Identifier::tag() - Code Metrics - Inspection of "Reduce complexity" - sop/asn1 - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( a25647...c0e57f )

by Joni

created 2016-06-03 08:40 UTC

Identifier::tag() A

↳ Parent: Identifier

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

Metric	Value
dl	0
loc	3
ccs	2
cts	2
cp	1
rs	10
c	0
b	0
f	0
cc	1
eloc	2
nc	1
nop	0
crap	1

<?php

namespace ASN1\Component;

use ASN1\Exception\DecodeException;
use ASN1\Feature\Encodable;


/**
 * Class to represent BER/DER identifier octets.
 */
class Identifier implements Encodable
{
	// Type class enumerations
	const CLASS_UNIVERSAL = 0b00;
	const CLASS_APPLICATION = 0b01;
	const CLASS_CONTEXT_SPECIFIC = 0b10;
	const CLASS_PRIVATE = 0b11;
	
	/**
	 * Mapping from type class to human readable name.
	 *
	 * @internal
	 *
	 * @var array
	 */
	const MAP_CLASS_TO_NAME = array(
		/* @formatter:off */
		self::CLASS_UNIVERSAL => "UNIVERSAL", 
		self::CLASS_APPLICATION => "APPLICATION", 
		self::CLASS_CONTEXT_SPECIFIC => "CONTEXT SPECIFIC", 
		self::CLASS_PRIVATE => "PRIVATE"
		/* @formatter:on */
	);
	
	// P/C enumerations
	const PRIMITIVE = 0b0;
	const CONSTRUCTED = 0b1;
	
	/**
	 * Type class.
	 *
	 * @var int
	 */
	private $_class;
	
	/**
	 * Primitive or Constructed.
	 *
	 * @var int
	 */
	private $_pc;
	
	/**
	 * Content type tag.
	 *
	 * @var int|string
	 */
	private $_tag;
	
	/**
	 * Constructor
	 *
	 * @param int $class Type class
	 * @param int $pc Privitive / Constructed
	 * @param int|string $tag Type tag number
	 */
	public function __construct($class, $pc, $tag) {
		$this->_class = 0b11 & $class;
		$this->_pc = 0b1 & $pc;
		$this->_tag = $tag;
	}
	
	/**
	 * Decode identifier component from DER data.
	 *
	 * @param string $data DER encoded data
	 * @param int|null $offset Reference to the variable that contains offset
	 *        into the data where to start parsing. Variable is updated to
	 *        the offset next to the parsed identifier. If null, start from
	 *        offset 0.
	 * @throws DecodeException If decoding fails
	 * @return self
	 */
	public static function fromDER($data, &$offset = null) {
		assert('is_string($data)', "got " . gettype($data));
		$idx = $offset ? $offset : 0;
		$datalen = strlen($data);
		if ($idx >= $datalen) {
			throw new DecodeException("Invalid offset.");
		}
		$byte = ord($data[$idx++]);
		// bits 8 and 7 (class)

		// 0 = universal, 1 = application, 2 = context-specific, 3 = private
		$class = (0b11000000 & $byte) >> 6;
		// bit 6 (0 = primitive / 1 = constructed)
		$pc = (0b00100000 & $byte) >> 5;
		// bits 5 to 1 (tag number)
		$tag = (0b00011111 & $byte);
		// long-form identifier
		if (0x1f == $tag) {
			$tag = self::_decodeLongFormTag($data, $idx);
		}
		if (isset($offset)) {
			$offset = $idx;
		}
		return new self($class, $pc, $tag);
	}
	
	/**
	 * Parse long form tag.
	 *
	 * @param string $data DER data
	 * @param int $offset Reference to the variable containing offset to data
	 * @throws DecodeException If decoding fails
	 * @return int|string Tag number
	 */
	private static function _decodeLongFormTag($data, &$offset) {
		$datalen = strlen($data);
		$tag = gmp_init(0, 10);
		while (true) {
			if ($offset >= $datalen) {
				throw new DecodeException(
					"Unexpected end of data while decoding" .
						 " long form identifier.");
			}
			$byte = ord($data[$offset++]);
			$tag <<= 7;
			$tag |= 0x7f & $byte;
			// last byte has bit 8 set to zero
			if (!(0x80 & $byte)) {
				break;
			}
		}
		return gmp_strval($tag, 10);
	}
	
	/**
	 *
	 * @see Encodable::toDER()
	 * @return string
	 */
	public function toDER() {
		$bytes = array();
		$byte = $this->_class << 6 | $this->_pc << 5;
		$tag = gmp_init($this->_tag, 10);
		if ($tag < 0x1f) {
			$bytes[] = $byte | $tag;
		} else { // long-form identifier
			$bytes[] = $byte | 0x1f;
			$octets = array();
			for (; $tag > 0; $tag >>= 7) {
				array_push($octets, gmp_intval(0x80 | ($tag & 0x7f)));
			}
			// last octet has bit 8 set to zero
			$octets[0] &= 0x7f;
			foreach (array_reverse($octets) as $octet) {
				$bytes[] = $octet;
			}
		}
		return pack("C*", ...$bytes);
	}
	
	/**
	 * Get class of the type.
	 *
	 * @return int
	 */
	public function typeClass() {
		return $this->_class;
	}
	
	/**
	 * Get P/C.
	 *
	 * @return int
	 */
	public function pc() {
		return $this->_pc;
	}
	
	/**
	 * Get the tag number.
	 *
	 * @return int|string
	 */
	public function tag() {
		return $this->_tag;
	}
	
	/**
	 * Check whether type is of an universal class.
	 *
	 * @return boolean
	 */
	public function isUniversal() {
		return self::CLASS_UNIVERSAL == $this->_class;
	}
	
	/**
	 * Check whether type is of an application class.
	 *
	 * @return boolean
	 */
	public function isApplication() {
		return self::CLASS_APPLICATION == $this->_class;
	}
	
	/**
	 * Check whether type is of a context specific class.
	 *
	 * @return boolean
	 */
	public function isContextSpecific() {
		return self::CLASS_CONTEXT_SPECIFIC == $this->_class;
	}
	
	/**
	 * Check whether type is of a private class.
	 *
	 * @return boolean
	 */
	public function isPrivate() {
		return self::CLASS_PRIVATE == $this->_class;
	}
	
	/**
	 * Check whether content is primitive type.
	 *
	 * @return boolean
	 */
	public function isPrimitive() {
		return self::PRIMITIVE == $this->_pc;
	}
	
	/**
	 * Check hether content is constructed type.
	 *
	 * @return boolean
	 */
	public function isConstructed() {
		return self::CONSTRUCTED == $this->_pc;
	}
	
	/**
	 * Get self with given type class.
	 *
	 * @param int $class One of <code>CLASS_*</code> enumerations
	 * @return self
	 */
	public function withClass($class) {
		$obj = clone $this;
		$obj->_class = $class;
		return $obj;
	}
	
	/**
	 * Get self with given type tag.
	 *
	 * @param int|string $tag Tag number
	 * @return self
	 */
	public function withTag($tag) {
		$obj = clone $this;
		$obj->_tag = $tag;
		return $obj;
	}
	
	/**
	 * Get human readable name of the type class.
	 *
	 * @param int $class
	 * @return string
	 */
	public static function classToName($class) {
		if (!array_key_exists($class, self::MAP_CLASS_TO_NAME)) {
			return "CLASS $class";
		}
		return self::MAP_CLASS_TO_NAME[$class];
	}
}


1		<?php
2
3		namespace ASN1\Component;
4
5		use ASN1\Exception\DecodeException;
6		use ASN1\Feature\Encodable;
7
8
9		/**
10		* Class to represent BER/DER identifier octets.
11		*/
12		class Identifier implements Encodable
13		{
14		// Type class enumerations
15		const CLASS_UNIVERSAL = 0b00;
16		const CLASS_APPLICATION = 0b01;
17		const CLASS_CONTEXT_SPECIFIC = 0b10;
18		const CLASS_PRIVATE = 0b11;
19
20		/**
21		* Mapping from type class to human readable name.
22		*
23		* @internal
24		*
25		* @var array
26		*/
27		const MAP_CLASS_TO_NAME = array(
28		/* @formatter:off */
29		self::CLASS_UNIVERSAL => "UNIVERSAL",
30		self::CLASS_APPLICATION => "APPLICATION",
31		self::CLASS_CONTEXT_SPECIFIC => "CONTEXT SPECIFIC",
32		self::CLASS_PRIVATE => "PRIVATE"
33		/* @formatter:on */
34		);
35
36		// P/C enumerations
37		const PRIMITIVE = 0b0;
38		const CONSTRUCTED = 0b1;
39
40		/**
41		* Type class.
42		*
43		* @var int
44		*/
45		private $_class;
46
47		/**
48		* Primitive or Constructed.
49		*
50		* @var int
51		*/
52		private $_pc;
53
54		/**
55		* Content type tag.
56		*
57		* @var int\|string
58		*/
59		private $_tag;
60
61		/**
62		* Constructor
63		*
64		* @param int $class Type class
65		* @param int $pc Privitive / Constructed
66		* @param int\|string $tag Type tag number
67		*/
68	313	public function __construct($class, $pc, $tag) {
69	313	$this->_class = 0b11 & $class;
70	313	$this->_pc = 0b1 & $pc;
71	313	$this->_tag = $tag;
72	313	}
73
74		/**
75		* Decode identifier component from DER data.
76		*
77		* @param string $data DER encoded data
78		* @param int\|null $offset Reference to the variable that contains offset
79		* into the data where to start parsing. Variable is updated to
80		* the offset next to the parsed identifier. If null, start from
81		* offset 0.
82		* @throws DecodeException If decoding fails
83		* @return self
84		*/
85	216	public static function fromDER($data, &$offset = null) {
86	216	assert('is_string($data)', "got " . gettype($data));
87	215	$idx = $offset ? $offset : 0;
88	215	$datalen = strlen($data);
89	215	if ($idx >= $datalen) {
90	1	throw new DecodeException("Invalid offset.");
91		}
92	214	$byte = ord($data[$idx++]);
93		// bits 8 and 7 (class)
		0 ignored issues – show Unused Code Comprehensibility introduced 2016-06-01 07:43 UTC by Report Bug Copy Issue Report `50%` of this comment could be valid code. Did you maybe forget this after debugging? Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it. The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production. This check looks for comments that seem to be mostly valid code and reports them. Loading history...
94		// 0 = universal, 1 = application, 2 = context-specific, 3 = private
95	214	$class = (0b11000000 & $byte) >> 6;
96		// bit 6 (0 = primitive / 1 = constructed)
97	214	$pc = (0b00100000 & $byte) >> 5;
98		// bits 5 to 1 (tag number)
99	214	$tag = (0b00011111 & $byte);
100		// long-form identifier
101	214	if (0x1f == $tag) {
102	7	$tag = self::_decodeLongFormTag($data, $idx);
103	6	}
104	213	if (isset($offset)) {
105	201	$offset = $idx;
106	201	}
107	213	return new self($class, $pc, $tag);
108		}
109
110		/**
111		* Parse long form tag.
112		*
113		* @param string $data DER data
114		* @param int $offset Reference to the variable containing offset to data
115		* @throws DecodeException If decoding fails
116		* @return int\|string Tag number
117		*/
118	7	private static function _decodeLongFormTag($data, &$offset) {
119	7	$datalen = strlen($data);
120	7	$tag = gmp_init(0, 10);
121	7	while (true) {
122	7	if ($offset >= $datalen) {
123	1	throw new DecodeException(
124		"Unexpected end of data while decoding" .
125	1	" long form identifier.");
126		}
127	7	$byte = ord($data[$offset++]);
128	7	$tag <<= 7;
129	7	$tag \|= 0x7f & $byte;
130		// last byte has bit 8 set to zero
131	7	if (!(0x80 & $byte)) {
132	6	break;
133		}
134	3	}
135	6	return gmp_strval($tag, 10);
136		}
137
138		/**
139		*
140		* @see Encodable::toDER()
141		* @return string
142		*/
143	117	public function toDER() {
144	117	$bytes = array();
145	117	$byte = $this->_class << 6 \| $this->_pc << 5;
146	117	$tag = gmp_init($this->_tag, 10);
147	117	if ($tag < 0x1f) {
148	114	$bytes[] = $byte \| $tag;
149	114	} else { // long-form identifier
150	4	$bytes[] = $byte \| 0x1f;
151	4	$octets = array();
152	4	for (; $tag > 0; $tag >>= 7) {
153	4	array_push($octets, gmp_intval(0x80 \| ($tag & 0x7f)));
154	4	}
155		// last octet has bit 8 set to zero
156	4	$octets[0] &= 0x7f;
157	4	foreach (array_reverse($octets) as $octet) {
158	4	$bytes[] = $octet;
159	4	}
160		}
161	117	return pack("C*", ...$bytes);
162		}
163
164		/**
165		* Get class of the type.
166		*
167		* @return int
168		*/
169	6	public function typeClass() {
170	6	return $this->_class;
171		}
172
173		/**
174		* Get P/C.
175		*
176		* @return int
177		*/
178	1	public function pc() {
179	1	return $this->_pc;
180		}
181
182		/**
183		* Get the tag number.
184		*
185		* @return int\|string
186		*/
187	203	public function tag() {
188	203	return $this->_tag;
189		}
190
191		/**
192		* Check whether type is of an universal class.
193		*
194		* @return boolean
195		*/
196	186	public function isUniversal() {
197	186	return self::CLASS_UNIVERSAL == $this->_class;
198		}
199
200		/**
201		* Check whether type is of an application class.
202		*
203		* @return boolean
204		*/
205	1	public function isApplication() {
206	1	return self::CLASS_APPLICATION == $this->_class;
207		}
208
209		/**
210		* Check whether type is of a context specific class.
211		*
212		* @return boolean
213		*/
214	194	public function isContextSpecific() {
215	194	return self::CLASS_CONTEXT_SPECIFIC == $this->_class;
216		}
217
218		/**
219		* Check whether type is of a private class.
220		*
221		* @return boolean
222		*/
223	1	public function isPrivate() {
224	1	return self::CLASS_PRIVATE == $this->_class;
225		}
226
227		/**
228		* Check whether content is primitive type.
229		*
230		* @return boolean
231		*/
232	79	public function isPrimitive() {
233	79	return self::PRIMITIVE == $this->_pc;
234		}
235
236		/**
237		* Check hether content is constructed type.
238		*
239		* @return boolean
240		*/
241	23	public function isConstructed() {
242	23	return self::CONSTRUCTED == $this->_pc;
243		}
244
245		/**
246		* Get self with given type class.
247		*
248		* @param int $class One of <code>CLASS_*</code> enumerations
249		* @return self
250		*/
251	6	public function withClass($class) {
252	6	$obj = clone $this;
253	6	$obj->_class = $class;
254	6	return $obj;
255		}
256
257		/**
258		* Get self with given type tag.
259		*
260		* @param int\|string $tag Tag number
261		* @return self
262		*/
263	6	public function withTag($tag) {
264	6	$obj = clone $this;
265	6	$obj->_tag = $tag;
266	6	return $obj;
267		}
268
269		/**
270		* Get human readable name of the type class.
271		*
272		* @param int $class
273		* @return string
274		*/
275	8	public static function classToName($class) {
276	8	if (!array_key_exists($class, self::MAP_CLASS_TO_NAME)) {
277	1	return "CLASS $class";
278		}
279	7	return self::MAP_CLASS_TO_NAME[$class];
280		}
281		}
282

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Identifier::tag() A

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