1 files changed, 28 insertions, 0 deletions
diff --git a/Crypto/src/cms/CounterSignatureDigestCalculator.cs b/Crypto/src/cms/CounterSignatureDigestCalculator.cs
new file mode 100644
index 000000000..6f8bf65a2
--- /dev/null
+++ b/Crypto/src/cms/CounterSignatureDigestCalculator.cs
@@ -0,0 +1,28 @@
+using System;
+
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Security;
+
+namespace Org.BouncyCastle.Cms
+{
+	internal class CounterSignatureDigestCalculator
+		: IDigestCalculator
+	{
+		private readonly string alg;
+		private readonly byte[] data;
+
+		internal CounterSignatureDigestCalculator(
+			string	alg,
+			byte[]	data)
+		{
+			this.alg = alg;
+			this.data = data;
+		}
+
+		public byte[] GetDigest()
+		{
+			IDigest digest = CmsSignedHelper.Instance.GetDigestInstance(alg);
+			return DigestUtilities.DoFinal(digest, data);
+		}
+	}
+}