pkc%feat(bls): replace Hash256 with BlsShareId, expose scalars and groups through RustCrypto 0.14 traits, allow secret retagging, subtraction, expose reduction, weighted public key derivation

contrib/codeql/lib/policy.qll

@@ -51,12 +51,17 @@ predicate isSecretType(TypeItem t) {
     // Scalar field wrapper holding secret key material
     t.getName().getText() = "Fr"
   ) and
-  // A share *of a signature* is published, so it holds nothing to protect. Excluded by
-  // exact name because `BlsSkShare` and `RawShare` match the same Share substring
-  // and do carry secret scalars.
-  not t.getName().getText() = "BlsSigShare" and
-  // Serde artifact to deserialize a tagged enum.
-  not t.getName().getText() = "__Seed"
+  not t.getName().getText() =
+    [
+      // A share *of a signature* is published, so it's non-secret. Excluded by exact name because
+      // `BlsSkShare` and `RawShare` match the same Share substring and do carry secret scalars.
+      "BlsSigShare",
+      // The identifier a share is issued against is the participant's, known to every member of the
+      // quorum; only the scalar the share carries is secret.
+      "BlsShareId",
+      // Serde artifact to deserialize a tagged enum.
+      "__Seed"
+    ]
 }
 
 /**

pkgs/pkc/Cargo.toml

@@ -8,18 +8,20 @@ license = "MIT"
 base58ck = { workspace = true, features = ["alloc"] }
 bitcoin_hashes = { workspace = true, features = ["alloc"] }
 blst = { version = "0.3", default-features = false, optional = true }
+ff = { version = "0.14", default-features = false, optional = true }
+group = { version = "0.14", default-features = false, optional = true }
 cfg-if = "1"
 dash-num = { version = "0.0.0", path = "../num" }
 dash-types = { version = "0.0.0", path = "../types", default-features = false }
 hex-conservative = { version = "0.3", default-features = false, features = [
   "alloc",
 ] }
-k256 = { version = "0.13", default-features = false, features = [
+k256 = { version = "0.14", default-features = false, features = [
   "arithmetic",
   "ecdsa",
   "sha256",
 ], optional = true }
-rand_core = { version = "0.6", default-features = false, optional = true }
+rand_core = { version = "0.10", default-features = false, optional = true }
 rstest = { version = "0.25", optional = true }
 serde = { version = "1", default-features = false, features = [
   "alloc",
@@ -36,15 +38,16 @@ zeroize = { version = "1", default-features = false, features = [
 bitcoin-consensus-encoding = { workspace = true, features = ["alloc"] }
 dash-dev = { version = "0.0.0", path = "../dev", features = ["full"] }
 divan = "0.1"
+getrandom = { version = "0.4", features = ["sys_rng"] }
 hex-conservative = "0.3"
-rand_core = { version = "0.6", features = ["getrandom"] }
+rand_core = { version = "0.10" }
 rstest = "0.25"
 serde = { version = "1", features = ["derive"] }
 
 [features]
 default = []
 std = ["base58ck/std", "bitcoin_hashes/std", "dash-types/std"]
-bls = ["dep:blst", "dep:rand_core", "dep:sha2"]
+bls = ["dep:blst", "dep:ff", "dep:group", "dep:rand_core", "dep:sha2"]
 ecdsa = ["dep:k256", "dep:rand_core"]
 serde = ["dep:serde", "dash-num/serde", "dash-types/serde"]
 full = ["ecdsa", "bls", "serde", "std", "tests"]

pkgs/pkc/bench/bls.rs

@@ -9,7 +9,8 @@
 use dash_pkc::bls::tests::{sequential_ids, test_ikm, test_msg};
 use dash_pkc::bls::{BlsPublicKey, BlsScChia, BlsScIetf, BlsScheme, BlsSecretKey, BlsSigShare, BlsSignature};
 use divan::{counter::ItemsCount, Bencher};
-use rand_core::OsRng;
+use getrandom::SysRng;
+use rand_core::UnwrapErr;
 
 /// Single signature creation.
 #[divan::bench(types = [BlsScChia, BlsScIetf])]
@@ -144,15 +145,15 @@ fn split_threshold<S: BlsScheme>(bencher: Bencher, n: usize) {
   let ids = sequential_ids(n);
   bencher
     .counter(ItemsCount::new(n))
-    .bench(|| sk.split(threshold, &ids, &mut OsRng));
+    .bench(|| sk.split(threshold, &ids, &mut UnwrapErr(SysRng)));
 }
 
 /// Threshold signature recovery via Lagrange interpolation.
 #[divan::bench(types = [BlsScChia, BlsScIetf], args = [3, 5, 10])]
 fn recover_threshold<S: BlsScheme>(bencher: Bencher, threshold: usize) {
   let sk = BlsSecretKey::<S>::generate(&test_ikm(1)).unwrap();
   let ids = sequential_ids(threshold * 2);
-  let shares = sk.split(threshold, &ids, &mut OsRng).unwrap();
+  let shares = sk.split(threshold, &ids, &mut UnwrapErr(SysRng)).unwrap();
   let msg = test_msg(42);
   let sig_shares: Vec<_> = shares.iter().map(|share| share.sign(S::msg_ref(&msg))).collect();
   let subset: Vec<&BlsSigShare<S>> = sig_shares.iter().take(threshold).collect();