Bech32::decodeSegwit() - 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 15:33 UTC

Bech32::decodeSegwit() C

↳ Parent: Bech32

Complexity

Conditions	7
Paths	7

Size

Total Lines	29
Code Lines	17

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	7
eloc	17
nc	7
nop	2
dl	0
loc	29
rs	6.7272
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 character in bech32 string");
            }

            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)
    {
        $programChars = array_values(unpack("C*", $witnessProgram->getProgram()->getBinary()));
        $programBits = self::convertBits($programChars, count($programChars), 8, 5);
        $encodeData = array_merge([$witnessProgram->getVersion()], $programBits);

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

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

Bit-Wasp / bitcoin-php

Pull Request — master (#503)

Bech32::decodeSegwit() C

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Duplication

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