|
| 1 | +use std::sync::Arc; |
| 2 | + |
| 3 | +use rustls::client::danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier}; |
| 4 | +use rustls::crypto::{CryptoProvider, WebPkiSupportedAlgorithms}; |
| 5 | +use rustls::pki_types::{CertificateDer, PrivateKeyDer, ServerName, UnixTime}; |
| 6 | +use rustls::server::ParsedCertificate; |
| 7 | +use rustls::{ClientConfig, DigitallySignedStruct, Error as TlsError, RootCertStore, SignatureScheme}; |
| 8 | + |
| 9 | +use crate::client::Result; |
| 10 | +use crate::Error; |
| 11 | + |
| 12 | +/// Options for tls connection. |
| 13 | +#[derive(Debug)] |
| 14 | +pub struct TlsOptions { |
| 15 | + identity: Option<(Vec<CertificateDer<'static>>, PrivateKeyDer<'static>)>, |
| 16 | + ca_certs: RootCertStore, |
| 17 | + hostname_verification: bool, |
| 18 | +} |
| 19 | + |
| 20 | +impl Clone for TlsOptions { |
| 21 | + fn clone(&self) -> Self { |
| 22 | + Self { |
| 23 | + identity: self.identity.as_ref().map(|id| (id.0.clone(), id.1.clone_key())), |
| 24 | + ca_certs: self.ca_certs.clone(), |
| 25 | + hostname_verification: self.hostname_verification, |
| 26 | + } |
| 27 | + } |
| 28 | +} |
| 29 | + |
| 30 | +impl Default for TlsOptions { |
| 31 | + /// Tls options with well-known ca roots. |
| 32 | + fn default() -> Self { |
| 33 | + let mut options = Self::no_ca(); |
| 34 | + options.ca_certs.extend(webpki_roots::TLS_SERVER_ROOTS.iter().cloned()); |
| 35 | + options |
| 36 | + } |
| 37 | +} |
| 38 | + |
| 39 | +// Rustls tends to make disable of hostname verification verbose since it exposes man-in-the-middle |
| 40 | +// attacks. Though, there are still attempts to disable hostname verification in rustls, but no got |
| 41 | +// merged until now. |
| 42 | +// * Allow disabling Hostname Verification: https://github.com/rustls/rustls/issues/578 |
| 43 | +// * Dangerous verifiers API proposal: https://github.com/rustls/rustls/pull/1197 |
| 44 | +#[derive(Debug)] |
| 45 | +struct TlsServerCertVerifier { |
| 46 | + roots: RootCertStore, |
| 47 | + supported: WebPkiSupportedAlgorithms, |
| 48 | + hostname_verification: bool, |
| 49 | +} |
| 50 | + |
| 51 | +impl TlsServerCertVerifier { |
| 52 | + fn new(roots: RootCertStore, hostname_verification: bool) -> Self { |
| 53 | + Self { |
| 54 | + roots, |
| 55 | + supported: CryptoProvider::get_default().unwrap().signature_verification_algorithms, |
| 56 | + hostname_verification, |
| 57 | + } |
| 58 | + } |
| 59 | +} |
| 60 | + |
| 61 | +impl ServerCertVerifier for TlsServerCertVerifier { |
| 62 | + fn verify_server_cert( |
| 63 | + &self, |
| 64 | + end_entity: &CertificateDer<'_>, |
| 65 | + intermediates: &[CertificateDer<'_>], |
| 66 | + server_name: &ServerName<'_>, |
| 67 | + _ocsp_response: &[u8], |
| 68 | + now: UnixTime, |
| 69 | + ) -> Result<ServerCertVerified, TlsError> { |
| 70 | + let cert = ParsedCertificate::try_from(end_entity)?; |
| 71 | + rustls::client::verify_server_cert_signed_by_trust_anchor( |
| 72 | + &cert, |
| 73 | + &self.roots, |
| 74 | + intermediates, |
| 75 | + now, |
| 76 | + self.supported.all, |
| 77 | + )?; |
| 78 | + |
| 79 | + if self.hostname_verification { |
| 80 | + rustls::client::verify_server_name(&cert, server_name)?; |
| 81 | + } |
| 82 | + Ok(ServerCertVerified::assertion()) |
| 83 | + } |
| 84 | + |
| 85 | + fn verify_tls12_signature( |
| 86 | + &self, |
| 87 | + message: &[u8], |
| 88 | + cert: &CertificateDer<'_>, |
| 89 | + dss: &DigitallySignedStruct, |
| 90 | + ) -> Result<HandshakeSignatureValid, TlsError> { |
| 91 | + rustls::crypto::verify_tls12_signature(message, cert, dss, &self.supported) |
| 92 | + } |
| 93 | + |
| 94 | + fn verify_tls13_signature( |
| 95 | + &self, |
| 96 | + message: &[u8], |
| 97 | + cert: &CertificateDer<'_>, |
| 98 | + dss: &DigitallySignedStruct, |
| 99 | + ) -> Result<HandshakeSignatureValid, TlsError> { |
| 100 | + rustls::crypto::verify_tls12_signature(message, cert, dss, &self.supported) |
| 101 | + } |
| 102 | + |
| 103 | + fn supported_verify_schemes(&self) -> Vec<SignatureScheme> { |
| 104 | + self.supported.supported_schemes() |
| 105 | + } |
| 106 | +} |
| 107 | + |
| 108 | +impl TlsOptions { |
| 109 | + /// Tls options with no ca certificates. Use [TlsOptions::default] if well-known ca roots is |
| 110 | + /// desirable. |
| 111 | + pub fn no_ca() -> Self { |
| 112 | + Self { ca_certs: RootCertStore::empty(), identity: None, hostname_verification: true } |
| 113 | + } |
| 114 | + |
| 115 | + /// Disables hostname verification in tls handshake. |
| 116 | + /// |
| 117 | + /// # Safety |
| 118 | + /// This exposes risk to man-in-the-middle attacks. |
| 119 | + pub unsafe fn with_no_hostname_verification(mut self) -> Self { |
| 120 | + self.hostname_verification = false; |
| 121 | + self |
| 122 | + } |
| 123 | + |
| 124 | + /// Adds new ca certificates. |
| 125 | + pub fn with_pem_ca_certs(mut self, certs: &str) -> Result<Self> { |
| 126 | + for r in rustls_pemfile::certs(&mut certs.as_bytes()) { |
| 127 | + let cert = match r { |
| 128 | + Ok(cert) => cert, |
| 129 | + Err(err) => return Err(Error::other(format!("fail to read cert {}", err), err)), |
| 130 | + }; |
| 131 | + if let Err(err) = self.ca_certs.add(cert) { |
| 132 | + return Err(Error::other(format!("fail to add cert {}", err), err)); |
| 133 | + } |
| 134 | + } |
| 135 | + Ok(self) |
| 136 | + } |
| 137 | + |
| 138 | + /// Specifies client identity for server to authenticate. |
| 139 | + pub fn with_pem_identity(mut self, cert: &str, key: &str) -> Result<Self> { |
| 140 | + let r: std::result::Result<Vec<_>, _> = rustls_pemfile::certs(&mut cert.as_bytes()).collect(); |
| 141 | + let certs = match r { |
| 142 | + Err(err) => return Err(Error::other(format!("fail to read cert {}", err), err)), |
| 143 | + Ok(certs) => certs, |
| 144 | + }; |
| 145 | + let key = match rustls_pemfile::private_key(&mut key.as_bytes()) { |
| 146 | + Err(err) => return Err(Error::other(format!("fail to read client private key {err}"), err)), |
| 147 | + Ok(None) => return Err(Error::BadArguments(&"no client private key")), |
| 148 | + Ok(Some(key)) => key, |
| 149 | + }; |
| 150 | + self.identity = Some((certs, key)); |
| 151 | + Ok(self) |
| 152 | + } |
| 153 | + |
| 154 | + fn take_roots(&mut self) -> RootCertStore { |
| 155 | + std::mem::replace(&mut self.ca_certs, RootCertStore::empty()) |
| 156 | + } |
| 157 | + |
| 158 | + pub(crate) fn into_config(mut self) -> Result<ClientConfig> { |
| 159 | + // This has to be called before server cert verifier to install default crypto provider. |
| 160 | + let builder = ClientConfig::builder(); |
| 161 | + let verifier = TlsServerCertVerifier::new(self.take_roots(), self.hostname_verification); |
| 162 | + let builder = builder.dangerous().with_custom_certificate_verifier(Arc::new(verifier)); |
| 163 | + if let Some((client_cert, client_key)) = self.identity.take() { |
| 164 | + match builder.with_client_auth_cert(client_cert, client_key) { |
| 165 | + Ok(config) => Ok(config), |
| 166 | + Err(err) => Err(Error::other(format!("invalid client private key {err}"), err)), |
| 167 | + } |
| 168 | + } else { |
| 169 | + Ok(builder.with_no_client_auth()) |
| 170 | + } |
| 171 | + } |
| 172 | +} |
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