mas_config/sections/
rate_limiting.rs

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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
// Copyright 2024 New Vector Ltd.
// Copyright 2024 The Matrix.org Foundation C.I.C.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.

use std::{num::NonZeroU32, time::Duration};

use governor::Quota;
use schemars::JsonSchema;
use serde::{de::Error as _, Deserialize, Serialize};

use crate::ConfigurationSection;

/// Configuration related to sending emails
#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct RateLimitingConfig {
    /// Account Recovery-specific rate limits
    #[serde(default)]
    pub account_recovery: AccountRecoveryRateLimitingConfig,
    /// Login-specific rate limits
    #[serde(default)]
    pub login: LoginRateLimitingConfig,
    /// Controls how many registrations attempts are permitted
    /// based on source address.
    #[serde(default = "default_registration")]
    pub registration: RateLimiterConfiguration,
}

#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct LoginRateLimitingConfig {
    /// Controls how many login attempts are permitted
    /// based on source IP address.
    /// This can protect against brute force login attempts.
    ///
    /// Note: this limit also applies to password checks when a user attempts to
    /// change their own password.
    #[serde(default = "default_login_per_ip")]
    pub per_ip: RateLimiterConfiguration,
    /// Controls how many login attempts are permitted
    /// based on the account that is being attempted to be logged into.
    /// This can protect against a distributed brute force attack
    /// but should be set high enough to prevent someone's account being
    /// casually locked out.
    ///
    /// Note: this limit also applies to password checks when a user attempts to
    /// change their own password.
    #[serde(default = "default_login_per_account")]
    pub per_account: RateLimiterConfiguration,
}

#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct AccountRecoveryRateLimitingConfig {
    /// Controls how many account recovery attempts are permitted
    /// based on source IP address.
    /// This can protect against causing e-mail spam to many targets.
    ///
    /// Note: this limit also applies to re-sends.
    #[serde(default = "default_account_recovery_per_ip")]
    pub per_ip: RateLimiterConfiguration,
    /// Controls how many account recovery attempts are permitted
    /// based on the e-mail address entered into the recovery form.
    /// This can protect against causing e-mail spam to one target.
    ///
    /// Note: this limit also applies to re-sends.
    #[serde(default = "default_account_recovery_per_address")]
    pub per_address: RateLimiterConfiguration,
}

#[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct RateLimiterConfiguration {
    /// A one-off burst of actions that the user can perform
    /// in one go without waiting.
    pub burst: NonZeroU32,
    /// How quickly the allowance replenishes, in number of actions per second.
    /// Can be fractional to replenish slower.
    pub per_second: f64,
}

impl ConfigurationSection for RateLimitingConfig {
    const PATH: Option<&'static str> = Some("rate_limiting");

    fn validate(&self, figment: &figment::Figment) -> Result<(), figment::Error> {
        let metadata = figment.find_metadata(Self::PATH.unwrap());

        let error_on_field = |mut error: figment::error::Error, field: &'static str| {
            error.metadata = metadata.cloned();
            error.profile = Some(figment::Profile::Default);
            error.path = vec![Self::PATH.unwrap().to_owned(), field.to_owned()];
            error
        };

        let error_on_nested_field =
            |mut error: figment::error::Error, container: &'static str, field: &'static str| {
                error.metadata = metadata.cloned();
                error.profile = Some(figment::Profile::Default);
                error.path = vec![
                    Self::PATH.unwrap().to_owned(),
                    container.to_owned(),
                    field.to_owned(),
                ];
                error
            };

        // Check one limiter's configuration for errors
        let error_on_limiter =
            |limiter: &RateLimiterConfiguration| -> Option<figment::error::Error> {
                let recip = limiter.per_second.recip();
                // period must be at least 1 nanosecond according to the governor library
                if recip < 1.0e-9 || !recip.is_finite() {
                    return Some(figment::error::Error::custom(
                        "`per_second` must be a number that is more than zero and less than 1_000_000_000 (1e9)",
                    ));
                }

                None
            };

        if let Some(error) = error_on_limiter(&self.account_recovery.per_ip) {
            return Err(error_on_nested_field(error, "account_recovery", "per_ip"));
        }
        if let Some(error) = error_on_limiter(&self.account_recovery.per_address) {
            return Err(error_on_nested_field(
                error,
                "account_recovery",
                "per_address",
            ));
        }

        if let Some(error) = error_on_limiter(&self.registration) {
            return Err(error_on_field(error, "registration"));
        }

        if let Some(error) = error_on_limiter(&self.login.per_ip) {
            return Err(error_on_nested_field(error, "login", "per_ip"));
        }
        if let Some(error) = error_on_limiter(&self.login.per_account) {
            return Err(error_on_nested_field(error, "login", "per_account"));
        }

        Ok(())
    }
}

impl RateLimitingConfig {
    pub(crate) fn is_default(config: &RateLimitingConfig) -> bool {
        config == &RateLimitingConfig::default()
    }
}

impl RateLimiterConfiguration {
    pub fn to_quota(self) -> Option<Quota> {
        let reciprocal = self.per_second.recip();
        if !reciprocal.is_finite() {
            return None;
        }
        Some(Quota::with_period(Duration::from_secs_f64(reciprocal))?.allow_burst(self.burst))
    }
}

fn default_login_per_ip() -> RateLimiterConfiguration {
    RateLimiterConfiguration {
        burst: NonZeroU32::new(3).unwrap(),
        per_second: 3.0 / 60.0,
    }
}

fn default_login_per_account() -> RateLimiterConfiguration {
    RateLimiterConfiguration {
        burst: NonZeroU32::new(1800).unwrap(),
        per_second: 1800.0 / 3600.0,
    }
}

fn default_registration() -> RateLimiterConfiguration {
    RateLimiterConfiguration {
        burst: NonZeroU32::new(3).unwrap(),
        per_second: 3.0 / 3600.0,
    }
}

fn default_account_recovery_per_ip() -> RateLimiterConfiguration {
    RateLimiterConfiguration {
        burst: NonZeroU32::new(3).unwrap(),
        per_second: 3.0 / 3600.0,
    }
}

fn default_account_recovery_per_address() -> RateLimiterConfiguration {
    RateLimiterConfiguration {
        burst: NonZeroU32::new(3).unwrap(),
        per_second: 1.0 / 3600.0,
    }
}

impl Default for RateLimitingConfig {
    fn default() -> Self {
        RateLimitingConfig {
            login: LoginRateLimitingConfig::default(),
            registration: default_registration(),
            account_recovery: AccountRecoveryRateLimitingConfig::default(),
        }
    }
}

impl Default for LoginRateLimitingConfig {
    fn default() -> Self {
        LoginRateLimitingConfig {
            per_ip: default_login_per_ip(),
            per_account: default_login_per_account(),
        }
    }
}

impl Default for AccountRecoveryRateLimitingConfig {
    fn default() -> Self {
        AccountRecoveryRateLimitingConfig {
            per_ip: default_account_recovery_per_ip(),
            per_address: default_account_recovery_per_address(),
        }
    }
}