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Merge pull request #19644 from Snuffleupagus/crypto-PDFBase

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Introduce a common base class for the `PDF17` and `PDF20` crypto classes
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Jonas Jenwald 2025-03-12 21:05:39 +01:00 • committed by GitHub
commit e4795f639c
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GPG key ID: B5690EEEBB952194
1 changed files with 26 additions and 44 deletions
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70
src/core/crypto.js
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@ -632,13 +632,26 @@ class AES256Cipher extends AESBaseCipher {
}
}
class PDF17 {
class PDFBase {
constructor() {
if (
(typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) &&
this.constructor === PDFBase
) {
unreachable("Cannot initialize PDFBase.");
}
}
_hash(password, input, userBytes) {
unreachable("Abstract method `_hash` called");
}
checkOwnerPassword(password, ownerValidationSalt, userBytes, ownerPassword) {
const hashData = new Uint8Array(password.length + 56);
hashData.set(password, 0);
hashData.set(ownerValidationSalt, password.length);
hashData.set(userBytes, password.length + ownerValidationSalt.length);
const result = calculateSHA256(hashData, 0, hashData.length);
const result = this._hash(password, hashData, userBytes);
return isArrayEqual(result, ownerPassword);
}
@ -646,7 +659,7 @@ class PDF17 {
const hashData = new Uint8Array(password.length + 8);
hashData.set(password, 0);
hashData.set(userValidationSalt, password.length);
const result = calculateSHA256(hashData, 0, hashData.length);
const result = this._hash(password, hashData, []);
return isArrayEqual(result, userPassword);
}
@ -655,7 +668,7 @@ class PDF17 {
hashData.set(password, 0);
hashData.set(ownerKeySalt, password.length);
hashData.set(userBytes, password.length + ownerKeySalt.length);
const key = calculateSHA256(hashData, 0, hashData.length);
const key = this._hash(password, hashData, userBytes);
const cipher = new AES256Cipher(key);
return cipher.decryptBlock(ownerEncryption, false, new Uint8Array(16));
}
@ -665,14 +678,20 @@ class PDF17 {
hashData.set(password, 0);
hashData.set(userKeySalt, password.length);
// `key` is the decryption key for the UE string.
const key = calculateSHA256(hashData, 0, hashData.length);
const key = this._hash(password, hashData, []);
const cipher = new AES256Cipher(key);
return cipher.decryptBlock(userEncryption, false, new Uint8Array(16));
}
}
class PDF20 {
#hash(password, input, userBytes) {
class PDF17 extends PDFBase {
_hash(password, input, userBytes) {
return calculateSHA256(input, 0, input.length);
}
}
class PDF20 extends PDFBase {
_hash(password, input, userBytes) {
// This refers to Algorithm 2.B as defined in ISO 32000-2.
let k = calculateSHA256(input, 0, input.length).subarray(0, 32);
let e = [0];
@ -713,43 +732,6 @@ class PDF20 {
}
return k.subarray(0, 32);
}
checkOwnerPassword(password, ownerValidationSalt, userBytes, ownerPassword) {
const hashData = new Uint8Array(password.length + 56);
hashData.set(password, 0);
hashData.set(ownerValidationSalt, password.length);
hashData.set(userBytes, password.length + ownerValidationSalt.length);
const result = this.#hash(password, hashData, userBytes);
return isArrayEqual(result, ownerPassword);
}
checkUserPassword(password, userValidationSalt, userPassword) {
const hashData = new Uint8Array(password.length + 8);
hashData.set(password, 0);
hashData.set(userValidationSalt, password.length);
const result = this.#hash(password, hashData, []);
return isArrayEqual(result, userPassword);
}
getOwnerKey(password, ownerKeySalt, userBytes, ownerEncryption) {
const hashData = new Uint8Array(password.length + 56);
hashData.set(password, 0);
hashData.set(ownerKeySalt, password.length);
hashData.set(userBytes, password.length + ownerKeySalt.length);
const key = this.#hash(password, hashData, userBytes);
const cipher = new AES256Cipher(key);
return cipher.decryptBlock(ownerEncryption, false, new Uint8Array(16));
}
getUserKey(password, userKeySalt, userEncryption) {
const hashData = new Uint8Array(password.length + 8);
hashData.set(password, 0);
hashData.set(userKeySalt, password.length);
// `key` is the decryption key for the UE string.
const key = this.#hash(password, hashData, []);
const cipher = new AES256Cipher(key);
return cipher.decryptBlock(userEncryption, false, new Uint8Array(16));
}
}
class CipherTransform {