CertificateHolder class

Represents a holder of X509Certificate2 instance. To learn more, visit the Work with Digital Signatures documentation article.

Remarks

CertificateHolder can be created by static factory methods only. It contains an instance of X509Certificate2 which is used to introduce private, public keys and certificate chains into the system. This class is applied in DigitalSignatureUtil and PdfDigitalSignatureDetails instead of obsolete methods with System.Security.Cryptography.X509Certificates.X509Certificate2 as parameters.

Properties

Name	Description
certificate	Returns the instance of X509Certificate2 which holds private, public keys and certificate chain.

Methods

Name	Description
create(cert_bytes, password)	Creates CertificateHolder object using byte array of PKCS12 store and its password.
create(file_name, password)	Creates CertificateHolder object using path to PKCS12 store and its password.
create(file_name, password, alias)	Creates CertificateHolder object using path to PKCS12 store, its password and the alias by using which private key and certificate will be found.

Examples

Shows how to sign encrypted document file.

# Create an X.509 certificate from a PKCS#12 store, which should contain a private key.
certificate_holder = aw.digitalsignatures.CertificateHolder.create(file_name=MY_DIR + 'morzal.pfx', password='aw')
# Create a comment, date, and decryption password which will be applied with our new digital signature.
sign_options = aw.digitalsignatures.SignOptions()
sign_options.comments = 'Comment'
sign_options.sign_time = datetime.datetime.now()
sign_options.decryption_password = 'docPassword'
# Set a local system filename for the unsigned input document, and an output filename for its new digitally signed copy.
input_file_name = MY_DIR + 'Encrypted.docx'
output_file_name = ARTIFACTS_DIR + 'DigitalSignatureUtil.DecryptionPassword.docx'
aw.digitalsignatures.DigitalSignatureUtil.sign(src_file_name=input_file_name, dst_file_name=output_file_name, cert_holder=certificate_holder, sign_options=sign_options)

Shows how to digitally sign documents.

# Create an X.509 certificate from a PKCS#12 store, which should contain a private key.
certificate_holder = aw.digitalsignatures.CertificateHolder.create(MY_DIR + 'morzal.pfx', 'aw')
# Create a comment and date which will be applied with our new digital signature.
sign_options = aw.digitalsignatures.SignOptions()
sign_options.comments = 'My comment'
sign_options.sign_time = datetime.datetime.now()
# Take an unsigned document from the local file system via a file stream,
# then create a signed copy of it determined by the filename of the output file stream.
with open(MY_DIR + 'Document.docx', 'rb') as stream_in:
    with open(ARTIFACTS_DIR + 'DigitalSignatureUtil.sign_document.docx', 'wb') as stream_out:
        aw.digitalsignatures.DigitalSignatureUtil.sign(stream_in, stream_out, certificate_holder, sign_options)

Shows how to add a signature line to a document, and then sign it using a digital certificate.

def test_sign(self):

    signee_name = "Ron Williams"
    src_document_path = MY_DIR + "Document.docx"
    dst_document_path = ARTIFACTS_DIR + "SignDocumentCustom.sign.docx"
    certificate_path = MY_DIR + "morzal.pfx"
    certificate_password = "aw"

    for signee_info in self._create_signees():
        if signee_info.name == signee_name:
            self._sign_document(src_document_path, dst_document_path, signee_info, certificate_path,
                                certificate_password)
            break
    else:
        raise Exception("Signee does not exist.")

def _sign_document(self, src_document_path: str, dst_document_path: str,
                   signee_info, certificate_path: str, certificate_password: str):
    """Creates a copy of a source document signed using provided signee information and X509 certificate."""

    document = aw.Document(src_document_path)
    builder = aw.DocumentBuilder(document)

    # Configure and insert a signature line, an object in the document that will display a signature that we sign it with.
    signature_line_options = aw.SignatureLineOptions()
    signature_line_options.signer = signee_info.name
    signature_line_options.signer_title = signee_info.position

    signature_line = builder.insert_signature_line(signature_line_options).signature_line
    signature_line.id = signee_info.person_id

    # First, we will save an unsigned version of our document.
    builder.document.save(dst_document_path)

    certificate_holder = aw.digitalsignatures.CertificateHolder.create(certificate_path, certificate_password)

    sign_options = aw.digitalsignatures.SignOptions()
    sign_options.signature_line_id = signee_info.person_id
    sign_options.signature_line_image = signee_info.image

    # Overwrite the unsigned document we saved above with a version signed using the certificate.
    aw.digitalsignatures.DigitalSignatureUtil.sign(dst_document_path, dst_document_path, certificate_holder,
                                                   sign_options)

class Signee:

    def __init__(self, guid: uuid.UUID, name: str, position: str, image: bytes):
        self.person_id = guid
        self.name = name
        self.position = position
        self.image = image

def _create_signees(self):

    return [
        ExSignDocumentCustom.Signee(uuid.uuid4(), "Ron Williams", "Chief Executive Officer",
                                    self.image_to_byte_array(IMAGE_DIR + "Logo.jpg")),
        ExSignDocumentCustom.Signee(uuid.uuid4(), "Stephen Morse", "Head of Compliance",
                                    self.image_to_byte_array(IMAGE_DIR + "Logo.jpg"))
    ]

CertificateHolder class