write_restricted.json

Die JSON-Datei des Beispiels „Ein Dokument, das sich frei lesen lässt und bittet, nicht kopiert zu werden“. Eine Seite, die sich ohne Passwort öffnet und wie jede andere druckt, aber die Anzeigesoftware bittet, das Kopieren und Einfügen ihres Textes zu verbieten. Der Text ist in der Datei verschlüsselt: Ein Programm, das sie Byte für Byte liest, findet darin keinen Satz.

JSON 474 Zeilen

Diese Datei ist eine Anfrage: Eine Anwendung sendet sie über das Netz an den Server, der das PDF erzeugt und zurücksendet. Sie erzeugt dieselbe Seite wie die Rust- und die Python-Fassung dieses Beispiels. Eine Anfrage nennt jede Datei, die sie verwendet, nie ihren Inhalt; der Aufruf trägt die Anfrage und die Dateien zusammen. Eine Schrift, die der Server bereits vorhält, etwa DejaVuSans, wird ohne Anhang genannt. Senden Sie die Anfrage an die Adresse, die die API-Seite angibt.

Wofür dieses Beispiel da ist

Denken Sie an eine auf dem Ladentisch liegende Preisliste. Jeder darf sie nehmen, lesen und mitnehmen: Dafür liegt sie da. Was man nicht sehen möchte, ist, dass die eigenen Absätze vierzehn Tage später Wort für Wort in der Broschüre eines anderen auftauchen. Die Datei unten ist diese Preisliste. Sie öffnet sich für jeden und trägt eine schriftliche Bitte, ihren Text in Ruhe zu lassen.

Was dieses Beispiel zeigt

Datei herunterladen Dasselbe Beispiel in Rust Dasselbe Beispiel in Python Ansehen, was sie erzeugt 
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{
  "metadata": {
    "title": "A document that reads freely and asks not to be copied"
  },
  "protection": {
    "owner_password": "the owner",
    "permissions": [
      "printing",
      "printing_at_full_resolution",
      "extracting_for_accessibility"
    ]
  },
  "items": [
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 760.0,
        "urx": 540.0,
        "ury": 781.6
      },
      "content": [
        "A document that reads freely"
      ],
      "font": "DejaVuSans",
      "font_size": 18.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 738.0,
        "urx": 540.0,
        "ury": 759.6
      },
      "content": [
        "and asks not to be copied"
      ],
      "font": "DejaVuSans",
      "font_size": 18.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 700.0,
        "urx": 540.0,
        "ury": 713.2
      },
      "content": [
        "Everything written in this file is scrambled: every word,"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 682.0,
        "urx": 540.0,
        "ury": 695.2
      },
      "content": [
        "every picture, under a key of two hundred and fifty-six bits."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 664.0,
        "urx": 540.0,
        "ury": 677.2
      },
      "content": [
        "It opens all the same. Nobody is asked for anything, which is"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 646.0,
        "urx": 540.0,
        "ury": 659.2
      },
      "content": [
        "what most protected files in the world do."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 628.0,
        "urx": 540.0,
        "ury": 641.2
      },
      "content": [
        "What it asks is asked of the reading software: let this be"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 610.0,
        "urx": 540.0,
        "ury": 623.2
      },
      "content": [
        "printed and read out loud, but do not let it be copied or"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 592.0,
        "urx": 540.0,
        "ury": 605.2
      },
      "content": [
        "changed. It is a request and not a lock, and software that"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 574.0,
        "urx": 540.0,
        "ury": 587.2
      },
      "content": [
        "pays no heed to it copies the page all the same."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 556.0,
        "urx": 540.0,
        "ury": 569.2
      },
      "content": [
        "The author's password lifts the request: the owner"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 520.0,
        "urx": 540.0,
        "ury": 535.6
      },
      "content": [
        "The other document of this pair"
      ],
      "font": "DejaVuSans",
      "font_size": 13.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 492.0,
        "urx": 540.0,
        "ury": 505.2
      },
      "content": [
        "A second document was written beside this one. That one shows"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 474.0,
        "urx": 540.0,
        "ury": 487.2
      },
      "content": [
        "nothing at all until its password is typed in, while the page"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 456.0,
        "urx": 540.0,
        "ury": 469.2
      },
      "content": [
        "you are reading opened on its own."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 420.0,
        "urx": 540.0,
        "ury": 435.6
      },
      "content": [
        "Where the key comes from"
      ],
      "font": "DejaVuSans",
      "font_size": 13.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 392.0,
        "urx": 540.0,
        "ury": 405.2
      },
      "content": [
        "The thirty-two bytes the key is built from are fixed in this"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 374.0,
        "urx": 540.0,
        "ury": 387.2
      },
      "content": [
        "example, so that it writes the same file on every run and one"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 356.0,
        "urx": 540.0,
        "ury": 369.2
      },
      "content": [
        "build can be compared with the last. A program takes them from"
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 338.0,
        "urx": 540.0,
        "ury": 351.2
      },
      "content": [
        "its operating system: a seed anybody can read locks nothing."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        1
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 760.0,
        "urx": 540.0,
        "ury": 775.6
      },
      "content": [
        "The first page, locked other ways"
      ],
      "font": "DejaVuSans",
      "font_size": 13.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 700.0,
        "urx": 540.0,
        "ury": 713.2
      },
      "content": [
        "Granting everything, it weighs 13441 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 682.0,
        "urx": 540.0,
        "ury": 695.2
      },
      "content": [
        "Granting changes, copying, notes, forms and assembly: 13444 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 664.0,
        "urx": 540.0,
        "ury": 677.2
      },
      "content": [
        "Under the older cipher earlier software knows: 13198 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 646.0,
        "urx": 540.0,
        "ury": 659.2
      },
      "content": [
        "With what it says of itself left readable: 13467 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 628.0,
        "urx": 540.0,
        "ury": 641.2
      },
      "content": [
        "Carrying one file, with only that file locked: 13635 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    },
    {
      "type": "text",
      "rect": {
        "llx": 72.0,
        "lly": 610.0,
        "urx": 540.0,
        "ury": 623.2
      },
      "content": [
        "Locked for one person's certificate instead: 14076 bytes."
      ],
      "font": "DejaVuSans",
      "font_size": 11.0,
      "pages": [
        2
      ]
    }
  ]
}