1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
use crate::anchors;
use crate::builder::{ConfigBuilder, WantsVerifier};
use crate::client::handy;
use crate::client::{ClientConfig, ResolvesClientCert};
use crate::error::Error;
use crate::key;
use crate::kx::SupportedKxGroup;
use crate::suites::SupportedCipherSuite;
use crate::verify::{self, CertificateTransparencyPolicy};
use crate::versions;
use crate::NoKeyLog;

use std::marker::PhantomData;
use std::sync::Arc;
use std::time::SystemTime;

impl ConfigBuilder<ClientConfig, WantsVerifier> {
    /// Choose how to verify client certificates.
    pub fn with_root_certificates(
        self,
        root_store: anchors::RootCertStore,
    ) -> ConfigBuilder<ClientConfig, WantsTransparencyPolicyOrClientCert> {
        ConfigBuilder {
            state: WantsTransparencyPolicyOrClientCert {
                cipher_suites: self.state.cipher_suites,
                kx_groups: self.state.kx_groups,
                versions: self.state.versions,
                root_store,
            },
            side: PhantomData::default(),
        }
    }

    #[cfg(feature = "dangerous_configuration")]
    /// Set a custom certificate verifier.
    pub fn with_custom_certificate_verifier(
        self,
        verifier: Arc<dyn verify::ServerCertVerifier>,
    ) -> ConfigBuilder<ClientConfig, WantsClientCert> {
        ConfigBuilder {
            state: WantsClientCert {
                cipher_suites: self.state.cipher_suites,
                kx_groups: self.state.kx_groups,
                versions: self.state.versions,
                verifier,
            },
            side: PhantomData::default(),
        }
    }
}

/// A config builder state where the caller needs to supply a certificate transparency policy or
/// client certificate resolver.
///
/// In this state, the caller can optionally enable certificate transparency, or ignore CT and
/// invoke one of the methods related to client certificates (as in the [`WantsClientCert`] state).
///
/// For more information, see the [`ConfigBuilder`] documentation.
#[derive(Clone, Debug)]
pub struct WantsTransparencyPolicyOrClientCert {
    cipher_suites: Vec<SupportedCipherSuite>,
    kx_groups: Vec<&'static SupportedKxGroup>,
    versions: versions::EnabledVersions,
    root_store: anchors::RootCertStore,
}

impl ConfigBuilder<ClientConfig, WantsTransparencyPolicyOrClientCert> {
    /// Set Certificate Transparency logs to use for server certificate validation.
    ///
    /// Because Certificate Transparency logs are sharded on a per-year basis and can be trusted or
    /// distrusted relatively quickly, rustls stores a validation deadline. Server certificates will
    /// be validated against the configured CT logs until the deadline expires. After the deadline,
    /// certificates will no longer be validated, and a warning message will be logged. The deadline
    /// may vary depending on how often you deploy builds with updated dependencies.
    pub fn with_certificate_transparency_logs(
        self,
        logs: &'static [&'static sct::Log],
        validation_deadline: SystemTime,
    ) -> ConfigBuilder<ClientConfig, WantsClientCert> {
        self.with_logs(Some(CertificateTransparencyPolicy::new(
            logs,
            validation_deadline,
        )))
    }

    /// Sets a single certificate chain and matching private key for use
    /// in client authentication.
    ///
    /// `cert_chain` is a vector of DER-encoded certificates.
    /// `key_der` is a DER-encoded RSA, ECDSA, or Ed25519 private key.
    ///
    /// This function fails if `key_der` is invalid.
    pub fn with_single_cert(
        self,
        cert_chain: Vec<key::Certificate>,
        key_der: key::PrivateKey,
    ) -> Result<ClientConfig, Error> {
        self.with_logs(None)
            .with_single_cert(cert_chain, key_der)
    }

    /// Do not support client auth.
    pub fn with_no_client_auth(self) -> ClientConfig {
        self.with_logs(None)
            .with_client_cert_resolver(Arc::new(handy::FailResolveClientCert {}))
    }

    /// Sets a custom [`ResolvesClientCert`].
    pub fn with_client_cert_resolver(
        self,
        client_auth_cert_resolver: Arc<dyn ResolvesClientCert>,
    ) -> ClientConfig {
        self.with_logs(None)
            .with_client_cert_resolver(client_auth_cert_resolver)
    }

    fn with_logs(
        self,
        ct_policy: Option<CertificateTransparencyPolicy>,
    ) -> ConfigBuilder<ClientConfig, WantsClientCert> {
        ConfigBuilder {
            state: WantsClientCert {
                cipher_suites: self.state.cipher_suites,
                kx_groups: self.state.kx_groups,
                versions: self.state.versions,
                verifier: Arc::new(verify::WebPkiVerifier::new(
                    self.state.root_store,
                    ct_policy,
                )),
            },
            side: PhantomData,
        }
    }
}

/// A config builder state where the caller needs to supply whether and how to provide a client
/// certificate.
///
/// For more information, see the [`ConfigBuilder`] documentation.
#[derive(Clone, Debug)]
pub struct WantsClientCert {
    cipher_suites: Vec<SupportedCipherSuite>,
    kx_groups: Vec<&'static SupportedKxGroup>,
    versions: versions::EnabledVersions,
    verifier: Arc<dyn verify::ServerCertVerifier>,
}

impl ConfigBuilder<ClientConfig, WantsClientCert> {
    /// Sets a single certificate chain and matching private key for use
    /// in client authentication.
    ///
    /// `cert_chain` is a vector of DER-encoded certificates.
    /// `key_der` is a DER-encoded RSA, ECDSA, or Ed25519 private key.
    ///
    /// This function fails if `key_der` is invalid.
    pub fn with_single_cert(
        self,
        cert_chain: Vec<key::Certificate>,
        key_der: key::PrivateKey,
    ) -> Result<ClientConfig, Error> {
        let resolver = handy::AlwaysResolvesClientCert::new(cert_chain, &key_der)?;
        Ok(self.with_client_cert_resolver(Arc::new(resolver)))
    }

    /// Do not support client auth.
    pub fn with_no_client_auth(self) -> ClientConfig {
        self.with_client_cert_resolver(Arc::new(handy::FailResolveClientCert {}))
    }

    /// Sets a custom [`ResolvesClientCert`].
    pub fn with_client_cert_resolver(
        self,
        client_auth_cert_resolver: Arc<dyn ResolvesClientCert>,
    ) -> ClientConfig {
        ClientConfig {
            cipher_suites: self.state.cipher_suites,
            kx_groups: self.state.kx_groups,
            alpn_protocols: Vec::new(),
            session_storage: handy::ClientSessionMemoryCache::new(256),
            max_fragment_size: None,
            client_auth_cert_resolver,
            enable_tickets: true,
            versions: self.state.versions,
            enable_sni: true,
            verifier: self.state.verifier,
            key_log: Arc::new(NoKeyLog {}),
            enable_early_data: false,
        }
    }
}