diff options
Diffstat (limited to 'lib/NVault.Crypto.Secp256k1/src')
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/ContextExtensions.cs | 274 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/IRandomSource.cs | 32 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs | 284 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/NVault.Crypto.Secp256k1.csproj | 27 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/Secp256HashFuncState.cs | 56 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/Secp256k1Context.cs | 76 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/Secp256k1SecretKey.cs | 58 | ||||
| -rw-r--r-- | lib/NVault.Crypto.Secp256k1/src/UnmanagedRandomSource.cs | 101 |
8 files changed, 908 insertions, 0 deletions
diff --git a/lib/NVault.Crypto.Secp256k1/src/ContextExtensions.cs b/lib/NVault.Crypto.Secp256k1/src/ContextExtensions.cs new file mode 100644 index 0000000..bb014df --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/ContextExtensions.cs @@ -0,0 +1,274 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; +using System.Security.Cryptography; +using System.Runtime.InteropServices; + +using VNLib.Hashing; +using VNLib.Utils; +using VNLib.Utils.Memory; +using VNLib.Utils.Extensions; + +using static NVault.Crypto.Secp256k1.LibSecp256k1; + +namespace NVault.Crypto.Secp256k1 +{ + /// <summary> + /// The callback function signature required for ECDH hash functions + /// </summary> + /// <param name="state">The callback state</param> + /// <returns>The return value to be passed as a result of the operation</returns> + public delegate int Secp256k1EcdhHashFunc(in Secp256HashFuncState state); + + public static unsafe class ContextExtensions + { + /// <summary> + /// Signs a 32byte message digest with the specified secret key on the current context and writes the signature to the specified buffer + /// </summary> + /// <param name="context"></param> + /// <param name="secretKey">The 32byte secret key used to sign messages from the user</param> + /// <param name="digest">The 32byte message digest to compute the signature of</param> + /// <param name="signature">The buffer to write the signature output to, must be at-least 64 bytes</param> + /// <returns>The number of bytes written to the signature buffer, or less than 1 if the operation failed</returns> + public static ERRNO SchnorSignDigest(this in Secp256k1Context context, ReadOnlySpan<byte> secretKey, ReadOnlySpan<byte> digest, Span<byte> signature) + { + //Check the signature buffer size + if (signature.Length < SignatureSize) + { + return ERRNO.E_FAIL; + } + + //Message digest must be exactly 32 bytes long + if (digest.Length != (int)HashAlg.SHA256) + { + return ERRNO.E_FAIL; + } + + //Secret key size must be exactly the size of the secret key struct + if(secretKey.Length != sizeof(Secp256k1SecretKey)) + { + return ERRNO.E_FAIL; + } + + //Stack allocated keypair + KeyPair keyPair = new(); + + //Init the secret key struct from key data + Secp256k1SecretKey secKeyStruct = MemoryMarshal.Read<Secp256k1SecretKey>(secretKey); + + //Randomize the context and create the keypair + if (!context.CreateKeyPair(&keyPair, &secKeyStruct)) + { + return ERRNO.E_FAIL; + } + + //Create the random nonce + byte* random = stackalloc byte[RandomBufferSize]; + + //Fill the buffer with random bytes + context.Lib.GetRandomBytes(new Span<byte>(random, RandomBufferSize)); + + try + { + fixed (byte* sigPtr = &MemoryMarshal.GetReference(signature), + digestPtr = &MemoryMarshal.GetReference(digest)) + { + //Sign the message hash and write the output to the signature buffer + if (context.Lib._signHash(context.Context, sigPtr, digestPtr, &keyPair, random) != 1) + { + return ERRNO.E_FAIL; + } + } + } + finally + { + //Erase entropy + MemoryUtil.InitializeBlock(random, RandomBufferSize); + + //Clear the keypair, contains the secret key, even if its stack allocated + MemoryUtil.ZeroStruct(&keyPair); + } + + //Signature size is always 64 bytes + return SignatureSize; + } + + /// <summary> + /// Generates an x-only Schnor encoded public key from the specified secret key on the + /// current context and writes it to the specified buffer. + /// </summary> + /// <param name="context"></param> + /// <param name="secretKey">The 32byte secret key used to derrive the public key from</param> + /// <param name="pubKeyBuffer">The buffer to write the x-only Schnor encoded public key</param> + /// <returns>The number of bytes written to the output buffer, or 0 if the operation failed</returns> + /// <exception cref="CryptographicException"></exception> + public static ERRNO GeneratePubKeyFromSecret(this in Secp256k1Context context, ReadOnlySpan<byte> secretKey, Span<byte> pubKeyBuffer) + { + if (secretKey.Length != sizeof(Secp256k1SecretKey)) + { + throw new CryptographicException($"Your secret key must be exactly {sizeof(Secp256k1SecretKey)} bytes long"); + } + + if (pubKeyBuffer.Length < XOnlyPublicKeySize) + { + throw new CryptographicException($"Your public key buffer must be at least {XOnlyPublicKeySize} bytes long"); + } + + //Protect for released lib + context.Lib.SafeLibHandle.ThrowIfClosed(); + + //Stack allocated keypair and x-only public key + Secp256k1PublicKey xOnlyPubKey = new(); + Secp256k1SecretKey secKeyStruct = MemoryMarshal.Read<Secp256k1SecretKey>(secretKey); + KeyPair keyPair = new(); + + try + { + //Init context and keypair + if (!context.CreateKeyPair(&keyPair, &secKeyStruct)) + { + return ERRNO.E_FAIL; + } + + //X-only public key from the keypair + if (context.Lib._createXonly(context.Context, &xOnlyPubKey, 0, &keyPair) != 1) + { + return ERRNO.E_FAIL; + } + + fixed (byte* pubBuffer = &MemoryMarshal.GetReference(pubKeyBuffer)) + { + //Serialize the public key to the buffer as an X-only public key without leading status byte + if (context.Lib._serializeXonly(context.Context, pubBuffer, &xOnlyPubKey) != 1) + { + return ERRNO.E_FAIL; + } + } + } + finally + { + //Clear the keypair, contains the secret key, even if its stack allocated + MemoryUtil.ZeroStruct(&keyPair); + } + + //PubKey length is constant + return XOnlyPublicKeySize; + } + + /// <summary> + /// Verifies that a given secret key is valid using the current context + /// </summary> + /// <param name="context"></param> + /// <param name="secretKey">The secret key to verify</param> + /// <returns>A boolean value that indicates if the secret key is valid or not</returns> + /// <exception cref="CryptographicException"></exception> + public static bool VerifySecretKey(this in Secp256k1Context context, ReadOnlySpan<byte> secretKey) + { + if (secretKey.Length != sizeof(Secp256k1SecretKey)) + { + throw new CryptographicException($"Your secret key must be exactly {sizeof(Secp256k1SecretKey)} bytes long"); + } + + context.Lib.SafeLibHandle.ThrowIfClosed(); + + //Get sec key ref and verify + fixed(byte* ptr = &MemoryMarshal.GetReference(secretKey)) + { + return context.Lib._secKeyVerify.Invoke(context.Context, ptr) == 1; + } + } + + + [StructLayout(LayoutKind.Sequential)] + private readonly ref struct EcdhHashFuncState + { + public readonly IntPtr HashFunc { get; init; } + public readonly IntPtr Opaque { get; init; } + public readonly int OutLen { get; init; } + } + + /// <summary> + /// Verifies that a given secret key is valid using the current context + /// </summary> + /// <param name="context"></param> + /// <param name="secretKey">The secret key to verify</param> + /// <returns>A boolean value that indicates if the secret key is valid or not</returns> + /// <exception cref="ArgumentException"></exception> + public static bool ComputeSharedKey(this in Secp256k1Context context, Span<byte> data, ReadOnlySpan<byte> xOnlyPubKey, ReadOnlySpan<byte> secretKey, Secp256k1EcdhHashFunc callback, IntPtr opaque) + { + if (secretKey.Length != sizeof(Secp256k1SecretKey)) + { + throw new ArgumentException($"Your secret key buffer must be exactly {sizeof(Secp256k1SecretKey)} bytes long"); + } + + //Init callback state struct + EcdhHashFuncState state = new() + { + HashFunc = Marshal.GetFunctionPointerForDelegate(callback), + Opaque = opaque, + OutLen = data.Length + }; + + context.Lib.SafeLibHandle.ThrowIfClosed(); + + //Stack allocated keypair and x-only public key + Secp256k1PublicKey peerPubKey = new(); + + //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, + &peerPubKey, + secKeyPtr, + UmanagedEcdhHashFuncCallback, + &state + ) == 1; + } + + /* + * Umanaged wrapper function for invoking the safe user callback + * from the unmanaged lib + */ + static int UmanagedEcdhHashFuncCallback(byte* output, byte* x32, byte* y32, void* opaque) + { + //Recover the callback + if (opaque == null) + { + return 0; + } + + EcdhHashFuncState* state = (EcdhHashFuncState*)opaque; + + //Init user-state structure + Secp256HashFuncState userState = new(output, state->OutLen, x32, 32, new(opaque)); + + //Recover the function pointer + Secp256k1EcdhHashFunc callback = Marshal.GetDelegateForFunctionPointer<Secp256k1EcdhHashFunc>(state->HashFunc); + + //Invoke the callback + return callback(in userState); + } + } + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/IRandomSource.cs b/lib/NVault.Crypto.Secp256k1/src/IRandomSource.cs new file mode 100644 index 0000000..4e1861d --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/IRandomSource.cs @@ -0,0 +1,32 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; + +namespace NVault.Crypto.Secp256k1 +{ + /// <summary> + /// Represents a generator for random data, that fills abinary buffer with random bytes + /// on demand. + /// </summary> + public interface IRandomSource + { + /// <summary> + /// Fills the given buffer with random bytes + /// </summary> + /// <param name="buffer">Binary buffer to fill with random data</param> + void GetRandomBytes(Span<byte> buffer); + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs b/lib/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs new file mode 100644 index 0000000..8dda269 --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/LibSecp256k1.cs @@ -0,0 +1,284 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; +using System.Runtime.InteropServices; + +using VNLib.Hashing; +using VNLib.Utils; +using VNLib.Utils.Native; +using VNLib.Utils.Extensions; + +namespace NVault.Crypto.Secp256k1 +{ + + internal unsafe delegate int EcdhHasFunc(byte* output, byte* x32, byte* y32, void* data); + + public unsafe class LibSecp256k1 : VnDisposeable + { + public const int SignatureSize = 64; + public const int RandomBufferSize = 32; + public const int XOnlyPublicKeySize = 32; + + public static readonly int SecretKeySize = sizeof(Secp256k1SecretKey); + + /* + * Unsafe structures that represent the native keypair and x-only public key + * structures. They hold character arrays + */ + [StructLayout(LayoutKind.Sequential, Size = 96)] + internal struct KeyPair + { + public fixed byte data[96]; + } + + /// <summary> + /// 1:1 with the secp256k1_pubkey structure + /// </summary> + [StructLayout(LayoutKind.Sequential, Size = 64)] + internal struct Secp256k1PublicKey + { + public fixed byte data[64]; + } + + + //Native methods + [SafeMethodName("secp256k1_context_create")] + internal delegate IntPtr ContextCreate(int flags); + + [SafeMethodName("secp256k1_context_destroy")] + internal delegate void ContextDestroy(IntPtr context); + + [SafeMethodName("secp256k1_context_randomize")] + internal delegate int RandomizeContext(IntPtr context, byte* seed32); + + [SafeMethodName("secp256k1_keypair_create")] + internal delegate int KeypairCreate(IntPtr context, KeyPair* keyPair, byte* secretKey); + + [SafeMethodName("secp256k1_keypair_xonly_pub")] + internal delegate int KeypairXOnlyPub(IntPtr ctx, Secp256k1PublicKey* pubkey, int pk_parity, KeyPair* keypair); + + [SafeMethodName("secp256k1_xonly_pubkey_serialize")] + internal delegate int XOnlyPubkeySerialize(IntPtr ctx, byte* output32, Secp256k1PublicKey* pubkey); + + [SafeMethodName("secp256k1_schnorrsig_sign32")] + internal delegate int SignHash(IntPtr ctx, byte* sig64, byte* msg32, KeyPair* keypair, byte* aux_rand32); + + [SafeMethodName("secp256k1_ec_seckey_verify")] + internal delegate int SecKeyVerify(IntPtr ctx, in byte* seckey); + + [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, + byte* output, + Secp256k1PublicKey* pubkey, + byte* scalar, + EcdhHasFunc hashFunc, + void* dataPtr + ); + + + /// <summary> + /// Loads the Secp256k1 library from the specified path and creates a wrapper class (loads methods from the library) + /// </summary> + /// <param name="dllPath">The realtive or absolute path to the shared library</param> + /// <param name="search">The DLL probing path pattern</param> + /// <returns>The <see cref="LibSecp256k1"/> library wrapper class</returns> + /// <exception cref="DllNotFoundException"></exception> + /// <exception cref="ArgumentNullException"></exception> + /// <exception cref="MissingMemberException"></exception> + /// <exception cref="EntryPointNotFoundException"></exception> + public static LibSecp256k1 LoadLibrary(string dllPath, DllImportSearchPath search, IRandomSource? random) + { + _ = dllPath?? throw new ArgumentNullException(nameof(dllPath)); + + //try to load the library + SafeLibraryHandle lib = SafeLibraryHandle.LoadLibrary(dllPath, search); + + //try to create the wrapper class, if it fails, dispose the library + try + { + //setup fallback random source if null + random ??= new FallbackRandom(); + + //Create the lib + return new LibSecp256k1(lib, random); + } + catch + { + //Dispose the library if the creation failed + lib.Dispose(); + throw; + } + } + + /// <summary> + /// Loads the Secp256k1 library from the specified path and creates a wrapper class (loads methods from the library) + /// </summary> + /// <param name="handle">The handle to the shared library</param> + /// <param name="random">An optional random source to create random entropy and secrets from</param> + /// <returns>The <see cref="LibSecp256k1"/> library wrapper class</returns> + /// <exception cref="ArgumentNullException"></exception> + /// <exception cref="MissingMemberException"></exception> + /// <exception cref="EntryPointNotFoundException"></exception> + public static LibSecp256k1 FromHandle(SafeLibraryHandle handle, IRandomSource? random) + { + _ = handle ?? throw new ArgumentNullException(nameof(handle)); + //setup fallback random source if null + random ??= new FallbackRandom(); + //Create the lib + return new LibSecp256k1(handle, random); + } + + /// <summary> + /// The underlying library handle + /// </summary> + public SafeLibraryHandle SafeLibHandle { get; } + + internal readonly KeypairCreate _createKeyPair; + internal readonly ContextCreate _create; + internal readonly RandomizeContext _randomize; + internal readonly ContextDestroy _destroy; + internal readonly KeypairXOnlyPub _createXonly; + internal readonly XOnlyPubkeySerialize _serializeXonly; + internal readonly SignHash _signHash; + internal readonly SecKeyVerify _secKeyVerify; + internal readonly PubKeySerialize _pubKeySerialize; + internal readonly Ecdh _ecdh; + internal readonly XOnlyPubkeyParse _xOnlyPubkeyParse; + private readonly IRandomSource _randomSource; + + /// <summary> + /// Creates a new instance of the <see cref="LibSecp256k1"/> class from the specified library handle + /// </summary> + /// <param name="handle">The library handle that referrences the secp256k1 platform specific library</param> + /// <remarks> + /// This method attempts to capture all the native methods from the library, which may throw if the library is not valid. + /// </remarks> + /// <exception cref="ArgumentNullException"></exception> + /// <exception cref="MissingMemberException"></exception> + /// <exception cref="EntryPointNotFoundException"></exception> + public LibSecp256k1(SafeLibraryHandle handle, IRandomSource randomSource) + { + //Store library handle + SafeLibHandle = handle ?? throw new ArgumentNullException(nameof(handle)); + + //Get all method handles and store them + _create = handle.DangerousGetMethod<ContextCreate>(); + _createKeyPair = handle.DangerousGetMethod<KeypairCreate>(); + _randomize = handle.DangerousGetMethod<RandomizeContext>(); + _destroy = handle.DangerousGetMethod<ContextDestroy>(); + _createXonly = handle.DangerousGetMethod<KeypairXOnlyPub>(); + _serializeXonly = handle.DangerousGetMethod<XOnlyPubkeySerialize>(); + _signHash = handle.DangerousGetMethod<SignHash>(); + _secKeyVerify = handle.DangerousGetMethod<SecKeyVerify>(); + _pubKeySerialize = handle.DangerousGetMethod<PubKeySerialize>(); + _ecdh = handle.DangerousGetMethod<Ecdh>(); + _xOnlyPubkeyParse = handle.DangerousGetMethod<XOnlyPubkeyParse>(); + + //Store random source + _randomSource = randomSource; + } + + /// <summary> + /// Creates a new instance of the <see cref="LibSecp256k1"/> class from the specified library handle + /// with a fallback random source + /// </summary> + /// <param name="handle">The library handle</param> + /// <exception cref="ArgumentNullException"></exception> + /// <exception cref="MissingMemberException"></exception> + /// <exception cref="EntryPointNotFoundException"></exception> + public LibSecp256k1(SafeLibraryHandle handle):this(handle, new FallbackRandom()) + {} + + /// <summary> + /// Generates a new secret key and writes it to the specified buffer. The buffer size must be exactly <see cref="SecretKeySize"/> bytes long + /// <para> + /// NOTE: You should verify this validity of the key against the library with a new <see cref="Secp256k1Context"/> + /// </para> + /// </summary> + /// <param name="buffer">The secret key buffer</param> + /// <exception cref="ArgumentException"></exception> + public void CreateSecretKey(Span<byte> buffer) + { + //Protect for released lib + SafeLibHandle.ThrowIfClosed(); + + if(buffer.Length != sizeof(Secp256k1SecretKey)) + { + throw new ArgumentException($"Buffer must be exactly {sizeof(Secp256k1SecretKey)} bytes long", nameof(buffer)); + } + + //Fill the buffer with random bytes + _randomSource.GetRandomBytes(buffer); + } + + /// <summary> + /// Fills the given buffer with random bytes from + /// the internal random source + /// </summary> + /// <param name="buffer">The buffer to fill with random data</param> + public void GetRandomBytes(Span<byte> buffer) + { + //Protect for released lib + SafeLibHandle.ThrowIfClosed(); + + _randomSource.GetRandomBytes(buffer); + } + + /// <summary> + /// Creates a new <see cref="Secp256k1Context"/> from the current managed library + /// </summary> + /// <param name="Lib"></param> + /// <returns>The new <see cref="Secp256k1Context"/> object from the library</returns> + /// <exception cref="OutOfMemoryException"></exception> + public Secp256k1Context CreateContext() + { + //Protect for released lib + SafeLibHandle.ThrowIfClosed(); + + //Create new context + IntPtr context = _create(1); + + if (context == IntPtr.Zero) + { + throw new OutOfMemoryException("Failed to create the new Secp256k1 context"); + } + + return new Secp256k1Context(this, context); + } + + protected override void Free() + { + //Free native library + SafeLibHandle.Dispose(); + } + + private record class FallbackRandom : IRandomSource + { + public void GetRandomBytes(Span<byte> buffer) + { + //Use the random generator from the crypto lib + RandomHash.GetRandomBytes(buffer); + } + } + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/NVault.Crypto.Secp256k1.csproj b/lib/NVault.Crypto.Secp256k1/src/NVault.Crypto.Secp256k1.csproj new file mode 100644 index 0000000..efd78ab --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/NVault.Crypto.Secp256k1.csproj @@ -0,0 +1,27 @@ +<Project Sdk="Microsoft.NET.Sdk"> + + <PropertyGroup> + <TargetFramework>net8.0</TargetFramework> + <Nullable>enable</Nullable> + <AllowUnsafeBlocks>true</AllowUnsafeBlocks> + <PackageReadmeFile>README.md</PackageReadmeFile> + <RootNamespace>NVault.Crypto.Secp256k1</RootNamespace> + <AssemblyName>NVault.Crypto.Secp256k1</AssemblyName> + </PropertyGroup> + + <PropertyGroup> + <Authors>Vaughn Nugent</Authors> + <Company>Vaughn Nugent</Company> + <Product>NVault.Crypto.Secp256k1</Product> + <Description>Provides a managed library for the Bitcoin Core secp256k1 library, along with other helper types for NVault</Description> + <Copyright>Copyright © 2024 Vaughn Nugent</Copyright> + <PackageProjectUrl>https://www.vaughnnugent.com/resources/software/modules/NVault</PackageProjectUrl> + <RepositoryUrl>https://github.com/VnUgE/NVault/tree/master/</RepositoryUrl> + </PropertyGroup> + + <ItemGroup> + <PackageReference Include="VNLib.Hashing.Portable" Version="0.1.0-ci0114" /> + <PackageReference Include="VNLib.Utils" Version="0.1.0-ci0114" /> + </ItemGroup> + +</Project> diff --git a/lib/NVault.Crypto.Secp256k1/src/Secp256HashFuncState.cs b/lib/NVault.Crypto.Secp256k1/src/Secp256HashFuncState.cs new file mode 100644 index 0000000..c82321c --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/Secp256HashFuncState.cs @@ -0,0 +1,56 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; +using System.Runtime.InteropServices; + +namespace NVault.Crypto.Secp256k1 +{ + [StructLayout(LayoutKind.Sequential)] + public unsafe readonly ref struct Secp256HashFuncState + { + + /// <summary> + /// The opaque pointer passed to the hash function + /// </summary> + public readonly IntPtr Opaque { get; } + + private readonly byte* _output; + private readonly byte* _xCoord; + private readonly int _outputLength; + private readonly int _xCoordLength; + + internal Secp256HashFuncState(byte* output, int outputLength, byte* xCoord, int xCoordLength, IntPtr opaque) + { + Opaque = opaque; + _output = output; + _outputLength = outputLength; + _xCoord = xCoord; + _xCoordLength = xCoordLength; + } + + /// <summary> + /// Gets the output buffer as a span + /// </summary> + /// <returns>The output buffer span</returns> + public readonly Span<byte> GetOutput() => new(_output, _outputLength); + + /// <summary> + /// Gets the x coordinate argument as a span + /// </summary> + /// <returns>The xcoordinate buffer span</returns> + public readonly ReadOnlySpan<byte> GetXCoordArg() => new(_xCoord, _xCoordLength); + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/Secp256k1Context.cs b/lib/NVault.Crypto.Secp256k1/src/Secp256k1Context.cs new file mode 100644 index 0000000..dfb3ff8 --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/Secp256k1Context.cs @@ -0,0 +1,76 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; + +using VNLib.Utils.Extensions; +using VNLib.Utils.Memory; + +using static NVault.Crypto.Secp256k1.LibSecp256k1; + +namespace NVault.Crypto.Secp256k1 +{ + /// <summary> + /// Represents a Secp256k1 context, it is used to randomize the instance, create key pairs, + /// and frees the context when disposed + /// </summary> + /// <param name="Lib">The <see cref="LibSecp256k1"/> library instance</param> + /// <param name="Context">A pointer to the initialized context instance</param> + public readonly record struct Secp256k1Context(LibSecp256k1 Lib, IntPtr Context) : IDisposable + { + /// <summary> + /// Randomizes the context with random data using the library's random source + /// </summary> + /// <returns>True if the context was successfully randomized, false otherwise</returns> + public unsafe readonly bool Randomize() + { + Lib.SafeLibHandle.ThrowIfClosed(); + + //Randomze the context + byte* entropy = stackalloc byte[RandomBufferSize]; + + //Get random bytes + Lib.GetRandomBytes(new Span<byte>(entropy, RandomBufferSize)); + + //call native randomize method + bool result = Lib._randomize(Context, entropy) == 1; + + //Zero the randomness buffer before returning to avoid leaking random data + MemoryUtil.InitializeBlock(entropy, RandomBufferSize); + + return result; + } + + internal unsafe readonly bool CreateKeyPair(KeyPair* keyPair, Secp256k1SecretKey* secretKey) + { + Lib.SafeLibHandle.ThrowIfClosed(); + + //Create the keypair from the secret key + return Lib._createKeyPair(Context, keyPair, (byte*)secretKey) == 1; + } + + /// <summary> + /// Releases the context instance and frees the memory + /// </summary> + public readonly void Dispose() + { + if (Context != IntPtr.Zero) + { + //Free the context + Lib._destroy(Context); + } + } + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/Secp256k1SecretKey.cs b/lib/NVault.Crypto.Secp256k1/src/Secp256k1SecretKey.cs new file mode 100644 index 0000000..35734ae --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/Secp256k1SecretKey.cs @@ -0,0 +1,58 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; +using System.Runtime.InteropServices; + +using VNLib.Utils.Memory; + +namespace NVault.Crypto.Secp256k1 +{ + /// <summary> + /// Represents a Secp256k1 secret key, the size is fixed, and should use + /// the sizeof() operator to get the size + /// </summary> + [StructLayout(LayoutKind.Sequential, Size = 32)] + public unsafe struct Secp256k1SecretKey + { + private fixed byte data[32]; + + /// <summary> + /// Implict cast to a span of raw bytes + /// </summary> + /// <param name="key">The secret key to cast</param> + public static implicit operator Span<byte>(Secp256k1SecretKey key) => new(key.data, 32); + + /// <summary> + /// Casts the secret key span to a <see cref="Secp256k1SecretKey"/> via a structure copy + /// </summary> + /// <param name="key">The key data to copy</param> + /// <exception cref="ArgumentOutOfRangeException"></exception> + public static explicit operator Secp256k1SecretKey(ReadOnlySpan<byte> key) => FromSpan(key); + + /// <summary> + /// Creates a new <see cref="Secp256k1SecretKey"/> from a span of bytes + /// by copying the bytes into the struct + /// </summary> + /// <param name="span">The secret key data to copy</param> + /// <returns>An initilaized <see cref="Secp256k1SecretKey"/></returns> + public static Secp256k1SecretKey FromSpan(ReadOnlySpan<byte> span) + { + Secp256k1SecretKey newKey = new(); + MemoryUtil.CopyStruct(span, ref newKey); + return newKey; + } + } +}
\ No newline at end of file diff --git a/lib/NVault.Crypto.Secp256k1/src/UnmanagedRandomSource.cs b/lib/NVault.Crypto.Secp256k1/src/UnmanagedRandomSource.cs new file mode 100644 index 0000000..360de21 --- /dev/null +++ b/lib/NVault.Crypto.Secp256k1/src/UnmanagedRandomSource.cs @@ -0,0 +1,101 @@ +// Copyright (C) 2024 Vaughn Nugent +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as +// published by the Free Software Foundation, either version 3 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. + +using System; +using System.Runtime.InteropServices; + +using VNLib.Utils; +using VNLib.Utils.Native; +using VNLib.Utils.Extensions; + +namespace NVault.Crypto.Secp256k1 +{ + + /// <summary> + /// A wrapper class for an unmanaged random source that conforms to the <see cref="IRandomSource"/> interface + /// </summary> + public class UnmanagedRandomSource : VnDisposeable, IRandomSource + { + public const string METHOD_NAME = "getRandomBytes"; + + unsafe delegate void UnmanagedRandomSourceDelegate(byte* buffer, int size); + + + private readonly bool OwnsHandle; + private readonly SafeLibraryHandle _library; + private readonly UnmanagedRandomSourceDelegate _getRandomBytes; + + /// <summary> + /// Loads the unmanaged random source from the given library + /// and attempts to get the random bytes method <see cref="METHOD_NAME"/> + /// </summary> + /// <param name="path"></param> + /// <param name="search"></param> + /// <returns>The wrapped library that conforms to the <see cref="IRandomSource"/></returns> + public static UnmanagedRandomSource LoadLibrary(string path, DllImportSearchPath search) + { + //Try to load the library + SafeLibraryHandle lib = SafeLibraryHandle.LoadLibrary(path, search); + try + { + return new UnmanagedRandomSource(lib, true); + } + catch + { + //release lib + lib.Dispose(); + throw; + } + } + + /// <summary> + /// Creates the unmanaged random source from the given library + /// </summary> + /// <param name="lib">The library handle to wrap</param> + /// <exception cref="ObjectDisposedException"></exception> + /// <exception cref="EntryPointNotFoundException"></exception> + public UnmanagedRandomSource(SafeLibraryHandle lib, bool ownsHandle) + { + lib.ThrowIfClosed(); + + _library = lib; + + //get the method delegate + _getRandomBytes = lib.DangerousGetMethod<UnmanagedRandomSourceDelegate>(METHOD_NAME); + + OwnsHandle = ownsHandle; + } + + public unsafe void GetRandomBytes(Span<byte> buffer) + { + _library.ThrowIfClosed(); + + //Fix buffer and call unmanaged method + fixed(byte* ptr = &MemoryMarshal.GetReference(buffer)) + { + _getRandomBytes(ptr, buffer.Length); + } + } + + ///<inheritdoc/> + protected override void Free() + { + if (OwnsHandle) + { + _library.Dispose(); + } + } + } +}
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