spec: port jolt-transcript to spongefish #1455
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,97 @@ | ||
| //! Local codecs for absorbing / decoding Jolt-native messages over a | ||
| //! byte-oriented spongefish sponge. | ||
| //! | ||
| //! Field-element codecs come from spongefish's `ark-ff` feature | ||
| //! (`spongefish::Encoding<[u8]>` is implemented for every `ark_ff::Fp<C, N>` | ||
| //! using big-endian canonical encoding per RFC8017). 128-bit-truncated | ||
| //! challenges decode through spongefish's built-in `u128` codec directly; | ||
| //! see [`crate::prover::OptimizedChallenge`]. | ||
| //! | ||
| //! This module keeps only `BytesMsg`, the length-prefixed byte string | ||
| //! framing that spongefish 0.6 does not provide. | ||
|
|
||
| use spongefish::{Encoding, NargDeserialize, VerificationError, VerificationResult}; | ||
|
|
||
| /// Length-prefixed byte string. 8-byte LE length keeps `BytesMsg(a) ; BytesMsg(b)` | ||
| /// distinguishable from `BytesMsg(a||b)`. | ||
| #[derive(Clone, Debug, PartialEq, Eq)] | ||
| pub struct BytesMsg(pub Vec<u8>); | ||
|
Comment on lines
+15
to
+18
Collaborator
There was a problem hiding this comment. Can we implement
Contributor
Author
There was a problem hiding this comment. Upstream = external spongefish crate. Wrapper enforces an 8-byte LE u64 length prefix so @mmaker — thoughts on adding
Contributor
There was a problem hiding this comment. I agree with you and @moodlezoup. This wrapper should be in spongefish and |
||
|
|
||
| impl BytesMsg { | ||
| /// Returns the inner bytes. | ||
| pub fn as_slice(&self) -> &[u8] { | ||
| &self.0 | ||
| } | ||
| } | ||
|
|
||
| impl From<Vec<u8>> for BytesMsg { | ||
| fn from(v: Vec<u8>) -> Self { | ||
| Self(v) | ||
| } | ||
| } | ||
|
|
||
| impl Encoding<[u8]> for BytesMsg { | ||
| fn encode(&self) -> impl AsRef<[u8]> { | ||
| let mut out = Vec::with_capacity(8 + self.0.len()); | ||
| out.extend_from_slice(&(self.0.len() as u64).to_le_bytes()); | ||
| out.extend_from_slice(&self.0); | ||
| out | ||
| } | ||
| } | ||
|
|
||
| impl NargDeserialize for BytesMsg { | ||
| fn deserialize_from_narg(buf: &mut &[u8]) -> VerificationResult<Self> { | ||
| if buf.len() < 8 { | ||
| return Err(VerificationError); | ||
| } | ||
| let mut len_bytes = [0u8; 8]; | ||
| len_bytes.copy_from_slice(&buf[..8]); | ||
| let len = u64::from_le_bytes(len_bytes) as usize; | ||
| let total = 8usize.checked_add(len).ok_or(VerificationError)?; | ||
| if buf.len() < total { | ||
| return Err(VerificationError); | ||
| } | ||
| let body = buf[8..total].to_vec(); | ||
| *buf = &buf[total..]; | ||
| Ok(BytesMsg(body)) | ||
| } | ||
| } | ||
|
|
||
| #[cfg(test)] | ||
| mod tests { | ||
| use super::*; | ||
|
|
||
| #[test] | ||
| fn bytes_msg_is_length_prefixed() { | ||
| let m = BytesMsg(vec![1, 2, 3, 4]); | ||
| let enc = m.encode(); | ||
| let bytes = enc.as_ref(); | ||
| assert_eq!(bytes.len(), 8 + 4); | ||
| assert_eq!(&bytes[..8], &4u64.to_le_bytes()); | ||
| assert_eq!(&bytes[8..], &[1, 2, 3, 4]); | ||
| } | ||
|
|
||
| #[test] | ||
| fn bytes_msg_narg_rejects_truncation() { | ||
| let m = BytesMsg(vec![9, 8, 7]); | ||
| let mut narg: Vec<u8> = Vec::new(); | ||
| narg.extend_from_slice(m.encode().as_ref()); | ||
| let _ = narg.pop(); | ||
| let mut cursor: &[u8] = &narg; | ||
| let before = cursor.len(); | ||
| let result = BytesMsg::deserialize_from_narg(&mut cursor); | ||
| assert!(result.is_err()); | ||
| assert_eq!(cursor.len(), before, "cursor must not advance on error"); | ||
| } | ||
|
|
||
| #[test] | ||
| fn bytes_msg_narg_rejects_oversized_length() { | ||
| let mut narg = Vec::new(); | ||
| narg.extend_from_slice(&u64::MAX.to_le_bytes()); | ||
| let mut cursor: &[u8] = &narg; | ||
| let before = cursor.len(); | ||
| let result = BytesMsg::deserialize_from_narg(&mut cursor); | ||
| assert!(result.is_err()); | ||
| assert_eq!(cursor.len(), before, "cursor must not advance on error"); | ||
| } | ||
| } | ||
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Instead of implementing these traits for
ark_bn254::Fr, can we do a blanket implementation overF: jolt_field::CanonicalByteslike we had inblanket.rs?There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Done —
FieldEl<F>/FieldElOptimized<F>now generic with per-impl bounds (CanonicalBytesfor Encoding,ReducingBytes/FromPrimitiveIntfor Decoding). 64-byte uniform constant stays hardcoded with a doc note (BN254-tuned; sound for any ≤254-bit field).