Complex classes like InputSigner often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use InputSigner, and based on these observations, apply Extract Interface, too.
1 | <?php |
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35 | class InputSigner |
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36 | { |
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37 | /** |
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38 | * @var array |
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39 | */ |
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40 | protected static $canSign = [ |
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41 | ScriptType::P2PKH, |
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42 | ScriptType::P2PK, |
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43 | ScriptType::MULTISIG |
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44 | ]; |
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45 | |||
46 | /** |
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47 | * @var array |
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48 | */ |
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49 | protected static $validP2sh = [ |
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50 | ScriptType::P2WKH, |
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51 | ScriptType::P2WSH, |
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52 | ScriptType::P2PKH, |
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53 | ScriptType::P2PK, |
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54 | ScriptType::MULTISIG |
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55 | ]; |
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56 | |||
57 | /** |
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58 | * @var EcAdapterInterface |
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59 | */ |
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60 | private $ecAdapter; |
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61 | |||
62 | /** |
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63 | * @var OutputData $scriptPubKey |
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64 | */ |
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65 | private $scriptPubKey; |
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66 | |||
67 | /** |
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68 | * @var OutputData $redeemScript |
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69 | */ |
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70 | private $redeemScript; |
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71 | |||
72 | /** |
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73 | * @var OutputData $witnessScript |
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74 | */ |
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75 | private $witnessScript; |
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76 | |||
77 | /** |
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78 | * @var OutputData |
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79 | */ |
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80 | private $signScript; |
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81 | |||
82 | /** |
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83 | * @var int |
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84 | */ |
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85 | private $sigVersion; |
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86 | |||
87 | /** |
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88 | * @var OutputData $witnessKeyHash |
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89 | */ |
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90 | private $witnessKeyHash; |
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91 | |||
92 | /** |
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93 | * @var TransactionInterface |
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94 | */ |
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95 | private $tx; |
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96 | |||
97 | /** |
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98 | * @var int |
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99 | */ |
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100 | private $nInput; |
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101 | |||
102 | /** |
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103 | * @var TransactionOutputInterface |
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104 | */ |
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105 | private $txOut; |
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106 | |||
107 | /** |
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108 | * @var PublicKeyInterface[] |
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109 | */ |
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110 | private $publicKeys = []; |
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111 | |||
112 | /** |
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113 | * @var TransactionSignatureInterface[] |
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114 | */ |
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115 | private $signatures = []; |
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116 | |||
117 | /** |
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118 | * @var int |
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119 | */ |
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120 | private $requiredSigs = 0; |
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121 | |||
122 | /** |
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123 | * @var Interpreter |
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124 | */ |
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125 | private $interpreter; |
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126 | |||
127 | /** |
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128 | * @var Checker |
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129 | */ |
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130 | private $signatureChecker; |
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131 | |||
132 | /** |
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133 | * @var TransactionSignatureSerializer |
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134 | */ |
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135 | private $txSigSerializer; |
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136 | |||
137 | /** |
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138 | * @var PublicKeySerializerInterface |
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139 | */ |
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140 | private $pubKeySerializer; |
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141 | |||
142 | /** |
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143 | * InputSigner constructor. |
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144 | * @param EcAdapterInterface $ecAdapter |
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145 | * @param TransactionInterface $tx |
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146 | * @param $nInput |
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147 | * @param TransactionOutputInterface $txOut |
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148 | * @param SignData $signData |
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149 | * @param TransactionSignatureSerializer|null $sigSerializer |
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150 | * @param PublicKeySerializerInterface|null $pubKeySerializer |
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151 | */ |
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152 | 88 | public function __construct(EcAdapterInterface $ecAdapter, TransactionInterface $tx, $nInput, TransactionOutputInterface $txOut, SignData $signData, TransactionSignatureSerializer $sigSerializer = null, PublicKeySerializerInterface $pubKeySerializer = null) |
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153 | { |
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154 | 88 | $inputs = $tx->getInputs(); |
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155 | 88 | if (!isset($inputs[$nInput])) { |
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156 | 2 | throw new \RuntimeException('No input at this index'); |
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157 | } |
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158 | |||
159 | 86 | $this->ecAdapter = $ecAdapter; |
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160 | 86 | $this->tx = $tx; |
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161 | 86 | $this->nInput = $nInput; |
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162 | 86 | $this->txOut = $txOut; |
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163 | 86 | $this->flags = $signData->hasSignaturePolicy() ? $signData->getSignaturePolicy() : Interpreter::VERIFY_NONE; |
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164 | 86 | $this->publicKeys = []; |
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165 | 86 | $this->signatures = []; |
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166 | |||
167 | 86 | $this->txSigSerializer = $sigSerializer ?: new TransactionSignatureSerializer(EcSerializer::getSerializer(DerSignatureSerializerInterface::class, true, $ecAdapter)); |
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168 | 86 | $this->pubKeySerializer = $pubKeySerializer ?: EcSerializer::getSerializer(PublicKeySerializerInterface::class, true, $ecAdapter); |
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169 | 86 | $this->signatureChecker = new Checker($this->ecAdapter, $this->tx, $nInput, $txOut->getValue(), $this->txSigSerializer, $this->pubKeySerializer); |
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170 | 86 | $this->interpreter = new Interpreter($this->ecAdapter); |
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171 | |||
172 | 86 | $this->solve($signData, $txOut->getScript(), $inputs[$nInput]->getScript(), isset($tx->getWitnesses()[$nInput]) ? $tx->getWitnesses()[$nInput]->all() : []); |
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173 | 58 | } |
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174 | |||
175 | /** |
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176 | * A snipped from OP_CHECKMULTISIG - verifies signatures according to the |
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177 | * order of the given public keys (taken from the script). |
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178 | * |
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179 | * @param ScriptInterface $script |
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180 | * @param BufferInterface[] $signatures |
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181 | * @param BufferInterface[] $publicKeys |
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182 | * @param int $sigVersion |
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183 | * @return \SplObjectStorage |
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184 | */ |
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185 | 10 | private function sortMultisigs(ScriptInterface $script, array $signatures, array $publicKeys, $sigVersion) |
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186 | { |
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187 | 10 | $sigCount = count($signatures); |
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188 | 10 | $keyCount = count($publicKeys); |
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189 | 10 | $ikey = $isig = 0; |
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190 | 10 | $fSuccess = true; |
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191 | 10 | $result = new \SplObjectStorage; |
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192 | |||
193 | 10 | while ($fSuccess && $sigCount > 0) { |
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194 | // Fetch the signature and public key |
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195 | 10 | $sig = $signatures[$isig]; |
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196 | 10 | $pubkey = $publicKeys[$ikey]; |
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197 | |||
198 | 10 | if ($this->signatureChecker->checkSig($script, $sig, $pubkey, $sigVersion, $this->flags)) { |
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199 | 10 | $result[$pubkey] = $sig; |
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200 | 10 | $isig++; |
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201 | 10 | $sigCount--; |
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202 | } |
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203 | |||
204 | 10 | $ikey++; |
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205 | 10 | $keyCount--; |
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206 | |||
207 | // If there are more signatures left than keys left, |
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208 | // then too many signatures have failed. Exit early, |
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209 | // without checking any further signatures. |
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210 | 10 | if ($sigCount > $keyCount) { |
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211 | $fSuccess = false; |
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212 | } |
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213 | } |
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214 | |||
215 | 10 | return $result; |
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216 | } |
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217 | |||
218 | /** |
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219 | * @param ScriptInterface $script |
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220 | * @return \BitWasp\Buffertools\BufferInterface[] |
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221 | */ |
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222 | 68 | private function evalPushOnly(ScriptInterface $script) |
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223 | { |
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224 | 68 | $stack = new Stack(); |
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225 | 68 | $this->interpreter->evaluate($script, $stack, SigHash::V0, $this->flags | Interpreter::VERIFY_SIGPUSHONLY, $this->signatureChecker); |
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226 | 68 | return $stack->all(); |
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227 | } |
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228 | |||
229 | /** |
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230 | * Create a script consisting only of push-data operations. |
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231 | * Suitable for a scriptSig. |
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232 | * |
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233 | * @param BufferInterface[] $buffers |
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234 | * @return ScriptInterface |
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235 | */ |
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236 | private function pushAll(array $buffers) |
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237 | { |
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238 | 50 | return ScriptFactory::sequence(array_map(function ($buffer) { |
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239 | 42 | if (!($buffer instanceof BufferInterface)) { |
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240 | throw new \RuntimeException('Script contained a non-push opcode'); |
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241 | } |
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242 | |||
243 | 42 | $size = $buffer->getSize(); |
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244 | 42 | if ($size === 0) { |
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245 | 4 | return Opcodes::OP_0; |
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246 | } |
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247 | |||
248 | 42 | $first = ord($buffer->getBinary()); |
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249 | 42 | if ($size === 1 && $first >= 1 && $first <= 16) { |
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250 | return \BitWasp\Bitcoin\Script\encodeOpN($first); |
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251 | } else { |
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252 | 42 | return $buffer; |
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253 | } |
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254 | 50 | }, $buffers)); |
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255 | } |
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256 | |||
257 | /** |
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258 | * Verify a scriptSig / scriptWitness against a scriptPubKey. |
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259 | * Useful for checking the outcome of certain things, like hash locks (p2sh) |
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260 | * |
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261 | * @param int $flags |
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262 | * @param ScriptInterface $scriptSig |
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263 | * @param ScriptInterface $scriptPubKey |
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264 | * @param ScriptWitnessInterface|null $scriptWitness |
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265 | * @return bool |
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266 | */ |
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267 | 26 | private function verifySolution($flags, ScriptInterface $scriptSig, ScriptInterface $scriptPubKey, ScriptWitnessInterface $scriptWitness = null) |
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268 | { |
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269 | 26 | return $this->interpreter->verify($scriptSig, $scriptPubKey, $flags, $this->signatureChecker, $scriptWitness); |
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270 | } |
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271 | |||
272 | /** |
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273 | * Evaluates a scriptPubKey against the provided chunks. |
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274 | * |
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275 | * @param ScriptInterface $scriptPubKey |
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276 | * @param array $chunks |
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277 | * @param int $sigVersion |
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278 | * @return bool |
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279 | */ |
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280 | 56 | private function evaluateSolution(ScriptInterface $scriptPubKey, array $chunks, $sigVersion) |
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281 | { |
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282 | 56 | $stack = new Stack($chunks); |
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283 | 56 | if (!$this->interpreter->evaluate($scriptPubKey, $stack, $sigVersion, $this->flags, $this->signatureChecker)) { |
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284 | 2 | return false; |
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285 | } |
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286 | |||
287 | 54 | if ($stack->isEmpty()) { |
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288 | return false; |
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289 | } |
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290 | |||
291 | 54 | if (false === $this->interpreter->castToBool($stack[-1])) { |
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292 | 4 | return false; |
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293 | } |
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294 | |||
295 | 50 | return true; |
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296 | } |
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297 | |||
298 | /** |
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299 | * This function is strictly for $canSign types. |
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300 | * It will extract signatures/publicKeys when given $outputData, and $stack. |
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301 | * $stack is the result of decompiling a scriptSig, or taking the witness data. |
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302 | * |
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303 | * @param OutputData $outputData |
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304 | * @param array $stack |
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305 | * @param int $sigVersion |
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306 | * @return string |
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307 | */ |
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308 | 64 | public function extractFromValues(OutputData $outputData, array $stack, $sigVersion) |
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309 | { |
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310 | 64 | $type = $outputData->getType(); |
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311 | 64 | $size = count($stack); |
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312 | |||
313 | 64 | if (ScriptType::P2PKH === $type) { |
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314 | 38 | $this->requiredSigs = 1; |
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315 | 38 | if ($size === 2) { |
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316 | 34 | if (!$this->evaluateSolution($outputData->getScript(), $stack, $sigVersion)) { |
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317 | 2 | throw new \RuntimeException('Existing signatures are invalid!'); |
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318 | } |
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319 | 32 | $this->signatures = [$this->txSigSerializer->parse($stack[0])]; |
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320 | 36 | $this->publicKeys = [$this->pubKeySerializer->parse($stack[1])]; |
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321 | } |
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322 | 28 | } else if (ScriptType::P2PK === $type) { |
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323 | 14 | $this->requiredSigs = 1; |
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324 | 14 | if ($size === 1) { |
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325 | 12 | if (!$this->evaluateSolution($outputData->getScript(), $stack, $sigVersion)) { |
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326 | 2 | throw new \RuntimeException('Existing signatures are invalid!'); |
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327 | } |
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328 | 10 | $this->signatures = [$this->txSigSerializer->parse($stack[0])]; |
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329 | } |
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330 | 12 | $this->publicKeys = [$this->pubKeySerializer->parse($outputData->getSolution())]; |
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331 | 14 | } else if (ScriptType::MULTISIG === $type) { |
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332 | 14 | $info = new Multisig($outputData->getScript(), $this->pubKeySerializer); |
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333 | 14 | $this->requiredSigs = $info->getRequiredSigCount(); |
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334 | 14 | $this->publicKeys = $info->getKeys(); |
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335 | 14 | $keyBufs = $info->getKeyBuffers(); |
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336 | 14 | if ($size > 1) { |
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337 | // Check signatures irrespective of scriptSig size, primes Checker cache, and need info |
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338 | 12 | $check = $this->evaluateSolution($outputData->getScript(), $stack, $sigVersion); |
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339 | 12 | $sigBufs = array_slice($stack, 1, $size - 1); |
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340 | 12 | $sigBufCount = count($sigBufs); |
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341 | |||
342 | // If we seem to have all signatures but fail evaluation, abort |
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343 | 12 | if ($sigBufCount === $this->requiredSigs && !$check) { |
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344 | 2 | throw new \RuntimeException('Existing signatures are invalid!'); |
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345 | } |
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346 | |||
347 | 10 | $keyToSigMap = $this->sortMultiSigs($outputData->getScript(), $sigBufs, $keyBufs, $sigVersion); |
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348 | |||
349 | // Here we learn if any signatures were invalid, it won't be in the map. |
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350 | 10 | if ($sigBufCount !== count($keyToSigMap)) { |
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351 | throw new \RuntimeException('Existing signatures are invalid!'); |
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352 | } |
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353 | |||
354 | 10 | foreach ($keyBufs as $idx => $key) { |
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355 | 10 | if (isset($keyToSigMap[$key])) { |
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356 | 12 | $this->signatures[$idx] = $this->txSigSerializer->parse($keyToSigMap[$key]); |
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357 | } |
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358 | } |
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359 | } |
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360 | } else { |
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361 | throw new \RuntimeException('Unsupported output type passed to extractFromValues'); |
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362 | } |
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363 | |||
364 | 58 | return $type; |
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365 | } |
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366 | |||
367 | /** |
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368 | * Checks $chunks (a decompiled scriptSig) for it's last element, |
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369 | * or defers to SignData. If both are provided, it checks the |
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370 | * value from $chunks against SignData. |
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371 | * |
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372 | * @param BufferInterface[] $chunks |
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373 | * @param SignData $signData |
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374 | * @return ScriptInterface |
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375 | */ |
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376 | 30 | private function findRedeemScript(array $chunks, SignData $signData) |
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377 | { |
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378 | 30 | if (count($chunks) > 0) { |
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379 | 22 | $redeemScript = new Script($chunks[count($chunks) - 1]); |
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380 | 22 | if ($signData->hasRedeemScript()) { |
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381 | 22 | if (!$redeemScript->equals($signData->getRedeemScript())) { |
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382 | 22 | throw new \RuntimeException('Extracted redeemScript did not match sign data'); |
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383 | } |
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384 | } |
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385 | } else { |
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386 | 26 | if (!$signData->hasRedeemScript()) { |
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387 | 2 | throw new \RuntimeException('Redeem script not provided in sign data or scriptSig'); |
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388 | } |
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389 | 24 | $redeemScript = $signData->getRedeemScript(); |
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390 | } |
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391 | |||
392 | 26 | return $redeemScript; |
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393 | } |
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394 | |||
395 | /** |
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396 | * Checks $witness (a witness structure) for it's last element, |
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397 | * or defers to SignData. If both are provided, it checks the |
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398 | * value from $chunks against SignData. |
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399 | * |
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400 | * @param BufferInterface[] $witness |
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401 | * @param SignData $signData |
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402 | * @return ScriptInterface |
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403 | */ |
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404 | 26 | private function findWitnessScript(array $witness, SignData $signData) |
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405 | { |
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406 | 26 | if (count($witness) > 0) { |
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407 | 18 | $witnessScript = new Script($witness[count($witness) - 1]); |
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408 | 18 | if ($signData->hasWitnessScript()) { |
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409 | 18 | if (!$witnessScript->equals($signData->getWitnessScript())) { |
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410 | 18 | throw new \RuntimeException('Extracted witnessScript did not match sign data'); |
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411 | } |
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412 | } |
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413 | } else { |
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414 | 22 | if (!$signData->hasWitnessScript()) { |
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415 | 4 | throw new \RuntimeException('Witness script not provided in sign data or witness'); |
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416 | } |
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417 | 18 | $witnessScript = $signData->getWitnessScript(); |
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418 | } |
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419 | |||
420 | 18 | return $witnessScript; |
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421 | } |
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422 | |||
423 | /** |
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424 | * Called upon instance creation. |
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425 | * |
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426 | * It ensures that violating the following prevents instance creation |
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427 | * - the scriptPubKey can be directly signed, or leads to P2SH/P2WSH/P2WKH |
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428 | * - the P2SH script covers signable types and P2WSH/P2WKH |
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429 | * - the witnessScript covers signable types only |
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430 | * |
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431 | * @param SignData $signData |
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432 | * @param ScriptInterface $scriptPubKey |
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433 | * @param ScriptInterface $scriptSig |
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434 | * @param BufferInterface[] $witness |
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435 | * @return $this |
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436 | */ |
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437 | 86 | private function solve(SignData $signData, ScriptInterface $scriptPubKey, ScriptInterface $scriptSig, array $witness) |
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494 | |||
495 | /** |
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496 | * @param ScriptInterface $scriptCode |
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497 | * @param int $sigHashType |
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498 | * @param int $sigVersion |
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499 | * @return BufferInterface |
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500 | */ |
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501 | 52 | public function calculateSigHashUnsafe(ScriptInterface $scriptCode, $sigHashType, $sigVersion) |
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509 | |||
510 | /** |
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511 | * @param int $sigHashType |
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512 | * @return BufferInterface |
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513 | */ |
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514 | 2 | public function getSigHash($sigHashType) |
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518 | |||
519 | /** |
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520 | * @param PrivateKeyInterface $key |
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521 | * @param ScriptInterface $scriptCode |
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522 | * @param int $sigHashType |
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523 | * @param int $sigVersion |
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524 | * @return TransactionSignatureInterface |
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525 | */ |
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526 | 50 | private function calculateSignature(PrivateKeyInterface $key, ScriptInterface $scriptCode, $sigHashType, $sigVersion) |
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532 | |||
533 | /** |
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534 | * @return bool |
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535 | */ |
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536 | 56 | public function isFullySigned() |
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540 | |||
541 | /** |
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542 | * @return int |
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543 | */ |
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544 | 50 | public function getRequiredSigs() |
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548 | |||
549 | /** |
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550 | * @return TransactionSignatureInterface[] |
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551 | */ |
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552 | 50 | public function getSignatures() |
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556 | |||
557 | /** |
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558 | * @return PublicKeyInterface[] |
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559 | */ |
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560 | 50 | public function getPublicKeys() |
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564 | |||
565 | /** |
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566 | * @return OutputData |
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567 | */ |
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568 | public function getSignScript() |
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569 | { |
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570 | return $this->signScript; |
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571 | } |
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572 | 56 | ||
573 | /** |
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574 | 56 | * @return OutputData |
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575 | */ |
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576 | public function getScriptPubKey() |
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580 | |||
581 | /** |
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582 | 56 | * @return OutputData |
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583 | 12 | */ |
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584 | 2 | public function getRedeemScript() |
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592 | 32 | ||
593 | 12 | /** |
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594 | 12 | * @return OutputData |
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595 | 12 | */ |
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596 | 12 | public function getWitnessScript() |
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604 | |||
605 | /** |
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606 | * @return bool |
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607 | */ |
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608 | public function isP2SH() |
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616 | |||
617 | /** |
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618 | 50 | * @return bool |
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619 | */ |
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620 | 50 | public function isP2WSH() |
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634 | 50 | ||
635 | 50 | /** |
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636 | * Sign the input using $key and $sigHashTypes |
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637 | 50 | * |
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638 | 22 | * @param PrivateKeyInterface $key |
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639 | 22 | * @param int $sigHashType |
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640 | 22 | * @return $this |
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641 | 22 | */ |
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642 | public function sign(PrivateKeyInterface $key, $sigHashType = SigHash::ALL) |
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681 | 50 | ||
682 | /** |
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683 | * Verifies the input using $flags for script verification |
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684 | * |
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685 | * @param int $flags |
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686 | * @return bool |
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687 | */ |
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688 | public function verify($flags = null) |
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722 | |||
723 | 50 | /** |
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724 | 18 | * Produces the script stack that solves the $outputType |
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725 | * |
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726 | * @param string $outputType |
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727 | 50 | * @return BufferInterface[] |
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728 | */ |
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729 | private function serializeSolution($outputType) |
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753 | |||
754 | /** |
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755 | * Produces a SigValues instance containing the scriptSig & script witness |
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756 | * |
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757 | * @return SigValues |
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758 | */ |
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759 | public function serializeSignatures() |
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799 | } |
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800 |
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: