diff --git a/src/main/java/org/jruby/ext/openssl/impl/Signed.java b/src/main/java/org/jruby/ext/openssl/impl/Signed.java
index 0acc45be..1dba04bf 100644
--- a/src/main/java/org/jruby/ext/openssl/impl/Signed.java
+++ b/src/main/java/org/jruby/ext/openssl/impl/Signed.java
@@ -354,19 +354,21 @@ private static X509AuxCertificate certificateFromASN1(ASN1Encodable current) thr
     }
 
     private static Set<AlgorithmIdentifier> algorithmIdentifiersFromASN1Set(ASN1Encodable content) {
-        ASN1Set set = (ASN1Set)content;
-        Set<AlgorithmIdentifier> result = new HashSet<AlgorithmIdentifier>();
-        for(Enumeration<?> e = set.getObjects(); e.hasMoreElements();) {
-            result.add(AlgorithmIdentifier.getInstance(e.nextElement()));
+        ASN1Set set = (ASN1Set) content;
+        final int len = set.size();
+        Set<AlgorithmIdentifier> result = new HashSet<>(len);
+        for (int i = 0; i < len; i++) {
+            result.add(AlgorithmIdentifier.getInstance(set.getObjectAt(i)));
         }
         return result;
     }
 
     private static Collection<SignerInfoWithPkey> signerInfosFromASN1Set(ASN1Encodable content) {
-        ASN1Set set = (ASN1Set)content;
-        Collection<SignerInfoWithPkey> result = new ArrayList<SignerInfoWithPkey>();
-        for(Enumeration<?> e = set.getObjects(); e.hasMoreElements();) {
-            result.add(SignerInfoWithPkey.getInstance(e.nextElement()));
+        ASN1Set set = (ASN1Set) content;
+        final int len = set.size();
+        Collection<SignerInfoWithPkey> result = new ArrayList<>();
+        for (int i = 0; i < len; i++) {
+            result.add(SignerInfoWithPkey.getInstance(set.getObjectAt(i)));
         }
         return result;
     }
diff --git a/src/main/java/org/jruby/ext/openssl/impl/SignerInfoWithPkey.java b/src/main/java/org/jruby/ext/openssl/impl/SignerInfoWithPkey.java
index 3efd3422..8b8fd66f 100644
--- a/src/main/java/org/jruby/ext/openssl/impl/SignerInfoWithPkey.java
+++ b/src/main/java/org/jruby/ext/openssl/impl/SignerInfoWithPkey.java
@@ -72,11 +72,15 @@ public class SignerInfoWithPkey implements ASN1Encodable {
     private ASN1OctetString         encryptedDigest;
     private ASN1Set                 unauthenticatedAttributes;
 
-    public static SignerInfoWithPkey getInstance(Object o) {
-        if(o instanceof SignerInfo) {
-            return (SignerInfoWithPkey)o;
-        } else if (o instanceof ASN1Sequence) {
-            return new SignerInfoWithPkey((ASN1Sequence)o);
+    public static SignerInfoWithPkey getInstance(ASN1Encodable o) {
+        if (o instanceof SignerInfo) {
+            final SignerInfo info = (SignerInfo) o;
+            return new SignerInfoWithPkey(info.getVersion(), info.getIssuerAndSerialNumber(), info.getDigestAlgorithm(),
+                                          info.getAuthenticatedAttributes(), info.getDigestEncryptionAlgorithm(),
+                                          info.getEncryptedDigest(), info.getUnauthenticatedAttributes());
+        }
+        if (o instanceof ASN1Sequence) {
+            return new SignerInfoWithPkey((ASN1Sequence) o);
         }
 
         throw new IllegalArgumentException("unknown object in factory: " + o.getClass().getName());
@@ -97,13 +101,13 @@ public SignerInfoWithPkey dup() {
     SignerInfoWithPkey() {
     }
 
-    public SignerInfoWithPkey(ASN1Integer              version,
-        IssuerAndSerialNumber   issuerAndSerialNumber,
-        AlgorithmIdentifier     digAlgorithm,
-        ASN1Set                 authenticatedAttributes,
-        AlgorithmIdentifier     digEncryptionAlgorithm,
-        ASN1OctetString         encryptedDigest,
-        ASN1Set                 unauthenticatedAttributes) {
+    public SignerInfoWithPkey(ASN1Integer version,
+                              IssuerAndSerialNumber issuerAndSerialNumber,
+                              AlgorithmIdentifier digAlgorithm,
+                              ASN1Set authenticatedAttributes,
+                              AlgorithmIdentifier digEncryptionAlgorithm,
+                              ASN1OctetString encryptedDigest,
+                              ASN1Set unauthenticatedAttributes) {
         this.version = version;
         this.issuerAndSerialNumber = issuerAndSerialNumber;
         this.digAlgorithm = digAlgorithm;
@@ -113,8 +117,8 @@ public SignerInfoWithPkey(ASN1Integer              version,
         this.unauthenticatedAttributes = unauthenticatedAttributes;
     }
 
-    public SignerInfoWithPkey(ASN1Sequence seq) {
-        Enumeration     e = seq.getObjects();
+    SignerInfoWithPkey(ASN1Sequence seq) {
+        Enumeration e = seq.getObjects();
 
         version = (ASN1Integer)e.nextElement();
         issuerAndSerialNumber = IssuerAndSerialNumber.getInstance(e.nextElement());
@@ -122,7 +126,7 @@ public SignerInfoWithPkey(ASN1Sequence seq) {
 
         Object obj = e.nextElement();
 
-        if(obj instanceof ASN1TaggedObject) {
+        if (obj instanceof ASN1TaggedObject) {
             authenticatedAttributes = ASN1Set.getInstance((ASN1TaggedObject)obj, false);
 
             digEncryptionAlgorithm = AlgorithmIdentifier.getInstance(e.nextElement());