Complex classes like TBSCertificate 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 TBSCertificate, and based on these observations, apply Extract Interface, too.
1 | <?php |
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28 | class TBSCertificate |
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29 | { |
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30 | // Certificate version enumerations |
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31 | const VERSION_1 = 0; |
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32 | const VERSION_2 = 1; |
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33 | const VERSION_3 = 2; |
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34 | |||
35 | /** |
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36 | * Certificate version. |
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37 | * |
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38 | * @var null|int |
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39 | */ |
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40 | protected $_version; |
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41 | |||
42 | /** |
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43 | * Serial number. |
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44 | * |
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45 | * @var null|string |
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46 | */ |
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47 | protected $_serialNumber; |
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48 | |||
49 | /** |
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50 | * Signature algorithm. |
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51 | * |
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52 | * @var null|SignatureAlgorithmIdentifier |
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53 | */ |
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54 | protected $_signature; |
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55 | |||
56 | /** |
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57 | * Certificate issuer. |
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58 | * |
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59 | * @var Name |
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60 | */ |
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61 | protected $_issuer; |
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62 | |||
63 | /** |
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64 | * Certificate validity period. |
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65 | * |
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66 | * @var Validity |
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67 | */ |
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68 | protected $_validity; |
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69 | |||
70 | /** |
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71 | * Certificate subject. |
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72 | * |
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73 | * @var Name |
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74 | */ |
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75 | protected $_subject; |
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76 | |||
77 | /** |
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78 | * Subject public key. |
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79 | * |
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80 | * @var PublicKeyInfo |
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81 | */ |
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82 | protected $_subjectPublicKeyInfo; |
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83 | |||
84 | /** |
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85 | * Issuer unique identifier. |
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86 | * |
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87 | * @var null|UniqueIdentifier |
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88 | */ |
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89 | protected $_issuerUniqueID; |
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90 | |||
91 | /** |
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92 | * Subject unique identifier. |
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93 | * |
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94 | * @var null|UniqueIdentifier |
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95 | */ |
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96 | protected $_subjectUniqueID; |
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97 | |||
98 | /** |
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99 | * Extensions. |
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100 | * |
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101 | * @var Extensions |
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102 | */ |
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103 | protected $_extensions; |
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104 | |||
105 | /** |
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106 | * Constructor. |
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107 | * |
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108 | * @param Name $subject Certificate subject |
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109 | * @param PublicKeyInfo $pki Subject public key |
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110 | * @param Name $issuer Certificate issuer |
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111 | * @param Validity $validity Validity period |
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112 | */ |
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113 | 29 | public function __construct(Name $subject, PublicKeyInfo $pki, Name $issuer, |
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121 | 29 | } |
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122 | |||
123 | /** |
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124 | * Initialize from ASN.1. |
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125 | * |
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126 | * @param Sequence $seq |
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127 | * |
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128 | * @return self |
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129 | 21 | */ |
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130 | public static function fromASN1(Sequence $seq): self |
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131 | 21 | { |
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132 | 21 | $idx = 0; |
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133 | 17 | if ($seq->hasTagged(0)) { |
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134 | 17 | ++$idx; |
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135 | 17 | $version = $seq->getTagged(0)->asExplicit()->asInteger()->intNumber(); |
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136 | 17 | } else { |
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137 | 17 | $version = self::VERSION_1; |
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138 | } |
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139 | 4 | $serial = $seq->at($idx++)->asInteger()->number(); |
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140 | $algo = AlgorithmIdentifier::fromASN1($seq->at($idx++)->asSequence()); |
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141 | 21 | if (!$algo instanceof SignatureAlgorithmIdentifier) { |
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142 | 21 | throw new \UnexpectedValueException( |
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143 | 21 | 'Unsupported signature algorithm ' . $algo->name() . '.'); |
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144 | 21 | } |
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145 | 21 | $issuer = Name::fromASN1($seq->at($idx++)->asSequence()); |
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146 | 1 | $validity = Validity::fromASN1($seq->at($idx++)->asSequence()); |
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147 | 1 | $subject = Name::fromASN1($seq->at($idx++)->asSequence()); |
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148 | $pki = PublicKeyInfo::fromASN1($seq->at($idx++)->asSequence()); |
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149 | 20 | $tbs_cert = new self($subject, $pki, $issuer, $validity); |
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150 | 20 | $tbs_cert->_version = $version; |
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151 | 20 | $tbs_cert->_serialNumber = $serial; |
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152 | 20 | $tbs_cert->_signature = $algo; |
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153 | 20 | if ($seq->hasTagged(1)) { |
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154 | 20 | $tbs_cert->_issuerUniqueID = UniqueIdentifier::fromASN1( |
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155 | 20 | $seq->getTagged(1)->asImplicit(Element::TYPE_BIT_STRING) |
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156 | 20 | ->asBitString()); |
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157 | 20 | } |
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158 | 1 | if ($seq->hasTagged(2)) { |
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159 | 1 | $tbs_cert->_subjectUniqueID = UniqueIdentifier::fromASN1( |
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160 | 1 | $seq->getTagged(2)->asImplicit(Element::TYPE_BIT_STRING) |
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161 | 1 | ->asBitString()); |
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162 | } |
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163 | 20 | if ($seq->hasTagged(3)) { |
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164 | 1 | $tbs_cert->_extensions = Extensions::fromASN1( |
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165 | 1 | $seq->getTagged(3)->asExplicit()->asSequence()); |
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166 | 1 | } |
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167 | 1 | return $tbs_cert; |
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168 | } |
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169 | 20 | ||
170 | 16 | /** |
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171 | 16 | * Initialize from certification request. |
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172 | 16 | * |
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173 | 16 | * Note that signature is not verified and must be done by the caller. |
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174 | * |
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175 | 20 | * @param CertificationRequest $cr |
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176 | * |
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177 | * @return self |
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178 | */ |
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179 | public static function fromCSR(CertificationRequest $cr): self |
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180 | { |
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181 | $cri = $cr->certificationRequestInfo(); |
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182 | $tbs_cert = new self($cri->subject(), $cri->subjectPKInfo(), new Name(), |
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183 | Validity::fromStrings(null, null)); |
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184 | // if CSR has Extension Request attribute |
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185 | if ($cri->hasAttributes()) { |
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186 | 1 | $attribs = $cri->attributes(); |
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187 | if ($attribs->hasExtensionRequest()) { |
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188 | 1 | $tbs_cert = $tbs_cert->withExtensions( |
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189 | 1 | $attribs->extensionRequest()->extensions()); |
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190 | 1 | } |
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191 | } |
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192 | 1 | // add Subject Key Identifier extension |
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193 | 1 | return $tbs_cert->withAdditionalExtensions( |
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194 | 1 | new SubjectKeyIdentifierExtension(false, |
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195 | 1 | $cri->subjectPKInfo()->keyIdentifier())); |
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196 | 1 | } |
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197 | 1 | ||
198 | /** |
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199 | * Get self with fields set from the issuer's certificate. |
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200 | * |
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201 | 1 | * Issuer shall be set to issuing certificate's subject. |
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202 | 1 | * Authority key identifier extensions shall be added with a key identifier |
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203 | 1 | * set to issuing certificate's public key identifier. |
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204 | 1 | * |
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205 | 1 | * @param Certificate $cert Issuing party's certificate |
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206 | * |
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207 | * @return self |
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208 | */ |
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209 | public function withIssuerCertificate(Certificate $cert): self |
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210 | { |
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211 | $obj = clone $this; |
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212 | // set issuer DN from cert's subject |
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213 | $obj->_issuer = $cert->tbsCertificate()->subject(); |
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214 | // add authority key identifier extension |
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215 | $key_id = $cert->tbsCertificate()->subjectPublicKeyInfo()->keyIdentifier(); |
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216 | $obj->_extensions = $obj->_extensions->withExtensions( |
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217 | new AuthorityKeyIdentifierExtension(false, $key_id)); |
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218 | 1 | return $obj; |
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219 | } |
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220 | 1 | ||
221 | /** |
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222 | 1 | * Get self with given version. |
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223 | * |
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224 | 1 | * If version is not set, appropriate version is automatically |
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225 | 1 | * determined during signing. |
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226 | 1 | * |
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227 | 1 | * @param int $version |
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228 | 1 | * |
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229 | 1 | * @return self |
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230 | */ |
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231 | public function withVersion(int $version): self |
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232 | { |
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233 | $obj = clone $this; |
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234 | $obj->_version = $version; |
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235 | return $obj; |
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236 | } |
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237 | |||
238 | /** |
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239 | * Get self with given serial number. |
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240 | * |
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241 | 4 | * @param int|string $serial Base 10 number |
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242 | * |
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243 | 4 | * @return self |
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244 | 4 | */ |
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245 | 4 | public function withSerialNumber($serial): self |
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246 | { |
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247 | $obj = clone $this; |
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248 | $obj->_serialNumber = strval($serial); |
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249 | return $obj; |
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250 | } |
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251 | |||
252 | /** |
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253 | * Get self with random positive serial number. |
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254 | 5 | * |
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255 | * @param int $size Number of random bytes |
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256 | 5 | * |
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257 | 5 | * @return self |
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258 | 5 | */ |
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259 | public function withRandomSerialNumber(int $size = 16): self |
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260 | { |
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261 | // ensure that first byte is always non-zero and having first bit unset |
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262 | $num = gmp_init(mt_rand(1, 0x7f), 10); |
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263 | for ($i = 1; $i < $size; ++$i) { |
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264 | $num <<= 8; |
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265 | $num += mt_rand(0, 0xff); |
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266 | } |
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267 | 1 | return $this->withSerialNumber(gmp_strval($num, 10)); |
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268 | } |
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269 | |||
270 | 1 | /** |
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271 | 1 | * Get self with given signature algorithm. |
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272 | 1 | * |
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273 | 1 | * @param SignatureAlgorithmIdentifier $algo |
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274 | * |
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275 | 1 | * @return self |
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276 | */ |
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277 | public function withSignature(SignatureAlgorithmIdentifier $algo): self |
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278 | { |
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279 | $obj = clone $this; |
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280 | $obj->_signature = $algo; |
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281 | return $obj; |
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282 | } |
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283 | |||
284 | 4 | /** |
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285 | * Get self with given issuer. |
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286 | 4 | * |
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287 | 4 | * @param Name $issuer |
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288 | 4 | * |
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289 | * @return self |
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290 | */ |
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291 | public function withIssuer(Name $issuer): self |
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292 | { |
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293 | $obj = clone $this; |
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294 | $obj->_issuer = $issuer; |
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295 | return $obj; |
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296 | } |
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297 | 1 | ||
298 | /** |
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299 | 1 | * Get self with given validity. |
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300 | 1 | * |
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301 | 1 | * @param Validity $validity |
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302 | * |
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303 | * @return self |
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304 | */ |
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305 | public function withValidity(Validity $validity): self |
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306 | { |
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307 | $obj = clone $this; |
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308 | $obj->_validity = $validity; |
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309 | return $obj; |
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310 | 2 | } |
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311 | |||
312 | 2 | /** |
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313 | 2 | * Get self with given subject. |
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314 | 2 | * |
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315 | * @param Name $subject |
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316 | * |
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317 | * @return self |
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318 | */ |
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319 | public function withSubject(Name $subject): self |
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320 | { |
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321 | $obj = clone $this; |
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322 | $obj->_subject = $subject; |
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323 | 2 | return $obj; |
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324 | } |
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325 | 2 | ||
326 | 2 | /** |
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327 | 2 | * Get self with given subject public key info. |
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328 | * |
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329 | * @param PublicKeyInfo $pub_key_info |
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330 | * |
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331 | * @return self |
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332 | */ |
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333 | public function withSubjectPublicKeyInfo(PublicKeyInfo $pub_key_info): self |
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334 | { |
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335 | $obj = clone $this; |
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336 | 1 | $obj->_subjectPublicKeyInfo = $pub_key_info; |
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337 | return $obj; |
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338 | 1 | } |
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339 | 1 | ||
340 | 1 | /** |
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341 | * Get self with issuer unique ID. |
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342 | * |
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343 | * @param UniqueIdentifier $id |
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344 | * |
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345 | * @return self |
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346 | */ |
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347 | public function withIssuerUniqueID(UniqueIdentifier $id): self |
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348 | { |
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349 | 6 | $obj = clone $this; |
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350 | $obj->_issuerUniqueID = $id; |
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351 | 6 | return $obj; |
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352 | 6 | } |
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353 | 6 | ||
354 | /** |
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355 | * Get self with subject unique ID. |
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356 | * |
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357 | * @param UniqueIdentifier $id |
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358 | * |
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359 | * @return self |
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360 | */ |
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361 | public function withSubjectUniqueID(UniqueIdentifier $id): self |
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362 | 4 | { |
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363 | $obj = clone $this; |
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364 | 4 | $obj->_subjectUniqueID = $id; |
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365 | 4 | return $obj; |
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366 | 4 | } |
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367 | |||
368 | /** |
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369 | * Get self with given extensions. |
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370 | * |
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371 | * @param Extensions $extensions |
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372 | * |
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373 | * @return self |
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374 | */ |
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375 | 4 | public function withExtensions(Extensions $extensions): self |
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380 | } |
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381 | |||
382 | /** |
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383 | * Get self with extensions added. |
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384 | * |
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385 | * @param Extension ...$exts One or more Extension objects |
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386 | * |
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387 | * @return self |
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388 | 3 | */ |
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389 | public function withAdditionalExtensions(Extension ...$exts): self |
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390 | 3 | { |
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391 | 3 | $obj = clone $this; |
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392 | 3 | $obj->_extensions = $obj->_extensions->withExtensions(...$exts); |
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393 | return $obj; |
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394 | } |
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395 | |||
396 | /** |
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397 | * Check whether version is set. |
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398 | * |
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399 | * @return bool |
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400 | 68 | */ |
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401 | public function hasVersion(): bool |
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402 | 68 | { |
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403 | return isset($this->_version); |
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404 | } |
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405 | |||
406 | /** |
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407 | * Get certificate version. |
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408 | * |
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409 | * @throws \LogicException If not set |
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410 | 68 | * |
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411 | * @return int |
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412 | 68 | */ |
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413 | 1 | public function version(): int |
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414 | { |
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415 | 67 | if (!$this->hasVersion()) { |
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416 | throw new \LogicException('version not set.'); |
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417 | } |
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418 | return $this->_version; |
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419 | } |
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420 | |||
421 | /** |
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422 | * Check whether serial number is set. |
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423 | 91 | * |
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424 | * @return bool |
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425 | 91 | */ |
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426 | public function hasSerialNumber(): bool |
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427 | { |
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428 | return isset($this->_serialNumber); |
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429 | } |
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430 | |||
431 | /** |
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432 | * Get serial number. |
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433 | 91 | * |
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434 | * @throws \LogicException If not set |
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435 | 91 | * |
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436 | 1 | * @return string Base 10 integer |
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437 | */ |
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438 | 90 | public function serialNumber(): string |
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439 | { |
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440 | if (!$this->hasSerialNumber()) { |
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441 | throw new \LogicException('serialNumber not set.'); |
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442 | } |
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443 | return $this->_serialNumber; |
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444 | } |
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445 | |||
446 | 68 | /** |
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447 | * Check whether signature algorithm is set. |
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448 | 68 | * |
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449 | * @return bool |
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450 | */ |
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451 | public function hasSignature(): bool |
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452 | { |
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453 | return isset($this->_signature); |
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454 | } |
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455 | |||
456 | 68 | /** |
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457 | * Get signature algorithm. |
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458 | 68 | * |
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459 | 1 | * @throws \LogicException If not set |
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460 | * |
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461 | 67 | * @return SignatureAlgorithmIdentifier |
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462 | */ |
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463 | public function signature(): SignatureAlgorithmIdentifier |
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464 | { |
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465 | if (!$this->hasSignature()) { |
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466 | throw new \LogicException('signature not set.'); |
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467 | } |
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468 | return $this->_signature; |
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469 | 68 | } |
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470 | |||
471 | 68 | /** |
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472 | * Get issuer. |
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473 | * |
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474 | * @return Name |
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475 | */ |
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476 | public function issuer(): Name |
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477 | { |
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478 | return $this->_issuer; |
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479 | 46 | } |
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480 | |||
481 | 46 | /** |
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482 | * Get validity period. |
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483 | * |
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484 | * @return Validity |
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485 | */ |
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486 | public function validity(): Validity |
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487 | { |
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488 | return $this->_validity; |
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489 | 68 | } |
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490 | |||
491 | 68 | /** |
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492 | * Get subject. |
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493 | * |
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494 | * @return Name |
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495 | */ |
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496 | public function subject(): Name |
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497 | { |
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498 | return $this->_subject; |
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499 | 68 | } |
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500 | |||
501 | 68 | /** |
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502 | * Get subject public key. |
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503 | * |
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504 | * @return PublicKeyInfo |
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505 | */ |
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506 | public function subjectPublicKeyInfo(): PublicKeyInfo |
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507 | { |
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508 | return $this->_subjectPublicKeyInfo; |
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509 | 7 | } |
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510 | |||
511 | 7 | /** |
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512 | * Whether issuer unique identifier is present. |
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513 | * |
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514 | * @return bool |
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515 | */ |
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516 | public function hasIssuerUniqueID(): bool |
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517 | { |
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518 | return isset($this->_issuerUniqueID); |
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519 | 4 | } |
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520 | |||
521 | 4 | /** |
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522 | 1 | * Get issuerUniqueID. |
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523 | * |
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524 | 3 | * @throws \LogicException If not set |
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525 | * |
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526 | * @return UniqueIdentifier |
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527 | */ |
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528 | public function issuerUniqueID(): UniqueIdentifier |
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529 | { |
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530 | if (!$this->hasIssuerUniqueID()) { |
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531 | throw new \LogicException('issuerUniqueID not set.'); |
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532 | 2 | } |
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533 | return $this->_issuerUniqueID; |
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534 | 2 | } |
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535 | |||
536 | /** |
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537 | * Whether subject unique identifier is present. |
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538 | * |
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539 | * @return bool |
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540 | */ |
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541 | public function hasSubjectUniqueID(): bool |
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542 | 2 | { |
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543 | return isset($this->_subjectUniqueID); |
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544 | 2 | } |
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545 | 1 | ||
546 | /** |
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547 | 1 | * Get subjectUniqueID. |
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548 | * |
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549 | * @throws \LogicException If not set |
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550 | * |
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551 | * @return UniqueIdentifier |
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552 | */ |
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553 | public function subjectUniqueID(): UniqueIdentifier |
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554 | { |
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555 | 62 | if (!$this->hasSubjectUniqueID()) { |
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556 | throw new \LogicException('subjectUniqueID not set.'); |
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557 | 62 | } |
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558 | return $this->_subjectUniqueID; |
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559 | } |
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560 | |||
561 | /** |
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562 | * Get extensions. |
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563 | * |
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564 | * @return Extensions |
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565 | 65 | */ |
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566 | public function extensions(): Extensions |
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569 | } |
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570 | 65 | ||
571 | 54 | /** |
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572 | * Generate ASN.1 structure. |
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573 | 65 | * |
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574 | 65 | * @return Sequence |
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575 | */ |
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576 | 65 | public function toASN1(): Sequence |
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577 | 65 | { |
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578 | 65 | $elements = []; |
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579 | 65 | $version = $this->version(); |
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580 | 6 | // if version is not default |
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581 | 6 | if (self::VERSION_1 !== $version) { |
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582 | $elements[] = new ExplicitlyTaggedType(0, new Integer($version)); |
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583 | 65 | } |
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584 | 4 | $serial = $this->serialNumber(); |
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585 | 4 | $signature = $this->signature(); |
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586 | // add required elements |
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587 | 65 | array_push($elements, new Integer($serial), $signature->toASN1(), |
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588 | 48 | $this->_issuer->toASN1(), $this->_validity->toASN1(), |
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589 | 48 | $this->_subject->toASN1(), $this->_subjectPublicKeyInfo->toASN1()); |
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590 | if (isset($this->_issuerUniqueID)) { |
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591 | 65 | $elements[] = new ImplicitlyTaggedType(1, |
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592 | $this->_issuerUniqueID->toASN1()); |
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593 | } |
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594 | if (isset($this->_subjectUniqueID)) { |
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595 | $elements[] = new ImplicitlyTaggedType(2, |
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596 | $this->_subjectUniqueID->toASN1()); |
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597 | } |
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598 | if (count($this->_extensions)) { |
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599 | $elements[] = new ExplicitlyTaggedType(3, |
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600 | $this->_extensions->toASN1()); |
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601 | } |
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602 | 12 | return new Sequence(...$elements); |
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603 | } |
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604 | |||
605 | 12 | /** |
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606 | 12 | * Create signed certificate. |
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607 | 12 | * |
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608 | 12 | * @param SignatureAlgorithmIdentifier $algo Algorithm used for signing |
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609 | * @param PrivateKeyInfo $privkey_info Private key used for signing |
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610 | 12 | * @param null|Crypto $crypto Crypto engine, use default if not set |
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611 | 12 | * |
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612 | * @return Certificate |
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613 | 12 | */ |
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614 | 12 | public function sign(SignatureAlgorithmIdentifier $algo, |
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629 | } |
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630 | |||
631 | 9 | /** |
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632 | 5 | * Determine minimum version for the certificate. |
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633 | * |
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634 | 4 | * @return int |
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635 | */ |
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636 | protected function _determineVersion(): int |
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637 | { |
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638 | // if extensions are present |
||
639 | if (count($this->_extensions)) { |
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640 | return self::VERSION_3; |
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641 | } |
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642 | // if UniqueIdentifier is present |
||
643 | if (isset($this->_issuerUniqueID) || isset($this->_subjectUniqueID)) { |
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644 | return self::VERSION_2; |
||
645 | } |
||
646 | return self::VERSION_1; |
||
647 | } |
||
648 | } |
||
649 |