Integrate local OpenSSL TSA for timestamping

Replaced HTTPTimeStamper with LocalOpensslTimestamp for TSA operations using a local OpenSSL CLI. Updated related configurations and dependencies to support this change, enhancing the timestamping process's reliability and security.

pythonProject/sign.py

@@ -7,11 +7,15 @@ from pyhanko.sign import signers, timestamps, fields
 from pyhanko_certvalidator import ValidationContext
 from typing_extensions import Buffer
 
+from pythonProject.timestamp import LocalOpensslTimestamp
+
 
 class SignOrchestrator:
     """Orchestrate the signature on document"""
 
-    def __init__(self, pkcs12_path: str, timestamp_url: str, pkcs12_password: Optional[bytes] = None):
+    def __init__(self, pkcs12_path: str,
+                 tsa_config_path: str, tsa_password: str, tsa_cert_chain: str,
+                 pkcs12_password: Optional[bytes] = None):
         # Load signer key material from PKCS#12 file
         # This assumes that any relevant intermediate certs are also included
         # in the PKCS#12 file.
@@ -20,9 +24,7 @@ class SignOrchestrator:
         )
 
         # Set up a timestamping client to fetch timestamps tokens
-        self.timestamper = timestamps.HTTPTimeStamper(
-            url=timestamp_url,
-        )
+        self.timestamper = LocalOpensslTimestamp(tsa_config_path, tsa_password, tsa_cert_chain)
 
         self.stamp_style = stamp.TextStampStyle(
             stamp_text="Signé par:\n%(signer_text)s\nLe %(ts)s",

pythonProject/sign_individual.py

@@ -1,6 +1,16 @@
 from sign import SignOrchestrator
 
-orchestrator = SignOrchestrator('./assets/dummy.p12','http://freetsa.org/tsr', pkcs12_password=None)
+"""
+This is a script to sign a file with the dummy assets
+
+It is created mainly for testing purpose
+"""
+
+orchestrator = SignOrchestrator('./assets/dummy.p12',
+                                '/home/julien/dev/chill/sign-pdf-worker/ts-authority/rootca.conf',
+                                '5678',
+                                '/home/julien/dev/chill/sign-pdf-worker/ts-authority/ca/tsa-chain.pem',
+                                pkcs12_password=None)
 
 with open('./assets/test.pdf', 'rb') as input:
     signed_content = orchestrator.sign(reason="first signer", signature_index=0,
@@ -11,9 +21,9 @@ with open('./assets/test.pdf', 'rb') as input:
         output.write(signed_content.read())
 
 with open('./assets/test_signed_0.pdf', 'rb') as input:
- signed_content = orchestrator.sign(reason="second signer", signature_index=1,
-                                    input_content=input.read(), box_place=(100, 600, 300, 660), on_page=0,
-                                    signer_text="M. Bah Mamadou")
+    signed_content = orchestrator.sign(reason="second signer", signature_index=1,
+                                       input_content=input.read(), box_place=(100, 600, 300, 660), on_page=0,
+                                       signer_text="M. Bah Mamadou")
 
- with open('./assets/test_signed_1.pdf', 'wb') as output:
-     output.write(signed_content.read())
+    with open('./assets/test_signed_1.pdf', 'wb') as output:
+        output.write(signed_content.read())

pythonProject/timestamp.py

@@ -0,0 +1,64 @@
+import logging
+import os
+
+from asn1crypto import tsp
+from asn1crypto.tsp import TimeStampResp
+from pyhanko.sign.timestamps import TimeStamper
+import subprocess
+
+LOGGER = logging.getLogger(__name__)
+LOGGER.setLevel(os.environ.get('LOG_LEVEL', logging.DEBUG))
+
+
+class LocalOpensslTimestamp(TimeStamper):
+    """
+        Apply a timestamp using a local openssl cli.
+
+        The class provides methods to request a timestamp response from a local OpenSSL TSA cli.
+    """
+    def __init__(self, path_config: str, password: str, path_chain: str):
+        super().__init__()
+        self.path_conf = path_config
+        self.password = password
+        self.path_chain = path_chain
+
+    def request_tsa_response(self, req: tsp.TimeStampReq) -> tsp.TimeStampResp:
+        with open('/tmp/request.tsq', 'wb') as request:
+            request.write(req.dump())
+
+        cmd = [
+            'openssl', 'ts', '-reply',
+            '-config', self.path_conf,
+            '-queryfile', '/tmp/request.tsq',
+            '-chain', self.path_chain,
+            '-out', '/tmp/response.tsr',
+            '-passin', f'pass:{self.password}'
+        ]
+
+        try:
+            subprocess.run(cmd, capture_output=True, check=True, timeout=10)
+        except subprocess.CalledProcessError as e:
+            LOGGER.error("Could not generate a timestamp")
+            LOGGER.error(f"response code: {e.returncode}")
+            LOGGER.error(f"stderr: {e.stderr}")
+            LOGGER.error(f"stdout: {e.stdout}")
+            LOGGER.error(f"error: {e.output}")
+
+            raise Exception("could not generate a timestamp")
+        except subprocess.TimeoutExpired as e:
+            LOGGER.error("timeout expired")
+            LOGGER.error(f"stderr: {e.stderr}")
+            LOGGER.error(f"stdout: {e.stdout}")
+            LOGGER.error(f"error: {e.output}")
+
+            raise e
+
+        with open('/tmp/response.tsr', mode='rb') as f:
+            tsp = TimeStampResp.load(f.read())
+
+        os.unlink('/tmp/response.tsr')
+
+        return tsp
+
+    async def async_request_tsa_response(self, req: tsp.TimeStampReq) -> tsp.TimeStampResp:
+        return self.request_tsa_response(req)

pythonProject/worker.py

@@ -19,13 +19,14 @@ for v in ['AMQP_URL', 'PKCS12_PATH', 'TIMESTAMP_URL', 'QUEUE_IN', 'EXCHANGE_OUT'
 
 DSN = os.environ.get('AMQP_URL')
 PKCS12_PATH = os.environ.get('PKCS12_PATH')
-TIMESTAMP_URL = os.environ.get('TIMESTAMP_URL')
 QUEUE_IN = os.environ.get('QUEUE_IN')
 EXCHANGE_OUT = os.environ.get('EXCHANGE_OUT')
 OUT_ROUTING_KEY = os.environ.get('OUT_ROUTING_KEY')
+TSA_CONFIG_PATH = os.environ.get('TSA_CONFIG_PATH')
+TSA_CERT_CHAIN = os.environ.get('TSA_CERT_CHAIN')
+TSA_KEY_PASSWORD = os.environ.get('TSA_KEY_PASSWORD')
 
-
-orchestrator = sign.SignOrchestrator(PKCS12_PATH, TIMESTAMP_URL, pkcs12_password=os.environ.get('PKCS12_PASSWORD', None))
+orchestrator = sign.SignOrchestrator(PKCS12_PATH, TSA_CONFIG_PATH, TSA_KEY_PASSWORD, TSA_CERT_CHAIN, pkcs12_password=os.environ.get('PKCS12_PASSWORD', None))
 
 parameters = pika.URLParameters(DSN)
 connection = pika.BlockingConnection(parameters)

ts-authority/rootca.conf

@@ -138,7 +138,7 @@ subjectKeyIdentifier    = hash
 default_tsa             = tsa_config1
 
 [ tsa_config1 ]
-dir                     = .                     # TSA root directory, same as root-ca
+dir                     = /home/julien/dev/chill/sign-pdf-worker/ts-authority                     # TSA root directory, same as root-ca
 serial                  = $dir/ca/tsa_serial       # current serial number (mandatory)
 signer_cert             = $dir/ca/tsa.crt     # signing certificate (optional)
 certs                   = $dir/ca/tsa-chain.pem # certification chain (optional)