refactor confidential.rs and clean up code

.github/workflows/cron-daily-fuzz.yml

@@ -1,5 +1,5 @@
 ######
-## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-fuzz.sh.
+## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-files.sh.
 ## Edit that script instead and re-run it.
 ######
 name: Fuzz

fuzz/Cargo.toml

@@ -1,5 +1,5 @@
 ######
-## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-fuzz.sh.
+## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-files.sh.
 ## Edit that script instead and re-run it.
 ######
 [package]

fuzz/generate-files.sh

@@ -11,7 +11,7 @@ source "$REPO_DIR/fuzz/fuzz-util.sh"
 # 1. Generate fuzz/Cargo.toml
 cat > "$REPO_DIR/fuzz/Cargo.toml" <<EOF
 ######
-## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-fuzz.sh.
+## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-files.sh.
 ## Edit that script instead and re-run it.
 ######
 [package]
@@ -38,6 +38,7 @@ use_self = "warn"
 
 [package.metadata.rbmt.lint]
 allowed_duplicates = [
+    "bitcoin_hashes",
     "bitcoin-internals",
     "hex-conservative",
     "getrandom",
@@ -61,7 +62,7 @@ done
 # 2. Generate .github/workflows/cron-daily-fuzz.yml
 cat > "$REPO_DIR/.github/workflows/cron-daily-fuzz.yml" <<EOF
 ######
-## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-fuzz.sh.
+## DO NOT EDIT THIS FILE DIRECTLY. It is generated by generate-files.sh.
 ## Edit that script instead and re-run it.
 ######
 name: Fuzz

rustfmt.toml

@@ -0,0 +1,81 @@
+ignore = [
+    "/",
+    "!/src/lib.rs",
+    "!/src/confidential/*.rs",
+]
+hard_tabs = false
+tab_spaces = 4
+newline_style = "Auto"
+indent_style = "Block"
+
+max_width = 100 # This is the number of characters.
+# `use_small_heuristics` is ignored if the granular width config values are explicitly set.
+use_small_heuristics = "Max"    # "Max" == All granular width settings same as `max_width`.
+# # Granular width configuration settings. These are percentages of `max_width`.
+# fn_call_width = 60
+# attr_fn_like_width = 70
+# struct_lit_width = 18
+# struct_variant_width = 35
+# array_width = 60
+# chain_width = 60
+# single_line_if_else_max_width = 50
+
+wrap_comments = false
+format_code_in_doc_comments = false
+comment_width = 100             # Default 80
+normalize_comments = false
+normalize_doc_attributes = false
+format_strings = false
+format_macro_matchers = false
+format_macro_bodies = true
+hex_literal_case = "Preserve"
+empty_item_single_line = true
+struct_lit_single_line = true
+fn_single_line = true           # Default false
+where_single_line = false
+imports_indent = "Block"
+imports_layout = "Mixed"
+imports_granularity = "Module"     # Default "Preserve"
+group_imports = "StdExternalCrate" # Default "Preserve"
+reorder_imports = true
+reorder_modules = true
+reorder_impl_items = false
+type_punctuation_density = "Wide"
+space_before_colon = false
+space_after_colon = true
+spaces_around_ranges = false
+binop_separator = "Front"
+remove_nested_parens = true
+combine_control_expr = true
+overflow_delimited_expr = false
+struct_field_align_threshold = 0
+enum_discrim_align_threshold = 0
+match_arm_blocks = false        # Default true
+match_arm_leading_pipes = "Never"
+force_multiline_blocks = false
+fn_params_layout = "Tall"
+brace_style = "SameLineWhere"
+control_brace_style = "AlwaysSameLine"
+trailing_semicolon = true
+trailing_comma = "Vertical"
+match_block_trailing_comma = false
+blank_lines_upper_bound = 1
+blank_lines_lower_bound = 0
+edition = "2021"
+style_edition = "2021"
+inline_attribute_width = 0
+format_generated_files = true
+merge_derives = true
+use_try_shorthand = false
+use_field_init_shorthand = false
+force_explicit_abi = true
+condense_wildcard_suffixes = false
+color = "Auto"
+unstable_features = false
+disable_all_formatting = false
+skip_children = false
+show_parse_errors = true
+error_on_line_overflow = false
+error_on_unformatted = false
+emit_mode = "Files"
+make_backup = false

src/blind.rs

@@ -23,9 +23,9 @@ use secp256k1_zkp::{
     rand::{CryptoRng, RngCore},
     PedersenCommitment, SecretKey, Tag, Tweak, Verification, ZERO_TWEAK,
 };
-use secp256k1_zkp::{Generator, RangeProof, Secp256k1, Signing, SurjectionProof};
+use secp256k1_zkp::{Generator, Secp256k1, Signing};
 
-use crate::{AddressParams, Script, TxIn};
+use crate::{AddressParams, RangeProof, Script, TxIn, SurjectionProof};
 
 use crate::{
     confidential::{Asset, AssetBlindingFactor, Nonce, Value, ValueBlindingFactor},
@@ -497,13 +497,7 @@ impl Asset {
             })
             .collect::<Result<Vec<_>, _>>()?;
 
-        let surjection_proof = SurjectionProof::new(
-            secp,
-            rng,
-            asset.into_tag(),
-            asset_bf.into_inner(),
-            inputs.as_ref(),
-        )?;
+        let surjection_proof = SurjectionProof::new(secp, rng, asset, asset_bf, inputs)?;
 
         Ok((out_asset, surjection_proof))
     }
@@ -657,7 +651,7 @@ impl TxOut {
             out_secrets.asset_bf,
         );
         let exp_value = Value::Explicit(out_secrets.value);
-        let (out_value, nonce, range_proof) = exp_value.blind(
+        let (out_value, nonce, rangeproof) = exp_value.blind(
             secp,
             out_secrets.value_bf,
             receiver_blinding_pk,
@@ -672,8 +666,8 @@ impl TxOut {
             nonce,
             script_pubkey: spk,
             witness: TxOutWitness {
-                surjection_proof: Some(Box::new(surjection_proof)),
-                rangeproof: Some(Box::new(range_proof)),
+                surjection_proof,
+                rangeproof,
             },
         };
         Ok(txout)
@@ -977,10 +971,10 @@ impl TxIn {
             let (comm, prf) = v.blind_with_shared_secret(secp, bf, blind_sk, &spk, &msg)?;
             if i == 0 {
                 self.asset_issuance.amount = comm;
-                self.witness.amount_rangeproof = Some(Box::new(prf));
+                self.witness.amount_rangeproof = prf;
             } else {
                 self.asset_issuance.inflation_keys = comm;
-                self.witness.inflation_keys_rangeproof = Some(Box::new(prf));
+                self.witness.inflation_keys_rangeproof = prf;
             }
         }
         Ok(())
@@ -1365,122 +1359,6 @@ impl From<ConfidentialTxOutError> for BlindError {
     }
 }
 
-/// A trait to create and verify explicit rangeproofs
-pub trait BlindValueProofs: Sized {
-    /// Outputs a `[RangeProof]` that blinded value
-    /// corresponfs to unblinded explicit value
-    fn blind_value_proof<C: secp256k1_zkp::Signing, R: RngCore + CryptoRng>(
-        rng: &mut R,
-        secp: &Secp256k1<C>,
-        explicit_val: u64,
-        value_commit: PedersenCommitment,
-        asset_gen: Generator,
-        vbf: ValueBlindingFactor,
-    ) -> Result<Self, secp256k1_zkp::Error>;
-
-    /// Verify that the Rangeproof proves that commitment
-    /// is actually bound to the explicit value
-    fn blind_value_proof_verify<C: secp256k1_zkp::Verification>(
-        &self,
-        secp: &Secp256k1<C>,
-        explicit_val: u64,
-        asset_gen: Generator,
-        value_commit: PedersenCommitment,
-    ) -> bool;
-}
-
-impl BlindValueProofs for RangeProof {
-    /// Outputs a [`RangeProof`] that blinded `value_commit`
-    /// corresponds to explicit value
-    fn blind_value_proof<C: secp256k1_zkp::Signing, R: RngCore + CryptoRng>(
-        rng: &mut R,
-        secp: &Secp256k1<C>,
-        explicit_val: u64,
-        value_commit: PedersenCommitment,
-        asset_gen: Generator,
-        vbf: ValueBlindingFactor,
-    ) -> Result<Self, secp256k1_zkp::Error> {
-        RangeProof::new(
-            secp,
-            explicit_val,        // min_value
-            value_commit,        // value_commit
-            explicit_val,        // value
-            vbf.into_inner(),    // blinding factor
-            &[],                 // message
-            &[],                 // add commitment
-            SecretKey::new(rng), // nonce
-            -1,                  // exp
-            0,                   // min bits
-            asset_gen,           // additional gen
-        )
-    }
-
-    /// Verify that the Rangeproof proves that commitment
-    /// is actually bound to the explicit value
-    fn blind_value_proof_verify<C: secp256k1_zkp::Verification>(
-        &self,
-        secp: &Secp256k1<C>,
-        explicit_val: u64,
-        asset_gen: Generator,
-        value_commit: PedersenCommitment,
-    ) -> bool {
-        let r = self.verify(secp, value_commit, &[], asset_gen);
-        match r {
-            Ok(e) => e.start == explicit_val && e.end - 1 == explicit_val,
-            Err(..) => false,
-        }
-    }
-}
-
-/// A trait to create and verify explicit surjection proofs
-pub trait BlindAssetProofs: Sized {
-    /// Outputs a `[SurjectionProof]` that blinded asset
-    /// corresponfs to unblinded explicit asset
-    fn blind_asset_proof<C: secp256k1_zkp::Signing, R: RngCore + CryptoRng>(
-        rng: &mut R,
-        secp: &Secp256k1<C>,
-        asset: AssetId,
-        abf: AssetBlindingFactor,
-    ) -> Result<Self, secp256k1_zkp::Error>;
-
-    /// Verify that the Surjection proves that asset commitment
-    /// is actually bound to the explicit asset
-    fn blind_asset_proof_verify(
-        &self,
-        secp: &Secp256k1<secp256k1_zkp::All>,
-        asset: AssetId,
-        asset_commit: Generator,
-    ) -> bool;
-}
-
-impl BlindAssetProofs for SurjectionProof {
-    fn blind_asset_proof<C: secp256k1_zkp::Signing, R: RngCore + CryptoRng>(
-        rng: &mut R,
-        secp: &Secp256k1<C>,
-        asset: AssetId,
-        abf: AssetBlindingFactor,
-    ) -> Result<Self, secp256k1_zkp::Error> {
-        let gen = Generator::new_unblinded(secp, asset.into_tag());
-        SurjectionProof::new(
-            secp,
-            rng,
-            asset.into_tag(),
-            abf.into_inner(),
-            &[(gen, asset.into_tag(), ZERO_TWEAK)],
-        )
-    }
-
-    fn blind_asset_proof_verify(
-        &self,
-        secp: &Secp256k1<secp256k1_zkp::All>,
-        asset: AssetId,
-        asset_commit: Generator,
-    ) -> bool {
-        let gen = Generator::new_unblinded(secp, asset.into_tag());
-        self.verify(secp, asset_commit, &[gen])
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;