pkc%feat(eddsa): add rudimentary Ed25519 support backed by ed25519-dalek

maint/codeql/rust/lib/imports.qll

@@ -87,6 +87,8 @@ private predicate isAllowlistedReexport(Use u) {
     or
     usePrefix(u) = "dash_types"
     or
+    usePrefix(u) = "ed25519_dalek"
+    or
     usePrefix(u) = "ff"
     or
     usePrefix(u) = "group"
@@ -100,6 +102,13 @@ private predicate isAllowlistedReexport(Use u) {
     usePrefix(u) = "zeroize"
   )
   or
+  fileOf(u).getAbsolutePath().matches("%pkgs/primitives/%") and
+  (
+    // `dash-pkc` names its hashes after the curve, the alias is the public API.
+    usePrefix(u) = "dash_pkc" and
+    u.getUseTree().getPath().getSegment().getIdentifier().getText() = "__EddsaPkHash"
+  )
+  or
   fileOf(u).getAbsolutePath().matches("%pkgs/script/%") and
   (
     // Workaround for the orphan rule, not part of public API

maint/codeql/rust/lib/pkc.qll

@@ -12,6 +12,12 @@
  */
 extensible predicate armOnly(string arm, string role, string name);
 
+/**
+ * Holds if `arm` cannot carry `name` at `role`, though the other arms offer
+ * it. Rows live in `pkc.model.yml`.
+ */
+extensible predicate armLacks(string arm, string role, string name);
+
 /**
  * Holds if `arm` cannot carry `trait` at `role`, though the other arms do.
  * Rows live in `pkc.model.yml`.

maint/codeql/rust/pkc.model.yml

@@ -64,7 +64,31 @@ extensions:
       # Recoverable signatures
       - ["Ecdsa", "SecretKey", "sign_recoverable"]        # Sign
       - ["Ecdsa", "PublicKey", "recover"]                 # Get public key from a signature
+  - addsTo:
+      pack: base-sdk/codeql-rust
+      extensible: armLacks
+    data:
+      # Ed25519
+      # Tweaking
+      - ["Eddsa", "SecretKey", "add_tweak"]               # Curve properties prevent this, see SLIP-0010
+      - ["Eddsa", "PublicKey", "add_tweak"]               # Curve properties prevent this, see SLIP-0010
+      - ["Eddsa", "PublicKey", "mul_tweak"]               # Curve properties prevent this, see SLIP-0010
   - addsTo:
       pack: base-sdk/codeql-rust
       extensible: armLacksTrait
-    data: []
+    data:
+      # Ed25519
+      # Consensus wire format
+      - ["Eddsa", "PublicKey", "Decode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "PublicKey", "Encode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "PublicKey", "SerBound"]                # Follows from `Decode`
+      - ["Eddsa", "PublicKey", "TypeId"]                  # Follows from `Decode`
+      - ["Eddsa", "SecretKey", "Decode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "SecretKey", "Encode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "SecretKey", "Hashable"]                # Follows from `Decode`
+      - ["Eddsa", "SecretKey", "TypeId"]                  # Follows from `Decode`
+      - ["Eddsa", "Signature", "Decode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "Signature", "Encode"]                  # Not a wire type, see `Unencodable`
+      - ["Eddsa", "Signature", "Hashable"]                # Follows from `Decode`
+      - ["Eddsa", "Signature", "SerBound"]                # Follows from `Decode`
+      - ["Eddsa", "Signature", "TypeId"]                  # Follows from `Decode`

maint/codeql/rust/pkc.ql

@@ -73,19 +73,24 @@ predicate shapeGap(TypeItem lacks, string role, string name, string arm) {
     lacking != arm and
     publicMethod(offers, name) and
     not publicMethod(lacks, name) and
-    not armOnly(arm, role, name)
+    not armOnly(arm, role, name) and
+    not armLacks(lacking, role, name)
   )
 }
 
 /**
  * Holds if `lacks` is missing `trait`, which `arm` carries for the same role
  * inclusive of derives gated by `cfg_attr`.
+ *
+ * Double-underscore traits are skipped, considered private implementation
+ * concerns not part of the public API.
  */
 predicate traitGap(TypeItem lacks, string role, string trait, string arm) {
   exists(TypeItem offers, string lacking |
     armRole(offers, arm, role) and
     armRole(lacks, lacking, role) and
     lacking != arm and
+    not trait.matches("\\_\\_%") and
     implementsPlainTrait(offers, trait) and
     not implementsPlainTrait(lacks, trait) and
     not hasDerive(lacks, trait) and

pkgs/pkc/Cargo.toml

@@ -21,6 +21,12 @@ group = { version = "0.14", default-features = false, optional = true }
 cfg-if = "1"
 dash-num = { version = "0.1.0-beta", path = "../num", default-features = false }
 dash-types = { version = "0.1.0-beta", path = "../types", default-features = false }
+ed25519-dalek = { version = "3", default-features = false, features = [
+  "fast",
+  "rand_core",
+  "signature",
+  "zeroize",
+], optional = true }
 hex-conservative = { workspace = true, features = [
   "alloc",
 ] }
@@ -65,8 +71,9 @@ codec = [
   "dash-types/codec",
 ]
 ecdsa = ["dep:rand_core", "dep:secp256k1"]
+eddsa = ["dep:ed25519-dalek", "dep:rand_core"]
 serde = ["codec", "dep:serde", "dash-num/serde", "dash-types/serde"]
-full = ["bls", "codec", "ecdsa", "serde", "std", "tests"]
+full = ["bls", "codec", "ecdsa", "eddsa", "serde", "std", "tests"]
 tests = ["std", "dep:rstest"]
 
 [lints]