securemail/php-gpg/libs/GPG/Public_Key.php

   1 <?php\r
   2 /** @package    php-gpg::GPG */\r
   3 \r
   4 /** require supporting files */\r
   5 require_once("Expanded_Key.php");\r
   6 \r
   7 define("PK_TYPE_ELGAMAL", 1);\r
   8 define("PK_TYPE_RSA", 0);\r
   9 define("PK_TYPE_UNKNOWN", -1);\r
  10 \r
  11 /**\r
  12  * Pure PHP implementation of PHP/GPG public key\r
  13  *\r
  14  * @package php-gpg::GPG\r
  15  * @link http://www.verysimple.com/\r
  16  * @copyright  1997-2011 VerySimple, Inc.\r
  17  * @license    http://www.gnu.org/licenses/lgpl.html  LGPL\r
  18  * @todo implement decryption\r
  19  * @version 1.0\r
  20  */\r
  21 class GPG_Public_Key {\r
  22     var $version;\r
  23         var $fp;\r
  24         var $key_id;\r
  25         var $user;\r
  26         var $public_key;\r
  27         var $type;\r
  28         \r
  29         function IsValid()\r
  30         {\r
  31                 return $this->version != -1 && $this->GetKeyType() != PK_TYPE_UNKNOWN;\r
  32         }\r
  33         \r
  34         function GetKeyType()\r
  35         {\r
  36                 if (!strcmp($this->type, "ELGAMAL")) return PK_TYPE_ELGAMAL;\r
  37                 if (!strcmp($this->type, "RSA")) return PK_TYPE_RSA;\r
  38                 return PK_TYPE_UNKNOWN;\r
  39         }\r
  40 \r
  41         function GetFingerprint()\r
  42         {\r
  43                 return strtoupper( trim(chunk_split($this->fp, 4, ' ')) );\r
  44         }\r
  45         \r
  46         function GetKeyId()\r
  47         {\r
  48                 return (strlen($this->key_id) == 16) ? strtoupper($this->key_id) : '0000000000000000';\r
  49         }\r
  50         \r
  51         function GetPublicKey()\r
  52         {\r
  53                 return str_replace("\n", "", $this->public_key);\r
  54         }\r
  55         \r
  56         function GPG_Public_Key($asc) {\r
  57                 $found = 0;\r
  58                 \r
  59                 // normalize line breaks\r
  60                 $asc = str_replace("\r\n", "\n", $asc);\r
  61                 \r
  62                 if (strpos($asc, "-----BEGIN PGP PUBLIC KEY BLOCK-----\n") === false)\r
  63                         throw new Exception("Missing header block in Public Key");\r
  64 \r
  65                 if (strpos($asc, "\n\n") === false)\r
  66                         throw new Exception("Missing body delimiter in Public Key");\r
  67                 \r
  68                 if (strpos($asc, "\n-----END PGP PUBLIC KEY BLOCK-----") === false)\r
  69                         throw new Exception("Missing footer block in Public Key");\r
  70                 \r
  71                 // get rid of everything except the base64 encoded key\r
  72                 $headerbody = explode("\n\n", str_replace("\n-----END PGP PUBLIC KEY BLOCK-----", "", $asc), 2);\r
  73                 $asc = trim($headerbody[1]);\r
  74                 \r
  75                 \r
  76                 $len = 0;\r
  77                 $s =  base64_decode($asc);\r
  78                 $sa = str_split($s);\r
  79                 \r
  80                 for($i = 0; $i < strlen($s);) {\r
  81                         $tag = ord($sa[$i++]);\r
  82                         \r
  83                         // echo 'TAG=' . $tag . '/';\r
  84                         \r
  85                         if(($tag & 128) == 0) break;\r
  86                         \r
  87                         if($tag & 64) {\r
  88                                 $tag &= 63;\r
  89                                 $len = ord($sa[$i++]);\r
  90                                 if ($len > 191 && $len < 224) $len = (($len - 192) << 8) + ord($sa[$i++]);\r
  91                                 else if ($len == 255) $len = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);\r
  92                                         else if ($len > 223 && $len < 255) $len = (1 << ($len & 0x1f));\r
  93                         } else {\r
  94                                 $len = $tag & 3;\r
  95                                 $tag = ($tag >> 2) & 15;\r
  96                                 if ($len == 0) $len = ord($sa[$i++]);\r
  97                                 else if($len == 1) $len = (ord($sa[$i++]) << 8) + ord($sa[$i++]);\r
  98                                         else if($len == 2) $len = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);\r
  99                                                 else $len = strlen($s) - 1;\r
 100                         }\r
 101                         \r
 102                         // echo $tag . ' ';\r
 103                         \r
 104                         if ($tag == 6 || $tag == 14) {\r
 105                                 $k = $i;\r
 106                                 $version = ord($sa[$i++]);\r
 107                                 $found = 1;\r
 108                                 $this->version = $version;\r
 109                                 \r
 110                                 $time = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);\r
 111                                 \r
 112                                 if($version == 2 || $version == 3) $valid = ord($sa[$i++]) << 8 + ord($sa[$i++]);\r
 113                                 \r
 114                                 $algo = ord($sa[$i++]);\r
 115                                 \r
 116                                 if($algo == 1 || $algo == 2) {\r
 117                                         $m = $i;\r
 118                                         $lm = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);\r
 119                                         $i += $lm + 2;\r
 120                                         \r
 121                                         $mod = substr($s, $m, $lm + 2);\r
 122                                         $le = floor((ord($sa[$i]) * 256 + ord($sa[$i+1]) + 7) / 8);\r
 123                                         $i += $le + 2;\r
 124                                         \r
 125                                         $this->public_key = base64_encode(substr($s, $m, $lm + $le + 4));\r
 126                                         $this->type = "RSA";\r
 127                                         \r
 128                                         if ($version == 3) {\r
 129                                                 $this->fp = '';\r
 130                                                 $this->key_id = bin2hex(substr($mod, strlen($mod) - 8, 8));\r
 131                                         } else if($version == 4) {\r
 132                                                 \r
 133                                                 // https://tools.ietf.org/html/rfc4880#section-12\r
 134                                                 $headerPos = strpos($s, chr(0x04));  // TODO: is this always the correct starting point for the pulic key packet 'version' field?\r
 135                                                 $delim = chr(0x01) . chr(0x00);  // TODO: is this the correct delimiter for the end of the public key packet? \r
 136                                                 $delimPos = strpos($s, $delim) + (3-$headerPos);\r
 137                                                 \r
 138                                                 // echo "POSITION: $delimPos\n";\r
 139                                                 \r
 140                                                 // this does not work, tried it with RSA 1024 and RSA 4096 keys generated by GnuPG v2 (2.0.29) on Windows running Apache and PHP 5.6.3\r
 141                                                 // $pkt = chr(0x99) . chr($delimPos >> 8) . chr($delimPos & 255) . substr($s, $headerPos, $delimPos);\r
 142                                                 \r
 143                                                 // this is the original signing string which seems to have only worked for key lengths of 1024 or less\r
 144                                                 $pkt = chr(0x99) . chr($len >> 8) . chr($len & 255) . substr($s, $k, $len); // use this for now\r
 145                                                 \r
 146                                                 $fp = sha1($pkt);\r
 147                                                 $this->fp = $fp;\r
 148                                                 $this->key_id = substr($fp, strlen($fp) - 16, 16);\r
 149                                                 \r
 150                                                 // uncomment to debug the start point for the signing string\r
 151 //                                              for ($ii = 5; $ii > -1; $ii--) {\r
 152 //                                                      $pkt = chr(0x99) . chr($ii >> 8) . chr($ii & 255) . substr($s, $headerPos, $ii);\r
 153 //                                                      $fp = sha1($pkt);\r
 154 //                                                      echo "LENGTH=" . $headerPos . '->' . $ii . " CHR(" . ord(substr($s,$ii, 1)) . ") = " . substr($fp, strlen($fp) - 16, 16) . "\n";\r
 155 //                                              }\r
 156 //                                              echo "\n";\r
 157                                                 \r
 158                                                 // uncomment to debug the end point for the signing string\r
 159 //                                              for ($ii = strlen($s); $ii > 1; $ii--) {\r
 160 //                                                      $pkt = chr(0x99) . chr($ii >> 8) . chr($ii & 255) . substr($s, $headerPos, $ii);\r
 161 //                                                      $fp = sha1($pkt);\r
 162 //                                                      echo "LENGTH=" . $headerPos . '->' . $ii . " CHR(" . ord(substr($s,$ii, 1)) . ") = " . substr($fp, strlen($fp) - 16, 16) . "\n";\r
 163 //                                              }\r
 164                                         } else {\r
 165                                                 throw new Exception('GPG Key Version ' . $version . ' is not supported');\r
 166                                         }\r
 167                                         $found = 2;\r
 168                                 } else if(($algo == 16 || $algo == 20) && $version == 4) {\r
 169                                                 $m = $i;\r
 170                                                 \r
 171                                                 $lp = floor((ord($sa[$i]) * 256 + ord($sa[$i +1]) + 7) / 8);\r
 172                                                 $i += $lp + 2;\r
 173                                                 \r
 174                                                 $lg = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);\r
 175                                                 $i += $lg + 2;\r
 176                                                 \r
 177                                                 $ly = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7)/8);\r
 178                                                 $i += $ly + 2;\r
 179                                                 \r
 180                                                 $this->public_key = base64_encode(substr($s, $m, $lp + $lg + $ly + 6));\r
 181                                                 \r
 182                                                 // TODO: should this be adjusted as it was for RSA (above)..?\r
 183                                                 \r
 184                                                 $pkt = chr(0x99) . chr($len >> 8) . chr($len & 255) . substr($s, $k, $len);\r
 185                                                 $fp = sha1($pkt);\r
 186                                                 $this->fp = $fp;\r
 187                                                 $this->key_id = substr($fp, strlen($fp) - 16, 16);\r
 188                                                 $this->type = "ELGAMAL";\r
 189                                                 $found = 3;\r
 190                                         } else {\r
 191                                                 $i = $k + $len;\r
 192                                         }\r
 193                         } else if ($tag == 13) {\r
 194                                         $this->user = substr($s, $i, $len);\r
 195                                         $i += $len;\r
 196                                 } else {\r
 197                                         $i += $len;\r
 198                                 }\r
 199                 }\r
 200                 \r
 201                 if($found < 2) {  \r
 202                         \r
 203                         throw new Exception("Unable to parse Public Key");\r
 204 //                      $this->version = "";\r
 205 //                      $this->fp = "";\r
 206 //                      $this->key_id = "";\r
 207 //                      $this->user = ""; \r
 208 //                      $this->public_key = "";\r
 209                 }\r
 210         }\r
 211         \r
 212         function GetExpandedKey()\r
 213         {\r
 214                 $ek = new Expanded_Key($this->public_key);\r
 215         }\r
 216 }\r
 217 \r
 218 ?>\r