Explicit Message Padding for OnionRealm0HopData #469
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| @@ -610,7 +611,7 @@ pub(crate) struct OnionRealm0HopData { | |||
| pub(crate) short_channel_id: u64, | |||
| pub(crate) amt_to_forward: u64, | |||
| pub(crate) outgoing_cltv_value: u32, | |||
| // 12 bytes of 0-padding | |||
| pub(crate) padding: PhantomData<[u8; 12]>, | |||
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It's too bad RFC 2000 (rust-lang/rust#44580) isn't in the stable Rust release yet. Then we could type alias this as:
pub(crate) type BytePadding<const N: usize> = ::std::marker::PhantomData<[u8; N]>;So this should be fine for now.
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We should probably do something like this anyway without generic constants. PhantomData has a somewhat specific meaning in Rust (that we have a template type that we're not going to instantiate). We probably just want a new type in ser.rs like (but with better names):
pub(crate) struct PaddingData<T: Default + std::convert::AsRef<[u8]>> {
t: std::marker::PhantomData<T>,
}
impl<T: Default + std::convert::AsRef<[u8]>> Writeable for PaddingData<T> {
#[inline]
fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
let nt: T = Default::default();
w.write_all(nt.as_ref())
}
}
lightning/src/util/ser.rs
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| impl Writeable for PhantomData<[u8; 12]> { | ||
| fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> { | ||
| w.write_all(&[0;12])?; |
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Nit: Space between ; and 12.
varunsrin
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| @@ -610,7 +611,7 @@ pub(crate) struct OnionRealm0HopData { | |||
| pub(crate) short_channel_id: u64, | |||
| pub(crate) amt_to_forward: u64, | |||
| pub(crate) outgoing_cltv_value: u32, | |||
| // 12 bytes of 0-padding | |||
| pub(crate) padding: PhantomData<[u8; 12]>, | |||
There was a problem hiding this comment.
We should probably do something like this anyway without generic constants. PhantomData has a somewhat specific meaning in Rust (that we have a template type that we're not going to instantiate). We probably just want a new type in ser.rs like (but with better names):
pub(crate) struct PaddingData<T: Default + std::convert::AsRef<[u8]>> {
t: std::marker::PhantomData<T>,
}
impl<T: Default + std::convert::AsRef<[u8]>> Writeable for PaddingData<T> {
#[inline]
fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
let nt: T = Default::default();
w.write_all(nt.as_ref())
}
}
|
@varunsrin #434 has been merged, so you should be able to rebase now. |
|
perfect, ill get to this by early next week |
|
Closing as abandoned. If you want to pick this back up just respond here and we can open it again :) |
Fixes #467