rex_v8 0.17.2

V8 isolate pool and SSR engine for the Rex framework
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
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

#![allow(clippy::unwrap_used)]

use rex_v8::fetch::{
    drain_fetch_queue, fetch_callback, is_private_ip, run_fetch_loop, validate_url_not_private,
};

#[test]
fn fetch_queue_starts_empty() {
    let pending = drain_fetch_queue();
    assert!(pending.is_empty());
}

#[test]
fn install_fetch_on_global() {
    rex_v8::init_v8();
    let mut isolate = v8::Isolate::new(v8::CreateParams::default());
    v8::scope!(scope, &mut isolate);
    let context = v8::Context::new(scope, Default::default());
    let scope = &mut v8::ContextScope::new(scope, context);
    let global = context.global(scope);

    let t = v8::FunctionTemplate::new(scope, fetch_callback);
    let f = t.get_function(scope).expect("fetch function template");
    let k = v8::String::new(scope, "fetch").expect("fetch string");
    global.set(scope, k.into(), f.into());

    let k = v8::String::new(scope, "fetch").unwrap();
    let v = global.get(scope, k.into()).unwrap();
    assert!(v.is_function());
}

#[test]
fn fetch_returns_promise() {
    rex_v8::init_v8();
    let mut isolate = v8::Isolate::new(v8::CreateParams::default());

    {
        v8::scope!(scope, &mut isolate);
        let context = v8::Context::new(scope, Default::default());
        let scope = &mut v8::ContextScope::new(scope, context);
        let global = context.global(scope);

        let t = v8::FunctionTemplate::new(scope, fetch_callback);
        let f = t.get_function(scope).expect("fetch fn");
        let k = v8::String::new(scope, "fetch").expect("fetch key");
        global.set(scope, k.into(), f.into());

        let code = "typeof fetch('http://example.com')";
        let source = v8::String::new(scope, code).unwrap();
        let script = v8::Script::compile(scope, source, None).unwrap();
        let result = script.run(scope).unwrap();
        assert_eq!(result.to_rust_string_lossy(scope), "object");
    }

    let pending = drain_fetch_queue();
    assert_eq!(pending.len(), 1);
    assert_eq!(pending[0].url, "http://example.com");
    assert_eq!(pending[0].method, "GET");
}

/// Integration test: verifies that `run_fetch_loop` can resolve a fetch promise
/// end-to-end. Requires a real HTTP server, so marked `#[ignore]` for CI.
#[test]
#[ignore]
fn test_run_fetch_loop_resolves_promise() {
    rex_v8::init_v8();
    let mut isolate = v8::Isolate::new(v8::CreateParams::default());

    let context = {
        v8::scope!(scope, &mut isolate);
        let context = v8::Context::new(scope, Default::default());
        let scope = &mut v8::ContextScope::new(scope, context);
        let global = context.global(scope);

        let t = v8::FunctionTemplate::new(scope, fetch_callback);
        let f = t.get_function(scope).expect("fetch fn");
        let k = v8::String::new(scope, "fetch").expect("fetch key");
        global.set(scope, k.into(), f.into());

        let code = r#"
            var _result = null;
            fetch('https://httpbin.org/get')
                .then(function(r) { return r.json(); })
                .then(function(data) { _result = data.url; });
        "#;
        let source = v8::String::new(scope, code).unwrap();
        let script = v8::Script::compile(scope, source, None).unwrap();
        script.run(scope);

        v8::Global::new(scope, context)
    };

    run_fetch_loop(&mut isolate, &context);

    {
        v8::scope_with_context!(scope, &mut isolate, &context);
        let global = context.open(scope).global(scope);
        let key = v8::String::new(scope, "_result").unwrap();
        let val = global.get(scope, key.into()).unwrap();
        let result_str = val.to_rust_string_lossy(scope);
        assert!(
            result_str.contains("httpbin.org"),
            "Expected resolved URL to contain httpbin.org, got: {result_str}"
        );
    }
}

#[test]
fn fetch_parses_init_options() {
    rex_v8::init_v8();
    let mut isolate = v8::Isolate::new(v8::CreateParams::default());

    {
        v8::scope!(scope, &mut isolate);
        let context = v8::Context::new(scope, Default::default());
        let scope = &mut v8::ContextScope::new(scope, context);
        let global = context.global(scope);

        let t = v8::FunctionTemplate::new(scope, fetch_callback);
        let f = t.get_function(scope).expect("fetch fn");
        let k = v8::String::new(scope, "fetch").expect("fetch key");
        global.set(scope, k.into(), f.into());

        let code = r#"fetch('http://example.com/api', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: '{"key": "value"}'
        })"#;
        let source = v8::String::new(scope, code).unwrap();
        let script = v8::Script::compile(scope, source, None).unwrap();
        script.run(scope);
    }

    let pending = drain_fetch_queue();
    assert_eq!(pending.len(), 1);
    assert_eq!(pending[0].method, "POST");
    assert_eq!(
        pending[0].headers.get("Content-Type").unwrap(),
        "application/json"
    );
    assert_eq!(pending[0].body.as_deref(), Some("{\"key\": \"value\"}"));
}

#[test]
fn ssrf_blocks_loopback_ipv4() {
    assert!(is_private_ip(&"127.0.0.1".parse().unwrap()));
    assert!(is_private_ip(&"127.0.0.2".parse().unwrap()));
}

#[test]
fn ssrf_blocks_private_ranges() {
    assert!(is_private_ip(&"10.0.0.1".parse().unwrap()));
    assert!(is_private_ip(&"172.16.0.1".parse().unwrap()));
    assert!(is_private_ip(&"192.168.1.1".parse().unwrap()));
}

#[test]
fn ssrf_blocks_link_local() {
    assert!(is_private_ip(&"169.254.169.254".parse().unwrap()));
}

#[test]
fn ssrf_blocks_ipv6_loopback() {
    assert!(is_private_ip(&"::1".parse().unwrap()));
}

#[test]
fn ssrf_allows_public_ip() {
    assert!(!is_private_ip(&"8.8.8.8".parse().unwrap()));
    assert!(!is_private_ip(&"93.184.216.34".parse().unwrap()));
}

#[tokio::test]
async fn ssrf_blocks_localhost_url() {
    let result = validate_url_not_private("http://127.0.0.1/secret").await;
    assert!(result.is_err());
    assert!(result.unwrap_err().contains("private address"));
}

#[tokio::test]
async fn ssrf_blocks_metadata_url() {
    let result = validate_url_not_private("http://169.254.169.254/latest/meta-data/").await;
    assert!(result.is_err());
}

#[tokio::test]
async fn ssrf_allowlist_permits_internal_origin() {
    std::env::set_var("REX_INTERNAL_ORIGIN", "http://127.0.0.1:8000");
    let result = validate_url_not_private("http://127.0.0.1:8000/api/data").await;
    assert!(result.is_ok());
    let result2 = validate_url_not_private("http://127.0.0.1:9999/secret").await;
    assert!(result2.is_err());
    std::env::remove_var("REX_INTERNAL_ORIGIN");
}