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
// Copyright 2015-2021 Benjamin Fry <benjaminfry@me.com>
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.

//! DNS over TLS server implementations for OpenSSL

use std::fs::File;
use std::io;
use std::io::Read;
use std::path::Path;

use crate::error::{ProtoError, ProtoResult};
use openssl::ssl::{SslAcceptor, SslMethod, SslOptions, SslVerifyMode};

pub use openssl::pkcs12::Pkcs12;
pub use openssl::pkey::{PKey, Private};
pub use openssl::stack::Stack;
pub use openssl::x509::X509;

/// Read the certificate from the specified path.
///
/// If the password is specified, then it will be used to decode the Certificate
#[allow(clippy::type_complexity)]
pub fn read_cert_pkcs12(
    path: &Path,
    password: Option<&str>,
) -> ProtoResult<((Option<X509>, Option<Stack<X509>>), Option<PKey<Private>>)> {
    let mut file = File::open(path).map_err(|e| {
        ProtoError::from(format!(
            "error opening pkcs12 cert file: {}: {}",
            path.display(),
            e
        ))
    })?;

    let mut pkcs12_bytes = vec![];
    file.read_to_end(&mut pkcs12_bytes).map_err(|e| {
        ProtoError::from(format!(
            "could not read pkcs12 from: {}: {}",
            path.display(),
            e
        ))
    })?;
    let pkcs12 = Pkcs12::from_der(&pkcs12_bytes).map_err(|e| {
        ProtoError::from(format!(
            "badly formatted pkcs12 from: {}: {}",
            path.display(),
            e
        ))
    })?;
    let parsed = pkcs12.parse2(password.unwrap_or("")).map_err(|e| {
        ProtoError::from(format!(
            "failed to open pkcs12 from: {}: {}",
            path.display(),
            e
        ))
    })?;

    Ok(((parsed.cert, parsed.ca), parsed.pkey))
}

/// Read the certificate from the specified path.
///
/// If the password is specified, then it will be used to decode the Certificate
pub fn read_cert_pem(path: &Path) -> ProtoResult<(X509, Option<Stack<X509>>)> {
    let mut file = File::open(path).map_err(|e| {
        ProtoError::from(format!(
            "error opening cert file: {}: {}",
            path.display(),
            e
        ))
    })?;

    let mut key_bytes = vec![];
    file.read_to_end(&mut key_bytes).map_err(|e| {
        ProtoError::from(format!(
            "could not read cert key from: {}: {}",
            path.display(),
            e
        ))
    })?;

    let cert_chain = X509::stack_from_pem(&key_bytes)?;
    let cert_count = cert_chain.len();
    let mut iter = cert_chain.into_iter();

    let cert = match iter.next() {
        None => {
            return Err(ProtoError::from(format!(
                "no certs read from file: {}",
                path.display()
            )))
        }
        Some(cert) => cert,
    };

    if cert_count < 1 {
        Ok((cert, None))
    } else {
        let mut stack = Stack::<X509>::new()?;
        for c in iter {
            stack.push(c)?;
        }
        Ok((cert, Some(stack)))
    }
}

/// Reads a private key from a pkcs8 formatted, and possibly encoded file
pub fn read_key_from_pkcs8(path: &Path, password: Option<&str>) -> ProtoResult<PKey<Private>> {
    let mut file = File::open(path)?;
    let mut buf = Vec::new();
    file.read_to_end(&mut buf)?;

    match password.map(str::as_bytes) {
        Some(password) => {
            PKey::private_key_from_pkcs8_passphrase(&buf, password).map_err(Into::into)
        }
        None => PKey::private_key_from_pkcs8_passphrase(&buf, &[0_u8; 0]).map_err(Into::into),
    }
}

/// Reads a private key from a der formatted file
pub fn read_key_from_der(path: &Path) -> ProtoResult<PKey<Private>> {
    let mut file = File::open(path)?;
    let mut buf = Vec::new();
    file.read_to_end(&mut buf)?;

    PKey::private_key_from_der(&buf).map_err(Into::into)
}

/// Construct the new Acceptor with the associated pkcs12 data
pub fn new_acceptor(
    cert: X509,
    chain: Option<Stack<X509>>,
    key: PKey<Private>,
) -> io::Result<SslAcceptor> {
    // TODO: make an internal error type with conversions
    let mut builder = SslAcceptor::mozilla_modern(SslMethod::tls())?;

    builder.set_private_key(&key)?;
    builder.set_certificate(&cert)?;
    builder.set_verify(SslVerifyMode::NONE);
    builder.set_options(
        SslOptions::NO_COMPRESSION
            | SslOptions::NO_SSLV2
            | SslOptions::NO_SSLV3
            | SslOptions::NO_TLSV1
            | SslOptions::NO_TLSV1_1,
    );

    if let Some(ref chain) = chain {
        for cert in chain {
            builder.add_extra_chain_cert(cert.to_owned())?;
        }
    }

    // validate our certificate and private key match
    builder.check_private_key()?;

    Ok(builder.build())
}