gauth 0.10.2

HTTP Client for Google OAuth2
Documentation 
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

use std::path::Path;

use serde_derive::Deserialize;
use url::Url;

use super::errors::{AuthError, Result};

// Auth code configs
const AUTH_CODE_RESP_TYPE: &str = "code";
const AUTH_CODE_STATE: &str = "pass-through value";
const AUTH_CODE_INCLUDE_GRANTED_SCOPES: &str = "true";
const AUTH_CODE_ACCESS_TYPE: &str = "offline";

#[derive(Deserialize, Debug)]
pub struct OauthConfig {
    pub installed: OauthCredentials,
}

#[derive(Deserialize, Debug)]
pub struct OauthCredentials {
    pub client_id: String,
    // Present in the credentials.json schema; not consumed today but kept
    // on the struct so the layout matches the file. `expect` over `allow`
    // so the suppression auto-fires if a future feature starts reading these.
    #[expect(dead_code)]
    pub project_id: String,
    pub auth_uri: String,
    pub token_uri: String,
    #[expect(dead_code)]
    pub auth_provider_x509_cert_url: String,
    pub client_secret: String,
    pub redirect_uris: Vec<String>,
}

impl OauthCredentials {
    pub fn redirect_uri(&self) -> Result<&String> {
        self.redirect_uris
            .first()
            .ok_or(AuthError::RedirectUriCfgError)
    }
}

pub fn auth_code_uri_str(credentials: &OauthCredentials, scope: &str) -> Result<String> {
    let auth_code_link = auth_code_uri(credentials, scope)?;
    Ok(auth_code_link.to_string())
}

pub fn read_oauth_config(p: &Path) -> Result<OauthConfig> {
    let b = std::fs::read(p)?;
    let cfg = serde_json::from_slice::<OauthConfig>(&b)?;
    Ok(cfg)
}

fn auth_code_uri(credentials: &OauthCredentials, scope: &str) -> Result<url::Url> {
    let mut uri = Url::parse(credentials.auth_uri.as_str())?;

    let params = vec![
        ("client_id", credentials.client_id.as_str()),
        ("response_type", AUTH_CODE_RESP_TYPE),
        ("redirect_uri", credentials.redirect_uri()?),
        ("include_granted_scopes", AUTH_CODE_INCLUDE_GRANTED_SCOPES),
        ("scope", scope),
        ("access_type", AUTH_CODE_ACCESS_TYPE),
        ("state", AUTH_CODE_STATE),
    ];

    for (k, v) in params.into_iter() {
        uri.query_pairs_mut().append_pair(k, v);
    }

    uri.query_pairs_mut().finish();
    Ok(uri)
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::Path;

    const FIXTURE: &str = "test_fixtures/oauth-credentials.json";

    #[test]
    fn read_oauth_config_parses_installed_app_schema() {
        let cfg = read_oauth_config(Path::new(FIXTURE)).unwrap();
        assert_eq!(
            cfg.installed.client_id,
            "test-client-id.apps.googleusercontent.com"
        );
        assert_eq!(cfg.installed.client_secret, "test-client-secret");
        assert_eq!(
            cfg.installed.token_uri,
            "https://oauth2.googleapis.com/token"
        );
        assert_eq!(cfg.installed.redirect_uris.len(), 2);
        assert_eq!(cfg.installed.redirect_uris[0], "urn:ietf:wg:oauth:2.0:oob");
    }

    #[test]
    fn read_oauth_config_missing_file_errors() {
        let err = read_oauth_config(Path::new("/no/such/file.json")).unwrap_err();
        assert!(
            matches!(err, AuthError::IOError(_)),
            "expected IoError, got: {err:?}"
        );
    }

    #[test]
    fn redirect_uri_returns_first_when_present() {
        let creds = OauthCredentials {
            client_id: "id".into(),
            project_id: "p".into(),
            auth_uri: "https://example.com/auth".into(),
            token_uri: "https://example.com/token".into(),
            auth_provider_x509_cert_url: "https://example.com/certs".into(),
            client_secret: "s".into(),
            redirect_uris: vec!["http://localhost".into(), "http://other".into()],
        };
        assert_eq!(creds.redirect_uri().unwrap(), "http://localhost");
    }

    #[test]
    fn redirect_uri_empty_errors() {
        let creds = OauthCredentials {
            client_id: "id".into(),
            project_id: "p".into(),
            auth_uri: "https://example.com/auth".into(),
            token_uri: "https://example.com/token".into(),
            auth_provider_x509_cert_url: "https://example.com/certs".into(),
            client_secret: "s".into(),
            redirect_uris: vec![],
        };
        assert!(matches!(
            creds.redirect_uri().unwrap_err(),
            AuthError::RedirectUriCfgError,
        ));
    }

    #[test]
    fn auth_code_uri_contains_scope_and_client_id() {
        let cfg = read_oauth_config(Path::new(FIXTURE)).unwrap();
        let uri =
            auth_code_uri_str(&cfg.installed, "https://www.googleapis.com/auth/drive").unwrap();
        assert!(uri.contains("client_id=test-client-id"));
        assert!(uri.contains("scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fdrive"));
        assert!(uri.contains("response_type=code"));
        assert!(uri.contains("access_type=offline"));
    }
}