ml-dsa: implement initial pkcs8/spki traits (#891)

Author: baloo

Cargo.lock

@@ -15,9 +15,11 @@ categories = ["cryptography"]
 keywords = ["crypto", "signature"]
 
 [features]
-default = ["rand_core"]
+default = ["rand_core", "alloc", "pkcs8"]
 zeroize = ["dep:zeroize", "hybrid-array/zeroize"]
 rand_core = ["dep:rand_core", "signature/rand_core"]
+alloc = ["pkcs8?/alloc"]
+pkcs8 = ["dep:const-oid", "dep:pkcs8"]
 
 [dependencies]
 hybrid-array = { version = "0.2.3", features = ["extra-sizes"] }
@@ -27,10 +29,14 @@ sha3 = "0.10.8"
 signature = "2.3.0-pre.4"
 zeroize = { version = "1.8.1", optional = true, default-features = false }
 
+const-oid = { version = "0.10.0-rc.1", features = ["db"], optional = true }
+pkcs8 = { version = "=0.11.0-rc.1", default-features = false, optional = true }
+
 [dev-dependencies]
 criterion = "0.5.1"
 hex = { version = "0.4.3", features = ["serde"] }
 hex-literal = "0.4.1"
+pkcs8 = { version = "=0.11.0-rc.1", features = ["pem"] }
 rand = "0.8.5"
 serde = { version = "1.0.215", features = ["derive"] }
 serde_json = "1.0.132"

ml-dsa/Cargo.toml

@@ -56,6 +56,26 @@ use rand_core::CryptoRngCore;
 #[cfg(feature = "zeroize")]
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
+#[cfg(feature = "pkcs8")]
+use {
+    const_oid::db::fips204,
+    pkcs8::{
+        der::{self, AnyRef},
+        spki::{
+            self, AlgorithmIdentifier, AssociatedAlgorithmIdentifier, SignatureAlgorithmIdentifier,
+            SubjectPublicKeyInfoRef,
+        },
+        AlgorithmIdentifierRef, PrivateKeyInfoRef,
+    },
+};
+
+#[cfg(all(feature = "alloc", feature = "pkcs8"))]
+use pkcs8::{
+    der::asn1::{BitString, BitStringRef},
+    spki::{SignatureBitStringEncoding, SubjectPublicKeyInfo},
+    EncodePublicKey,
+};
+
 use crate::algebra::{AlgebraExt, Elem, NttMatrix, NttVector, Truncate, Vector};
 use crate::crypto::H;
 use crate::hint::Hint;
@@ -124,6 +144,24 @@ impl<P: MlDsaParams> signature::SignatureEncoding for Signature<P> {
     type Repr = EncodedSignature<P>;
 }
 
+#[cfg(feature = "alloc")]
+impl<P: MlDsaParams> SignatureBitStringEncoding for Signature<P> {
+    fn to_bitstring(&self) -> der::Result<BitString> {
+        BitString::new(0, self.encode().to_vec())
+    }
+}
+
+#[cfg(feature = "pkcs8")]
+impl<P> AssociatedAlgorithmIdentifier for Signature<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Params = AnyRef<'static>;
+
+    const ALGORITHM_IDENTIFIER: AlgorithmIdentifierRef<'static> = P::ALGORITHM_IDENTIFIER;
+}
+
 // This method takes a slice of slices so that we can accommodate the varying calculations (direct
 // for test vectors, 0... for sign/sign_deterministic, 1... for the pre-hashed version) without
 // having to allocate memory for components.
@@ -156,6 +194,46 @@ impl<P: MlDsaParams> signature::KeypairRef for KeyPair<P> {
     type VerifyingKey = VerifyingKey<P>;
 }
 
+#[cfg(feature = "pkcs8")]
+impl<P> TryFrom<PrivateKeyInfoRef<'_>> for KeyPair<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Error = pkcs8::Error;
+
+    fn try_from(private_key_info: pkcs8::PrivateKeyInfoRef<'_>) -> pkcs8::Result<Self> {
+        match private_key_info.algorithm {
+            alg if alg == P::ALGORITHM_IDENTIFIER => {}
+            other => return Err(spki::Error::OidUnknown { oid: other.oid }.into()),
+        };
+
+        let seed = Array::try_from(private_key_info.private_key.as_bytes())
+            .map_err(|_| pkcs8::Error::KeyMalformed)?;
+        Ok(P::key_gen_internal(&seed))
+    }
+}
+
+/// The `Signer` implementation for `KeyPair` uses the optional deterministic variant of ML-DSA, and
+/// only supports signing with an empty context string.
+impl<P: MlDsaParams> signature::Signer<Signature<P>> for KeyPair<P> {
+    fn try_sign(&self, msg: &[u8]) -> Result<Signature<P>, Error> {
+        self.signing_key.sign_deterministic(msg, &[])
+    }
+}
+
+#[cfg(feature = "pkcs8")]
+impl<P> SignatureAlgorithmIdentifier for KeyPair<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Params = AnyRef<'static>;
+
+    const SIGNATURE_ALGORITHM_IDENTIFIER: AlgorithmIdentifier<Self::Params> =
+        Signature::<P>::ALGORITHM_IDENTIFIER;
+}
+
 /// An ML-DSA signing key
 #[derive(Clone, PartialEq)]
 pub struct SigningKey<P: MlDsaParams> {
@@ -384,8 +462,35 @@ impl<P: MlDsaParams> signature::RandomizedSigner<Signature<P>> for SigningKey<P>
     }
 }
 
+#[cfg(feature = "pkcs8")]
+impl<P> SignatureAlgorithmIdentifier for SigningKey<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Params = AnyRef<'static>;
+
+    const SIGNATURE_ALGORITHM_IDENTIFIER: AlgorithmIdentifier<Self::Params> =
+        Signature::<P>::ALGORITHM_IDENTIFIER;
+}
+
+#[cfg(feature = "pkcs8")]
+impl<P> TryFrom<PrivateKeyInfoRef<'_>> for SigningKey<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Error = pkcs8::Error;
+
+    fn try_from(private_key_info: pkcs8::PrivateKeyInfoRef<'_>) -> pkcs8::Result<Self> {
+        let keypair = KeyPair::try_from(private_key_info)?;
+
+        Ok(keypair.signing_key)
+    }
+}
+
 /// An ML-DSA verification key
-#[derive(Clone, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct VerifyingKey<P: ParameterSet> {
     rho: B32,
     t1: Vector<P::K>,
@@ -488,6 +593,61 @@ impl<P: MlDsaParams> signature::Verifier<Signature<P>> for VerifyingKey<P> {
     }
 }
 
+#[cfg(feature = "pkcs8")]
+impl<P> SignatureAlgorithmIdentifier for VerifyingKey<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Params = AnyRef<'static>;
+
+    const SIGNATURE_ALGORITHM_IDENTIFIER: AlgorithmIdentifier<Self::Params> =
+        Signature::<P>::ALGORITHM_IDENTIFIER;
+}
+
+#[cfg(feature = "alloc")]
+impl<P> EncodePublicKey for VerifyingKey<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    fn to_public_key_der(&self) -> spki::Result<der::Document> {
+        let public_key = self.encode();
+        let subject_public_key = BitStringRef::new(0, &public_key)?;
+
+        SubjectPublicKeyInfo {
+            algorithm: P::ALGORITHM_IDENTIFIER,
+            subject_public_key,
+        }
+        .try_into()
+    }
+}
+
+#[cfg(feature = "pkcs8")]
+impl<P> TryFrom<SubjectPublicKeyInfoRef<'_>> for VerifyingKey<P>
+where
+    P: MlDsaParams,
+    P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
+{
+    type Error = spki::Error;
+
+    fn try_from(spki: SubjectPublicKeyInfoRef<'_>) -> spki::Result<Self> {
+        match spki.algorithm {
+            alg if alg == P::ALGORITHM_IDENTIFIER => {}
+            other => return Err(spki::Error::OidUnknown { oid: other.oid }),
+        };
+
+        Ok(Self::decode(
+            &EncodedVerifyingKey::<P>::try_from(
+                spki.subject_public_key
+                    .as_bytes()
+                    .ok_or_else(|| der::Tag::BitString.value_error())?,
+            )
+            .map_err(|_| pkcs8::Error::KeyMalformed)?,
+        ))
+    }
+}
+
 /// `MlDsa44` is the parameter set for security category 2.
 #[derive(Default, Clone, Debug, PartialEq)]
 pub struct MlDsa44;
@@ -505,6 +665,16 @@ impl ParameterSet for MlDsa44 {
     const TAU: usize = 39;
 }
 
+#[cfg(feature = "pkcs8")]
+impl AssociatedAlgorithmIdentifier for MlDsa44 {
+    type Params = AnyRef<'static>;
+
+    const ALGORITHM_IDENTIFIER: AlgorithmIdentifierRef<'static> = AlgorithmIdentifierRef {
+        oid: fips204::ID_ML_DSA_44,
+        parameters: None,
+    };
+}
+
 /// `MlDsa65` is the parameter set for security category 3.
 #[derive(Default, Clone, Debug, PartialEq)]
 pub struct MlDsa65;
@@ -522,6 +692,16 @@ impl ParameterSet for MlDsa65 {
     const TAU: usize = 49;
 }
 
+#[cfg(feature = "pkcs8")]
+impl AssociatedAlgorithmIdentifier for MlDsa65 {
+    type Params = AnyRef<'static>;
+
+    const ALGORITHM_IDENTIFIER: AlgorithmIdentifierRef<'static> = AlgorithmIdentifierRef {
+        oid: fips204::ID_ML_DSA_65,
+        parameters: None,
+    };
+}
+
 /// `MlKem87` is the parameter set for security category 5.
 #[derive(Default, Clone, Debug, PartialEq)]
 pub struct MlDsa87;
@@ -539,6 +719,16 @@ impl ParameterSet for MlDsa87 {
     const TAU: usize = 60;
 }
 
+#[cfg(feature = "pkcs8")]
+impl AssociatedAlgorithmIdentifier for MlDsa87 {
+    type Params = AnyRef<'static>;
+
+    const ALGORITHM_IDENTIFIER: AlgorithmIdentifierRef<'static> = AlgorithmIdentifierRef {
+        oid: fips204::ID_ML_DSA_87,
+        parameters: None,
+    };
+}
+
 /// A parameter set that knows how to generate key pairs
 pub trait KeyGen: MlDsaParams {
     /// The type that is returned by key generation

ml-dsa/src/lib.rs

@@ -0,0 +1,4 @@
+-----BEGIN PRIVATE KEY-----
+MDICAQAwCwYJYIZIAWUDBAMRBCAAAQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRob
+HB0eHw==
+-----END PRIVATE KEY-----

ml-dsa/tests/examples/ML-DSA-44.priv

@@ -0,0 +1,30 @@
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----

ml-dsa/tests/examples/ML-DSA-44.pub

@@ -0,0 +1,4 @@
+-----BEGIN PRIVATE KEY-----
+MDICAQAwCwYJYIZIAWUDBAMSBCAAAQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRob
+HB0eHw==
+-----END PRIVATE KEY-----

ml-dsa/tests/examples/ML-DSA-65.priv

@@ -0,0 +1,44 @@
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----

ml-dsa/tests/examples/ML-DSA-65.pub

@@ -0,0 +1,4 @@
+-----BEGIN PRIVATE KEY-----
+MDICAQAwCwYJYIZIAWUDBAMTBCAAAQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRob
+HB0eHw==
+-----END PRIVATE KEY-----