Perl

Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

See more OpenSSL Examples

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

The in.dat file contains the original data that was signed, and can contain text or binary data of any type. The above OpenSSL command does the following:

1. Creates a SHA256 digest of the contents of the input file.
2. Verifies the SHA256 digest using the public key.

Perl

use chilkat();

$success = 0;

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

$pubKey = chilkat::CkPublicKey->new();

# Load the public key from an PEM file:
$success = $pubKey->LoadFromFile("pubKey.pem");
if ($success == 0) {
    print $pubKey->lastErrorText() . "\r\n";
    exit;
}

# Load the data of the original file that was signed.
$bdFileData = chilkat::CkBinData->new();
$success = $bdFileData->LoadFile("in.dat");

# Load the signature.
$bdSig = chilkat::CkBinData->new();
$success = $bdSig->LoadFile("signature.sig");

$rsa = chilkat::CkRsa->new();

# Import the public key into the RSA component:
$success = $rsa->UsePublicKey($pubKey);
if ($success == 0) {
    print $rsa->lastErrorText() . "\r\n";
    exit;
}

# OpenSSL uses big-endian.
$rsa->put_LittleEndian(0);

$success = $rsa->VerifyBd($bdFileData,"sha256",$bdSig);
if ($success != 1) {
    print $rsa->lastErrorText() . "\r\n";
    print "The signature was invalid." . "\r\n";
    exit;
}

print "The signature was verified." . "\r\n";