Identifier::intTag() - Code Metrics - Inspection of "Delegate large integer handling to own class" - sop/asn1 - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 9bb5cc...d08348 )

by Joni

created 2017-11-07 06:40 UTC

Identifier::intTag() A

↳ Parent: Identifier

Complexity

Conditions	1
Paths	1

Size

Total Lines	4
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

Metric	Value
dl	0
loc	4
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

declare(strict_types = 1);

namespace ASN1\Component;

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

/**
 * 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 = [ /* @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 BigInt
     */
    private $_tag;
    
    /**
     * Constructor.
     *
     * @param int $class Type class
     * @param int $pc Primitive / Constructed
     * @param int|string $tag Type tag number
     */
    public function __construct(int $class, int $pc, $tag)
    {
        $this->_class = 0b11 & $class;
        $this->_pc = 0b1 & $pc;
        $this->_tag = new BigInt($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(string $data, int &$offset = null): self
    {
        $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 string Tag number
     */
    private static function _decodeLongFormTag(string $data, int &$offset): string
    {
        $datalen = strlen($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(): string
    {
        $bytes = [];
        $byte = $this->_class << 6 | $this->_pc << 5;
        $tag = $this->_tag->gmpObj();
        if ($tag < 0x1f) {
            $bytes[] = $byte | $tag;
        } else { // long-form identifier
            $bytes[] = $byte | 0x1f;
            $octets = [];
            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(): int
    {
        return $this->_class;
    }
    
    /**
     * Get P/C.
     *
     * @return int
     */
    public function pc(): int
    {
        return $this->_pc;
    }
    
    /**
     * Get the tag number.
     *
     * @return string Base 10 integer string
     */
    public function tag(): string
    {
        return $this->_tag->base10();
    }
    
    /**
     * Get the tag as an integer.
     *
     * @return int
     */
    public function intTag(): int
    {
        return $this->_tag->intVal();
    }
    
    /**
     * Check whether type is of an universal class.
     *
     * @return boolean
     */
    public function isUniversal(): bool
    {
        return self::CLASS_UNIVERSAL == $this->_class;
    }
    
    /**
     * Check whether type is of an application class.
     *
     * @return boolean
     */
    public function isApplication(): bool
    {
        return self::CLASS_APPLICATION == $this->_class;
    }
    
    /**
     * Check whether type is of a context specific class.
     *
     * @return boolean
     */
    public function isContextSpecific(): bool
    {
        return self::CLASS_CONTEXT_SPECIFIC == $this->_class;
    }
    
    /**
     * Check whether type is of a private class.
     *
     * @return boolean
     */
    public function isPrivate(): bool
    {
        return self::CLASS_PRIVATE == $this->_class;
    }
    
    /**
     * Check whether content is primitive type.
     *
     * @return boolean
     */
    public function isPrimitive(): bool
    {
        return self::PRIMITIVE == $this->_pc;
    }
    
    /**
     * Check hether content is constructed type.
     *
     * @return boolean
     */
    public function isConstructed(): bool
    {
        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(int $class): self
    {
        $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): self
    {
        $obj = clone $this;
        $obj->_tag = new BigInt($tag);
        return $obj;
    }
    
    /**
     * Get human readable name of the type class.
     *
     * @param int $class
     * @return string
     */
    public static function classToName(int $class): string
    {
        if (!array_key_exists($class, self::MAP_CLASS_TO_NAME)) {
            return "CLASS $class";
        }
        return self::MAP_CLASS_TO_NAME[$class];
    }
}


1		<?php
2
3		declare(strict_types = 1);
4
5		namespace ASN1\Component;
6
7		use ASN1\Exception\DecodeException;
8		use ASN1\Feature\Encodable;
9		use ASN1\Util\BigInt;
10
11		/**
12		* Class to represent BER/DER identifier octets.
13		*/
14		class Identifier implements Encodable
15		{
16		// Type class enumerations
17		const CLASS_UNIVERSAL = 0b00;
18		const CLASS_APPLICATION = 0b01;
19		const CLASS_CONTEXT_SPECIFIC = 0b10;
20		const CLASS_PRIVATE = 0b11;
21
22		/**
23		* Mapping from type class to human readable name.
24		*
25		* @internal
26		*
27		* @var array
28		*/
29		const MAP_CLASS_TO_NAME = [ /* @formatter:off */
30		self::CLASS_UNIVERSAL => "UNIVERSAL",
31		self::CLASS_APPLICATION => "APPLICATION",
32		self::CLASS_CONTEXT_SPECIFIC => "CONTEXT SPECIFIC",
33		self::CLASS_PRIVATE => "PRIVATE",
34		/* @formatter:on */
35		];
36
37		// P/C enumerations
38		const PRIMITIVE = 0b0;
39		const CONSTRUCTED = 0b1;
40
41		/**
42		* Type class.
43		*
44		* @var int
45		*/
46		private $_class;
47
48		/**
49		* Primitive or Constructed.
50		*
51		* @var int
52		*/
53		private $_pc;
54
55		/**
56		* Content type tag.
57		*
58		* @var BigInt
59		*/
60		private $_tag;
61
62		/**
63		* Constructor.
64		*
65		* @param int $class Type class
66		* @param int $pc Primitive / Constructed
67		* @param int\|string $tag Type tag number
68		*/
69	315	public function __construct(int $class, int $pc, $tag)
70		{
71	315	$this->_class = 0b11 & $class;
72	315	$this->_pc = 0b1 & $pc;
73	315	$this->_tag = new BigInt($tag);
74	315	}
75
76		/**
77		* Decode identifier component from DER data.
78		*
79		* @param string $data DER encoded data
80		* @param int\|null $offset Reference to the variable that contains offset
81		* into the data where to start parsing. Variable is updated to
82		* the offset next to the parsed identifier. If null, start from
83		* offset 0.
84		* @throws DecodeException If decoding fails
85		* @return self
86		*/
87	217	public static function fromDER(string $data, int &$offset = null): self
88		{
89	217	$idx = $offset ? $offset : 0;
90	217	$datalen = strlen($data);
91	217	if ($idx >= $datalen) {
92	1	throw new DecodeException("Invalid offset.");
93		}
94	216	$byte = ord($data[$idx++]);
95		// 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...
96		// 0 = universal, 1 = application, 2 = context-specific, 3 = private
97	216	$class = (0b11000000 & $byte) >> 6;
98		// bit 6 (0 = primitive / 1 = constructed)
99	216	$pc = (0b00100000 & $byte) >> 5;
100		// bits 5 to 1 (tag number)
101	216	$tag = (0b00011111 & $byte);
102		// long-form identifier
103	216	if (0x1f == $tag) {
104	8	$tag = self::_decodeLongFormTag($data, $idx);
105		}
106	215	if (isset($offset)) {
107	201	$offset = $idx;
108		}
109	215	return new self($class, $pc, $tag);
110		}
111
112		/**
113		* Parse long form tag.
114		*
115		* @param string $data DER data
116		* @param int $offset Reference to the variable containing offset to data
117		* @throws DecodeException If decoding fails
118		* @return string Tag number
119		*/
120	8	private static function _decodeLongFormTag(string $data, int &$offset): string
121		{
122	8	$datalen = strlen($data);
123	8	$tag = gmp_init(0, 10);
124	8	while (true) {
125	8	if ($offset >= $datalen) {
126	1	throw new DecodeException(
127		"Unexpected end of data while decoding" .
128	1	" long form identifier.");
129		}
130	8	$byte = ord($data[$offset++]);
131	8	$tag <<= 7;
132	8	$tag \|= 0x7f & $byte;
133		// last byte has bit 8 set to zero
134	8	if (!(0x80 & $byte)) {
135	7	break;
136		}
137		}
138	7	return gmp_strval($tag, 10);
139		}
140
141		/**
142		*
143		* @see Encodable::toDER()
144		* @return string
145		*/
146	117	public function toDER(): string
147		{
148	117	$bytes = [];
149	117	$byte = $this->_class << 6 \| $this->_pc << 5;
150	117	$tag = $this->_tag->gmpObj();
151	117	if ($tag < 0x1f) {
152	114	$bytes[] = $byte \| $tag;
153		} else { // long-form identifier
154	4	$bytes[] = $byte \| 0x1f;
155	4	$octets = [];
156	4	for (; $tag > 0; $tag >>= 7) {
157	4	array_push($octets, gmp_intval(0x80 \| ($tag & 0x7f)));
158		}
159		// last octet has bit 8 set to zero
160	4	$octets[0] &= 0x7f;
161	4	foreach (array_reverse($octets) as $octet) {
162	4	$bytes[] = $octet;
163		}
164		}
165	117	return pack("C*", ...$bytes);
166		}
167
168		/**
169		* Get class of the type.
170		*
171		* @return int
172		*/
173	6	public function typeClass(): int
174		{
175	6	return $this->_class;
176		}
177
178		/**
179		* Get P/C.
180		*
181		* @return int
182		*/
183	1	public function pc(): int
184		{
185	1	return $this->_pc;
186		}
187
188		/**
189		* Get the tag number.
190		*
191		* @return string Base 10 integer string
192		*/
193	203	public function tag(): string
194		{
195	203	return $this->_tag->base10();
196		}
197
198		/**
199		* Get the tag as an integer.
200		*
201		* @return int
202		*/
203	2	public function intTag(): int
204		{
205	2	return $this->_tag->intVal();
206		}
207
208		/**
209		* Check whether type is of an universal class.
210		*
211		* @return boolean
212		*/
213	186	public function isUniversal(): bool
214		{
215	186	return self::CLASS_UNIVERSAL == $this->_class;
216		}
217
218		/**
219		* Check whether type is of an application class.
220		*
221		* @return boolean
222		*/
223	1	public function isApplication(): bool
224		{
225	1	return self::CLASS_APPLICATION == $this->_class;
226		}
227
228		/**
229		* Check whether type is of a context specific class.
230		*
231		* @return boolean
232		*/
233	194	public function isContextSpecific(): bool
234		{
235	194	return self::CLASS_CONTEXT_SPECIFIC == $this->_class;
236		}
237
238		/**
239		* Check whether type is of a private class.
240		*
241		* @return boolean
242		*/
243	1	public function isPrivate(): bool
244		{
245	1	return self::CLASS_PRIVATE == $this->_class;
246		}
247
248		/**
249		* Check whether content is primitive type.
250		*
251		* @return boolean
252		*/
253	79	public function isPrimitive(): bool
254		{
255	79	return self::PRIMITIVE == $this->_pc;
256		}
257
258		/**
259		* Check hether content is constructed type.
260		*
261		* @return boolean
262		*/
263	23	public function isConstructed(): bool
264		{
265	23	return self::CONSTRUCTED == $this->_pc;
266		}
267
268		/**
269		* Get self with given type class.
270		*
271		* @param int $class One of <code>CLASS_*</code> enumerations
272		* @return self
273		*/
274	6	public function withClass(int $class): self
275		{
276	6	$obj = clone $this;
277	6	$obj->_class = $class;
278	6	return $obj;
279		}
280
281		/**
282		* Get self with given type tag.
283		*
284		* @param int\|string $tag Tag number
285		* @return self
286		*/
287	6	public function withTag($tag): self
288		{
289	6	$obj = clone $this;
290	6	$obj->_tag = new BigInt($tag);
291	6	return $obj;
292		}
293
294		/**
295		* Get human readable name of the type class.
296		*
297		* @param int $class
298		* @return string
299		*/
300	8	public static function classToName(int $class): string
301		{
302	8	if (!array_key_exists($class, self::MAP_CLASS_TO_NAME)) {
303	1	return "CLASS $class";
304		}
305	7	return self::MAP_CLASS_TO_NAME[$class];
306		}
307		}
308

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Identifier::intTag() A

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