pdfEncryptedWriter

Emits an /Encrypt-protected PDF — wraps pdfWriter with the Standard Security Handlers.

Module pdfEncryptedWriter | Source packages/front/office/pdf/src/document/encryptedWriter.js | Deps pdfErrors, pdfWriter, pdfStandardV5, pdfStandardV6, pdfStandardV4, pdfAesGcm | Worker-safe yes

Encrypts a from-scratch indirect-object graph (same shape as pdfWriter's indirects) and emits the result with an /Encrypt dictionary. Supports:

• V=4, R=4 (PDF 1.6) — method 'AESV2' (AES-128-CBC, default) or 'V2' (RC4-128), delegated to pdfStandardV4.
• V=5, R=5 (historical AES-256, Adobe Extension Level 3) — delegated to pdfStandardV5.
• V=5, R=6 (ISO 32000-2:2020 hardening) — delegated to pdfStandardV6. Method 'AESV3' (AES-256-CBC, default) or 'AESV4' (AES-256-GCM, ISO TS 32003 — requires pdfAesGcm).

An optional distinct cipher for /Type /EmbeddedFile streams (/EFF, ISO 32000-1 §7.6.5) is selected via opts.encrypt.effMethod, validated against the same (version, method) rules as the main method. Every string and stream.raw payload in the indirect graph is walked and encrypted in place (fresh IV per object) before the /Encrypt indirect is appended and the trailer patched.

Resolve

const ew = runtime.resolve('pdfEncryptedWriter');
// Returns: { writeEncryptedDocument }

API

EncWriteOpts

Mirrors pdfWriter's WriteOpts (indirects, root, info?, id?, version?) plus:

{
    encrypt: {
        version: 4 | 5,
        revision: 4 | 5 | 6,
        method?:     'AESV2' | 'V2' | 'AESV3' | 'AESV4',  // default per version
        effMethod?:  'AESV2' | 'V2' | 'AESV3' | 'AESV4',  // optional, /Type /EmbeddedFile only
        keyBits?:    number,           // default 128 (V4) / 256 (V5)
        ownerPassword?: string | Uint8Array,
        userPassword?:  string | Uint8Array,
        permissions?:   number,        // /P bitmask (Table 24)
        encryptMetadata?: boolean,     // default true
        randomBytes?: (n: number) => Uint8Array  // default globalThis.crypto.getRandomValues
    }
}

randomBytes supplies every key, salt and IV the writer draws. When it is omitted the writer uses globalThis.crypto.getRandomValues, read at call time; when neither exists the call throws pdf/crypto/enc-writer/no-random before producing any output. There is no non-cryptographic fallback.

EncWriteResult

{
    bytes: Uint8Array, encryptObjNum: number,
    fek: Uint8Array, id: [Uint8Array, Uint8Array],
    O, U, OE?, UE?, Perms?: Uint8Array,
    version, revision, method, effMethod
}

Examples

V=5 R=6, AES-256-CBC, deterministic (test) randomness

const ew = runtime.resolve('pdfEncryptedWriter');
const out = ew.writeEncryptedDocument({
    indirects, root: { num: 1, gen: 0 },
    encrypt: {
        version: 5, revision: 6,
        ownerPassword: 'owner', userPassword: 'user',
        permissions: -4,
        randomBytes: makeDeterministicRand(1)   // test-only PRNG
    }
});
out.bytes;   // encrypted PDF, ready to write to disk

V=4 R=4, legacy RC4-128

const out = ew.writeEncryptedDocument({
    indirects, root: { num: 1, gen: 0 },
    encrypt: { version: 4, revision: 4, method: 'V2', userPassword: 'user' }
});

Distinct cipher for embedded-file streams (/EFF)

const out = ew.writeEncryptedDocument({
    indirects, root: { num: 1, gen: 0 },
    encrypt: {
        version: 5, revision: 6, method: 'AESV3',
        effMethod: 'AESV4',   // embedded files get AES-GCM, everything else AES-CBC
        userPassword: 'user'
    }
});

Recovering the FEK to decrypt

const v6 = runtime.resolve('pdfStandardV6');
const r = v6.tryPassword(typedEncryptDict, 'user', false);
r.fileEncryptionKey; // === out.fek, when the password matches

Errors

See also

• pdfWriter — the base emitter this wraps.
• pdfStandardV4 · pdfStandardV5 · pdfStandardV6 · pdfAesGcm
• pdfSecurity — the read-side dispatcher.