
78		*/
79	3	public static function explodeDER(string $data): array
80		{
81	3	$offset = 0;
82	3	$identifier = Identifier::fromDER($data, $offset);
83	3	if (!$identifier->isConstructed()) {
84	1	throw new DecodeException('Element is not constructed.');
85		}
86	2	$length = Length::expectFromDER($data, $offset);
87	2	if ($length->isIndefinite()) {
88	1	throw new DecodeException(
89	1	'Explode not implemented for indefinite length encoding.');
90		}
91	1	$end = $offset + $length->intLength();
92	1	$parts = [];
93	1	while ($offset < $end) {
94		// start of the element
95	1	$idx = $offset;
96		// skip identifier
97	1	Identifier::fromDER($data, $offset);
98		// decode element length
99	1	$length = Length::expectFromDER($data, $offset)->intLength();
100		// extract der encoding of the element
101	1	$parts[] = substr($data, $idx, $offset - $idx + $length);
102		// update offset over content
103	1	$offset += $length;
104		}
105	1	return $parts;
106		}
107
108		/**
109		* Get self with an element at the given index replaced by another.
110		*
111		* @param int $idx Element index
112		* @param Element $el New element to insert into the structure
113		*
114		* @throws \OutOfBoundsException
115		*/
116	2	public function withReplaced(int $idx, Element $el): self
117		{
118	2	if (!isset($this->_elements[$idx])) {
119	1	throw new \OutOfBoundsException(
120	1	"Structure doesn't have element at index {$idx}.");
121		}
122	1	$obj = clone $this;
123	1	$obj->_elements[$idx] = $el;
124	1	return $obj;
125		}
126
127		/**
128		* Get self with an element inserted before the given index.
129		*
130		* @param int $idx Element index
131		* @param Element $el New element to insert into the structure
132		*
133		* @throws \OutOfBoundsException
134		*/
135	4	public function withInserted(int $idx, Element $el): self
136		{
137	4	if (count($this->_elements) < $idx \|\| $idx < 0) {
138	1	throw new \OutOfBoundsException("Index {$idx} is out of bounds.");
139		}
140	3	$obj = clone $this;
141	3	array_splice($obj->_elements, $idx, 0, [$el]);
142	3	return $obj;
143		}
144
145		/**
146		* Get self with an element appended to the end.
147		*
148		* @param Element $el Element to insert into the structure
149		*/
150	2	public function withAppended(Element $el): self
151		{
152	2	$obj = clone $this;
153	2	array_push($obj->_elements, $el);
154	2	return $obj;
155		}
156
157		/**
158		* Get self with an element prepended in the beginning.
159		*
160		* @param Element $el Element to insert into the structure
161		*/
162	1	public function withPrepended(Element $el): self
163		{
164	1	$obj = clone $this;
165	1	array_unshift($obj->_elements, $el);
166	1	return $obj;
167		}
168
169		/**
170		* Get self with an element at the given index removed.
171		*
172		* @param int $idx Element index
173		*
174		* @throws \OutOfBoundsException
175		*/
176	4	public function withoutElement(int $idx): self
177		{
178	4	if (!isset($this->_elements[$idx])) {
179	1	throw new \OutOfBoundsException(
180	1	"Structure doesn't have element at index {$idx}.");
181		}
182	3	$obj = clone $this;
183	3	array_splice($obj->_elements, $idx, 1);
184	3	return $obj;
185		}
186
187		/**
188		* Get elements in the structure.
189		*
190		* @return UnspecifiedType[]
191		*/
192	2	public function elements(): array
193		{
194	2	if (!isset($this->_unspecifiedTypes)) {
195	1	$this->_unspecifiedTypes = array_map(
196		function (Element $el) {
197	1	return new UnspecifiedType($el);
198	1	}, $this->_elements);
199		}
200	2	return $this->_unspecifiedTypes;
201		}
202
203		/**
204		* Check whether the structure has an element at the given index, optionally
205		* satisfying given tag expectation.
206		*
207		* @param int $idx Index 0..n
208		* @param null\|int $expectedTag Optional type tag expectation
209		*/
210	9	public function has(int $idx, ?int $expectedTag = null): bool
211		{
212	9	if (!isset($this->_elements[$idx])) {
213	2	return false;
214		}
215	7	if (isset($expectedTag)) {
216	4	if (!$this->_elements[$idx]->isType($expectedTag)) {
217	1	return false;
218		}
219		}
220	6	return true;
221		}
222
223		/**
224		* Get the element at the given index, optionally checking that the element
225		* has a given tag.
226		*
227		* @param int $idx Index 0..n
228		*
229		* @throws \OutOfBoundsException If element doesn't exists
230		* @throws \UnexpectedValueException If expectation fails
231		*/
232	5	public function at(int $idx): UnspecifiedType
233		{
234	5	if (!isset($this->_elements[$idx])) {
235	1	throw new \OutOfBoundsException(
236	1	"Structure doesn't have an element at index {$idx}.");
237		}
238	4	return new UnspecifiedType($this->_elements[$idx]);
239		}
240
241		/**
242		* Check whether the structure contains a context specific element with a
243		* given tag.
244		*
245		* @param int $tag Tag number
246		*/
247	6	public function hasTagged(int $tag): bool
248		{
249		// lazily build lookup map
250	6	if (!isset($this->_taggedMap)) {
251	6	$this->_taggedMap = [];
252	6	foreach ($this->_elements as $element) {
253	6	if ($element->isTagged()) {
254	6	$this->_taggedMap[$element->tag()] = $element;
255		}
256		}
257		}
258	6	return isset($this->_taggedMap[$tag]);
259		}
260
261		/**
262		* Get a context specific element tagged with a given tag.
263		*
264		* @throws \LogicException If tag doesn't exists
265		*/
266	3	public function getTagged(int $tag): TaggedType
267		{
268	3	if (!$this->hasTagged($tag)) {
269	1	throw new \LogicException("No tagged element for tag {$tag}.");
270		}
271	2	return $this->_taggedMap[$tag];
272		}
273
274		/**
275		* @see \Countable::count()
276		*/
277	4	public function count(): int
278		{
279	4	return count($this->_elements);
280		}
281
282		/**
283		* Get an iterator for the `UnspecifiedElement` objects.
284		*
285		* @see \IteratorAggregate::getIterator()
286		*/
287	1	public function getIterator(): \ArrayIterator
288		{
289	1	return new \ArrayIterator($this->elements());
290		}
291
292		/**
293		* {@inheritdoc}
294		*/
295	35	protected function _encodedContentDER(): string
296		{
297	35	$data = '';
298	35	foreach ($this->_elements as $element) {
299	31	$data .= $element->toDER();
300		}
301	35	return $data;
302		}
303
304		/**
305		* {@inheritdoc}
306		*
307		* @return self
308		*/
309	43	protected static function _decodeFromDER(Identifier $identifier,
310		string $data, int &$offset): ElementBase
311		{
312	43	if (!$identifier->isConstructed()) {
313	2	throw new DecodeException(
314	2	'Structured element must have constructed bit set.');
315		}
316	41	$idx = $offset;
317	41	$length = Length::expectFromDER($data, $idx);
318	40	if ($length->isIndefinite()) {
319	24	$type = self::_decodeIndefiniteLength($data, $idx);
320		} else {
321	16	$type = self::_decodeDefiniteLength($data, $idx,
322	16	$length->intLength());
323		}
324	38	$offset = $idx;
325	38	return $type;
326		}
327
328		/**
329		* Decode elements for a definite length.
330		*
331		* @param string $data DER data
332		* @param int $offset Offset to data
333		* @param int $length Number of bytes to decode
334		*
335		* @throws DecodeException
336		*/
337	16	private static function _decodeDefiniteLength(string $data, int &$offset,
338		int $length): ElementBase
339		{
340	16	$idx = $offset;
341	16	$end = $idx + $length;
342	16	$elements = [];
343	16	while ($idx < $end) {
344	12	$elements[] = Element::fromDER($data, $idx);
345		// check that element didn't overflow length
346	12	if ($idx > $end) {
347	1	throw new DecodeException("Structure's content overflows length.");
348		}
349		}
350	15	$offset = $idx;
351		// return instance by static late binding
352	15	return new static(...$elements);
353		}
354
355		/**
356		* Decode elements for an indefinite length.
357		*
358		* @param string $data DER data
359		* @param int $offset Offset to data
360		*
361		* @throws DecodeException
362		*/
363	24	private static function _decodeIndefiniteLength(string $data, int &$offset): ElementBase
364		{
365	24	$idx = $offset;
366	24	$elements = [];
367	24	$end = strlen($data);
368	24	while (true) {
369	24	if ($idx >= $end) {
370	1	throw new DecodeException(
371	1	'Unexpected end of data while decoding indefinite length structure.');
372		}
373	24	$el = Element::fromDER($data, $idx);
374	24	if ($el->isType(self::TYPE_EOC)) {
375	23	break;
376		}
377	23	$elements[] = $el;
378		}
379	23	$offset = $idx;
380	23	$type = new static(...$elements);
381	23	$type->_indefiniteLength = true;
382	23	return $type;
383		}
384		}
385

sop / asn1

GitHub Access Token became invalid

Structure::withPrepended() A last analyzed 2025-01-08 14:01 UTC

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like

Structure::withPrepended() A
last analyzed 2025-01-08 14:01 UTC