removed source of possible panic from nym-kkt

invalid KEM mapping will now return an Err rather than panicking

Cargo.lock

@@ -1891,7 +1891,6 @@ dependencies = [
  "curve25519-dalek-derive",
  "digest 0.10.7",
  "fiat-crypto",
- "rand_core 0.6.4",
  "rustc_version 0.4.1",
  "serde",
  "subtle 2.6.1",
@@ -6633,14 +6632,9 @@ dependencies = [
 name = "nym-kkt"
 version = "0.1.0"
 dependencies = [
- "aead",
- "arc-swap",
  "blake3",
- "bytes",
  "classic-mceliece-rust",
  "criterion",
- "curve25519-dalek",
- "futures",
  "libcrux-ecdh",
  "libcrux-kem",
  "libcrux-ml-kem",
@@ -6648,14 +6642,8 @@ dependencies = [
  "libcrux-sha3",
  "libcrux-traits",
  "nym-crypto",
- "pin-project",
  "rand 0.9.2",
- "strum",
  "thiserror 2.0.12",
- "tokio",
- "tokio-util",
- "tracing",
- "zeroize",
 ]
 
 [[package]]

common/nym-kkt/Cargo.toml

@@ -6,38 +6,25 @@ edition = { workspace = true }
 license.workspace = true
 
 [dependencies]
-arc-swap = { workspace = true }
-bytes = { workspace = true }
-futures = { workspace = true }
-tracing = { workspace = true }
-pin-project = { workspace = true }
 blake3 = { workspace = true }
-aead = { workspace = true }
-strum = { workspace = true, features = ["derive"] }
 thiserror = { workspace = true }
-tokio = { workspace = true, features = ["full"] }
-tokio-util = { workspace = true, features = ["codec"] }
-
-
 
 # internal
-nym-crypto = { path = "../crypto", features = ["asymmetric", "serde"]}
+nym-crypto = { path = "../crypto", features = ["asymmetric", "serde"] }
 
 libcrux-traits = { git = "https://github.com/cryspen/libcrux" }
 libcrux-kem = { git = "https://github.com/cryspen/libcrux" }
 libcrux-psq = { git = "https://github.com/cryspen/libcrux", features = ["test-utils"] }
 libcrux-sha3 = { git = "https://github.com/cryspen/libcrux" }
 libcrux-ml-kem = { git = "https://github.com/cryspen/libcrux" }
-libcrux-ecdh = { git = "https://github.com/cryspen/libcrux", features = ["codec"]}
+libcrux-ecdh = { git = "https://github.com/cryspen/libcrux", features = ["codec"] }
 
 rand = "0.9.2"
-curve25519-dalek = {version = "4.1.3", features = ["rand_core", "serde"] }
-zeroize = { workspace = true, features = ["zeroize_derive"] }
-classic-mceliece-rust = { git = "https://github.com/georgio/classic-mceliece-rust", features = ["mceliece460896f","zeroize"]}
+classic-mceliece-rust = { git = "https://github.com/georgio/classic-mceliece-rust", features = ["mceliece460896f", "zeroize"] }
 
 
 [dev-dependencies]
-criterion = {workspace = true}
+criterion = { workspace = true }
 
 [[bench]]
 name = "benches"

common/nym-kkt/src/ciphersuite.rs

@@ -63,15 +63,15 @@ impl<'a> EncapsulationKey<'a> {
                 }
             }
             KEM::X25519 => Ok(EncapsulationKey::X25519(libcrux_kem::PublicKey::decode(
-                map_kem_to_libcrux_kem(kem),
+                map_kem_to_libcrux_kem(kem)?,
                 bytes,
             )?)),
             KEM::MlKem768 => Ok(EncapsulationKey::MlKem768(libcrux_kem::PublicKey::decode(
-                map_kem_to_libcrux_kem(kem),
+                map_kem_to_libcrux_kem(kem)?,
                 bytes,
             )?)),
             KEM::XWing => Ok(EncapsulationKey::XWing(libcrux_kem::PublicKey::decode(
-                map_kem_to_libcrux_kem(kem),
+                map_kem_to_libcrux_kem(kem)?,
                 bytes,
             )?)),
         }
@@ -291,11 +291,13 @@ impl Display for Ciphersuite {
     }
 }
 
-pub const fn map_kem_to_libcrux_kem(kem: KEM) -> Algorithm {
+pub const fn map_kem_to_libcrux_kem(kem: KEM) -> Result<Algorithm, KKTError> {
     match kem {
-        KEM::MlKem768 => Algorithm::MlKem768,
-        KEM::XWing => Algorithm::XWingKemDraft06,
-        KEM::X25519 => Algorithm::X25519,
-        KEM::McEliece => panic!("McEliece is not supported in libcrux_kem"),
+        KEM::MlKem768 => Ok(Algorithm::MlKem768),
+        KEM::XWing => Ok(Algorithm::XWingKemDraft06),
+        KEM::X25519 => Ok(Algorithm::X25519),
+        KEM::McEliece => Err(KKTError::KEMMapping {
+            info: "attempted to map McEliece KEM to libcrux_kem",
+        }),
     }
 }

common/nym-kkt/src/error.rs

@@ -13,6 +13,10 @@ pub enum KKTError {
     SigVerifError,
     #[error("Ciphersuite Decoding Error: {}", info)]
     CiphersuiteDecodingError { info: String },
+
+    #[error("KEM mapping failure: {}", info)]
+    KEMMapping { info: &'static str },
+
     #[error("Insecure Encapsulation Key Hash Length")]
     InsecureHashLen,