1 files changed, 102 insertions, 0 deletions
diff --git a/crypto/src/bcpg/ECDHPublicBCPGKey.cs b/crypto/src/bcpg/ECDHPublicBCPGKey.cs
new file mode 100644
index 000000000..b85379586
--- /dev/null
+++ b/crypto/src/bcpg/ECDHPublicBCPGKey.cs
@@ -0,0 +1,102 @@
+using System;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Math.EC;
+
+namespace Org.BouncyCastle.Bcpg
+{
+ /// <remarks>Base class for an ECDH Public Key.</remarks>
+ public class ECDHPublicBcpgKey
+ : ECPublicBcpgKey
+ {
+ private byte reserved;
+ private byte hashFunctionId;
+ private byte symAlgorithmId;
+
+ /// <param name="bcpgIn">The stream to read the packet from.</param>
+ public ECDHPublicBcpgKey(
+ BcpgInputStream bcpgIn)
+ : base(bcpgIn)
+ {
+ int length = bcpgIn.ReadByte();
+ byte[] kdfParameters = new byte[length];
+ if (kdfParameters.Length != 3)
+ throw new InvalidOperationException("kdf parameters size of 3 expected.");
+
+ bcpgIn.ReadFully(kdfParameters);
+
+ reserved = kdfParameters[0];
+ hashFunctionId = kdfParameters[1];
+ symAlgorithmId = kdfParameters[2];
+
+ VerifyHashAlgorithm();
+ VerifySymmetricKeyAlgorithm();
+ }
+
+ public ECDHPublicBcpgKey(
+ DerObjectIdentifier oid,
+ ECPoint point,
+ int hashAlgorithm,
+ int symmetricKeyAlgorithm)
+ : base(oid, point)
+ {
+ reserved = 1;
+ hashFunctionId = (byte)hashAlgorithm;
+ symAlgorithmId = (byte)symmetricKeyAlgorithm;
+
+ VerifyHashAlgorithm();
+ VerifySymmetricKeyAlgorithm();
+ }
+
+ public virtual byte Reserved
+ {
+ get { return reserved; }
+ }
+
+ public virtual byte HashAlgorithm
+ {
+ get { return hashFunctionId; }
+ }
+
+ public virtual byte SymmetricKeyAlgorithm
+ {
+ get { return symAlgorithmId; }
+ }
+
+ public override void Encode(
+ BcpgOutputStream bcpgOut)
+ {
+ base.Encode(bcpgOut);
+ bcpgOut.WriteByte(0x3);
+ bcpgOut.WriteByte(reserved);
+ bcpgOut.WriteByte(hashFunctionId);
+ bcpgOut.WriteByte(symAlgorithmId);
+ }
+
+ private void VerifyHashAlgorithm()
+ {
+ switch ((HashAlgorithmTag)hashFunctionId)
+ {
+ case HashAlgorithmTag.Sha256:
+ case HashAlgorithmTag.Sha384:
+ case HashAlgorithmTag.Sha512:
+ break;
+ default:
+ throw new InvalidOperationException("Hash algorithm must be SHA-256 or stronger.");
+ }
+ }
+
+ private void VerifySymmetricKeyAlgorithm()
+ {
+ switch ((SymmetricKeyAlgorithmTag)symAlgorithmId)
+ {
+ case SymmetricKeyAlgorithmTag.Aes128:
+ case SymmetricKeyAlgorithmTag.Aes192:
+ case SymmetricKeyAlgorithmTag.Aes256:
+ break;
+ default:
+ throw new InvalidOperationException("Symmetric key algorithm must be AES-128 or stronger.");
+ }
+ }
+ }
+}
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