Added Service.get_fingerprint()

Perspectives/Service.py

@@ -1,5 +1,10 @@
 """Classes for representing application services"""
 
+import re
+import ssl
+
+from Fingerprint import Fingerprint
+
 class Service:
     """Representation of a application service"""
 
@@ -14,6 +19,18 @@ def __init__(self, hostname, port, type=None):
     def __str__(self):
         return "%s:%s,%s" % (self.hostname, self.port, self.type)
 
+    # ssl.get_server_certificate() doesn't terminate the PEM correctly,
+    # it is missing a newline before the END line. This re detects that.
+    bad_cert_end_re = re.compile("(\S)(-----END CERTIFICATE-----)$",
+                                 re.MULTILINE)
+
+    def get_fingerprint(self):
+        """Return the Service's certificate fingerprint"""
+        cert_pem = ssl.get_server_certificate((self.hostname, self.port))
+        # Fix missing newline before END line
+        cert_pem = self.bad_cert_end_re.sub(r"\1\n\2", cert_pem)
+        return Fingerprint.from_certificate_PEM(cert_pem)
+
 class ServiceType:
     """Constants for service types"""
     # Determined experimentally. I don't know where these are documented.