Enable PDFDocEncoding support for metadata

src/Smalot/PdfParser/Document.php

@@ -32,6 +32,8 @@
 
 namespace Smalot\PdfParser;
 
+use Smalot\PdfParser\Encoding\PDFDocEncoding;
+
 /**
  * Technical references :
  * - http://www.mactech.com/articles/mactech/Vol.15/15.09/PDFIntro/index.html
@@ -149,6 +151,47 @@ protected function buildDetails()
             $details['Pages'] = 0;
         }
 
+        // Decode and repair encoded document properties
+        foreach ($details as $key => $value) {
+            if (\is_string($value)) {
+                // If the string is already UTF-8 encoded, that means we only
+                // need to repair Adobe's ham-fisted insertion of line-feeds
+                // every ~127 characters, which doesn't seem to be multi-byte
+                // safe
+                if (mb_check_encoding($value, 'UTF-8')) {
+                    // Remove literal backslash + line-feed "\\r"
+                    $value = str_replace("\x5c\x0d", '', $value);
+
+                    // Remove backslash plus bytes written into high part of
+                    // multibyte unicode character
+                    while (preg_match("/\x5c\x5c\xe0([\xb4-\xb8])(.)/", $value, $match)) {
+                        $diff = (\ord($match[1]) - 182) * 64;
+                        $newbyte = PDFDocEncoding::convertPDFDoc2UTF8(\chr(\ord($match[2]) + $diff));
+                        $value = preg_replace("/\x5c\x5c\xe0".$match[1].$match[2].'/', $newbyte, $value);
+                    }
+
+                    // Remove bytes written into low part of multibyte unicode
+                    // character
+                    while (preg_match("/(.)\x9c\xe0([\xb3-\xb7])/", $value, $match)) {
+                        $diff = \ord($match[2]) - 181;
+                        $newbyte = \chr(\ord($match[1]) + $diff);
+                        $value = preg_replace('/'.$match[1]."\x9c\xe0".$match[2].'/', $newbyte, $value);
+                    }
+
+                    // Remove this byte string that Adobe occasionally adds
+                    // between two single byte characters in a unicode string
+                    $value = str_replace("\xe5\xb0\x8d", '', $value);
+
+                    $details[$key] = $value;
+                } else {
+                    // If the string is just PDFDocEncoding, remove any line-feeds
+                    // and decode the whole thing.
+                    $value = str_replace("\\\r", '', $value);
+                    $details[$key] = PDFDocEncoding::convertPDFDoc2UTF8($value);
+                }
+            }
+        }
+
         $details = array_merge($details, $this->metadata);
 
         $this->details = $details;

src/Smalot/PdfParser/Encoding/PDFDocEncoding.php

@@ -0,0 +1,189 @@
+<?php
+
+/**
+ * @file    This file is part of the PdfParser library.
+ *
+ * @author  Brian Huisman <bhuisman@greywyvern.com>
+ *
+ * @date    2023-06-28
+ *
+ * @license LGPLv3
+ *
+ * @url     <https://github.com/smalot/pdfparser>
+ *
+ *  PdfParser is a pdf library written in PHP, extraction oriented.
+ *  Copyright (C) 2017 - Sébastien MALOT <sebastien@malot.fr>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with this program.
+ *  If not, see <http://www.pdfparser.org/sites/default/LICENSE.txt>.
+ */
+
+// Source : https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/pdfreference1.2.pdf
+// Source : https://ia801001.us.archive.org/1/items/pdf1.7/pdf_reference_1-7.pdf
+
+namespace Smalot\PdfParser\Encoding;
+
+/**
+ * Class PDFDocEncoding
+ */
+class PDFDocEncoding
+{
+    public static function getCodePage(): array
+    {
+        return [
+            "\x18" => "\u{02d8}", // breve
+            "\x19" => "\u{02c7}", // caron
+            "\x1a" => "\u{02c6}", // circumflex
+            "\x1b" => "\u{02d9}", // dotaccent
+            "\x1c" => "\u{02dd}", // hungarumlaut
+            "\x1d" => "\u{02db}", // ogonek
+            "\x1e" => "\u{02de}", // ring
+            "\x1f" => "\u{02dc}", // tilde
+            "\x7f" => '',
+            "\x80" => "\u{2022}", // bullet
+            "\x81" => "\u{2020}", // dagger
+            "\x82" => "\u{2021}", // daggerdbl
+            "\x83" => "\u{2026}", // ellipsis
+            "\x84" => "\u{2014}", // emdash
+            "\x85" => "\u{2013}", // endash
+            "\x86" => "\u{0192}", // florin
+            "\x87" => "\u{2044}", // fraction
+            "\x88" => "\u{2039}", // guilsinglleft
+            "\x89" => "\u{203a}", // guilsinglright
+            "\x8a" => "\u{2212}", // minus
+            "\x8b" => "\u{2030}", // perthousand
+            "\x8c" => "\u{201e}", // quotedblbase
+            "\x8d" => "\u{201c}", // quotedblleft
+            "\x8e" => "\u{201d}", // quotedblright
+            "\x8f" => "\u{2018}", // quoteleft
+            "\x90" => "\u{2019}", // quoteright
+            "\x91" => "\u{201a}", // quotesinglbase
+            "\x92" => "\u{2122}", // trademark
+            "\x93" => "\u{fb01}", // fi
+            "\x94" => "\u{fb02}", // fl
+            "\x95" => "\u{0141}", // Lslash
+            "\x96" => "\u{0152}", // OE
+            "\x97" => "\u{0160}", // Scaron
+            "\x98" => "\u{0178}", // Ydieresis
+            "\x99" => "\u{017d}", // Zcaron
+            "\x9a" => "\u{0131}", // dotlessi
+            "\x9b" => "\u{0142}", // lslash
+            "\x9c" => "\u{0153}", // oe
+            "\x9d" => "\u{0161}", // scaron
+            "\x9e" => "\u{017e}", // zcaron
+            "\x9f" => '',
+            "\xa0" => "\u{20ac}", // Euro
+            "\xa1" => "\u{00a1}", // exclamdown
+            "\xa2" => "\u{00a2}", // cent
+            "\xa3" => "\u{00a3}", // sterling
+            "\xa4" => "\u{00a4}", // currency
+            "\xa5" => "\u{00a5}", // yen
+            "\xa6" => "\u{00a6}", // brokenbar
+            "\xa7" => "\u{00a7}", // section
+            "\xa8" => "\u{00a8}", // dieresis
+            "\xa9" => "\u{00a9}", // copyright
+            "\xaa" => "\u{00aa}", // ordfeminine
+            "\xab" => "\u{00ab}", // guillemotleft
+            "\xac" => "\u{00ac}", // logicalnot
+            "\xad" => '',
+            "\xae" => "\u{00ae}", // registered
+            "\xaf" => "\u{00af}", // macron
+            "\xb0" => "\u{00b0}", // degree
+            "\xb1" => "\u{00b1}", // plusminus
+            "\xb2" => "\u{00b2}", // twosuperior
+            "\xb3" => "\u{00b3}", // threesuperior
+            "\xb4" => "\u{00b4}", // acute
+            "\xb5" => "\u{00b5}", // mu
+            "\xb6" => "\u{00b6}", // paragraph
+            "\xb7" => "\u{00b7}", // periodcentered
+            "\xb8" => "\u{00b8}", // cedilla
+            "\xb9" => "\u{00b9}", // onesuperior
+            "\xba" => "\u{00ba}", // ordmasculine
+            "\xbb" => "\u{00bb}", // guillemotright
+            "\xbc" => "\u{00bc}", // onequarter
+            "\xbd" => "\u{00bd}", // onehalf
+            "\xbe" => "\u{00be}", // threequarters
+            "\xbf" => "\u{00bf}", // questiondown
+            "\xc0" => "\u{00c0}", // Agrave
+            "\xc1" => "\u{00c1}", // Aacute
+            "\xc2" => "\u{00c2}", // Acircumflex
+            "\xc3" => "\u{00c3}", // Atilde
+            "\xc4" => "\u{00c4}", // Adieresis
+            "\xc5" => "\u{00c5}", // Aring
+            "\xc6" => "\u{00c6}", // AE
+            "\xc7" => "\u{00c7}", // Ccedill
+            "\xc8" => "\u{00c8}", // Egrave
+            "\xc9" => "\u{00c9}", // Eacute
+            "\xca" => "\u{00ca}", // Ecircumflex
+            "\xcb" => "\u{00cb}", // Edieresis
+            "\xcc" => "\u{00cc}", // Igrave
+            "\xcd" => "\u{00cd}", // Iacute
+            "\xce" => "\u{00ce}", // Icircumflex
+            "\xcf" => "\u{00cf}", // Idieresis
+            "\xd0" => "\u{00d0}", // Eth
+            "\xd1" => "\u{00d1}", // Ntilde
+            "\xd2" => "\u{00d2}", // Ograve
+            "\xd3" => "\u{00d3}", // Oacute
+            "\xd4" => "\u{00d4}", // Ocircumflex
+            "\xd5" => "\u{00d5}", // Otilde
+            "\xd6" => "\u{00d6}", // Odieresis
+            "\xd7" => "\u{00d7}", // multiply
+            "\xd8" => "\u{00d8}", // Oslash
+            "\xd9" => "\u{00d9}", // Ugrave
+            "\xda" => "\u{00da}", // Uacute
+            "\xdb" => "\u{00db}", // Ucircumflex
+            "\xdc" => "\u{00dc}", // Udieresis
+            "\xdd" => "\u{00dd}", // Yacute
+            "\xde" => "\u{00de}", // Thorn
+            "\xdf" => "\u{00df}", // germandbls
+            "\xe0" => "\u{00e0}", // agrave
+            "\xe1" => "\u{00e1}", // aacute
+            "\xe2" => "\u{00e2}", // acircumflex
+            "\xe3" => "\u{00e3}", // atilde
+            "\xe4" => "\u{00e4}", // adieresis
+            "\xe5" => "\u{00e5}", // aring
+            "\xe6" => "\u{00e6}", // ae
+            "\xe7" => "\u{00e7}", // ccedilla
+            "\xe8" => "\u{00e8}", // egrave
+            "\xe9" => "\u{00e9}", // eacute
+            "\xea" => "\u{00ea}", // ecircumflex
+            "\xeb" => "\u{00eb}", // edieresis
+            "\xec" => "\u{00ec}", // igrave
+            "\xed" => "\u{00ed}", // iacute
+            "\xee" => "\u{00ee}", // icircumflex
+            "\xef" => "\u{00ef}", // idieresis
+            "\xf0" => "\u{00f0}", // eth
+            "\xf1" => "\u{00f1}", // ntilde
+            "\xf2" => "\u{00f2}", // ograve
+            "\xf3" => "\u{00f3}", // oacute
+            "\xf4" => "\u{00f4}", // ocircumflex
+            "\xf5" => "\u{00f5}", // otilde
+            "\xf6" => "\u{00f6}", // odieresis
+            "\xf7" => "\u{00f7}", // divide
+            "\xf8" => "\u{00f8}", // oslash
+            "\xf9" => "\u{00f9}", // ugrave
+            "\xfa" => "\u{00fa}", // uacute
+            "\xfb" => "\u{00fb}", // ucircumflex
+            "\xfc" => "\u{00fc}", // udieresis
+            "\xfd" => "\u{00fd}", // yacute
+            "\xfe" => "\u{00fe}", // thorn
+            "\xff" => "\u{00ff}",  // ydieresis
+        ];
+    }
+
+    public static function convertPDFDoc2UTF8(string $content): string
+    {
+        return strtr($content, static::getCodePage());
+    }
+}

tests/PHPUnit/Integration/DocumentTest.php

@@ -271,4 +271,31 @@ public function testExtractXMPMetadata(): void
         // Metadata.
         self::assertStringContainsString("Enhance PdfParser\u{2019}s Metadata Capabilities", $details['dc:title']);
     }
+
+    /**
+     * Tests PDFDocEncoding decode of Document Properties
+     *
+     * @see https://github.com/smalot/pdfparser/issues/609
+     */
+    public function testPDFDocEncodingDecode(): void
+    {
+        $document = (new Parser())->parseFile($this->rootDir.'/samples/Issue609.pdf');
+
+        $details = $document->getDetails();
+
+        // These test that Adobe-inserted \r are removed from a UTF-8
+        // escaped metadata string, and the surrounding characters are
+        // repaired
+        $testKeywords = '˘ˇˆ˙˝˛˞˜•†‡…—–ƒ⁄‹›−‰„“”‘’‚™fiflŁŒŠŸŽıłœšž€¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ';
+        self::assertStringContainsString($testKeywords, $details['Keywords']);
+
+        $testKeywords = 'added line-feeds often destroy multibyte characters';
+        self::assertStringContainsString($testKeywords, $details['Keywords']);
+
+        // This tests that the PDFDocEncoding characters that differ
+        // from CP-1252 are decoded to their correct UTF-8 code points
+        // as well as removing \r line-feeds
+        $testSubject = '•†‡…—–ƒ⁄‹›−‰„“”‘’‚™ŁŒŠŸŽıłœšž';
+        self::assertStringContainsString($testSubject, $details['Subject']);
+    }
 }