Hash function includes Rust-specific debug information making cross-platform verification impossible

[Frank-en-stein]

Problem

The Operation::hash() function in crates/jstz_proto/src/operation.rs uses Rust's {:?} debug formatting for certain types (HeaderMap, HttpBody), which includes Rust-specific type information and debug formatting. This makes it impossible for non-Rust systems or even rust systems with different versions to reproduce or verify operation hashes.

Evidence

Two unit tests have been added that prove this issue:

• test_hash_includes_debug_info_problem
• test_non_rust_system_hash_reproduction_challenge

Test Output

Hashed string: edpkuifh2JiPVYfEM4LuGBcPjhHR1GS88bc4ciNUqg15UcWM5zjFmn42jstz://tz1cD5CuvAALcxgypqBXcBQEA8dkLJivoFjU/testPOST{"content-type": "application/json"}HttpBody(Some([104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]))

The hash includes:

• Rust struct names: HttpBody
• Rust Option wrapper: Some([...])
• Rust byte array representation: [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]
• Debug-formatted headers with quotes and colons

Code Location

The problematic code is in Operation::hash() around lines 84-91:

Content::RunFunction(RunFunction {
    uri,
    method,
    headers,
    body,
    ..
}) => Blake2b::from(
    format!("{public_key}{nonce}{uri}{method}{headers:?}{body:?}").as_bytes(),
),

Also in OracleResponse around line 106:

format!("{}{}{}{:?}", public_key, nonce, request_id, response).as_bytes(),

Solution Needed

The hash function should use deterministic, language-agnostic serialization (e.g., canonical JSON or binary encoding) instead of Rust's debug formatting. This ensures:

• Cross-platform compatibility
• Version stability
• Proper cryptographic hash generation

Reference Branch

Tests demonstrating this issue are available in branch: fix/hash-debug-formatting-issue

cargo test -p jstz_proto operation::test -- --nocapture