security_rust/protocol/
open_redirect.rs

1// Copyright (c) 2026 erik <erik@erik.xyz> — https://erik.xyz
2
3use regex::Regex;
4use std::sync::LazyLock;
5
6use crate::{AttackCategory, DetectionResult, Detector, Severity};
7
8static PATTERNS: LazyLock<Vec<Regex>> = LazyLock::new(|| {
9    vec![
10        Regex::new(r"(?i)//[^/\s]+\.[a-z]{2,}").unwrap(),
11        Regex::new(r"(?i)javascript\s*:").unwrap(),
12        Regex::new(r"(?i)data\s*:\s*text/html").unwrap(),
13        Regex::new(r"(?i)data\s*:\s*text/plain").unwrap(),
14    ]
15});
16
17pub struct OpenRedirectDetector;
18
19impl Detector for OpenRedirectDetector {
20    fn name(&self) -> &'static str {
21        "open_redirect"
22    }
23
24    fn detect(&self, input: &str) -> Option<DetectionResult> {
25        for re in PATTERNS.iter() {
26            for m in re.find_iter(input) {
27                let start = m.start();
28                // Skip // matches that are part of a URL scheme (e.g. https://)
29                if start > 0 && input.as_bytes()[start - 1] == b':' {
30                    continue;
31                }
32                return Some(DetectionResult {
33                    attack_type: "open_redirect".into(),
34                    category: AttackCategory::Protocol,
35                    severity: Severity::Medium,
36                    matched_pattern: m.as_str().to_string(),
37                    offset: start,
38                    message: "Open redirect detected".into(),
39                });
40            }
41        }
42        None
43    }
44}
45
46#[cfg(test)]
47mod tests {
48    use super::*;
49
50    fn assert_detected(input: &str) {
51        crate::test_helpers::assert_detected(
52            &OpenRedirectDetector,
53            input,
54            AttackCategory::Protocol,
55            Severity::Medium,
56        );
57    }
58
59    fn assert_clean(input: &str) {
60        crate::test_helpers::assert_clean(&OpenRedirectDetector, input);
61    }
62
63    #[test]
64    fn name_is_open_redirect() {
65        assert_eq!(OpenRedirectDetector.name(), "open_redirect");
66    }
67
68    #[test]
69    fn detects_double_slash_url() {
70        assert_detected("//evil.com/phishing");
71        assert_detected("//attacker.org/steal?u=1");
72        assert_detected("https://ok.com//evil.com"); // scheme match skipped, later redirect still caught
73    }
74
75    #[test]
76    fn detects_javascript_uri() {
77        assert_detected("javascript:alert(document.cookie)");
78    }
79
80    #[test]
81    fn detects_data_html_uri() {
82        assert_detected("data:text/html,<script>alert(1)</script>");
83    }
84
85    #[test]
86    fn detects_data_plain_uri() {
87        assert_detected("data: text/plain;base64,SGVsbG8=");
88    }
89
90    #[test]
91    fn detects_mixed_case() {
92        assert_detected("JAVASCRIPT:alert(1)");
93        assert_detected("//Evil.Com/");
94    }
95
96    #[test]
97    fn rejects_scheme_urls() {
98        assert_clean("https://evil.com/phishing");
99        assert_clean("http://example.com/");
100        assert_clean("file:///etc/passwd");
101    }
102
103    #[test]
104    fn rejects_benign_paths() {
105        assert_clean("example.com/redirect");
106        assert_clean("java script: alert(1)");
107        assert_clean("data:image/png;base64,AA==");
108    }
109
110    #[test]
111    fn rejects_near_misses() {
112        assert_clean("//evil/com");
113        assert_clean("//evil.c");
114        assert_clean("// evil.com");
115    }
116
117    #[test]
118    fn rejects_empty_and_whitespace() {
119        assert_clean("");
120        assert_clean("   ");
121    }
122
123    #[test]
124    fn rejects_unicode_text() {
125        assert_clean("重定向到登录页");
126    }
127}
security_rust/protocol/open_redirect.rs

security_rust/protocol/
open_redirect.rs
