[IMP] add sign method for RPS additional sign for NFS-e Paulistana

src/erpbrasil/assinatura/assinatura.py

@@ -10,6 +10,19 @@
 _logger = logging.getLogger(__name__)
 
 
+class XMLSignerWithSHA1(signxml.XMLSigner):
+    """
+    Extension of the `XMLSigner` class that adds support for the SHA1 hash algorithm
+    to the XML signature process.
+    Note:
+        SHA1-based algorithms are not supported in the default configuration because
+        they are not secure, but in the NF-e project, other more modern algorithms
+        are still not accepted.
+    """
+    def check_deprecated_methods(self):
+        "Override to disable deprecated Check"
+
+
 class Assinatura(object):
 
     def __init__(self, certificado):
@@ -48,14 +61,15 @@ def assina_xml2(self, xml_element, reference, getchildren=False):
             if element.text is not None and not element.text.strip():
                 element.text = None
 
-        signer = signxml.XMLSigner(
+        signer = XMLSignerWithSHA1(
             method=signxml.methods.enveloped,
             signature_algorithm="rsa-sha1",
             digest_algorithm='sha1',
             c14n_algorithm='http://www.w3.org/TR/2001/REC-xml-c14n-20010315'
         )
 
-        signer.namespaces = {"ds": "http://www.w3.org/2000/09/xmldsig#"}
+        signer.excise_empty_xmlns_declarations = True
+        signer.namespaces = {None: signxml.namespaces.ds}
 
         ref_uri = ('#%s' % reference) if reference else None
 
@@ -91,7 +105,7 @@ def assina_xml2(self, xml_element, reference, getchildren=False):
 
     def assina_nfse(self, xml_etree):
 
-        signer = signxml.XMLSigner(
+        signer = XMLSignerWithSHA1(
             method=signxml.methods.enveloped,
             signature_algorithm="rsa-sha1",
             digest_algorithm='sha1',
@@ -103,11 +117,8 @@ def assina_nfse(self, xml_etree):
             key=self.chave_privada,
             cert=self.cert,
         )
-
         signed_root = etree.tostring(signed_root, encoding=str)
 
-        signed_root = signed_root.replace('\r', '').replace('\n', '')
-
         return signed_root
 
     def assina_string(self, message):
@@ -122,6 +133,27 @@ def assina_string(self, message):
         )
         return signature
 
+
+    def sign_pkcs1v15_sha1(self, data):
+        """
+        Sign data using PKCS1v15 padding and SHA1 hash algorithm.
+
+        This method is specifically tailored for the NFSe Paulistana RPS signing process.
+
+        Args:
+            data (bytes): Data to be signed.
+
+        Returns:
+            bytes: Generated signature.
+        """
+        private_key = self.certificado.key
+        signature = private_key.sign(
+            data,
+            padding.PKCS1v15(),
+            hashes.SHA1()
+        )
+        return signature
+
     def assina_pdf(self, arquivo, dados_assinatura, algoritmo='sha256'):
         try:
             from endesive import pdf