rama-tls 0.3.0

rama TLS-agnostic types and utilities
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
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362

use rama_core::extensions::Extensions;
use rama_core::telemetry::tracing;
use std::{fmt, io};

use crate::{
    CipherSuite, ECPointFormat, ExtensionId, ProtocolVersion, SecureTransport, SupportedGroup,
    client::NegotiatedTlsParameters,
};

use crate::client::ClientHello;

#[derive(Debug, Clone)]
/// Data which can be hashed using [`Self::hash`],
/// and which is also displayed as a "ja3" hash.
///
/// Computed using [`Ja3::compute`].
pub struct Ja3 {
    version: ProtocolVersion,
    cipher_suites: Vec<CipherSuite>,
    extensions: Option<Vec<ExtensionId>>,
    supported_groups: Option<Vec<SupportedGroup>>,
    ec_point_formats: Option<Vec<ECPointFormat>>,
}

impl Ja3 {
    /// Compute the [`Ja3`] (hash).
    ///
    /// As specified by <https://github.com/salesforce/ja3`>.
    pub fn compute(ext: &Extensions) -> Result<Self, Ja3ComputeError> {
        let client_hello = ext
            .get_ref::<SecureTransport>()
            .and_then(|st| st.client_hello())
            .ok_or(Ja3ComputeError::MissingClientHello)?;
        let negotiated_tls_version = ext
            .get_ref::<NegotiatedTlsParameters>()
            .map(|param| param.protocol_version);
        Self::compute_from_client_hello(client_hello, negotiated_tls_version)
    }

    /// Compute the [`Ja3`] (hash) from a reference to a [`ClientHello`].
    ///
    /// In case your source is [`Extensions`] you can use [`Self::compute`] instead.
    ///
    /// [`ClientHello`]: crate::client::ClientHello
    pub fn compute_from_client_hello(
        client_hello: &ClientHello,
        negotiated_tls_version: Option<ProtocolVersion>,
    ) -> Result<Self, Ja3ComputeError> {
        let version = negotiated_tls_version.unwrap_or_else(|| {
            tracing::trace!(
                "negotiated tls protocol version missing: fallback to client hello tls"
            );
            client_hello.protocol_version()
        });

        let cipher_suites: Vec<_> = client_hello
            .cipher_suites()
            .iter()
            .filter(|c| !c.is_grease())
            .copied()
            .collect();
        if cipher_suites.is_empty() {
            return Err(Ja3ComputeError::EmptyCipherSuites);
        }

        let mut extensions = None;
        let mut supported_groups = None;
        let mut ec_point_formats = None;

        let ce_extensions = client_hello.extensions();
        for ext in ce_extensions {
            if ext.id().is_grease() {
                continue;
            }

            extensions.get_or_insert_with(Vec::default).push(ext.id());

            match ext {
                crate::client::ClientHelloExtension::SupportedGroups(vec) => {
                    let vec: Vec<_> = vec.iter().filter(|g| !g.is_grease()).copied().collect();
                    if !vec.is_empty() {
                        supported_groups = Some(vec)
                    }
                }
                crate::client::ClientHelloExtension::ECPointFormats(vec) if !vec.is_empty() => {
                    ec_point_formats = Some(vec.clone())
                }
                _ => (),
            }
        }

        Ok(Self {
            version,
            cipher_suites,
            extensions,
            supported_groups,
            ec_point_formats,
        })
    }

    #[inline]
    /// compute the "ja3" hash from this [`Ja3`] data structure as a String.
    #[must_use]
    pub fn hash(&self) -> String {
        format!("{self:x}")
    }

    /// compute the "ja3" hash from this [`Ja3`] data structure into the writer.
    #[expect(
        clippy::panic,
        reason = "debug-only assertion: md5::Context::write_all is infallible in practice"
    )]
    fn hash_to(&self, w: &mut impl fmt::Write, lower: bool) -> fmt::Result {
        let mut ctx = md5::Context::new();
        _ = self.write_to_io(&mut ctx).inspect_err(|err| {
            if cfg!(debug_assertions) {
                panic!("md5 ingest failed: {err:?}");
            }
        });
        let digest = ctx.finalize();
        if lower {
            write!(w, "{digest:x}",)?;
        } else {
            write!(w, "{digest:X}",)?;
        }
        Ok(())
    }
}

macro_rules! impl_write_to {
    ($w:ident, $this:ident) => {{
        write!($w, "{}", u16::from($this.version))?;

        let mut sep = ',';
        for cipher_suite in &$this.cipher_suites {
            write!($w, "{sep}{}", u16::from(*cipher_suite))?;
            sep = '-';
        }

        match &$this.extensions {
            Some(ext) => {
                sep = ',';
                for ext in ext {
                    write!($w, "{sep}{}", u16::from(*ext))?;
                    sep = '-';
                }
            }
            None => write!($w, ",")?,
        }

        match &$this.supported_groups {
            Some(supported_groups) => {
                sep = ',';
                for g in supported_groups {
                    write!($w, "{sep}{}", u16::from(*g))?;
                    sep = '-';
                }
            }
            None => write!($w, ",")?,
        }

        match &$this.ec_point_formats {
            Some(ec_point_formats) => {
                sep = ',';
                for p in ec_point_formats {
                    write!($w, "{sep}{}", u8::from(*p))?;
                    sep = '-';
                }
            }
            None => write!($w, ",")?,
        }

        Ok(())
    }};
}

impl Ja3 {
    fn write_to_io(&self, w: &mut impl io::Write) -> io::Result<()> {
        impl_write_to!(w, self)
    }

    fn write_to_fmt(&self, w: &mut impl fmt::Write) -> fmt::Result {
        impl_write_to!(w, self)
    }
}

impl fmt::Display for Ja3 {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.write_to_fmt(f)
    }
}

impl fmt::LowerHex for Ja3 {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.hash_to(f, true)?;
        Ok(())
    }
}

impl fmt::UpperHex for Ja3 {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.hash_to(f, false)?;
        Ok(())
    }
}

#[derive(Debug, Clone)]
/// error identifying a failure in [`Ja3::compute`]
pub enum Ja3ComputeError {
    /// missing [`ClientHello`]
    ///
    /// [`ClientHello`]: crate::client::ClientHello
    MissingClientHello,
    /// cipher suites was empty
    EmptyCipherSuites,
}

impl fmt::Display for Ja3ComputeError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::MissingClientHello => {
                write!(f, "Ja3 Compute Error: missing client hello")
            }
            Self::EmptyCipherSuites => {
                write!(f, "Ja3 Compute Error: empty cipher suites")
            }
        }
    }
}

impl std::error::Error for Ja3ComputeError {}

#[cfg(test)]
mod tests {
    use crate::client::parse_client_hello;

    use super::*;

    #[derive(Debug)]
    struct TestCase {
        client_hello: Vec<u8>,
        pcap: &'static str,
        expected_ja3_str: &'static str,
        expected_ja3_hash: &'static str,
    }

    #[test]
    fn test_ja3_compute() {
        // src: <https://github.com/jabedude/ja3-rs/blob/a30d1bea03d2230b1239d437c3f6af7fb7699338/src/lib.rs#L380>
        let test_cases = [
            TestCase {
                client_hello: vec![
                    0x3, 0x3, 0x86, 0xad, 0xa4, 0xcc, 0x19, 0xe7, 0x14, 0x54, 0x54, 0xfd, 0xe7,
                    0x37, 0x33, 0xdf, 0x66, 0xcb, 0xf6, 0xef, 0x3e, 0xc0, 0xa1, 0x54, 0xc6, 0xdd,
                    0x14, 0x5e, 0xc0, 0x83, 0xac, 0xb9, 0xb4, 0xe7, 0x20, 0x1c, 0x64, 0xae, 0xa7,
                    0xa2, 0xc3, 0xe1, 0x8c, 0xd1, 0x25, 0x2, 0x4d, 0xf7, 0x86, 0x4a, 0xc7, 0x19,
                    0xd0, 0xc4, 0xbd, 0xfb, 0x40, 0xc2, 0xef, 0x7f, 0x6d, 0xd3, 0x9a, 0xa7, 0x53,
                    0xdf, 0xdd, 0x0, 0x22, 0x1a, 0x1a, 0x13, 0x1, 0x13, 0x2, 0x13, 0x3, 0xc0, 0x2b,
                    0xc0, 0x2f, 0xc0, 0x2c, 0xc0, 0x30, 0xcc, 0xa9, 0xcc, 0xa8, 0xc0, 0x13, 0xc0,
                    0x14, 0x0, 0x9c, 0x0, 0x9d, 0x0, 0x2f, 0x0, 0x35, 0x0, 0xa, 0x1, 0x0, 0x1,
                    0x91, 0xa, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0, 0x20, 0x0, 0x1e, 0x0, 0x0, 0x1b, 0x67,
                    0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x61, 0x64, 0x73, 0x2e, 0x67, 0x2e, 0x64, 0x6f,
                    0x75, 0x62, 0x6c, 0x65, 0x63, 0x6c, 0x69, 0x63, 0x6b, 0x2e, 0x6e, 0x65, 0x74,
                    0x0, 0x17, 0x0, 0x0, 0xff, 0x1, 0x0, 0x1, 0x0, 0x0, 0xa, 0x0, 0xa, 0x0, 0x8,
                    0x9a, 0x9a, 0x0, 0x1d, 0x0, 0x17, 0x0, 0x18, 0x0, 0xb, 0x0, 0x2, 0x1, 0x0, 0x0,
                    0x23, 0x0, 0x0, 0x0, 0x10, 0x0, 0xe, 0x0, 0xc, 0x2, 0x68, 0x32, 0x8, 0x68,
                    0x74, 0x74, 0x70, 0x2f, 0x31, 0x2e, 0x31, 0x0, 0x5, 0x0, 0x5, 0x1, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0xd, 0x0, 0x14, 0x0, 0x12, 0x4, 0x3, 0x8, 0x4, 0x4, 0x1, 0x5,
                    0x3, 0x8, 0x5, 0x5, 0x1, 0x8, 0x6, 0x6, 0x1, 0x2, 0x1, 0x0, 0x12, 0x0, 0x0,
                    0x0, 0x33, 0x0, 0x2b, 0x0, 0x29, 0x9a, 0x9a, 0x0, 0x1, 0x0, 0x0, 0x1d, 0x0,
                    0x20, 0x59, 0x8, 0x6f, 0x41, 0x9a, 0xa5, 0xaa, 0x1d, 0x81, 0xe3, 0x47, 0xf0,
                    0x25, 0x5f, 0x92, 0x7, 0xfc, 0x4b, 0x13, 0x74, 0x51, 0x46, 0x98, 0x8, 0x74,
                    0x3b, 0xde, 0x57, 0x86, 0xe8, 0x2c, 0x74, 0x0, 0x2d, 0x0, 0x2, 0x1, 0x1, 0x0,
                    0x2b, 0x0, 0xb, 0xa, 0xfa, 0xfa, 0x3, 0x4, 0x3, 0x3, 0x3, 0x2, 0x3, 0x1, 0x0,
                    0x1b, 0x0, 0x3, 0x2, 0x0, 0x2, 0xba, 0xba, 0x0, 0x1, 0x0, 0x0, 0x15, 0x0, 0xbd,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                ],
                pcap: "chrome-grease-single.pcap",
                expected_ja3_str: "771,4865-4866-4867-49195-49199-49196-49200-52393-52392-49171-49172-156-157-47-53-10,0-23-65281-10-11-35-16-5-13-18-51-45-43-27-21,29-23-24,0",
                expected_ja3_hash: "66918128f1b9b03303d77c6f2eefd128",
            },
            TestCase {
                client_hello: vec![
                    0x3, 0x3, 0xf6, 0x65, 0xb, 0x22, 0x13, 0xf1, 0xc3, 0xe9, 0xe7, 0xb3, 0xdc, 0x9,
                    0xe4, 0x4b, 0xcb, 0x6e, 0x5, 0xaf, 0x8f, 0x2f, 0x41, 0x8d, 0x15, 0xa8, 0x88,
                    0x46, 0x24, 0x83, 0xca, 0x9, 0x7c, 0x95, 0x20, 0x12, 0xc4, 0x5e, 0x71, 0x8b,
                    0xb9, 0xc9, 0xa9, 0x37, 0x93, 0x4c, 0x41, 0xa6, 0xe8, 0x9e, 0x8f, 0x15, 0x78,
                    0x52, 0xe, 0x3c, 0x28, 0xba, 0xab, 0xa3, 0x34, 0x8b, 0x53, 0x82, 0x83, 0x75,
                    0x24, 0x0, 0x3e, 0x13, 0x2, 0x13, 0x3, 0x13, 0x1, 0xc0, 0x2c, 0xc0, 0x30, 0x0,
                    0x9f, 0xcc, 0xa9, 0xcc, 0xa8, 0xcc, 0xaa, 0xc0, 0x2b, 0xc0, 0x2f, 0x0, 0x9e,
                    0xc0, 0x24, 0xc0, 0x28, 0x0, 0x6b, 0xc0, 0x23, 0xc0, 0x27, 0x0, 0x67, 0xc0,
                    0xa, 0xc0, 0x14, 0x0, 0x39, 0xc0, 0x9, 0xc0, 0x13, 0x0, 0x33, 0x0, 0x9d, 0x0,
                    0x9c, 0x0, 0x3d, 0x0, 0x3c, 0x0, 0x35, 0x0, 0x2f, 0x0, 0xff, 0x1, 0x0, 0x1,
                    0x75, 0x0, 0x0, 0x0, 0x10, 0x0, 0xe, 0x0, 0x0, 0xb, 0x65, 0x78, 0x61, 0x6d,
                    0x70, 0x6c, 0x65, 0x2e, 0x63, 0x6f, 0x6d, 0x0, 0xb, 0x0, 0x4, 0x3, 0x0, 0x1,
                    0x2, 0x0, 0xa, 0x0, 0xc, 0x0, 0xa, 0x0, 0x1d, 0x0, 0x17, 0x0, 0x1e, 0x0, 0x19,
                    0x0, 0x18, 0x33, 0x74, 0x0, 0x0, 0x0, 0x10, 0x0, 0xe, 0x0, 0xc, 0x2, 0x68,
                    0x32, 0x8, 0x68, 0x74, 0x74, 0x70, 0x2f, 0x31, 0x2e, 0x31, 0x0, 0x16, 0x0, 0x0,
                    0x0, 0x17, 0x0, 0x0, 0x0, 0xd, 0x0, 0x30, 0x0, 0x2e, 0x4, 0x3, 0x5, 0x3, 0x6,
                    0x3, 0x8, 0x7, 0x8, 0x8, 0x8, 0x9, 0x8, 0xa, 0x8, 0xb, 0x8, 0x4, 0x8, 0x5, 0x8,
                    0x6, 0x4, 0x1, 0x5, 0x1, 0x6, 0x1, 0x3, 0x3, 0x2, 0x3, 0x3, 0x1, 0x2, 0x1, 0x3,
                    0x2, 0x2, 0x2, 0x4, 0x2, 0x5, 0x2, 0x6, 0x2, 0x0, 0x2b, 0x0, 0x9, 0x8, 0x3,
                    0x4, 0x3, 0x3, 0x3, 0x2, 0x3, 0x1, 0x0, 0x2d, 0x0, 0x2, 0x1, 0x1, 0x0, 0x33,
                    0x0, 0x26, 0x0, 0x24, 0x0, 0x1d, 0x0, 0x20, 0x37, 0x98, 0x48, 0x7f, 0x2f, 0xbc,
                    0x86, 0xf9, 0xb8, 0x2, 0xcd, 0x31, 0xf0, 0x4, 0x30, 0xa9, 0x2f, 0x29, 0x61,
                    0xac, 0xec, 0xc9, 0x2f, 0xf7, 0x45, 0xad, 0xd9, 0x67, 0x7, 0x14, 0x62, 0x1,
                    0x0, 0x15, 0x0, 0xb6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                    0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
                ],
                pcap: "curl.pcap",
                expected_ja3_str: "771,4866-4867-4865-49196-49200-159-52393-52392-52394-49195-49199-158-49188-49192-107-49187-49191-103-49162-49172-57-49161-49171-51-157-156-61-60-53-47-255,0-11-10-13172-16-22-23-13-43-45-51-21,29-23-30-25-24,0-1-2",
                expected_ja3_hash: "456523fc94726331a4d5a2e1d40b2cd7",
            },
        ];
        for test_case in test_cases {
            let ext = Extensions::new();
            ext.insert(SecureTransport::with_client_hello(
                parse_client_hello(&test_case.client_hello).expect(test_case.pcap),
            ));

            let ja3 = Ja3::compute(&ext).expect(test_case.pcap);

            assert_eq!(
                test_case.expected_ja3_str,
                format!("{ja3}"),
                "pcap: {}",
                test_case.pcap,
            );

            assert_eq!(
                test_case.expected_ja3_hash,
                format!("{ja3:x}"),
                "pcap: {}",
                test_case.pcap,
            );
        }
    }
}