Remove intermediate allocations from ToString methods

Author: stephentoub

src/System.Security.Cryptography.X509Certificates/src/System/Security/Cryptography/X509Certificates/X509Certificate.cs

@@ -262,32 +262,42 @@ public virtual String ToString(bool fVerbose)
             StringBuilder sb = new StringBuilder();
 
             // Subject
-            sb.Append("[Subject]" + Environment.NewLine + "  ");
-            sb.Append(this.Subject);
+            sb.AppendLine("[Subject]");
+            sb.Append("  ");
+            sb.AppendLine(this.Subject);
 
             // Issuer
-            sb.Append(Environment.NewLine + Environment.NewLine + "[Issuer]" + Environment.NewLine + "  ");
-            sb.Append(this.Issuer);
+            sb.AppendLine();
+            sb.AppendLine("[Issuer]");
+            sb.Append("  ");
+            sb.AppendLine(this.Issuer);
 
             // Serial Number
-            sb.Append(Environment.NewLine + Environment.NewLine + "[Serial Number]" + Environment.NewLine + "  ");
+            sb.AppendLine();
+            sb.AppendLine("[Serial Number]");
+            sb.Append("  ");
             byte[] serialNumber = this.GetSerialNumber();
             Array.Reverse(serialNumber);
-            sb.Append(serialNumber.ToHexStringUpper());
+            sb.AppendLine(serialNumber.ToHexStringUpper());
 
             // NotBefore
-            sb.Append(Environment.NewLine + Environment.NewLine + "[Not Before]" + Environment.NewLine + "  ");
-            sb.Append(FormatDate(this.GetNotBefore()));
+            sb.AppendLine();
+            sb.AppendLine("[Not Before]");
+            sb.Append("  ");
+            sb.AppendLine(FormatDate(this.GetNotBefore()));
 
             // NotAfter
-            sb.Append(Environment.NewLine + Environment.NewLine + "[Not After]" + Environment.NewLine + "  ");
-            sb.Append(FormatDate(this.GetNotAfter()));
+            sb.AppendLine();
+            sb.AppendLine("[Not After]");
+            sb.Append("  ");
+            sb.AppendLine(FormatDate(this.GetNotAfter()));
 
             // Thumbprint
-            sb.Append(Environment.NewLine + Environment.NewLine + "[Thumbprint]" + Environment.NewLine + "  ");
-            sb.Append(this.GetCertHash().ToHexStringUpper());
+            sb.AppendLine();
+            sb.AppendLine("[Thumbprint]");
+            sb.Append("  ");
+            sb.AppendLine(this.GetCertHash().ToHexStringUpper());
 
-            sb.Append(Environment.NewLine);
             return sb.ToString();
         }
 
@@ -362,4 +372,3 @@ internal static String FormatDate(DateTime date)
         private const X509KeyStorageFlags KeyStorageFlagsAll = (X509KeyStorageFlags)0x1f;
     }
 }
-

src/System.Security.Cryptography.X509Certificates/src/System/Security/Cryptography/X509Certificates/X509Certificate2.cs

@@ -307,146 +307,156 @@ public override String ToString(bool verbose)
                 return ToString();
 
             StringBuilder sb = new StringBuilder();
-            String newLine = Environment.NewLine;
-            String newLine2 = newLine + newLine;
-            String newLinesp2 = newLine + "  ";
 
             // Version
-            sb.Append("[Version]");
-            sb.Append(newLinesp2);
-            sb.Append("V" + this.Version);
+            sb.AppendLine("[Version]");
+            sb.Append("  V");
+            sb.Append(this.Version);
 
             // Subject
-            sb.Append(newLine2);
-            sb.Append("[Subject]");
-            sb.Append(newLinesp2);
+            sb.AppendLine();
+            sb.AppendLine();
+            sb.AppendLine("[Subject]");
+            sb.Append("  ");
             sb.Append(this.SubjectName.Name);
             String simpleName = GetNameInfo(X509NameType.SimpleName, false);
             if (simpleName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Simple Name: ");
                 sb.Append(simpleName);
             }
             String emailName = GetNameInfo(X509NameType.EmailName, false);
             if (emailName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Email Name: ");
                 sb.Append(emailName);
             }
             String upnName = GetNameInfo(X509NameType.UpnName, false);
             if (upnName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("UPN Name: ");
                 sb.Append(upnName);
             }
             String dnsName = GetNameInfo(X509NameType.DnsName, false);
             if (dnsName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("DNS Name: ");
                 sb.Append(dnsName);
             }
 
             // Issuer
-            sb.Append(newLine2);
-            sb.Append("[Issuer]");
-            sb.Append(newLinesp2);
+            sb.AppendLine();
+            sb.AppendLine();
+            sb.AppendLine("[Issuer]");
+            sb.Append("  ");
             sb.Append(this.IssuerName.Name);
             simpleName = GetNameInfo(X509NameType.SimpleName, true);
             if (simpleName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Simple Name: ");
                 sb.Append(simpleName);
             }
             emailName = GetNameInfo(X509NameType.EmailName, true);
             if (emailName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Email Name: ");
                 sb.Append(emailName);
             }
             upnName = GetNameInfo(X509NameType.UpnName, true);
             if (upnName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("UPN Name: ");
                 sb.Append(upnName);
             }
             dnsName = GetNameInfo(X509NameType.DnsName, true);
             if (dnsName.Length > 0)
             {
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("DNS Name: ");
                 sb.Append(dnsName);
             }
 
             // Serial Number
-            sb.Append(newLine2);
-            sb.Append("[Serial Number]");
-            sb.Append(newLinesp2);
-            sb.Append(this.SerialNumber);
+            sb.AppendLine();
+            sb.AppendLine();
+            sb.AppendLine("[Serial Number]");
+            sb.Append("  ");
+            sb.AppendLine(this.SerialNumber);
 
             // NotBefore
-            sb.Append(newLine2);
-            sb.Append("[Not Before]");
-            sb.Append(newLinesp2);
-            sb.Append(FormatDate(this.NotBefore));
+            sb.AppendLine();
+            sb.AppendLine("[Not Before]");
+            sb.Append("  ");
+            sb.AppendLine(FormatDate(this.NotBefore));
 
             // NotAfter
-            sb.Append(newLine2);
-            sb.Append("[Not After]");
-            sb.Append(newLinesp2);
-            sb.Append(FormatDate(this.NotAfter));
+            sb.AppendLine();
+            sb.AppendLine("[Not After]");
+            sb.Append("  ");
+            sb.AppendLine(FormatDate(this.NotAfter));
 
             // Thumbprint
-            sb.Append(newLine2);
-            sb.Append("[Thumbprint]");
-            sb.Append(newLinesp2);
-            sb.Append(this.Thumbprint);
+            sb.AppendLine();
+            sb.AppendLine("[Thumbprint]");
+            sb.Append("  ");
+            sb.AppendLine(this.Thumbprint);
 
             // Signature Algorithm
-            sb.Append(newLine2);
-            sb.Append("[Signature Algorithm]");
-            sb.Append(newLinesp2);
-            sb.Append(this.SignatureAlgorithm.FriendlyName + "(" + this.SignatureAlgorithm.Value + ")");
+            sb.AppendLine();
+            sb.AppendLine("[Signature Algorithm]");
+            sb.Append("  ");
+            sb.Append(this.SignatureAlgorithm.FriendlyName);
+            sb.Append('(');
+            sb.Append(this.SignatureAlgorithm.Value);
+            sb.AppendLine(")");
 
             // Public Key
-            sb.Append(newLine2);
+            sb.AppendLine();
             sb.Append("[Public Key]");
             // It could throw if it's some user-defined CryptoServiceProvider
             try
             {
                 PublicKey pubKey = this.PublicKey;
 
-                String temp = pubKey.Oid.FriendlyName;
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Algorithm: ");
-                sb.Append(temp);
+                sb.Append(pubKey.Oid.FriendlyName);
                 // So far, we only support RSACryptoServiceProvider & DSACryptoServiceProvider Keys
                 try
                 {
-                    temp = pubKey.Key.KeySize.ToString();
-                    sb.Append(newLinesp2);
+                    sb.AppendLine();
+                    sb.Append("  ");
                     sb.Append("Length: ");
-                    sb.Append(temp);
+                    sb.Append(pubKey.Key.KeySize);
                 }
                 catch (NotSupportedException)
                 {
                 }
 
-                temp = pubKey.EncodedKeyValue.Format(true);
-                sb.Append(newLinesp2);
+                sb.AppendLine();
+                sb.Append("  ");
                 sb.Append("Key Blob: ");
-                sb.Append(temp);
+                sb.AppendLine(pubKey.EncodedKeyValue.Format(true));
 
-                temp = pubKey.EncodedParameters.Format(true);
-                sb.Append(newLinesp2);
+                sb.Append("  ");
                 sb.Append("Parameters: ");
-                sb.Append(temp);
+                sb.Append(pubKey.EncodedParameters.Format(true));
             }
             catch (CryptographicException)
             {
@@ -459,29 +469,31 @@ public override String ToString(bool verbose)
             X509ExtensionCollection extensions = this.Extensions;
             if (extensions.Count > 0)
             {
-                sb.Append(newLine2);
+                sb.AppendLine();
+                sb.AppendLine();
                 sb.Append("[Extensions]");
-                String temp;
                 foreach (X509Extension extension in extensions)
                 {
                     try
                     {
-                        temp = extension.Oid.FriendlyName;
-                        sb.Append(newLine);
-                        sb.Append("* " + temp);
-                        sb.Append("(" + extension.Oid.Value + "):");
-
-                        temp = extension.Format(true);
-                        sb.Append(newLinesp2);
-                        sb.Append(temp);
+                        sb.AppendLine();
+                        sb.Append("* ");
+                        sb.Append(extension.Oid.FriendlyName);
+                        sb.Append('(');
+                        sb.Append(extension.Oid.Value);
+                        sb.Append("):");
+
+                        sb.AppendLine();
+                        sb.Append("  ");
+                        sb.Append(extension.Format(true));
                     }
                     catch (CryptographicException)
                     {
                     }
                 }
             }
 
-            sb.Append(newLine);
+            sb.AppendLine();
             return sb.ToString();
         }
 
@@ -518,4 +530,3 @@ private static X509Extension CreateCustomExtensionIfAny(Oid oid)
         private volatile X509ExtensionCollection _lazyExtensions;
     }
 }
-

src/System.Security.Cryptography.X509Certificates/tests/CertTests.cs

@@ -104,6 +104,30 @@ public static void X509CertStoreChain()
             }
         }
 
+        [Fact]
+        public static void X509CertEmptyToString()
+        {
+            using (var c = new X509Certificate())
+            {
+                string expectedResult = "System.Security.Cryptography.X509Certificates.X509Certificate";
+                Assert.Equal(expectedResult, c.ToString());
+                Assert.Equal(expectedResult, c.ToString(false));
+                Assert.Equal(expectedResult, c.ToString(true));
+            }
+        }
+
+        [Fact]
+        public static void X509Cert2EmptyToString()
+        {
+            using (var c2 = new X509Certificate2())
+            {
+                string expectedResult = "System.Security.Cryptography.X509Certificates.X509Certificate2";
+                Assert.Equal(expectedResult, c2.ToString());
+                Assert.Equal(expectedResult, c2.ToString(false));
+                Assert.Equal(expectedResult, c2.ToString(true));
+            }
+        }
+
         [Fact]
         [ActiveIssue(1993, PlatformID.AnyUnix)]
         public static void X509Cert2ToStringVerbose()
@@ -113,7 +137,7 @@ public static void X509Cert2ToStringVerbose()
 
             foreach (X509Certificate2 c in store.Certificates)
             {
-                Assert.NotNull(c.ToString(true));
+                Assert.False(string.IsNullOrWhiteSpace(c.ToString(true)));
             }
         }