Protect Signature creation from components containing '\0'

Author: nulltoken

LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj

@@ -59,6 +59,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CheckoutFixture.cs" />
+    <Compile Include="SignatureFixture.cs" />
     <Compile Include="FilterBranchFixture.cs" />
     <Compile Include="RemoveFixture.cs" />
     <Compile Include="RemoteFixture.cs" />

LibGit2Sharp.Tests/SignatureFixture.cs

@@ -0,0 +1,32 @@
+using System;
+using LibGit2Sharp.Tests.TestHelpers;
+using Xunit;
+using Xunit.Extensions;
+
+namespace LibGit2Sharp.Tests
+{
+    public class SignatureFixture : BaseFixture
+    {
+        [Theory]
+        [InlineData("\0Leading zero")]
+        [InlineData("Trailing zero\0")]
+        [InlineData("Zero \0inside")]
+        [InlineData("\0")]
+        [InlineData("\0\0\0")]
+        public void CreatingASignatureWithANameContainingZerosThrows(string name)
+        {
+            Assert.Throws<ArgumentException>(() => new Signature(name, "[email protected]", DateTimeOffset.Now));
+        }
+
+        [Theory]
+        [InlineData("\0[email protected]")]
+        [InlineData("[email protected]\0")]
+        [InlineData("Zero@\0inside.com")]
+        [InlineData("\0")]
+        [InlineData("\0\0\0")]
+        public void CreatingASignatureWithAnEmailContainingZerosThrows(string email)
+        {
+            Assert.Throws<ArgumentException>(() => new Signature("Me", email, DateTimeOffset.Now));
+        }
+    }
+}

LibGit2Sharp/Core/Ensure.cs

@@ -39,6 +39,37 @@ public static void ArgumentNotNullOrEmptyString(string argumentValue, string arg
             }
         }
 
+        /// <summary>
+        /// Checks a string argument to ensure it doesn't contain a zero byte.
+        /// </summary>
+        /// <param name="argumentValue">The argument value to check.</param>
+        /// <param name="argumentName">The name of the argument.</param>
+        public static void ArgumentDoesNotContainZeroByte(string argumentValue, string argumentName)
+        {
+            if (string.IsNullOrEmpty(argumentValue))
+            {
+                return;
+            }
+
+            int zeroPos = -1;
+            for (var i = 0; i < argumentValue.Length; i++)
+            {
+                if (argumentValue[i] == '\0')
+                {
+                    zeroPos = i;
+                    break;
+                }
+            }
+
+            if (zeroPos == -1)
+            {
+                return;
+            }
+
+            throw new ArgumentException(
+                string.Format("Zero bytes ('\\0') are not allowed. A zero byte has been found at position {0}.", zeroPos), argumentName);
+        }
+
         private static readonly Dictionary<GitErrorCode, Func<string, GitErrorCode, GitErrorCategory, LibGit2SharpException>>
             GitErrorsToLibGit2SharpExceptions =
                 new Dictionary<GitErrorCode, Func<string, GitErrorCode, GitErrorCategory, LibGit2SharpException>>

LibGit2Sharp/Signature.cs

@@ -35,6 +35,9 @@ internal Signature(IntPtr signaturePtr)
         /// <param name="when">The when.</param>
         public Signature(string name, string email, DateTimeOffset when)
         {
+            Ensure.ArgumentDoesNotContainZeroByte(name, "name");
+            Ensure.ArgumentDoesNotContainZeroByte(email, "email");
+
             this.name = name;
             this.email = email;
             this.when = when;