Perl

Verify an RSA Signature Against the Signed Hash

See more Apple Keychain Examples

Demonstrates how to validate an RSA Signature against the hash that was signed. Perl

use chilkat();

$success = 0;

$bd = chilkat::CkBinData->new();

for ($i = 0; $i <= 100; $i++) {
    $bd->AppendEncoded("000102030405060708090A0B0C0D0E0F","hex");
}

$sha256_base64 = $bd->getHash("sha256","base64");
print "sha256 hash in base64 format: " . $sha256_base64 . "\r\n";

$base64_rsa_sig = "AwF2BbOvL6jA5DwmMAc9n6J2Cc8PI6Rj5W079+aKJcIEtPWRzHor0Bvc3aftGM3Jbgj6SXlIC3M3RYS7UZOnfiHKFNZgbxaNT5WwsWooK42ZkC8DBZl0p7OunBUKd5SciUo+TKilioeUkriN3L1Zl9hwi3HVDVqgVo3XXskwIftSqLSFlepTLTmOWj9Y93dp8J4D9RyLtNgFQBc0WB22tyJTsuY56mLcWe1AMF3LizB9OrbwjynF2u16xWlrJdugccz795fJBUV9aQSD+8S3KeqwQhoi8RK1uhD68aGCyaSpBq0NZ8COAkn7MXaF4POxrAAt8udfHM+PRfSOptcH/w==";

# Get the public key to be used for signature verification.
$pubKey = chilkat::CkPublicKey->new();
$success = $pubKey->LoadFromFile("rsaKeys/chilkat-rsa-2048.pem");
if ($success == 0) {
    print $pubKey->lastErrorText() . "\r\n";
    exit;
}

$rsa = chilkat::CkRsa->new();
$success = $rsa->UsePublicKey($pubKey);
if ($success == 0) {
    print $rsa->lastErrorText() . "\r\n";
    exit;
}

# Verify the hash against the signature.
$rsa->put_EncodingMode("base64");
$success = $rsa->VerifyHashENC($sha256_base64,"sha256",$base64_rsa_sig);

if ($success == 0) {
    print $rsa->lastErrorText() . "\r\n";
    print "Signature invalid." . "\r\n";
}
else {
    print "Signature valid." . "\r\n";
}