diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,8 @@
+### 0.5.2.1
+
+- Obtain signatures indirectly, via *bitArrayGetData*.
+- Use more pattern synonyms internally to reach better readability.
+
 ### 0.5.2.0
 
 - Use *getConstructedEndRepr* when the end of the sequence is required to be
diff --git a/Data/X509/OCSP.hs b/Data/X509/OCSP.hs
--- a/Data/X509/OCSP.hs
+++ b/Data/X509/OCSP.hs
@@ -191,6 +191,26 @@
                             | OCSPRespCertUnknown
                             deriving (Show, Eq, Bounded, Enum)
 
+pattern Asn1OCSPResponseEmpty :: OCSPResponseStatus -> [ASN1]
+pattern Asn1OCSPResponseEmpty rst <-
+    [ Start Sequence
+    , Enumerated (toEnum . fromIntegral -> rst)
+    , End Sequence
+    ]
+
+pattern Asn1OCSPResponseValue :: OCSPResponseStatus -> ByteString -> [ASN1]
+pattern Asn1OCSPResponseValue rst val <-
+    [ Start Sequence
+    , Enumerated (toEnum . fromIntegral -> rst)
+    , Start (Container Context 0)
+    , Start Sequence
+    , OID OidBasicOCSPResponse
+    , OctetString val
+    , End Sequence
+    , End (Container Context 0)
+    , End Sequence
+    ]
+
 -- | Decode OCSP response.
 --
 -- The value of the /certificate id/ is expected to be equal to what was
@@ -204,57 +224,46 @@
     -> L.ByteString             -- ^ Raw encoded OCSP response
     -> Either ASN1Error (Maybe OCSPResponse)
 decodeOCSPResponse certId resp = decodeASN1 DER resp >>= \case
-    [ Start Sequence
-      , Enumerated (toEnum . fromIntegral -> v)
-      , End Sequence
-      ] -> Right $ Just $ OCSPResponse v Nothing
-    [ Start Sequence
-      , Enumerated (toEnum . fromIntegral -> v)
-      , Start (Container Context 0)
-      , Start Sequence
-      , OID OidBasicOCSPResponse
-      , OctetString resp'
-      , End Sequence
-      , End (Container Context 0)
-      , End Sequence
-      ] -> do
-          pl <- decodeASN1' DER resp'
-          Right $
-              case pl of
-                  Start Sequence
-                    : Start Sequence
-                    : Start (Container Context ctx)
-                    : c1 | ctx `elem` [0..2] -> do
-                        let skipVersion
-                                | ctx == 0 = drop 1 . skipCurrentContainer
-                                | otherwise = id
-                        Just $ getCurrentContainerContents $
-                            drop 2 $ skipCurrentContainer $ skipVersion c1
-                  _ -> Nothing
-              >>= \case
-                      Start Sequence
-                        : (fromASN1 -> Right (cId, c2)) | cId == certId ->
-                            case c2 of
-                                Other Context (toEnum -> n) _
-                                  : c3 -> Just (n, c3)
-                                Start (Container Context (toEnum -> n))
-                                  : c3 -> Just (n, skipCurrentContainer c3)
-                                _ -> Nothing
-                      _ -> Nothing
-              >>= \(n, tc1) -> case tc1 of
-                                   tu@(ASN1Time TimeGeneralized _ _)
-                                     : c4 -> Just (n, tu, c4)
-                                   _ -> Nothing
-              >>= \(st, tu, tc2) -> do
-                  let nu = case tc2 of
-                               Start (Container Context 0)
-                                 : t@(ASN1Time TimeGeneralized _ _)
-                                 : End (Container Context 0)
-                                 : _ -> Just t
-                               _ -> Nothing
-                  Just $ OCSPResponse v $
-                      Just $ OCSPResponsePayload
-                          (OCSPResponseCertData st tu nu) pl
+    Asn1OCSPResponseEmpty rst ->
+        Right $ Just $ OCSPResponse rst Nothing
+    Asn1OCSPResponseValue rst val -> do
+        pl <- decodeASN1' DER val
+        Right $
+            case pl of
+                Start Sequence
+                  : Start Sequence
+                  : Start (Container Context ctx)
+                  : c1 | ctx `elem` [0..2] -> do
+                      let skipVersion
+                              | ctx == 0 = drop 1 . skipCurrentContainer
+                              | otherwise = id
+                      Just $ getCurrentContainerContents $
+                          drop 2 $ skipCurrentContainer $ skipVersion c1
+                _ -> Nothing
+            >>= \case
+                    Start Sequence
+                      : (fromASN1 -> Right (cId, c2)) | cId == certId ->
+                          case c2 of
+                              Other Context (toEnum -> st) _
+                                : c3 -> Just (st, c3)
+                              Start (Container Context (toEnum -> st))
+                                : c3 -> Just (st, skipCurrentContainer c3)
+                              _ -> Nothing
+                    _ -> Nothing
+            >>= \(st, tc1) -> case tc1 of
+                                  tu@(ASN1Time TimeGeneralized _ _)
+                                    : c4 -> Just (st, tu, c4)
+                                  _ -> Nothing
+            >>= \(cst, tu, tc2) -> do
+                let nu = case tc2 of
+                             Start (Container Context 0)
+                               : t@(ASN1Time TimeGeneralized _ _)
+                               : End (Container Context 0)
+                               : _ -> Just t
+                             _ -> Nothing
+                Just $ OCSPResponse rst $
+                    Just $ OCSPResponsePayload
+                        (OCSPResponseCertData cst tu nu) pl
     _ -> Right Nothing
 
 -- | Verification data from OCSP response payload.
@@ -311,10 +320,15 @@
 getOCSPResponseVerificationData
     :: OCSPResponse             -- ^ OCSP response
     -> Maybe OCSPResponseVerificationData
-getOCSPResponseVerificationData (ocspRespPayload -> Just pl) =
-    getOCSPResponseVerificationData' $ ocspRespASN1 pl
-getOCSPResponseVerificationData _ = Nothing
+getOCSPResponseVerificationData =
+    ocspRespPayload >=> getOCSPResponseVerificationData' . ocspRespASN1
 
+pattern Asn1OCSPResponseCerts :: ASN1S
+pattern Asn1OCSPResponseCerts certs <-
+    Start (Container Context 0)
+    : Start Sequence
+    : certs@(Start Sequence : _)
+
 -- | Get verification data from OCSP response payload.
 --
 -- This is a variant of 'getOCSPResponseVerificationData' that accepts the
@@ -326,22 +340,21 @@
 getOCSPResponseVerificationData' (Start Sequence : c1@(Start Sequence : _))
     | (join bimap $ map fst -> (encodeASN1' DER -> resp, c2)) <-
         getConstructedEndRepr $ map (, []) c1
-    , Right (alg, BitString (BitArray _ sig) : c3) <- fromASN1 c2 =
-        case c3 of
-            [End Sequence] -> Just []
-            _ | Start (Container Context 0)
-                  : Start Sequence
-                  : certs@(Start Sequence : _) <-
-                      getCurrentContainerContents c3 ->
-                          reverse <$> collectCerts certs []
-              | otherwise -> Nothing
-        >>= Just . OCSPResponseVerificationData resp alg sig
+    , Right (alg, BitString (bitArrayGetData -> sig) : c3) <-
+        fromASN1 c2 =
+            case c3 of
+                [End Sequence] -> Just []
+                (getCurrentContainerContents -> Asn1OCSPResponseCerts certs) ->
+                    reverse <$> collectCerts certs []
+                _ -> Nothing
+            >>= Just . OCSPResponseVerificationData resp alg sig
     where collectCerts (Start Sequence : c4) certs
               | (c5@(Start Sequence : c6), next) <- getConstructedEnd 0 c4
               , Right (cert, End Sequence : c7) <- fromASN1 c6
-              , Right (alg, [BitString (BitArray _ sig)]) <- fromASN1 c7 =
-                  collectCerts next $
-                      (Signed cert alg sig, encodeASN1' DER c5) : certs
+              , Right (alg, [BitString (bitArrayGetData -> sig)]) <-
+                  fromASN1 c7 =
+                      collectCerts next $
+                          (Signed cert alg sig, encodeASN1' DER c5) : certs
           collectCerts [End Sequence, End (Container Context 0)] certs =
               Just certs
           collectCerts _ _ =
diff --git a/x509-ocsp.cabal b/x509-ocsp.cabal
--- a/x509-ocsp.cabal
+++ b/x509-ocsp.cabal
@@ -1,7 +1,7 @@
 cabal-version:          2.4
 
 name:                   x509-ocsp
-version:                0.5.2.0
+version:                0.5.2.1
 synopsis:               Basic X509 OCSP implementation
 description:            Build X509 OCSP requests and parse responses
 homepage:               https://github.com/lyokha/x509-ocsp