awaforge

pdfStandardV5

AGPL-3.0-onlyRelease 2L4

Standard Security Handler R=5 (historical AES-256, PDF 1.7 Adobe Extension Level 3).

Module pdfStandardV5 | Source packages/front/office/pdf/src/crypto/standardV5.js | Deps pdfErrors, aes, cbc, sha256, bitArray, pdfAesGcm | Worker-safe yes

Implements the R=5 derivation: SHA-256 of password + validation salt → file encryption key via AES-CBC over /OE//UE. This algorithm was deprecated by ISO 32000-2 in favor of R=6 hardening, but remains needed to read PDFs produced between 2009 and 2018. pdfAesGcm is an optional dependency, only required when a /CF crypt filter resolves to AESV4 (ISO/TS 32003).

Resolve

const v5 = runtime.resolve('pdfStandardV5');
// Returns: { tryPassword, decryptString, decryptStream,
//            encryptString, encryptStream,
//            buildUUE, buildOOE, buildPerms }

API

Method Signature Returns
tryPassword (typedEncrypt: { O, U, OE, UE }, password: string | Uint8Array, isOwner: boolean) => { fileEncryptionKey: Uint8Array | null } null on rejection.
decryptString (typedEncrypt: { method? }, fek, objNum, gen, ciphertext) => Uint8Array AES-256-CBC (or AES-GCM when typedEncrypt.method === 'AESV4'), §7.6.4. objNum/gen are accepted but unused (V5 keys are not per-object).
decryptStream same signature as decryptString Alias — identical implementation.
encryptString (typedEncrypt: { method? }, fek, objNum, gen, plaintext, iv) => Uint8Array Encrypts (write side). iv must be 16 bytes for AES-CBC or 12 bytes for AESV4.
encryptStream same signature as encryptString Alias — identical implementation.
buildUUE (password, fek, valSalt: Uint8Array, keySalt: Uint8Array) => { U: Uint8Array(48), UE: Uint8Array(32) } Builds /U + /UE per Algorithm 2.A.
buildOOE (password, fek, U48: Uint8Array, valSalt, keySalt) => { O: Uint8Array(48), OE: Uint8Array(32) } Builds /O + /OE.
buildPerms (p: number, fek, encryptMetadata: boolean, randomBytes: (n) => Uint8Array) => Uint8Array(16) Algorithm 10 — encrypted /Perms block.

Examples

Owner then user password attempt

const v5 = runtime.resolve('pdfStandardV5');
let r = v5.tryPassword(enc, ownerPwd, true);
if (!r.fileEncryptionKey) r = v5.tryPassword(enc, userPwd, false);
if (!r.fileEncryptionKey) throw new Error('bad password');
const plain = v5.decryptStream(enc, r.fileEncryptionKey, num, gen, encStream);

Building a fresh /O, /U, /OE, /UE set (write side)

const v5 = runtime.resolve('pdfStandardV5');
const { U, UE } = v5.buildUUE(userPwd, fek, valSalt, keySalt);
const { O, OE } = v5.buildOOE(ownerPwd, fek, U, valSalt2, keySalt2);
const permsBlock = v5.buildPerms(pBitmask, fek, true, cryptoRandomBytes);

Errors

Code Class When
pdf/crypto/v5/missing-fw EncryptionError fw bundle incomplete (thrown at module construction).
pdf/crypto/v5/bad-password EncryptionError Invalid password argument.
pdf/crypto/v5/bad-ciphertext-len EncryptionError Length not a multiple of 16.
pdf/crypto/v5/aes-schedule-failed EncryptionError fw key schedule failed.
pdf/crypto/v5/cbc-decrypt-failed EncryptionError fw CBC decrypt failed.
pdf/crypto/v5/bad-O-U EncryptionError /O or /U not at least 48 bytes.
pdf/crypto/v5/bad-OE-UE EncryptionError /OE or /UE not exactly 32 bytes.
pdf/crypto/v5/bad-string EncryptionError Encrypted string shorter than 32 bytes (IV + 1 block).
pdf/crypto/v5/missing-gcm EncryptionError method === 'AESV4' requested but pdfAesGcm was not supplied.
pdf/crypto/v5/bad-pt-len EncryptionError Plaintext length not a multiple of 16 (encryptString/CBC path).
pdf/crypto/v5/aes-encrypt-schedule EncryptionError fw key schedule failed on the encrypt side.
pdf/crypto/v5/cbc-encrypt-failed EncryptionError fw CBC encrypt failed.
pdf/crypto/v5/encrypt-bad-input EncryptionError encryptString plaintext is not a Uint8Array.
pdf/crypto/v5/encrypt-bad-iv EncryptionError iv has the wrong length for the resolved method.
pdf/crypto/v5/perms-schedule EncryptionError AES-256-ECB schedule failed while building /Perms.

See also