Perl Requires Chilkat v11.0.0+

Decrypt S/MIME and Verify S/MIME Signatures

See more MIME Examples

_LANGUAGE_ example to decrypt S/MIME and verify S/MIME signatures. The S/MIME is unwrapped to get the original MIME prior to signing/encrypting. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $mime = Chilkat2::Mime->new;

# Load an S/MIME message from a file:
my $success = $mime->LoadMimeFile('signedMime.txt');
if (!$success) {
    print $mime->LastErrorText, "\n";
    exit;
}

# The ContainsEncryptedParts/ContainsSignedParts methods
# can be called to determine if the MIME is encrypted and/or signed:
my $isEncrypted = $mime->ContainsEncryptedParts();
my $isSigned = $mime->ContainsSignedParts();

# We don't want the "unwrap extras".  You'll see what those
# are in a few moments...
$mime->UnwrapExtras(0);

# To verify the signature, call UnwrapSecurity.  This will
# verify the signature(s) and decrypt the S/MIME and restore
# the MIME to the unsigned/unencrypted state.
# The results of what was found are present in the MIME object's
# properties, as well as extra header fields that are added
# to the unwrapped MIME.
$success = $mime->UnwrapSecurity();
if (!$success) {
    # UnwrapSecurity returns 1 if all signatures were
    # verified and all parts decrypted.
    print $mime->LastErrorText, "\n";
    exit;
}

# The mime.UnwrapExtras property controls whether or not
# these additional fields are added to the unwrapped MIME:
#
# X-NumPartsSigned: 1
# X-SignaturesValid: yes
# X-NumPartsEncrypted: 1
# X-Decrypted: no
#
# The X-NumPartsSigned/X-SignaturesValid headers are added
# if the MIME was signed.
#
# The X-NumPartsEncrypted/X-Decrypted headers are added
# if the MIME was encrypted.
#

# If the MIME was signed, get the certificate used for signing.
if ($isSigned) {
    my $signerCert = Chilkat2::Cert->new;

    # The NumSignerCerts property indicates how many certificates
    # were used for signing.  This example will assume the value is 1.
    # To get the 1st signer cert, call LastSignerCert with an index of 0:
    $success = $mime->LastSignerCert(0, $signerCert);
    if ($success) {
        print '**** Signer Cert: ', $signerCert->SubjectCN, "\n";
    }
}

# If the MIME was encrypted, get the certificate used for decryption
if ($isEncrypted) {
    # The NumDecryptCerts property indicates how many certificates
    # were used for decrypting.  This example will assume the value is 1.
    # To get the 1st decrypt cert, call LastDecryptCert with an index of 0:
    my $decryptCert = Chilkat2::Cert->new;
    $success = $mime->LastDecryptCert(0, $decryptCert);
    if ($success) {
        print '**** Decrypt Cert: ', $decryptCert->SubjectCN, "\n";
    }
}

# Display the unwrapped MIME:
print $mime->GetMime(), "\n";

# Save the unwrapped MIME to a file:
$success = $mime->SaveMime('unwrappedMime.txt');