Bech32::hrpExpand() - Code Metrics - Inspection of "Bech32: initial implementation and tests" - Bit-Wasp/bitcoin-php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#503)

by thomas

created 2017-08-05 14:56 UTC

Bech32::hrpExpand() A

↳ Parent: Bech32

Complexity

Conditions	2
Paths	2

Size

Total Lines	12
Code Lines	8

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	8
CRAP Score	2

Importance

Changes

Metric	Value
cc	2
eloc	8
nc	2
nop	2
dl	0
loc	12
ccs	8
cts	8
cp	1
crap	2
rs	9.4285
c	0
b	0
f	0

<?php

namespace BitWasp\Bitcoin;

use BitWasp\Bitcoin\Script\WitnessProgram;
use BitWasp\Buffertools\Buffer;

class Bech32
{
    protected static $CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";

    protected static $CHARSET_REV = [
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        15, -1, 10, 17, 21, 20, 26, 30,  7,  5, -1, -1, -1, -1, -1, -1,
        -1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
        1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1,
        -1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
        1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1
    ];

    /**
     * @param int[] $values
     * @param int $numValues
     * @return int
     */
    public static function polyMod(array $values, $numValues)
    {
        $generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3];
        $chk = 1;
        for ($i = 0; $i < $numValues; $i++) {
            $top = $chk >> 25;
            $chk = ($chk & 0x1ffffff) << 5 ^ $values[$i];

            for ($j = 0; $j < 5; $j++) {
                $value = (($top >> $j) & 1) ? $generator[$j] : 0;
                $chk ^= $value;
            }
        }

        return $chk;
    }

    /**
     * @param string $hrp
     * @param int $hrpLen
     * @return array
     */
    public static function hrpExpand($hrp, $hrpLen)
    {
        $expand1 = [];
        $expand2 = [];
        for ($i = 0; $i < $hrpLen; $i++) {
            $o = ord($hrp[$i]);
            $expand1[] = $o >> 5;
            $expand2[] = $o & 31;
        }

        return array_merge($expand1, [0], $expand2);
    }

    /**
     * @param string $hrp
     * @param int[] $convertedDataChars
     * @return bool
     */
    public static function verifyChecksum($hrp, array $convertedDataChars)
    {
        $expandHrp = self::hrpExpand($hrp, strlen($hrp));
        $r = array_merge($expandHrp, $convertedDataChars);
        $poly = self::polyMod($r, count($r));
        return $poly === 1;
    }

    /**
     * @param string $sBech
     * @return array
     */
    public static function decodeCheck($sBech)
    {
        $length = strlen($sBech);
        if ($length > 90) {
            throw new \RuntimeException("Bech32 string cannot exceed 90 characters in length");
        }

        $chars = array_values(unpack("C*", $sBech));

        $haveUpper = false;
        $haveLower = false;
        $positionOne = -1;

        for ($i = 0; $i < $length; $i++) {
            $x = $chars[$i];
            if ($x < 33 || $x > 126) {
                throw new \RuntimeException("Out of range value for bech");
            }

            if ($x >= 0x61 && $x <= 0x7a) {
                $haveLower = true;
            }

            if ($x >= 0x41 && $x <= 0x5a) {
                $haveUpper = true;
                $x = $chars[$i] = $x + 0x20;
            }

            // find location of last '1' character
            if ($x === 0x31) {
                $positionOne = $i;
            }
        }

        if ($haveUpper && $haveLower) {
            throw new \RuntimeException("Data contains mixture of higher/lower case characters");
        }

        if ($positionOne < 1 || ($positionOne + 7) > $length) {
            throw new \RuntimeException("Invalid location for '1' character");
        }

        $hrp = [];
        for ($i = 0; $i < $positionOne; $i++) {
            $hrp[$i] = chr($chars[$i]);
        }

        $hrp = implode("", $hrp);
        $data = [];
        for ($i = $positionOne + 1; $i < $length; $i++) {
            $data[] = ($chars[$i] & 0x80) ? -1 : self::$CHARSET_REV[$chars[$i]];
        }

        if (!self::verifyChecksum($hrp, $data)) {
            throw new \RuntimeException("Invalid bech32 checksum");
        }

        return [$hrp, array_slice($data, 0, -6)];
    }

    /**
     * @param array $data
     * @param int $inLen
     * @param int $fromBits
     * @param int $toBits
     * @param bool $pad
     * @return array
     */
    public static function convertBits(array $data, $inLen, $fromBits, $toBits, $pad = true)
    {
        $acc = 0;
        $bits = 0;
        $ret = [];
        $maxv = (1 << $toBits) - 1;
        $maxacc = (1 << ($fromBits + $toBits - 1)) - 1;

        for ($i = 0; $i < $inLen; $i++) {
            $value = $data[$i];
            if ($value < 0 || $value >> $fromBits) {
                throw new \InvalidArgumentException("Invalid value for convert bits");
            }

            $acc = (($acc << $fromBits) | $value) & $maxacc;
            $bits += $fromBits;

            while ($bits >= $toBits) {
                $bits -= $toBits;
                $ret[] = (($acc >> $bits) & $maxv);
            }
        }

        if ($pad) {
            if ($bits) {
                $ret[] = ($acc << $toBits - $bits) & $maxv;
            }
        } else if ($bits >= $fromBits || ((($acc << ($toBits - $bits))) & $maxv)) {
            throw new \RuntimeException("Invalid data");
        }

        return $ret;
    }

    /**
     * @param string $hrp
     * @param int[] $convertedDataChars
     * @return array
     */
    public static function createChecksum($hrp, array $convertedDataChars)
    {
        $values = array_merge(self::hrpExpand($hrp, strlen($hrp)), $convertedDataChars);
        $polyMod = self::polyMod(array_merge($values, [0, 0, 0, 0, 0, 0]), count($values) + 6) ^ 1;
        $results = [];
        for ($i = 0; $i < 6; $i++) {
            $results[$i] = ($polyMod >> 5 * (5 - $i)) & 31;
        }

        return $results;
    }

    /**
     * @param string $hrp
     * @param array $combinedDataChars
     * @return string
     */
    public static function encode($hrp, array $combinedDataChars)
    {
        $cs = self::createChecksum($hrp, $combinedDataChars);
        $combined = array_merge($combinedDataChars, $cs);
        $return = "{$hrp}1";
        for ($i = 0, $n = count($combined); $i < $n; $i++) {
            $return .= self::$CHARSET[$combined[$i]];
        }

        return $return;
    }

    /**
     * @param string $hrp
     * @param WitnessProgram $witnessProgram
     * @return string
     */
    public static function encodeSegwit($hrp, WitnessProgram $witnessProgram)
    {
        $prog = $witnessProgram->getProgram();
        $d = array_values(unpack("C*", $prog->getBinary()));
        $bits = self::convertBits($d, count($d), 8, 5);

        $data = array_merge(
            [$witnessProgram->getVersion()],
            $bits
        );

        return self::encode(
            $hrp,
            $data
        );
    }

    /**
     * @param string $hrp
     * @param string $bech32
     * @return WitnessProgram
     */
    public static function decodeSegwit($hrp, $bech32)
    {
        list ($hrpGot, $data) = self::decodeCheck($bech32);
        if ($hrpGot !== $hrp) {
            throw new \RuntimeException("Invalid prefix for address");
        }

        $decoded = self::convertBits(array_slice($data, 1), count($data) - 1, 5, 8, false);
        $decodeLen = count($decoded);
        if ($decodeLen < 2 || $decodeLen > 40) {
            throw new \RuntimeException("Invalid segwit address");
        }

        if ($data[0] > 16) {
            throw new \RuntimeException("Invalid witness program version");
        }

        $bytes = '';
        foreach ($decoded as $char) {
            $bytes .= chr($char);
        }
        $decoded = new Buffer($bytes);

        if (0 === $data[0]) {
            return WitnessProgram::v0($decoded);
        }

        return new WitnessProgram($data[0], $decoded);
    }
}


1		<?php
2
3		namespace BitWasp\Bitcoin;
4
5		use BitWasp\Bitcoin\Script\WitnessProgram;
6		use BitWasp\Buffertools\Buffer;
7
8		class Bech32
9		{
10		protected static $CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
11
12		protected static $CHARSET_REV = [
13		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
14		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
15		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
16		15, -1, 10, 17, 21, 20, 26, 30, 7, 5, -1, -1, -1, -1, -1, -1,
17		-1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
18		1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1,
19		-1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
20		1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1
21		];
22
23		/**
24		* @param int[] $values
25		* @param int $numValues
26		* @return int
27		*/
28	46	public static function polyMod(array $values, $numValues)
29		{
30	46	$generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3];
31	46	$chk = 1;
32	46	for ($i = 0; $i < $numValues; $i++) {
33	46	$top = $chk >> 25;
34	46	$chk = ($chk & 0x1ffffff) << 5 ^ $values[$i];
35
36	46	for ($j = 0; $j < 5; $j++) {
37	46	$value = (($top >> $j) & 1) ? $generator[$j] : 0;
38	46	$chk ^= $value;
39		}
40		}
41
42	46	return $chk;
43		}
44
45		/**
46		* @param string $hrp
47		* @param int $hrpLen
48		* @return array
49		*/
50	46	public static function hrpExpand($hrp, $hrpLen)
51		{
52	46	$expand1 = [];
53	46	$expand2 = [];
54	46	for ($i = 0; $i < $hrpLen; $i++) {
55	46	$o = ord($hrp[$i]);
56	46	$expand1[] = $o >> 5;
57	46	$expand2[] = $o & 31;
58		}
59
60	46	return array_merge($expand1, [0], $expand2);
61		}
62
63		/**
64		* @param string $hrp
65		* @param int[] $convertedDataChars
66		* @return bool
67		*/
68	46	public static function verifyChecksum($hrp, array $convertedDataChars)
69		{
70	46	$expandHrp = self::hrpExpand($hrp, strlen($hrp));
71	46	$r = array_merge($expandHrp, $convertedDataChars);
72	46	$poly = self::polyMod($r, count($r));
73	46	return $poly === 1;
74		}
75
76		/**
77		* @param string $sBech
78		* @return array
79		*/
80	48	public static function decodeCheck($sBech)
81		{
82	48	$length = strlen($sBech);
83	48	if ($length > 90) {
84		throw new \RuntimeException("Bech32 string cannot exceed 90 characters in length");
85		}
86
87	48	$chars = array_values(unpack("C*", $sBech));
88
89	48	$haveUpper = false;
90	48	$haveLower = false;
91	48	$positionOne = -1;
92
93	48	for ($i = 0; $i < $length; $i++) {
94	48	$x = $chars[$i];
95	48	if ($x < 33 \|\| $x > 126) {
96		throw new \RuntimeException("Out of range value for bech");
97		}
98
99	48	if ($x >= 0x61 && $x <= 0x7a) {
100	38	$haveLower = true;
101		}
102
103	48	if ($x >= 0x41 && $x <= 0x5a) {
104	12	$haveUpper = true;
105	12	$x = $chars[$i] = $x + 0x20;
106		}
107
108		// find location of last '1' character
109	48	if ($x === 0x31) {
110	48	$positionOne = $i;
111		}
112		}
113
114	48	if ($haveUpper && $haveLower) {
115	2	throw new \RuntimeException("Data contains mixture of higher/lower case characters");
116		}
117
118	46	if ($positionOne < 1 \|\| ($positionOne + 7) > $length) {
119		throw new \RuntimeException("Invalid location for '1' character");
120		}
121
122	46	$hrp = [];
123	46	for ($i = 0; $i < $positionOne; $i++) {
124	46	$hrp[$i] = chr($chars[$i]);
125		}
126
127	46	$hrp = implode("", $hrp);
128	46	$data = [];
129	46	for ($i = $positionOne + 1; $i < $length; $i++) {
130	46	$data[] = ($chars[$i] & 0x80) ? -1 : self::$CHARSET_REV[$chars[$i]];
131		}
132
133	46	if (!self::verifyChecksum($hrp, $data)) {
134	12	throw new \RuntimeException("Invalid bech32 checksum");
135		}
136
137	44	return [$hrp, array_slice($data, 0, -6)];
138		}
139
140		/**
141		* @param array $data
142		* @param int $inLen
143		* @param int $fromBits
144		* @param int $toBits
145		* @param bool $pad
146		* @return array
147		*/
148	32	public static function convertBits(array $data, $inLen, $fromBits, $toBits, $pad = true)
149		{
150	32	$acc = 0;
151	32	$bits = 0;
152	32	$ret = [];
153	32	$maxv = (1 << $toBits) - 1;
154	32	$maxacc = (1 << ($fromBits + $toBits - 1)) - 1;
155
156	32	for ($i = 0; $i < $inLen; $i++) {
157	32	$value = $data[$i];
158	32	if ($value < 0 \|\| $value >> $fromBits) {
159		throw new \InvalidArgumentException("Invalid value for convert bits");
160		}
161
162	32	$acc = (($acc << $fromBits) \| $value) & $maxacc;
163	32	$bits += $fromBits;
164
165	32	while ($bits >= $toBits) {
166	32	$bits -= $toBits;
167	32	$ret[] = (($acc >> $bits) & $maxv);
168		}
169		}
170
171	32	if ($pad) {
172	12	if ($bits) {
173	12	$ret[] = ($acc << $toBits - $bits) & $maxv;
174		}
175	32	} else if ($bits >= $fromBits \|\| ((($acc << ($toBits - $bits))) & $maxv)) {
176	4	throw new \RuntimeException("Invalid data");
177		}
178
179	28	return $ret;
180		}
181
182		/**
183		* @param string $hrp
184		* @param int[] $convertedDataChars
185		* @return array
186		*/
187	12	public static function createChecksum($hrp, array $convertedDataChars)
188		{
189	12	$values = array_merge(self::hrpExpand($hrp, strlen($hrp)), $convertedDataChars);
190	12	$polyMod = self::polyMod(array_merge($values, [0, 0, 0, 0, 0, 0]), count($values) + 6) ^ 1;
191	12	$results = [];
192	12	for ($i = 0; $i < 6; $i++) {
193	12	$results[$i] = ($polyMod >> 5 * (5 - $i)) & 31;
194		}
195
196	12	return $results;
197		}
198
199		/**
200		* @param string $hrp
201		* @param array $combinedDataChars
202		* @return string
203		*/
204	12	public static function encode($hrp, array $combinedDataChars)
205		{
206	12	$cs = self::createChecksum($hrp, $combinedDataChars);
207	12	$combined = array_merge($combinedDataChars, $cs);
208	12	$return = "{$hrp}1";
209	12	for ($i = 0, $n = count($combined); $i < $n; $i++) {
210	12	$return .= self::$CHARSET[$combined[$i]];
211		}
212
213	12	return $return;
214		}
215
216		/**
217		* @param string $hrp
218		* @param WitnessProgram $witnessProgram
219		* @return string
220		*/
221	12	public static function encodeSegwit($hrp, WitnessProgram $witnessProgram)
222		{
223	12	$prog = $witnessProgram->getProgram();
224	12	$d = array_values(unpack("C*", $prog->getBinary()));
225	12	$bits = self::convertBits($d, count($d), 8, 5);
226
227	12	$data = array_merge(
228	12	[$witnessProgram->getVersion()],
229		$bits
230		);
231
232	12	return self::encode(
233		$hrp,
234		$data
235		);
236		}
237
238		/**
239		* @param string $hrp
240		* @param string $bech32
241		* @return WitnessProgram
242		*/
243	38	public static function decodeSegwit($hrp, $bech32)
244		{
245	38	list ($hrpGot, $data) = self::decodeCheck($bech32);
246	34	if ($hrpGot !== $hrp) {
247	14	throw new \RuntimeException("Invalid prefix for address");
248		}
249
250	32	$decoded = self::convertBits(array_slice($data, 1), count($data) - 1, 5, 8, false);
251	28	$decodeLen = count($decoded);
252	28	if ($decodeLen < 2 \|\| $decodeLen > 40) {
253	4	throw new \RuntimeException("Invalid segwit address");
254		}
255
256	24	if ($data[0] > 16) {
257	2	throw new \RuntimeException("Invalid witness program version");
258		}
259
260	22	$bytes = '';
261	22	foreach ($decoded as $char) {
262	22	$bytes .= chr($char);
263		}
264	22	$decoded = new Buffer($bytes);
265
266	22	if (0 === $data[0]) {
267	16	return WitnessProgram::v0($decoded);
268		}
269
270	6	return new WitnessProgram($data[0], $decoded);
271		}
272		}
273

Bit-Wasp / bitcoin-php

Pull Request — master (#503)

Bech32::hrpExpand() A

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