1 files changed, 18 insertions, 0 deletions
diff --git a/src/cryptography/x509/base.py b/src/cryptography/x509/base.py
index 156bc493..498ccbb9 100644
--- a/src/cryptography/x509/base.py
+++ b/src/cryptography/x509/base.py
@@ -126,6 +126,12 @@ class Certificate(object):
         """
 
     @abc.abstractproperty
+    def signature_algorithm_oid(self):
+        """
+        Returns the ObjectIdentifier of the signature algorithm.
+        """
+
+    @abc.abstractproperty
     def extensions(self):
         """
         Returns an Extensions object.
@@ -190,6 +196,12 @@ class CertificateRevocationList(object):
         """
 
     @abc.abstractproperty
+    def signature_algorithm_oid(self):
+        """
+        Returns the ObjectIdentifier of the signature algorithm.
+        """
+
+    @abc.abstractproperty
     def issuer(self):
         """
         Returns the X509Name with the issuer of this CRL.
@@ -278,6 +290,12 @@ class CertificateSigningRequest(object):
         """
 
     @abc.abstractproperty
+    def signature_algorithm_oid(self):
+        """
+        Returns the ObjectIdentifier of the signature algorithm.
+        """
+
+    @abc.abstractproperty
     def extensions(self):
         """
         Returns the extensions in the signing request.