_ Git - dnssec-prover/blob - wasmpack/src/lib.rs

   1 //! WASM-compatible verification wrappers
   2
   3 use dnssec_prover::ser::parse_rr_stream;
   4 use dnssec_prover::validation::{verify_rr_stream, ValidationError};
   5 use dnssec_prover::query::{ProofBuilder, QueryBuf};
   6
   7 use wasm_bindgen::prelude::wasm_bindgen;
   8
   9 extern crate alloc;
  10 use alloc::collections::VecDeque;
  11
  12 use core::fmt::Write;
  13
  14 #[global_allocator]
  15 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
  16
  17 #[wasm_bindgen]
  18 pub struct WASMProofBuilder(ProofBuilder, VecDeque<QueryBuf>);
  19
  20 #[wasm_bindgen]
  21 /// Builds a proof builder which can generate a proof for records of the given `ty`pe at the given
  22 /// `name`.
  23 ///
  24 /// After calling this [`get_next_query`] should be called to fetch the initial query.
  25 pub fn init_proof_builder(mut name: String, ty: u16) -> Option<WASMProofBuilder> {
  26         if !name.ends_with('.') { name.push('.'); }
  27         if let Ok(qname) = name.try_into() {
  28                 let (builder, initial_query) = ProofBuilder::new(&qname, ty);
  29                 let mut queries = VecDeque::with_capacity(4);
  30                 queries.push_back(initial_query);
  31                 Some(WASMProofBuilder(builder, queries))
  32         } else {
  33                 None
  34         }
  35 }
  36
  37 #[wasm_bindgen]
  38 /// Processes a response to a query previously fetched from [`get_next_query`].
  39 ///
  40 /// After calling this, [`get_next_query`] should be called until pending queries are exhausted and
  41 /// no more pending queries exist, at which point [`get_unverified_proof`] should be called.
  42 pub fn process_query_response(proof_builder: &mut WASMProofBuilder, response: Vec<u8>) {
  43         if response.len() < u16::MAX as usize {
  44                 let mut answer = QueryBuf::new_zeroed(response.len() as u16);
  45                 answer.copy_from_slice(&response);
  46                 if let Ok(queries) = proof_builder.0.process_response(&answer) {
  47                         for query in queries {
  48                                 proof_builder.1.push_back(query);
  49                         }
  50                 }
  51         }
  52 }
  53
  54
  55 #[wasm_bindgen]
  56 /// Gets the next query (if any) that should be sent to the resolver for the given proof builder.
  57 ///
  58 /// Once the resolver responds [`process_query_response`] should be called with the response.
  59 pub fn get_next_query(proof_builder: &mut WASMProofBuilder) -> Option<Vec<u8>> {
  60         if let Some(query) = proof_builder.1.pop_front() {
  61                 Some(query.into_vec())
  62         } else {
  63                 None
  64         }
  65 }
  66
  67 #[wasm_bindgen]
  68 /// Gets the final, unverified, proof once all queries fetched via [`get_next_query`] have
  69 /// completed and their responses passed to [`process_query_response`].
  70 pub fn get_unverified_proof(proof_builder: WASMProofBuilder) -> Option<Vec<u8>> {
  71         proof_builder.0.finish_proof().ok().map(|(proof, _ttl)| proof)
  72 }
  73
  74 #[wasm_bindgen]
  75 /// Verifies an RFC 9102-formatted proof and returns the [`VerifiedRRStream`] in JSON form.
  76 pub fn verify_byte_stream(stream: Vec<u8>) -> String {
  77         match do_verify_byte_stream(stream) {
  78                 Ok(r) => r,
  79                 Err(e) => format!("{{\"error\":\"{:?}\"}}", e),
  80         }
  81 }
  82
  83 fn do_verify_byte_stream(stream: Vec<u8>) -> Result<String, ValidationError> {
  84         let rrs = parse_rr_stream(&stream).map_err(|()| ValidationError::Invalid)?;
  85         let verified_rrs = verify_rr_stream(&rrs)?;
  86         let mut resp = String::new();
  87         write!(&mut resp, "{}",
  88                 format_args!("{{\"valid_from\": {}, \"expires\": {}, \"max_cache_ttl\": {}, \"verified_rrs\": [",
  89                 verified_rrs.valid_from, verified_rrs.expires, verified_rrs.max_cache_ttl)
  90         ).expect("Write to a String shouldn't fail");
  91         for (idx, rr) in verified_rrs.verified_rrs.iter().enumerate() {
  92                 write!(&mut resp, "{}{}", if idx != 0 { ", " } else { "" }, rr.json())
  93                         .expect("Write to a String shouldn't fail");
  94         }
  95         resp += "]}";
  96         Ok(resp)
  97 }