DhcpOptionsBuffer - EnumerateCorruptRadiusAttributeUnderflow

bobbymcr · Jan 19, 2020 · 675bdca · 675bdca
1 parent 878fad5
commit 675bdca
Showing 1 changed file with 37 additions and 0 deletions.
diff --git a/DhcpServer.Test/DhcpOptionsBufferTest.cs b/DhcpServer.Test/DhcpOptionsBufferTest.cs
@@ -144,5 +144,42 @@ public void EnumerateCorruptRadiusAttribute()
 
             span.Slice(0, charsWritten).ToString().Should().Be(ExpectedRadiusAttributes);
         }
+
+        [TestMethod]
+        public void EnumerateCorruptRadiusAttributeUnderflow()
+        {
+            const string ExpectedRadiusAttributes =
+@"UserName={61}
+None={FE010A00000000}
+";
+            Memory<byte> options = new Memory<byte>(new byte[17]);
+            DhcpOptionsBuffer buffer = new DhcpOptionsBuffer(options, Memory<byte>.Empty, Memory<byte>.Empty);
+            DhcpOption option = buffer.Slice(0, DhcpOptionTag.RelayAgentInformation, 12);
+            int i = 0;
+            option.Data.Span[i++] = (byte)DhcpRelayAgentSubOptionCode.RadiusAttributes;
+            option.Data.Span[i++] = 10;        // sub-option #1 length
+            option.Data.Span[i++] = (byte)RadiusAttributeType.UserName;
+            option.Data.Span[i++] = 3;         // attribute #1 length
+            option.Data.Span[i++] = (byte)'a'; // attribute #1 data
+            option.Data.Span[i++] = 254;       // attribute #2 code
+            option.Data.Span[i++] = 1;         // attribute #2 length (BAD -> will underflow)
+            option.Data.Span[i++] = 10;        // attribute #2 data
+            Span<char> span = new Span<char>(new char[100]);
+
+            int charsWritten = 0;
+            foreach (DhcpRelayAgentInformationSubOption subOption in option.RelayAgentInformation())
+            {
+                foreach (RadiusAttribute attribute in subOption.RadiusAttributes())
+                {
+                    Span<char> destination = span.Slice(charsWritten);
+                    attribute.TryFormat(destination, out int c).Should().BeTrue();
+                    destination[c++] = '\r';
+                    destination[c++] = '\n';
+                    charsWritten += c;
+                }
+            }
+
+            span.Slice(0, charsWritten).ToString().Should().Be(ExpectedRadiusAttributes);
+        }
     }
 }