refactor: simplify interface

mattrglobal · Jan 15, 2024 · d941eef · d941eef
1 parent 1fc4412
commit d941eef
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Showing 17 changed files with 251 additions and 433 deletions.
diff --git a/src/common/hash_param/h2s.rs b/src/common/hash_param/h2s.rs
@@ -5,36 +5,19 @@ use crate::{
     Error,
 };
 
-use super::{
-    constant::{DEFAULT_DST_SUFFIX_H2S, XOF_NO_OF_BYTES},
-    ExpandMessageParameter,
-};
+use super::{constant::XOF_NO_OF_BYTES, ExpandMessageParameter};
 
 pub(crate) trait HashToScalarParameter: ExpandMessageParameter {
-    /// Default domain separation tag for `hash_to_scalar` operation.
-    fn default_hash_to_scalar_dst() -> Vec<u8> {
-        [Self::ID.as_octets(), DEFAULT_DST_SUFFIX_H2S.as_bytes()].concat()
-    }
-
     /// Hash arbitrary data to `n` number of scalars as specified in BBS
     /// specification.
-    fn hash_to_scalar(
-        msg_octets: &[u8],
-        dst: Option<&[u8]>,
-    ) -> Result<Scalar, Error> {
-        let default_hash_to_scalar_dst = Self::default_hash_to_scalar_dst();
-        let dst_octets = dst.unwrap_or(&default_hash_to_scalar_dst);
-
-        if !dst_octets.is_ascii() {
+    fn hash_to_scalar(msg_octets: &[u8], dst: &[u8]) -> Result<Scalar, Error> {
+        if !dst.is_ascii() {
             return Err(Error::BadParams {
                 cause: "non-ascii dst".to_owned(),
             });
         }
-        let mut expander = Self::Expander::init_expand(
-            msg_octets,
-            dst_octets,
-            XOF_NO_OF_BYTES,
-        );
+        let mut expander =
+            Self::Expander::init_expand(msg_octets, dst, XOF_NO_OF_BYTES);
 
         let mut buf = [0u8; 64];
         expander.read_into(&mut buf[16..]);

diff --git a/src/schemes/bbs/api/proof.rs b/src/schemes/bbs/api/proof.rs
@@ -65,12 +65,11 @@ where
     let verify_signature = request.verify_signature.unwrap_or(true);
     if verify_signature {
         // Verify the signature to check the messages supplied are valid
-        if !(signature.verify::<_, _, _, I::Ciphersuite>(
+        if !(signature.verify::<_, _, _, I>(
             &pk,
             request.header.as_ref(),
             &generators,
             &digested_messages,
-            Some(I::api_id()),
         )?) {
             return Err(Error::SignatureVerification);
         }
@@ -91,14 +90,13 @@ where
         _parse_request_helper::<T, I>(request)?;
 
     // Generate the proof
-    let proof = Proof::new::<_, _, I::Ciphersuite>(
+    let proof = Proof::new::<_, _, I>(
         &pk,
         &signature,
         request.header.as_ref(),
         request.presentation_header.as_ref(),
         &generators,
         &proof_messages,
-        Some(I::api_id()),
     )?;
 
     Ok(proof.to_octets())
@@ -132,13 +130,12 @@ where
     let generators =
         MemoryCachedGenerators::<I>::new(total_message_count, None)?;
 
-    proof.verify::<_, _, I::Ciphersuite>(
+    proof.verify::<_, _, I>(
         &public_key,
         request.header.as_ref(),
         request.presentation_header.as_ref(),
         &generators,
         &messages,
-        Some(I::api_id()),
     )
 }
 
@@ -157,14 +154,13 @@ where
         _parse_request_helper::<T, I>(request)?;
 
     // Generate the proof
-    let proof = Proof::new_with_rng::<_, _, _, I::Ciphersuite>(
+    let proof = Proof::new_with_rng::<_, _, _, I>(
         &pk,
         &signature,
         request.header.as_ref(),
         request.presentation_header.as_ref(),
         &generators,
         &proof_messages,
-        Some(I::api_id()),
         rng,
     )?;
 

diff --git a/src/schemes/bbs/api/signature.rs b/src/schemes/bbs/api/signature.rs
@@ -37,13 +37,12 @@ where
     let generators = MemoryCachedGenerators::<I>::new(messages.len(), None)?;
 
     // Produce the signature and return
-    Signature::new::<_, _, _, I::Ciphersuite>(
+    Signature::new::<_, _, _, I>(
         &sk,
         &pk,
         request.header.as_ref(),
         &generators,
         &messages,
-        Some(I::api_id()),
     )
     .map(|sig| sig.to_octets())
 }
@@ -68,11 +67,10 @@ where
     // Parse signature from request
     let signature = Signature::from_octets(request.signature)?;
 
-    signature.verify::<_, _, _, I::Ciphersuite>(
+    signature.verify::<_, _, _, I>(
         &pk,
         request.header.as_ref(),
         &generators,
         &messages,
-        Some(I::api_id()),
     )
 }
diff --git a/src/schemes/bbs/ciphersuites.rs b/src/schemes/bbs/ciphersuites.rs
@@ -3,7 +3,7 @@ use crate::{
     common::{
         ciphersuite::CipherSuiteId,
         hash_param::{
-            constant::{DEFAULT_DST_SUFFIX_H2S, XOF_NO_OF_BYTES},
+            constant::XOF_NO_OF_BYTES,
             h2c::HashToCurveParameter,
             h2s::HashToScalarParameter,
         },
@@ -16,7 +16,7 @@ use crate::{
     },
     Error,
 };
-use blstrs::Scalar;
+
 use group::Group;
 
 /// BBS BLS12-381 ciphersuites.
@@ -88,9 +88,4 @@ pub(crate) trait BbsCiphersuiteParameters:
     fn p2() -> G2Projective {
         G2Projective::generator()
     }
-
-    fn hash_to_e(data_to_hash: &[u8], api_id: &[u8]) -> Result<Scalar, Error> {
-        let e_dst = [api_id, DEFAULT_DST_SUFFIX_H2S.as_bytes()].concat();
-        Self::hash_to_scalar(data_to_hash, Some(&e_dst))
-    }
 }
diff --git a/src/schemes/bbs/ciphersuites/bls12_381_g1_sha_256.rs b/src/schemes/bbs/ciphersuites/bls12_381_g1_sha_256.rs
@@ -155,7 +155,7 @@ pub const SCALAR_OCTETS_LENGTH: usize = OCTET_SCALAR_LENGTH;
 #[cfg_attr(docsrs, doc(cfg(feature = "__private_bbs_fixtures_generator_api")))]
 pub fn hash_to_scalar(
     msg_octets: &[u8],
-    dst: Option<&[u8]>,
+    dst: &[u8],
 ) -> Result<[u8; OCTET_SCALAR_LENGTH], Error> {
     let scalars =
         Bls12381Sha256CipherSuiteParameter::hash_to_scalar(msg_octets, dst);
@@ -188,7 +188,7 @@ pub fn map_message_to_scalar_as_hash(
 #[cfg(feature = "__private_bbs_fixtures_generator_api")]
 #[cfg_attr(docsrs, doc(cfg(feature = "__private_bbs_fixtures_generator_api")))]
 pub fn default_hash_to_scalar_dst() -> Vec<u8> {
-    Bls12381Sha256CipherSuiteParameter::default_hash_to_scalar_dst()
+    Bls12381Sha256InterfaceParameter::default_hash_to_scalar_dst()
 }
 
 /// Return the default map message to scalar as hash dst.

diff --git a/src/schemes/bbs/ciphersuites/bls12_381_g1_shake_256.rs b/src/schemes/bbs/ciphersuites/bls12_381_g1_shake_256.rs
@@ -155,7 +155,7 @@ pub const SCALAR_OCTETS_LENGTH: usize = OCTET_SCALAR_LENGTH;
 #[cfg_attr(docsrs, doc(cfg(feature = "__private_bbs_fixtures_generator_api")))]
 pub fn hash_to_scalar(
     msg_octets: &[u8],
-    dst: Option<&[u8]>,
+    dst: &[u8],
 ) -> Result<[u8; OCTET_SCALAR_LENGTH], Error> {
     let scalars: Result<blstrs::Scalar, Error> =
         Bls12381Shake256CipherSuiteParameter::hash_to_scalar(msg_octets, dst);
@@ -188,7 +188,7 @@ pub fn map_message_to_scalar_as_hash(
 #[cfg(feature = "__private_bbs_fixtures_generator_api")]
 #[cfg_attr(docsrs, doc(cfg(feature = "__private_bbs_fixtures_generator_api")))]
 pub fn default_hash_to_scalar_dst() -> Vec<u8> {
-    Bls12381Shake256CipherSuiteParameter::default_hash_to_scalar_dst()
+    Bls12381Shake256InterfaceParameter::default_hash_to_scalar_dst()
 }
 
 /// Return the default map message to scalar as hash dst.