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PKCS7 Sign Text using RSA 2048, SHA256, Base64 Output

See more Digital Signatures Examples

Demonstrates how to sign text using 2048-bit RSA with SHA256, producing PKCS#7 output in Base64. The certificate w/ private key used for signing is loaded from a .p12/.pfx file.

Chilkat PHP Extension Downloads

PHP Extension
<?php

include("chilkat.php");

$success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$cert = new CkCert();

// Load the cert and private key.  Whatever the private key happens to be,
// such as RSA or ECC, then Chilkat will use it.  If the private key is 
// a 2048-bit RSA key, then that's what will be used..
$success = $cert->LoadPfxFile('qa_data/pfx/myCertAndKey.p12','password');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$crypt = new CkCrypt2();

$success = $crypt->SetSigningCert($cert);
if ($success != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

// Use SHA-256
$crypt->put_HashAlgorithm('sha256');

// Hash the utf-8 byte representation of the string
$crypt->put_Charset('utf-8');

// Return the result in base64
$crypt->put_EncodingMode('base64');

// Sign some text..
$textToSign = 'This is the text to be hashed and signed.';
$sigBase64 = $crypt->opaqueSignStringENC($textToSign);
if ($crypt->get_LastMethodSuccess() != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print $sigBase64 . "\n";

// The result:
// MIIS2wYJKoZIhvcNAQc ... zGeeY4Oxg==

?>