PAdES Digital Signatures

★ Pro — Commercial License Required

PAdES B-T, B-LT, and B-LTA signature levels require the Pro package.

TCPDF-Next Pro implements the full PAdES pipeline (ETSI EN 319 142) using CertificateInfo, DigitalSigner, ByteRangeCalculator, and SignatureAppearance.

Signature Levels

Level	Enum Value	What It Adds
B-B	SignatureLevel::PAdES_B_B	CMS signature with signing certificate
B-T	SignatureLevel::PAdES_B_T	RFC 3161 signature timestamp
B-LT	SignatureLevel::PAdES_B_LT	Revocation data (OCSP + CRL) via DSS
B-LTA	SignatureLevel::PAdES_B_LTA	Document timestamp for indefinite validity

CertificateInfo

Loads and parses X.509 certificates and private keys from PEM or PKCS#12 files.

use Yeeefang\TcpdfNext\Pro\Security\Signature\CertificateInfo;

// From PEM files
$cert = CertificateInfo::fromPem('/certs/signing.pem', '/certs/signing.key', 'pw');
$cert->chain(['/certs/intermediate.pem', '/certs/root.pem']);

// From PKCS#12 (chain extracted automatically)
$cert = CertificateInfo::fromPkcs12('/certs/signing.p12', 'p12-password');

// Inspect certificate details
echo $cert->subjectCN();        // "John Doe"
echo $cert->issuerCN();         // "Acme Intermediate CA"
echo $cert->validFrom();        // DateTimeImmutable
echo $cert->ocspResponderUrl(); // "https://ocsp.acme.com"

DigitalSigner

Generates the CMS/PKCS#7 signature container and orchestrates timestamp and LTV embedding.

use Yeeefang\TcpdfNext\Core\Document;
use Yeeefang\TcpdfNext\Pro\Security\Signature\DigitalSigner;
use Yeeefang\TcpdfNext\Pro\Security\Timestamp\TsaClient;
use Yeeefang\TcpdfNext\Contracts\Enums\SignatureLevel;

$pdf  = Document::create()->addPage()->text('Contract document.');
$cert = CertificateInfo::fromPkcs12('/certs/signer.p12', 'pw');
$tsa  = new TsaClient('https://tsa.example.com/timestamp');

$signer = new DigitalSigner($cert);
$signer->level(SignatureLevel::PAdES_B_LTA);
$signer->timestampAuthority($tsa);
$signer->reason('Document approval');
$signer->location('Taipei, Taiwan');

$signer->sign($pdf);
$pdf->save('/output/signed.pdf');

At B-LT and B-LTA levels, LtvManager is invoked internally to fetch OCSP responses and CRLs and build the DSS dictionary.

ByteRangeCalculator

Manages the signature placeholder and computes byte ranges. Handled internally by DigitalSigner; direct use is for advanced scenarios.

SignatureAppearance

Controls the visible representation of the signature on the page. Signatures are invisible by default.

use Yeeefang\TcpdfNext\Pro\Security\Signature\SignatureAppearance;

$appearance = SignatureAppearance::create()
    ->page(1)
    ->position(x: 20.0, y: 250.0, width: 80.0, height: 30.0)
    ->text("Digitally signed by John Doe\nDate: 2026-02-16")
    ->image('/images/handwritten-signature.png')
    ->imagePosition('left')  // 'left', 'right', 'top', 'bottom', 'background'
    ->fontSize(8);

$signer->appearance($appearance);
$signer->sign($pdf);

Complete B-LTA Example

use Yeeefang\TcpdfNext\Core\Document;
use Yeeefang\TcpdfNext\Pro\Security\Signature\{DigitalSigner, CertificateInfo, SignatureAppearance};
use Yeeefang\TcpdfNext\Pro\Security\Timestamp\TsaClient;
use Yeeefang\TcpdfNext\Contracts\Enums\SignatureLevel;

$pdf = Document::create()
    ->addPage()
    ->font('Helvetica', size: 14, style: 'B')
    ->text('Purchase Agreement')
    ->font('Helvetica', size: 11)
    ->text('This agreement is entered into on February 16, 2026...');

$cert = CertificateInfo::fromPkcs12('/certs/legal.p12', 'passphrase');
$tsa  = new TsaClient('https://tsa.example.com/timestamp');

$signer = new DigitalSigner($cert);
$signer->level(SignatureLevel::PAdES_B_LTA);
$signer->timestampAuthority($tsa);
$signer->appearance(
    SignatureAppearance::create()
        ->page(1)
        ->position(x: 20.0, y: 250.0, width: 80.0, height: 25.0)
        ->text("Signed by Legal Dept.\n2026-02-16")
);
$signer->reason('Purchase agreement execution');
$signer->location('Taipei, Taiwan');

$signer->sign($pdf);
$pdf->save('/contracts/purchase-agreement-signed.pdf');

Next Steps

• Long-Term Validation -- DSS, OCSP, CRL, and archival timestamps.
• HSM Integration -- Sign with hardware security modules via PKCS#11.
• Pro Package Overview -- Full module listing and license information.