1 files changed, 61 insertions, 0 deletions
diff --git a/crypto/src/pqc/asn1/SphincsPlusPublicKey.cs b/crypto/src/pqc/asn1/SphincsPlusPublicKey.cs
new file mode 100644
index 000000000..41e2158a7
--- /dev/null
+++ b/crypto/src/pqc/asn1/SphincsPlusPublicKey.cs
@@ -0,0 +1,61 @@
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Pqc.Asn1
+{
+    /**
+     * See https://datatracker.ietf.org/doc/draft-uni-qsckeys-sphincsplus/00/ for details.
+     * ASN.1 Encoding for a
+     * SphincsPlus public key for fully populated:
+     * <pre>
+     *   SPHINCSPPLUSPublicKey := SEQUENCE {
+     *     pkseed          OCTET STRING,     --n-byte public key seed
+     *     pkroot          OCTET STRING      --n-byte public hypertree root
+     *   }
+     * </pre>
+     */
+    public sealed class SphincsPlusPublicKey
+        : Asn1Encodable
+    {
+        public static SphincsPlusPublicKey GetInstance(object obj)
+        {
+            if (obj == null)
+                return null;
+            if (obj is SphincsPlusPublicKey sphincsPlusPublicKey)
+                return sphincsPlusPublicKey;
+            return new SphincsPlusPublicKey(Asn1Sequence.GetInstance(obj));
+        }
+
+        public static SphincsPlusPublicKey GetInstance(Asn1TaggedObject taggedObject, bool declaredExplicit)
+        {
+            return GetInstance(Asn1Sequence.GetInstance(taggedObject, declaredExplicit));
+        }
+
+        private readonly byte[] m_pkseed;
+        private readonly byte[] m_pkroot;
+
+        public SphincsPlusPublicKey(byte[] pkseed, byte[] pkroot)
+        {
+            m_pkseed = pkseed;
+            m_pkroot = pkroot;
+        }
+
+        private SphincsPlusPublicKey(Asn1Sequence seq)
+        {
+            m_pkseed = Arrays.Clone(Asn1OctetString.GetInstance(seq[0]).GetOctets());
+            m_pkroot = Arrays.Clone(Asn1OctetString.GetInstance(seq[1]).GetOctets());
+        }
+
+        public byte[] GetPkroot() => Arrays.Clone(m_pkroot);
+
+        public byte[] GetPkseed() => Arrays.Clone(m_pkseed);
+
+        public override Asn1Object ToAsn1Object()
+        {
+            Asn1EncodableVector v = new Asn1EncodableVector();
+            v.Add(new DerOctetString(m_pkseed));
+            v.Add(new DerOctetString(m_pkroot));
+            return new DerSequence(v);
+        }
+    }
+}