public void CalcHmac(byte[] key, int keyLen, byte[] data, int dataLen, byte[] hmac)
{
var keyHandle = default(GCHandle);
var dataHandle = default(GCHandle);
var hmacHandle = default(GCHandle);
try
{
keyHandle = GCHandle.Alloc(key, GCHandleType.Pinned);
dataHandle = GCHandle.Alloc(data, GCHandleType.Pinned);
hmacHandle = GCHandle.Alloc(hmac, GCHandleType.Pinned);
var outputLength = 0;
if (OpenSsl.HMAC(OpenSsl.EVP_sha1(),
keyHandle.AddrOfPinnedObject(), keyLen,
dataHandle.AddrOfPinnedObject(), dataLen,
hmacHandle.AddrOfPinnedObject(), ref outputLength) == IntPtr.Zero)
{
throw new Exception($"Cannot calculate HMAC: {OpenSsl.GetLastError()}");
}
}
finally
{
if (keyHandle.IsAllocated)
{
keyHandle.Free();
}
if (dataHandle.IsAllocated)
{
dataHandle.Free();
}
if (hmacHandle.IsAllocated)
{
hmacHandle.Free();
}
}
}
