// 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 .
using System;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using VNLib.Utils.Memory;
using static NVault.Crypto.Noscrypt.LibNoscrypt;
using NCResult = System.Int64;
namespace NVault.Crypto.Noscrypt
{
public static class NCUtil
{
///
/// Gets a span of bytes from the current secret key
/// structure
///
///
/// The secret key data span
public unsafe static Span AsSpan(this ref NCSecretKey key)
{
//Safe to cast secret key to bytes, then we can make a span to its memory
ref byte asBytes = ref Unsafe.As(ref key);
return MemoryMarshal.CreateSpan(ref asBytes, sizeof(NCSecretKey));
}
///
/// Gets a span of bytes from the current public key
/// structure
///
///
/// The public key data as a data span
public unsafe static Span AsSpan(this ref NCPublicKey key)
{
//Safe to cast secret key to bytes, then we can make a span to its memory
ref byte asBytes = ref Unsafe.As(ref key);
return MemoryMarshal.CreateSpan(ref asBytes, sizeof(NCPublicKey));
}
///
/// Casts a span of bytes to a secret key reference. Note that
/// the new structure reference will point to the same memory
/// as the span.
///
/// The secret key data
/// A mutable secret key reference
///
public unsafe static ref NCSecretKey AsSecretKey(Span span)
{
ArgumentOutOfRangeException.ThrowIfLessThan(span.Length, sizeof(NCSecretKey), nameof(span));
ref byte asBytes = ref MemoryMarshal.GetReference(span);
return ref Unsafe.As(ref asBytes);
}
///
/// Casts a span of bytes to a public key reference. Note that
/// the new structure reference will point to the same memory
/// as the span.
///
/// The public key data span
/// A mutable reference to the public key structure
///
public unsafe static ref NCPublicKey AsPublicKey(Span span)
{
ArgumentOutOfRangeException.ThrowIfLessThan(span.Length, sizeof(NCPublicKey), nameof(span));
ref byte asBytes = ref MemoryMarshal.GetReference(span);
return ref Unsafe.As(ref asBytes);
}
///
/// Casts a read-only span of bytes to a secret key reference. Note that
/// the new structure reference will point to the same memory as the span.
///
/// The secret key data span
/// A readonly refernce to the secret key structure
///
public unsafe static ref readonly NCSecretKey AsSecretKey(ReadOnlySpan span)
{
ArgumentOutOfRangeException.ThrowIfLessThan(span.Length, sizeof(NCSecretKey), nameof(span));
ref byte asBytes = ref MemoryMarshal.GetReference(span);
return ref Unsafe.As(ref asBytes);
}
///
/// Casts a read-only span of bytes to a public key reference. Note that
/// the new structure reference will point to the same memory as the span.
///
/// The public key data span
/// A readonly reference to the public key structure
///
public unsafe static ref readonly NCPublicKey AsPublicKey(ReadOnlySpan span)
{
ArgumentOutOfRangeException.ThrowIfLessThan(span.Length, sizeof(NCPublicKey), nameof(span));
ref byte asBytes = ref MemoryMarshal.GetReference(span);
return ref Unsafe.As(ref asBytes);
}
///
/// Initializes a new NostrCrypto context wraper directly that owns the internal context.
/// This may be done once at app startup and is thread-safe for the rest of the
/// application lifetime.
///
///
/// The heap to allocate the context from
/// The random entropy data to initialize the context with
/// The library wrapper handle
public static NostrCrypto InitializeCrypto(this LibNoscrypt library, IUnmangedHeap heap, ReadOnlySpan entropy32)
{
ArgumentNullException.ThrowIfNull(library);
ArgumentNullException.ThrowIfNull(heap);
//Initialize the context
NCContext context = library.Initialize(heap, entropy32);
//Create the crypto interface
return new NostrCrypto(context, true);
}
internal static void CheckResult(NCResult result, bool raiseOnFailure) where T : Delegate
{
//Only negative values are errors
if (result >= NC_SUCCESS)
{
return;
}
NCResult asPositive = -result;
// Error code are only 8 bits, if an argument error occured, the
// argument number will be in the next upper 8 bits
byte errorCode = (byte)(asPositive & 0xFF);
byte argNumber = (byte)((asPositive >> 8) & 0xFF);
switch (errorCode)
{
case E_NULL_PTR:
RaiseNullArgExceptionForArgumentNumber(argNumber);
break;
case E_INVALID_ARG:
RaiseArgExceptionForArgumentNumber(argNumber);
break;
case E_ARGUMENT_OUT_OF_RANGE:
RaiseOORExceptionForArgumentNumber(argNumber);
break;
case E_INVALID_CTX:
throw new InvalidOperationException("The library context object is null or invalid");
case E_OPERATION_FAILED:
RaiseOperationFailedException(raiseOnFailure);
break;
}
}
private static void RaiseOperationFailedException(bool raise)
{
if (raise)
{
throw new InvalidOperationException("The operation failed for an unknown reason");
}
}
private static void RaiseNullArgExceptionForArgumentNumber(int argNumber) where T : Delegate
{
//Get delegate parameters
Type type = typeof(T);
ParameterInfo arg = type.GetMethod("Invoke")!.GetParameters()[argNumber];
throw new ArgumentNullException(arg.Name, "Argument is null or invalid cannot continue");
}
private static void RaiseArgExceptionForArgumentNumber(int argNumber) where T : Delegate
{
//Get delegate parameters
Type type = typeof(T);
ParameterInfo arg = type.GetMethod("Invoke")!.GetParameters()[argNumber];
throw new ArgumentException("Argument is null or invalid cannot continue", arg.Name);
}
private static void RaiseOORExceptionForArgumentNumber(int argNumber) where T : Delegate
{
//Get delegate parameters
Type type = typeof(T);
ParameterInfo arg = type.GetMethod("Invoke")!.GetParameters()[argNumber];
throw new ArgumentOutOfRangeException(arg.Name, "Argument is out of range of acceptable values");
}
}
}