core_crypto/mls/credential/
x509.rs

1use std::fmt;
2
3use derive_more::derive;
4use openmls::prelude::Credential as MlsCredential;
5use openmls_traits::types::SignatureScheme;
6use openmls_x509_credential::CertificateKeyPair;
7use wire_e2e_identity::{
8    HashAlgorithm, WireIdentityReader, legacy::id::WireQualifiedClientId, pki_env::PkiEnvironment,
9};
10#[cfg(test)]
11use x509_cert::der::Encode;
12use zeroize::Zeroize;
13
14use super::{Error, Result};
15#[cfg(test)]
16use crate::mls_provider::PkiKeypair;
17#[cfg(test)]
18use crate::test_utils::x509::X509Certificate;
19use crate::{
20    CipherSuite, ClientId, Credential, CredentialType, OpenMlsError, RecursiveError,
21    mls::credential::ext::CredentialExt as _,
22};
23
24#[derive(core_crypto_macros::Debug, Clone, Zeroize, derive::Constructor)]
25#[zeroize(drop)]
26pub struct CertificatePrivateKey {
27    #[sensitive]
28    value: Vec<u8>,
29}
30
31impl CertificatePrivateKey {
32    pub(crate) fn into_inner(mut self) -> Vec<u8> {
33        std::mem::take(&mut self.value)
34    }
35}
36
37/// Represents a x509 certificate chain supplied by the client
38/// It can fetch it after an end-to-end identity process where it can get back a certificate
39/// from the Authentication Service
40#[derive(Clone)]
41pub struct CertificateBundle {
42    /// x509 certificate chain
43    /// First entry is the leaf certificate and each subsequent is its issuer
44    pub certificate_chain: Vec<Vec<u8>>,
45    /// Leaf certificate private key
46    pub private_key: CertificatePrivateKey,
47    /// Signature scheme of private key
48    pub signature_scheme: SignatureScheme,
49}
50
51impl fmt::Debug for CertificateBundle {
52    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
53        use base64::prelude::*;
54
55        #[derive(derive_more::Debug)]
56        #[debug("{}", BASE64_STANDARD.encode(_0))]
57        // this only exists for the debug impl, which is ignored by the dead code check
58        #[expect(dead_code)]
59        struct CertificateDebugHelper<'a>(&'a Vec<u8>);
60
61        let certificates = self
62            .certificate_chain
63            .iter()
64            .map(CertificateDebugHelper)
65            .collect::<Vec<_>>();
66        f.debug_struct("CertificateBundle")
67            .field("certificate_chain", &certificates)
68            .field("private_key", &self.private_key)
69            .finish()
70    }
71}
72
73impl CertificateBundle {
74    /// Create a certificate bundle from a DER-encoded certificate chain and raw private key bytes.
75    pub fn from_raw(certificate_chain: Vec<Vec<u8>>, private_key: Vec<u8>, signature_scheme: SignatureScheme) -> Self {
76        Self {
77            certificate_chain,
78            private_key: CertificatePrivateKey::new(private_key),
79            signature_scheme,
80        }
81    }
82
83    /// Reads the client_id from the leaf certificate
84    pub async fn get_client_id(&self, pki_env: &PkiEnvironment) -> Result<ClientId> {
85        let leaf = self.certificate_chain.first().ok_or(Error::InvalidIdentity)?;
86
87        let hash_alg = match self.signature_scheme {
88            SignatureScheme::ECDSA_SECP256R1_SHA256 | SignatureScheme::ED25519 => HashAlgorithm::SHA256,
89            SignatureScheme::ECDSA_SECP384R1_SHA384 => HashAlgorithm::SHA384,
90            SignatureScheme::ED448 | SignatureScheme::ECDSA_SECP521R1_SHA512 => HashAlgorithm::SHA512,
91        };
92
93        let identity = leaf
94            .extract_identity(pki_env, hash_alg)
95            .await
96            .map_err(|_| Error::InvalidIdentity)?;
97
98        use wire_e2e_identity::legacy::id as legacy_id;
99
100        let client_id: legacy_id::ClientId = identity
101            .client_id
102            .parse::<WireQualifiedClientId>()
103            .map_err(RecursiveError::e2e_identity("parsing wire qualified client id"))?
104            .into();
105        let client_id: Vec<u8> = client_id.into();
106        let client_id = ClientId::new_from_bytes(client_id).map_err(RecursiveError::context("client id from bytes"))?;
107        Ok(client_id)
108    }
109
110    /// Reads the 'Not Before' claim from the leaf certificate
111    pub fn get_created_at(&self) -> Result<u64> {
112        let leaf = self.certificate_chain.first().ok_or(Error::InvalidIdentity)?;
113        leaf.extract_created_at().map_err(|_| Error::InvalidIdentity)
114    }
115}
116
117impl Credential {
118    /// Create a new x509 credential from a certificate bundle.
119    pub fn x509(cipher_suite: CipherSuite, cert: CertificateBundle) -> Result<Self> {
120        let earliest_validity = cert.get_created_at().map_err(RecursiveError::context(
121            "getting credential 'not before' claim from leaf cert in Credential::x509",
122        ))?;
123        let sk = cert.private_key.into_inner();
124        let chain = cert.certificate_chain;
125
126        let kp =
127            CertificateKeyPair::new(sk, chain.clone()).map_err(OpenMlsError::wrap("creating certificate key pair"))?;
128
129        let credential = MlsCredential::new_x509(chain).map_err(OpenMlsError::wrap("creating x509 credential"))?;
130
131        let cb = Credential {
132            cipher_suite,
133            credential_type: CredentialType::X509,
134            mls_credential: credential,
135            signature_key_pair: kp.0,
136            earliest_validity,
137        };
138        Ok(cb)
139    }
140
141    /// Check an X509 Credential for expiration or revocation
142    ///
143    /// For now we only care about X509 credentials which require the pki_env as an external resource.
144    /// As soon as we have validation logic for other types the pki_env parameter becomes very smelly.
145    /// Other credential types will just return.
146    pub(crate) async fn check(&self, pki_env: &PkiEnvironment) -> Result<()> {
147        if self.credential_type == CredentialType::X509 {
148            let cert = self
149                .mls_credential()
150                .parse_leaf_cert()
151                .map_err(RecursiveError::context("parsing leaf certificate"))?
152                // This can actually never happen and points to a type issue with credentials
153                .expect("parse_leaf_cert to return a Certificate");
154
155            pki_env
156                .validate_cert(&cert)
157                .await
158                .map_err(RecursiveError::e2e_identity("validating credential certificate"))?;
159        }
160        Ok(())
161    }
162}
163
164#[cfg(test)]
165fn new_rand_client(domain: Option<String>) -> (ClientId, String) {
166    let rand_str = |n: usize| {
167        use rand::distributions::{Alphanumeric, DistString as _};
168        Alphanumeric.sample_string(&mut rand::thread_rng(), n)
169    };
170    let user_id = uuid::Uuid::new_v4();
171    let domain = domain.unwrap_or_else(|| format!("{}.com", rand_str(6)));
172    let device_id = rand::random::<u64>();
173    let client_id = ClientId::new(user_id, device_id, &domain);
174    (client_id, domain)
175}
176
177#[cfg(test)]
178impl CertificateBundle {
179    // test functions are not held to the same standard as real functions
180    #![allow(missing_docs)]
181
182    /// Generates a certificate that is later turned into a [Credential]
183    ///
184    /// `name` is not known to be a qualified e2ei client id so we invent a new one
185    pub fn rand(name: &ClientId, signer: &crate::test_utils::x509::X509Certificate) -> Self {
186        // here in our tests client_id is generally just "alice" or "bob"
187        // so we will use it to augment handle & display_name
188        // and not a real client_id, instead we'll generate a random one
189        let handle = format!("{name}_wire");
190        let display_name = format!("{name} Smith");
191        Self::new(&handle, &display_name, None, None, signer)
192    }
193
194    pub fn new_with_exact_client_id(client_id: &ClientId, signer: &crate::test_utils::x509::X509Certificate) -> Self {
195        // Unlike Self::rand() above, this uses the provided client ID and does not generate a new
196        // one.
197        // TODO: this should all be reworked by the time WPB-19540 is done.
198        let rand_str = |n: usize| {
199            use rand::distributions::{Alphanumeric, DistString as _};
200            Alphanumeric.sample_string(&mut rand::thread_rng(), n)
201        };
202        let name = rand_str(10);
203        let handle = format!("{name}_wire");
204        let display_name = format!("{name} Smith");
205        Self::new(&handle, &display_name, Some(client_id), None, signer)
206    }
207
208    /// Generates a certificate that is later turned into a [Credential]
209    pub fn new(
210        handle: &str,
211        display_name: &str,
212        client_id: Option<&ClientId>,
213        cert_keypair: Option<PkiKeypair>,
214        signer: &crate::test_utils::x509::X509Certificate,
215    ) -> Self {
216        Self::new_with_expiration(handle, display_name, client_id, cert_keypair, signer, None)
217    }
218
219    pub fn new_with_expiration(
220        handle: &str,
221        display_name: &str,
222        client_id: Option<&ClientId>,
223        cert_keypair: Option<PkiKeypair>,
224        signer: &crate::test_utils::x509::X509Certificate,
225        expiration: Option<std::time::Duration>,
226    ) -> Self {
227        // here in our tests client_id is generally just "alice" or "bob"
228        // so we will use it to augment handle & display_name
229        // and not a real client_id, instead we'll generate a random one
230        let domain = "world.com";
231        let (client_id, domain) = client_id
232            .cloned()
233            .map(|cid| (cid, domain.to_string()))
234            .unwrap_or_else(|| new_rand_client(Some(domain.to_string())));
235
236        let mut cert_params = crate::test_utils::x509::CertificateParams {
237            domain: domain.into(),
238            common_name: Some(display_name.to_string()),
239            handle: Some(handle.to_string()),
240            client_id: Some(client_id),
241            cert_keypair,
242            ..Default::default()
243        };
244
245        if let Some(expiration) = expiration {
246            cert_params.expiration = expiration;
247        }
248
249        let cert = signer.create_and_sign_end_identity(cert_params);
250        Self::from_certificate_and_issuer(&cert, signer)
251    }
252
253    pub fn new_with_default_values(
254        signer: &crate::test_utils::x509::X509Certificate,
255        expiration: Option<std::time::Duration>,
256    ) -> Self {
257        Self::new_with_expiration("alice_wire@world.com", "Alice Smith", None, None, signer, expiration)
258    }
259
260    pub fn from_self_signed_certificate(cert: &X509Certificate) -> Self {
261        Self::from_certificate_and_issuer(cert, cert)
262    }
263
264    pub fn from_certificate_and_issuer(cert: &X509Certificate, issuer: &X509Certificate) -> Self {
265        Self {
266            certificate_chain: vec![cert.certificate.to_der().unwrap(), issuer.certificate.to_der().unwrap()],
267            private_key: CertificatePrivateKey::new(cert.pki_keypair.signing_key_bytes()),
268            signature_scheme: cert.signature_scheme,
269        }
270    }
271}
core_crypto/mls/credential/x509.rs

core_crypto/mls/credential/
x509.rs
