From facfa81eb94ca64826050181497bea3dfb2ef50b Mon Sep 17 00:00:00 2001
From: th4s <th4s@metavoid.xyz>
Date: Tue, 5 Sep 2023 16:20:50 +0200
Subject: [PATCH] Add spansy and start with assertion on `VerifiedTranscript`

---
 tlsn/Cargo.toml                  |  1 +
 tlsn/tlsn-verifier/Cargo.toml    |  2 ++
 tlsn/tlsn-verifier/src/assert.rs |  3 +++
 tlsn/tlsn-verifier/src/lib.rs    | 15 +++++++++++----
 4 files changed, 17 insertions(+), 4 deletions(-)
 create mode 100644 tlsn/tlsn-verifier/src/assert.rs

diff --git a/tlsn/Cargo.toml b/tlsn/Cargo.toml
index 7fbcc2f537..43639469f8 100644
--- a/tlsn/Cargo.toml
+++ b/tlsn/Cargo.toml
@@ -31,6 +31,7 @@ mpz-garble = { git = "https://github.com/privacy-scaling-explorations/mpz", rev
 mpz-ot = { git = "https://github.com/privacy-scaling-explorations/mpz", rev = "a98fd8a" }
 mpz-share-conversion = { git = "https://github.com/privacy-scaling-explorations/mpz", rev = "a98fd8a" }
 
+spansy = {git = "https://github.com/sinui0/spansy", rev = "23a6b0a"}
 
 futures = "0.3"
 tokio-util = "0.7"
diff --git a/tlsn/tlsn-verifier/Cargo.toml b/tlsn/tlsn-verifier/Cargo.toml
index d7e05333a8..2728e2be7a 100644
--- a/tlsn/tlsn-verifier/Cargo.toml
+++ b/tlsn/tlsn-verifier/Cargo.toml
@@ -17,6 +17,8 @@ tlsn-utils.workspace = true
 
 mpz-core.workspace = true
 
+spansy.workspace = true
+
 webpki-roots.workspace = true
 p256.workspace = true
 thiserror.workspace = true
diff --git a/tlsn/tlsn-verifier/src/assert.rs b/tlsn/tlsn-verifier/src/assert.rs
new file mode 100644
index 0000000000..f3ec2c7caa
--- /dev/null
+++ b/tlsn/tlsn-verifier/src/assert.rs
@@ -0,0 +1,3 @@
+pub struct VerifiedTranscript {
+    pub(crate) data: Vec<u8>,
+}
diff --git a/tlsn/tlsn-verifier/src/lib.rs b/tlsn/tlsn-verifier/src/lib.rs
index c4b7c36936..26071f371b 100644
--- a/tlsn/tlsn-verifier/src/lib.rs
+++ b/tlsn/tlsn-verifier/src/lib.rs
@@ -34,6 +34,9 @@ use tlsn_core::{
 };
 use utils::invert_range::invert_range;
 
+mod assert;
+use assert::VerifiedTranscript;
+
 /// Valid characters for redacted parts in transcripts
 pub const VALID_REDACTMENT_CHARS: &[u8] = b"x";
 
@@ -75,7 +78,7 @@ impl Verifier {
     /// Sets a new session proof and verifies it.
     pub fn set_session_proof(&mut self, session_proof: SessionProof) -> Result<(), VerifierError> {
         self.session_proof = Some(session_proof);
-        let verify_result = self.verify();
+        let verify_result = self.verify_session_proof();
 
         if verify_result.is_err() {
             self.session_proof = None;
@@ -95,7 +98,7 @@ impl Verifier {
         proof: SubstringsProof,
         transcript: Transcript,
         direction: Direction,
-    ) -> Result<(), VerifierError> {
+    ) -> Result<VerifiedTranscript, VerifierError> {
         let header = self
             .session_proof
             .as_ref()
@@ -142,10 +145,14 @@ impl Verifier {
             return Err(VerifierError::InvalidRedactedTranscript);
         }
 
-        Ok(())
+        let verified_transcript = VerifiedTranscript {
+            data: transcript.data().to_vec(),
+        };
+
+        Ok(verified_transcript)
     }
 
-    fn verify(&self) -> Result<(), VerifierError> {
+    fn verify_session_proof(&self) -> Result<(), VerifierError> {
         if let Some(notary_pk) = self.notary_pubkey {
             self.verify_notary_signature(notary_pk)?;
         }