Generate RSA Key and Sign a String

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

 Chilkat Perl Module Downloads for Windows, Linux, and MAC OS X

use chilkat();

$rsa = new chilkat::CkRsa();

#  Any string argument automatically begins the 30-day trial.
$success = $rsa->UnlockComponent("30-day trial");
if ($success != 1) {
    print "RSA component unlock failed" . "\n";
    exit;
}

#  Generate a 1024-bit RSA key pair.
$rsa->GenerateKey(1024);

#  This example will sign a string, and receive the signature
#  in a hex-encoded string.  Therefore, set the encoding mode
#  to "hex":
$rsa->put_EncodingMode("hex");

#  If some other non-Chilkat application or web service is going to be verifying
#  the signature, it is important to match the byte-ordering.
#  The LittleEndian property may be set to 1
#  for little-endian byte ordering,
#  or 0  for big-endian byte ordering.
#  Microsoft apps typically use little-endian, while
#  OpenSSL and other services (such as Amazon CloudFront)
#  use big-endian.
$rsa->put_LittleEndian(0);

$strData = "This is the string to be signed.";

#  Sign the string using the  md5 hash algorithm.
#  Other valid choices are "md2", "sha256", "sha384",
#  "sha512", and "sha-1".
$hexSig = $rsa->signStringENC($strData,"md5");

print $hexSig . "\r\n";
print $rsa->lastErrorText() . "\r\n";

#  Now verify the signature:
$success = $rsa->VerifyStringENC($strData,"md5",$hexSig);
if ($success == 1) {
    print "Signature verified!" . "\n";
}
else {
    print $rsa->lastErrorText() . "\r\n";
}

#  Try it with an invalid signature:
$success = $rsa->VerifyStringENC($strData,"md5","not a valid sig");
if ($success == 1) {
    print "Signature verified!" . "\n";
}
else {
    print $rsa->lastErrorText() . "\r\n";
}

#  Try it with invalid data:
$success = $rsa->VerifyStringENC("Not the original data","md5",$hexSig);
if ($success == 1) {
    print "Signature verified!" . "\n";
}
else {
    print $rsa->lastErrorText() . "\r\n";
}

#  Try it with the wrong hash algorithm:
$success = $rsa->VerifyStringENC($strData,"sha-1",$hexSig);
if ($success == 1) {
    print "Signature verified!" . "\n";
}
else {
    print $rsa->lastErrorText() . "\r\n";
}