openssl_probe/
lib.rs

1use std::env;
2use std::path::{Path, PathBuf};
3
4/// The OpenSSL environment variable to configure what certificate file to use.
5pub const ENV_CERT_FILE: &'static str = "SSL_CERT_FILE";
6
7/// The OpenSSL environment variable to configure what certificates directory to use.
8pub const ENV_CERT_DIR: &'static str = "SSL_CERT_DIR";
9
10pub struct ProbeResult {
11    pub cert_file: Option<PathBuf>,
12    pub cert_dir: Option<PathBuf>,
13}
14
15/// Probe the system for the directory in which CA certificates should likely be
16/// found.
17///
18/// This will only search known system locations.
19pub fn find_certs_dirs() -> Vec<PathBuf> {
20    cert_dirs_iter().map(Path::to_path_buf).collect()
21}
22
23// TODO: when we bump to 0.2, make this the `find_certs_dirs` function
24fn cert_dirs_iter() -> impl Iterator<Item = &'static Path> {
25    // see http://gagravarr.org/writing/openssl-certs/others.shtml
26    [
27        "/var/ssl",
28        "/usr/share/ssl",
29        "/usr/local/ssl",
30        "/usr/local/openssl",
31        "/usr/local/etc/openssl",
32        "/usr/local/share",
33        "/usr/lib/ssl",
34        "/usr/ssl",
35        "/etc/openssl",
36        "/etc/pki/ca-trust/extracted/pem",
37        "/etc/pki/tls",
38        "/etc/ssl",
39        "/etc/certs",
40        "/opt/etc/ssl", // Entware
41        "/data/data/com.termux/files/usr/etc/tls",
42        "/boot/system/data/ssl",
43    ]
44    .iter().map(Path::new).filter(|p| p.exists())
45}
46
47/// Probe for SSL certificates on the system, then configure the SSL certificate `SSL_CERT_FILE`
48/// and `SSL_CERT_DIR` environment variables in this process for OpenSSL to use.
49///
50/// Preconfigured values in the environment variables will not be overwritten if the paths they
51/// point to exist and are accessible.
52pub fn init_ssl_cert_env_vars() {
53    try_init_ssl_cert_env_vars();
54}
55
56/// Probe for SSL certificates on the system, then configure the SSL certificate `SSL_CERT_FILE`
57/// and `SSL_CERT_DIR` environment variables in this process for OpenSSL to use.
58///
59/// Preconfigured values in the environment variables will not be overwritten if the paths they
60/// point to exist and are accessible.
61///
62/// Returns `true` if any certificate file or directory was found while probing.
63/// Combine this with `has_ssl_cert_env_vars()` to check whether previously configured environment
64/// variables are valid.
65pub fn try_init_ssl_cert_env_vars() -> bool {
66    let ProbeResult { cert_file, cert_dir } = probe();
67    // we won't be overwriting existing env variables because if they're valid probe() will have
68    // returned them unchanged
69    if let Some(path) = &cert_file {
70        env::set_var(ENV_CERT_FILE, path);
71    }
72    if let Some(path) = &cert_dir {
73        env::set_var(ENV_CERT_DIR, path);
74    }
75
76    cert_file.is_some() || cert_dir.is_some()
77}
78
79/// Check whether the OpenSSL `SSL_CERT_FILE` and/or `SSL_CERT_DIR` environment variable is
80/// configured in this process with an existing file or directory.
81///
82/// That being the case would indicate that certificates will be found successfully by OpenSSL.
83///
84/// Returns `true` if either variable is set to an existing file or directory.
85pub fn has_ssl_cert_env_vars() -> bool {
86    let probe = probe_from_env();
87    probe.cert_file.is_some() || probe.cert_dir.is_some()
88}
89
90fn probe_from_env() -> ProbeResult {
91    let var = |name| {
92        env::var_os(name)
93            .map(PathBuf::from)
94            .filter(|p| p.exists())
95    };
96    ProbeResult {
97        cert_file: var(ENV_CERT_FILE),
98        cert_dir: var(ENV_CERT_DIR),
99    }
100}
101
102pub fn probe() -> ProbeResult {
103    let mut result = probe_from_env();
104    for certs_dir in cert_dirs_iter() {
105        // cert.pem looks to be an openssl 1.0.1 thing, while
106        // certs/ca-certificates.crt appears to be a 0.9.8 thing
107        let cert_filenames = [
108            "cert.pem",
109            "certs.pem",
110            "ca-bundle.pem",
111            "cacert.pem",
112            "ca-certificates.crt",
113            "certs/ca-certificates.crt",
114            "certs/ca-root-nss.crt",
115            "certs/ca-bundle.crt",
116            "CARootCertificates.pem",
117            "tls-ca-bundle.pem",
118        ];
119        if result.cert_file.is_none() {
120            result.cert_file = cert_filenames
121                .iter()
122                .map(|fname| certs_dir.join(fname))
123                .find(|p| p.exists());
124        }
125        if result.cert_dir.is_none() {
126            let cert_dir = certs_dir.join("certs");
127            if cert_dir.exists() {
128                result.cert_dir = Some(cert_dir);
129            }
130        }
131        if result.cert_file.is_some() && result.cert_dir.is_some() {
132            break;
133        }
134    }
135    result
136}
openssl_probe/lib.rs

openssl_probe/
lib.rs
