2 files changed, 22 insertions, 6 deletions
diff --git a/back-end/libs/NVault.Crypto.Secp256k1/src/ContextExtensions.cs b/back-end/libs/NVault.Crypto.Secp256k1/src/ContextExtensions.cs
index f5327df..9931698 100644
--- a/back-end/libs/NVault.Crypto.Secp256k1/src/ContextExtensions.cs
+++ b/back-end/libs/NVault.Crypto.Secp256k1/src/ContextExtensions.cs
@@ -254,7 +254,7 @@ namespace NVault.Crypto.Secp256k1
         {
             if (secretKey.Length != SecretKeySize)
             {
-                throw new ArgumentException($"Your public key buffer must be exactly {SecretKeySize} bytes long");
+                throw new ArgumentException($"Your secret key buffer must be exactly {SecretKeySize} bytes long");
             }
 
             //Init callback state struct
@@ -265,17 +265,28 @@ namespace NVault.Crypto.Secp256k1
                 OutLen = data.Length
             };
 
+            context.Lib.SafeLibHandle.ThrowIfClosed();
+
             //Stack allocated keypair and x-only public key
-            Secp256k1PublicKey pubKeyStruct = new();
-            //Recover the x-only public key structure
-            MemoryUtil.CopyStruct(xOnlyPubKey, &pubKeyStruct);
+            Secp256k1PublicKey peerPubKey = new();
 
-            context.Lib.SafeLibHandle.ThrowIfClosed();
+            //Parse the public key from the buffer
+            fixed (byte* pubkeyPtr = &MemoryMarshal.GetReference(xOnlyPubKey))
+            {
+                context.Lib._xOnlyPubkeyParse(context.Context, &peerPubKey, pubkeyPtr);
+            }
 
             fixed (byte* dataPtr = &MemoryMarshal.GetReference(data),
                     secKeyPtr = &MemoryMarshal.GetReference(secretKey))
             {
-                return context.Lib._ecdh.Invoke(context.Context, dataPtr, &pubKeyStruct, secKeyPtr, UmanagedEcdhHashFuncCallback, &state) == 1;
+                return context.Lib._ecdh.Invoke(
+                    context.Context, 
+                    dataPtr, 
+                    &peerPubKey, 
+                    secKeyPtr, 
+                    UmanagedEcdhHashFuncCallback, 
+                    &state
+                    ) == 1;
             }
 
             /*
diff --git a/back-end/libs/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs b/back-end/libs/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs
index 5aeed00..f3afc33 100644
--- a/back-end/libs/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs
+++ b/back-end/libs/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs
@@ -82,6 +82,9 @@ namespace NVault.Crypto.Secp256k1
         [SafeMethodName("secp256k1_ec_pubkey_serialize")]
         internal delegate int PubKeySerialize(IntPtr ctx, byte* outPubKey, ulong* outLen, Secp256k1PublicKey* pubKey, uint flags);
 
+        [SafeMethodName("secp256k1_xonly_pubkey_parse")]
+        internal delegate int XOnlyPubkeyParse(IntPtr ctx, Secp256k1PublicKey* pubkey, byte* input32);
+
         [SafeMethodName("secp256k1_ecdh")]
         internal delegate int Ecdh(
             IntPtr ctx, 
@@ -143,6 +146,7 @@ namespace NVault.Crypto.Secp256k1
         internal readonly SecKeyVerify _secKeyVerify;
         internal readonly PubKeySerialize _pubKeySerialize;
         internal readonly Ecdh _ecdh;
+        internal readonly XOnlyPubkeyParse _xOnlyPubkeyParse;
         private readonly IRandomSource _randomSource;
 
         /// <summary>
@@ -171,6 +175,7 @@ namespace NVault.Crypto.Secp256k1
             _secKeyVerify = handle.DangerousGetMethod<SecKeyVerify>();
             _pubKeySerialize = handle.DangerousGetMethod<PubKeySerialize>();
             _ecdh = handle.DangerousGetMethod<Ecdh>();
+            _xOnlyPubkeyParse = handle.DangerousGetMethod<XOnlyPubkeyParse>();
             
             //Store random source
             _randomSource = randomSource;