diff --git a/source/cfdi-cert.py b/source/cfdi_cert.py
similarity index 82%
rename from source/cfdi-cert.py
rename to source/cfdi_cert.py
index 4b7ea77..ec1937f 100644
--- a/source/cfdi-cert.py
+++ b/source/cfdi_cert.py
@@ -6,7 +6,6 @@ import datetime
 import getpass
 from pathlib import Path
 
-import xmlsec
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
 from cryptography import x509
@@ -20,15 +19,17 @@ from conf import TOKEN
 
 class SATCertificate(object):
 
-    def __init__(self, cer=b'', key=b'', password=''):
+    def __init__(self, cer=b'', key=b'', pem=b'', password=''):
         self._error = ''
         self._init_values()
         self._get_data_cer(cer)
         self._get_data_key(key, password)
+        self._get_data_pem(pem)
 
     def _init_values(self):
         self._rfc = ''
         self._serial_number = ''
+        self._serial_number2 = ''
         self._not_before = None
         self._not_after = None
         self._is_fiel = False
@@ -37,9 +38,11 @@ class SATCertificate(object):
         self._cer_pem = ''
         self._cer_txt = ''
         self._key_enc = b''
+        self._key_pem = b''
         self._p12 = b''
         self._cer_modulus = 0
         self._key_modulus = 0
+        self._issuer = ''
         return
 
     def __str__(self):
@@ -66,9 +69,12 @@ class SATCertificate(object):
         obj = x509.load_der_x509_certificate(cer, default_backend())
         self._rfc = obj.subject.get_attributes_for_oid(
             NameOID.X500_UNIQUE_IDENTIFIER)[0].value.split(' ')[0]
+        self._serial_number2 = obj.serial_number
         self._serial_number = '{0:x}'.format(obj.serial_number)[1::2]
         self._not_before = obj.not_valid_before
         self._not_after = obj.not_valid_after
+        self._issuer = ','.join([i.rfc4514_string() for i in obj.issuer])
+
         now = datetime.datetime.utcnow()
         self._is_valid_time = (now > self.not_before) and (now < self.not_after)
         if not self._is_valid_time:
@@ -81,6 +87,7 @@ class SATCertificate(object):
         self._cer_pem = obj.public_bytes(serialization.Encoding.PEM).decode()
         self._cer_txt = ''.join(self._cer_pem.split('\n')[1:-2])
         self._cer_modulus = obj.public_key().public_numbers().n
+
         return
 
     def _get_data_key(self, key, password):
@@ -126,6 +133,14 @@ class SATCertificate(object):
         )
         return key_pem
 
+    def _get_data_pem(self, pem):
+        if not pem:
+            return
+
+        self._key_pem = serialization.load_pem_private_key(
+            pem, None, backend=default_backend())
+        return
+
     # Not work
     def _get_p12(self):
         obj = serialization.pkcs12.serialize_key_and_certificates('test',
@@ -139,7 +154,26 @@ class SATCertificate(object):
         firma = private_key.sign(data, padding.PKCS1v15(), hashes.SHA256())
         return base64.b64encode(firma).decode()
 
+    def _sign_with_pem(self, data, name_hash):
+        if name_hash == 'sha256':
+            type_hash = hashes.SHA256()
+        elif name_hash == 'sha1':
+            type_hash = hashes.SHA1()
+
+        firma = self._key_pem.sign(data, padding.PKCS1v15(), type_hash)
+        return base64.b64encode(firma).decode()
+
+    def sign_sha1(self, data, password=''):
+        if self._key_pem:
+            return self._sign_with_pem(data, 'sha1')
+
+        private_key = self._get_key(password)
+        firma = private_key.sign(data, padding.PKCS1v15(), hashes.SHA1())
+        return base64.b64encode(firma).decode()
+
     def sign_xml(self, tree):
+        import xmlsec
+
         node = xmlsec.tree.find_node(tree, xmlsec.constants.NodeSignature)
         ctx = xmlsec.SignatureContext()
         key = xmlsec.Key.from_memory(self.key_pem, xmlsec.constants.KeyDataFormatPem)
@@ -157,6 +191,10 @@ class SATCertificate(object):
     def serial_number(self):
         return self._serial_number
 
+    @property
+    def serial_number2(self):
+        return self._serial_number2
+
     @property
     def not_before(self):
         return self._not_before
@@ -197,6 +235,10 @@ class SATCertificate(object):
     def key_enc(self):
         return self._key_enc
 
+    @property
+    def issuer(self):
+        return self._issuer
+
     @property
     def p12(self):
         return self._get_p12()
@@ -204,52 +246,3 @@ class SATCertificate(object):
     @property
     def error(self):
         return self._error
-
-
-def main(args):
-    # ~ contra = getpass.getpass('Introduce la contraseña del archivo KEY: ')
-    contra = '12345678a'
-    if not contra.strip():
-        msg = 'La contraseña es requerida'
-        print(msg)
-        return
-
-    path_cer = Path(args.cer)
-    path_key = Path(args.key)
-
-    if not path_cer.is_file():
-        msg = 'El archivo CER es necesario'
-        print(msg)
-        return
-
-    if not path_key.is_file():
-        msg = 'El archivo KEY es necesario'
-        print(msg)
-        return
-
-    cer = path_cer.read_bytes()
-    key = path_key.read_bytes()
-    cert = SATCertificate(cer, key, contra)
-
-    if cert.error:
-        print(cert.error)
-    else:
-        print(cert)
-    return
-
-
-def _process_command_line_arguments():
-    parser = argparse.ArgumentParser(description='CFDI Certificados')
-
-    help = 'Archivo CER'
-    parser.add_argument('-c', '--cer', help=help, default='')
-    help = 'Archivo KEY'
-    parser.add_argument('-k', '--key', help=help, default='')
-
-    args = parser.parse_args()
-    return args
-
-
-if __name__ == '__main__':
-    args = _process_command_line_arguments()
-    main(args)