pdf.js/src/core/decrypt_stream.js
Calixte Denizet bc87f4e8d6 Add the possibility to create a pdf from different ones (bug 1997379)
For now it's just possible to create a single pdf in selecting some pages in different pdf sources.
The merge is for now pretty basic (it's why it's still a WIP) none of these data are merged for now:
 - the struct trees
 - the page labels
 - the outlines
 - named destinations
For there are 2 new ref tests where some new pdfs are created: one with some extracted pages and an other
one (encrypted) which is just rewritten.
The ref images are generated from the original pdfs in selecting the page we want and the new images are
taken from the generated pdfs.
2025-11-07 14:57:48 +01:00

62 lines
1.6 KiB
JavaScript

/* Copyright 2012 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { DecodeStream } from "./decode_stream.js";
const chunkSize = 512;
class DecryptStream extends DecodeStream {
constructor(str, maybeLength, decrypt) {
super(maybeLength);
this.stream = str;
this.dict = str.dict;
this.decrypt = decrypt;
this.nextChunk = null;
this.initialized = false;
}
readBlock() {
let chunk;
if (this.initialized) {
chunk = this.nextChunk;
} else {
chunk = this.stream.getBytes(chunkSize);
this.initialized = true;
}
if (!chunk?.length) {
this.eof = true;
return;
}
this.nextChunk = this.stream.getBytes(chunkSize);
const hasMoreData = this.nextChunk?.length > 0;
const decrypt = this.decrypt;
chunk = decrypt(chunk, !hasMoreData);
const bufferLength = this.bufferLength,
newLength = bufferLength + chunk.length,
buffer = this.ensureBuffer(newLength);
buffer.set(chunk, bufferLength);
this.bufferLength = newLength;
}
getOriginalStream() {
return this;
}
}
export { DecryptStream };