Key Package Generation / Join API 1.x (#226)

* Fix CI (#223)

* feat(mls-rs): Verify the update path even in case of a self removal (#224)

* Fix bug where double-hitting a ciphertext deleted the whole ratchet (#228)

Co-authored-by: Marta Mularczyk <[email protected]>

* Work around rust < 1.78 crash (#231)

Somehow the DWARF info generated by the compiler for the
`hash`-replacement assignment is confusing to LLVM, which crashes.

By using a different form for the same operation, the compiler is happy.

* Avoid intermediate Vec in TreeKemPublic::update_hashes (#230)

[slice, slice].concat() creates an intermediate Vec, which can be
avoided by chaining updated_leaves and trailing_blanks before the first
Vec is created.

* Add API for deleting exporters (#227)

* Add API for deleting exporters

* Apply suggestions from code review

Co-authored-by: Stephane Raux <[email protected]>

---------

Co-authored-by: Marta Mularczyk <[email protected]>
Co-authored-by: Tom Leavy <[email protected]>
Co-authored-by: Stephane Raux <[email protected]>

* Key package generation 1.x

* Fix clippy warnings

* Initial implementation of group join 1.x

* Add example for 1x API

* Apply suggestions from code review

* Add SigningData struct

* Fixup

* Add more tests

* Fixup

* Fixup

---------

Co-authored-by: Félix Lescaudey de Maneville <[email protected]>
Co-authored-by: Marta Mularczyk <[email protected]>
Co-authored-by: Mike Hommey <[email protected]>
Co-authored-by: Tom Leavy <[email protected]>
Co-authored-by: Stephane Raux <[email protected]>

.github/workflows/native_build.yml

@@ -54,7 +54,9 @@ jobs:
         run: cargo test --no-default-features --features std,test_util,non-fips  --verbose --workspace
       - name: Examples
         working-directory: mls-rs
-        run: cargo run --example basic_usage
+        run: |
+          cargo run --example basic_usage
+          cargo run --example api_1x
   AsyncBuildAndTest:
     strategy:
       matrix:

mls-rs-core/src/identity.rs

@@ -12,8 +12,17 @@ mod x509;
 
 pub use basic::*;
 pub use credential::*;
+use mls_rs_codec::{MlsDecode, MlsEncode, MlsSize};
 pub use provider::*;
 pub use signing_identity::*;
 
 #[cfg(feature = "x509")]
 pub use x509::*;
+
+use crate::crypto::SignatureSecretKey;
+
+#[derive(Clone, Debug, MlsEncode, MlsSize, MlsDecode, PartialEq)]
+pub struct SigningData {
+    pub signing_identity: SigningIdentity,
+    pub signing_key: SignatureSecretKey,
+}

mls-rs/Cargo.toml

@@ -121,6 +121,10 @@ unexpected_cfgs = { level = "warn", check-cfg = ['cfg(mls_build_async)', 'cfg(co
 name = "basic_usage"
 required-features = []
 
+[[example]]
+name = "api_1x"
+required-features = []
+
 [[example]]
 name = "x509"
 required-features = ["x509"]

mls-rs/examples/api_1x.rs

@@ -0,0 +1,92 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// Copyright by contributors to this project.
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+use std::convert::Infallible;
+
+use mls_rs::{
+    client_builder::MlsConfig,
+    error::MlsError,
+    identity::{
+        basic::{BasicCredential, BasicIdentityProvider},
+        SigningIdentity,
+    },
+    CipherSuite, CipherSuiteProvider, Client, CryptoProvider, ExtensionList, KeyPackageStorage,
+};
+use mls_rs_core::key_package::KeyPackageData;
+
+const CIPHERSUITE: CipherSuite = CipherSuite::CURVE25519_AES128;
+
+fn main() -> Result<(), MlsError> {
+    let crypto_provider = mls_rs_crypto_openssl::OpensslCryptoProvider::default();
+
+    // Create clients for Alice and Bob
+    let alice = make_client(crypto_provider.clone(), "alice")?;
+    let bob = make_client(crypto_provider.clone(), "bob")?;
+
+    // Bob generates key package. We store secrets in memory, no need for any storage.
+    let key_package_generation = bob
+        .key_package_builder(CIPHERSUITE, None)?
+        .valid_for_sec(123)
+        .build()?;
+
+    let stored_secrets = key_package_generation.key_package_data;
+
+    // Alice creates a group with Bob.
+    let mut alice_group = alice.create_group(ExtensionList::default(), Default::default())?;
+
+    let welcomes = alice_group
+        .commit_builder()
+        .add_member(key_package_generation.key_package_message)?
+        .build()?
+        .welcome_messages;
+
+    alice_group.apply_pending_commit()?;
+
+    // Bob joins
+    let mut bob_group = bob.group_joiner(&welcomes[0], stored_secrets)?.join()?.0;
+
+    // Alice and bob can chat
+    let msg = alice_group.encrypt_application_message(b"hello world", Default::default())?;
+    let msg = bob_group.process_incoming_message(msg)?;
+
+    println!("Received message: {:?}", msg);
+
+    Ok(())
+}
+
+#[derive(Clone)]
+struct NoOpKeyPackageStorage;
+
+impl KeyPackageStorage for NoOpKeyPackageStorage {
+    type Error = Infallible;
+
+    fn delete(&mut self, _: &[u8]) -> Result<(), Infallible> {
+        Ok(())
+    }
+
+    fn get(&self, _: &[u8]) -> Result<Option<KeyPackageData>, Infallible> {
+        Ok(None)
+    }
+
+    fn insert(&mut self, _: Vec<u8>, _: KeyPackageData) -> Result<(), Infallible> {
+        Ok(())
+    }
+}
+
+fn make_client<P: CryptoProvider + Clone>(
+    crypto_provider: P,
+    name: &str,
+) -> Result<Client<impl MlsConfig>, MlsError> {
+    let cipher_suite = crypto_provider.cipher_suite_provider(CIPHERSUITE).unwrap();
+    let (secret, public) = cipher_suite.signature_key_generate().unwrap();
+    let basic_identity = BasicCredential::new(name.as_bytes().to_vec());
+    let signing_identity = SigningIdentity::new(basic_identity.into_credential(), public);
+
+    Ok(Client::builder()
+        .identity_provider(BasicIdentityProvider)
+        .crypto_provider(crypto_provider)
+        .signing_identity(signing_identity, secret, CIPHERSUITE)
+        .key_package_repo(NoOpKeyPackageStorage)
+        .build())
+}

mls-rs/src/client.rs

@@ -5,9 +5,11 @@
 use crate::cipher_suite::CipherSuite;
 use crate::client_builder::{recreate_config, BaseConfig, ClientBuilder, MakeConfig};
 use crate::client_config::ClientConfig;
-use crate::group::framing::MlsMessage;
+use crate::group::framing::{MlsMessage, MlsMessageDescription};
 
-use crate::group::{cipher_suite_provider, validate_group_info_joiner, GroupInfo};
+use crate::group::{
+    cipher_suite_provider, find_key_package_generation, validate_group_info_joiner, GroupInfo,
+};
 use crate::group::{
     framing::MlsMessagePayload, snapshot::Snapshot, ExportedTree, Group, NewMemberInfo,
 };
@@ -17,7 +19,9 @@ use crate::group::{
     message_signature::AuthenticatedContent,
     proposal::{AddProposal, Proposal},
 };
+use crate::group_joiner::GroupJoiner;
 use crate::identity::SigningIdentity;
+use crate::key_package::builder::KeyPackageBuilder;
 use crate::key_package::{KeyPackageGeneration, KeyPackageGenerator};
 use crate::protocol_version::ProtocolVersion;
 use crate::tree_kem::node::NodeIndex;
@@ -27,8 +31,10 @@ use mls_rs_core::crypto::{CryptoProvider, SignatureSecretKey};
 use mls_rs_core::error::{AnyError, IntoAnyError};
 use mls_rs_core::extension::{ExtensionError, ExtensionList, ExtensionType};
 use mls_rs_core::group::{GroupStateStorage, ProposalType};
-use mls_rs_core::identity::{CredentialType, IdentityProvider, MemberValidationContext};
-use mls_rs_core::key_package::KeyPackageStorage;
+use mls_rs_core::identity::{
+    CredentialType, IdentityProvider, MemberValidationContext, SigningData,
+};
+use mls_rs_core::key_package::{KeyPackageData, KeyPackageStorage};
 
 use crate::group::external_commit::ExternalCommitBuilder;
 
@@ -483,6 +489,24 @@ where
         Ok(key_pkg_gen)
     }
 
+    #[cfg_attr(all(feature = "ffi", not(test)), safer_ffi_gen::safer_ffi_gen_ignore)]
+    pub fn key_package_builder(
+        &self,
+        cipher_suite: CipherSuite,
+        signing_data: Option<SigningData>,
+    ) -> Result<
+        KeyPackageBuilder<<C::CryptoProvider as CryptoProvider>::CipherSuiteProvider>,
+        MlsError,
+    > {
+        let cipher_suite_provider = self
+            .config
+            .crypto_provider()
+            .cipher_suite_provider(cipher_suite)
+            .ok_or(MlsError::UnsupportedCipherSuite(cipher_suite))?;
+
+        KeyPackageBuilder::new(self, cipher_suite_provider, signing_data)
+    }
+
     /// Create a group with a specific group_id.
     ///
     /// This function behaves the same way as
@@ -557,11 +581,40 @@ where
         tree_data: Option<ExportedTree<'_>>,
         welcome_message: &MlsMessage,
     ) -> Result<(Group<C>, NewMemberInfo), MlsError> {
-        Group::join(
-            welcome_message,
-            tree_data,
+        let MlsMessageDescription::Welcome {
+            key_package_refs, ..
+        } = welcome_message.description()
+        else {
+            return Err(MlsError::UnexpectedMessageType);
+        };
+
+        let key_package_data =
+            find_key_package_generation(&self.config.key_package_repo(), &key_package_refs).await?;
+
+        let mut joiner = self
+            .group_joiner(welcome_message, key_package_data)
+            .await?
+            .signature_secret_key(self.signer()?.clone());
+
+        if let Some(tree) = tree_data {
+            joiner = joiner.ratchet_tree(tree);
+        }
+
+        joiner.join().await
+    }
+
+    #[cfg_attr(all(feature = "ffi", not(test)), safer_ffi_gen::safer_ffi_gen_ignore)]
+    #[cfg_attr(not(mls_build_async), maybe_async::must_be_sync)]
+    pub async fn group_joiner<'a, 'b>(
+        &self,
+        welcome_message: &'a MlsMessage,
+        key_package_data: KeyPackageData,
+    ) -> Result<GroupJoiner<'a, 'b, C>, MlsError> {
+        GroupJoiner::new(
             self.config.clone(),
-            self.signer()?.clone(),
+            welcome_message,
+            key_package_data,
+            self.signer.clone(),
         )
         .await
     }

mls-rs/src/extension.rs

@@ -5,8 +5,6 @@
 pub use mls_rs_core::extension::{ExtensionType, MlsCodecExtension, MlsExtension};
 
 pub(crate) use built_in::*;
-#[cfg(feature = "last_resort_key_package_ext")]
-pub(crate) use recommended::*;
 
 /// Default extension types required by the MLS RFC.
 pub mod built_in;

mls-rs/src/external_client.rs

@@ -13,10 +13,7 @@ mod config;
 mod group;
 
 pub(crate) use config::ExternalClientConfig;
-use mls_rs_core::{
-    crypto::{CryptoProvider, SignatureSecretKey},
-    identity::SigningIdentity,
-};
+use mls_rs_core::{crypto::CryptoProvider, identity::SigningData};
 
 use builder::{ExternalBaseConfig, ExternalClientBuilder};
 
@@ -39,7 +36,7 @@ pub use group::{ExternalGroup, ExternalReceivedMessage, ExternalSnapshot};
 /// the resulting group state.
 pub struct ExternalClient<C> {
     config: C,
-    signing_data: Option<(SignatureSecretKey, SigningIdentity)>,
+    signing_data: Option<SigningData>,
 }
 
 impl ExternalClient<()> {
@@ -52,10 +49,7 @@ impl<C> ExternalClient<C>
 where
     C: ExternalClientConfig + Clone,
 {
-    pub(crate) fn new(
-        config: C,
-        signing_data: Option<(SignatureSecretKey, SigningIdentity)>,
-    ) -> Self {
+    pub(crate) fn new(config: C, signing_data: Option<SigningData>) -> Self {
         Self {
             config,
             signing_data,

mls-rs/src/external_client/builder.rs

@@ -276,7 +276,10 @@ impl<C: IntoConfig> ExternalClientBuilder<C> {
         signing_identity: SigningIdentity,
     ) -> ExternalClientBuilder<IntoConfigOutput<C>> {
         let mut c = self.0.into_config();
-        c.0.signing_data = Some((signer, signing_identity));
+        c.0.signing_data = Some(SigningData {
+            signing_identity,
+            signing_key: signer,
+        });
         ExternalClientBuilder(c)
     }
 }
@@ -520,7 +523,7 @@ impl Default for Settings {
 /// Definitions meant to be private that are inaccessible outside this crate. They need to be marked
 /// `pub` because they appear in public definitions.
 mod private {
-    use mls_rs_core::{crypto::SignatureSecretKey, identity::SigningIdentity};
+    use mls_rs_core::identity::SigningData;
 
     use super::{IntoConfigOutput, Settings};
 
@@ -533,7 +536,7 @@ mod private {
         pub(crate) identity_provider: Ip,
         pub(crate) mls_rules: Mpf,
         pub(crate) crypto_provider: Cp,
-        pub(crate) signing_data: Option<(SignatureSecretKey, SigningIdentity)>,
+        pub(crate) signing_data: Option<SigningData>,
     }
 
     pub trait IntoConfig {
@@ -557,7 +560,7 @@ mod private {
 
 use mls_rs_core::{
     crypto::SignatureSecretKey,
-    identity::{IdentityProvider, SigningIdentity},
+    identity::{IdentityProvider, SigningData, SigningIdentity},
 };
 use private::{Config, ConfigInner, IntoConfig};