1use hmac::{Hmac, KeyInit, Mac};
2use sha2::Sha256;
3use std::fmt;
4
5use crate::Timestamp;
6
7#[derive(Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
9pub struct SensitiveString(String);
10
11impl fmt::Display for SensitiveString {
12 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
13 write!(f, "REDACTED")
14 }
15}
16
17impl fmt::Debug for SensitiveString {
18 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
19 write!(f, "{:?}", "REDACTED")
20 }
21}
22
23impl std::ops::Deref for SensitiveString {
24 type Target = str;
25 fn deref(&self) -> &Self::Target {
26 &self.0
27 }
28}
29
30impl From<String> for SensitiveString {
31 fn from(s: String) -> Self {
32 SensitiveString(s)
33 }
34}
35
36impl From<&str> for SensitiveString {
37 fn from(s: &str) -> Self {
38 SensitiveString(s.to_string())
39 }
40}
41
42impl AsRef<str> for SensitiveString {
43 fn as_ref(&self) -> &str {
44 &self.0
45 }
46}
47
48impl SensitiveString {
49 pub fn expose(&self) -> &str {
51 &self.0
52 }
53}
54
55pub fn hmac_sha256(key: impl AsRef<[u8]>, message: impl AsRef<[u8]>) -> String {
71 let mut mac = Hmac::<Sha256>::new_from_slice(key.as_ref()).unwrap();
72 mac.update(message.as_ref());
73 let mac = mac.finalize().into_bytes();
74 hex::encode(mac)
75}
76
77type Timer = fn() -> Timestamp;
78
79#[derive(Debug)]
81pub struct Signer {
82 api_key: SensitiveString,
83 api_secret: SensitiveString,
84 recv_window: Timestamp,
86 timer: Timer,
87}
88
89impl Signer {
90 pub fn new(
92 api_key: SensitiveString,
93 api_secret: SensitiveString,
94 recv_window: Timestamp,
95 timer: Option<Timer>,
96 ) -> Self {
97 Self {
98 api_key,
99 api_secret,
100 recv_window,
101 timer: timer.unwrap_or(timestamp),
102 }
103 }
104
105 pub fn sign(&self, s: &str) -> (String, String) {
109 let timestamp = (self.timer)();
110 (self.sign_at(s, timestamp), timestamp.to_string())
111 }
112
113 pub fn sign_at(&self, s: &str, timestamp: Timestamp) -> String {
116 let api_key = self.api_key.expose();
117 let api_secret = self.api_secret.expose();
118 let message = format!("{timestamp}{}{}{s}", api_key, self.recv_window);
119
120 hmac_sha256(api_secret, message)
121 }
122}
123
124pub fn timestamp() -> Timestamp {
126 std::time::UNIX_EPOCH.elapsed().unwrap().as_millis() as Timestamp
127}
128
129pub fn create_stream_signature(expires: Timestamp, api_secret: SensitiveString) -> String {
131 let api_secret = api_secret.expose();
132 let message = format!("GET/realtime{expires}");
133 hmac_sha256(api_secret, message)
134}
135
136#[cfg(test)]
137mod tests {
138 use super::*;
139
140 #[test]
141 fn sign_get_request() {
142 let api_key = SensitiveString("API_KEY".to_string());
143 let api_secret = SensitiveString("API_SECRET".to_string());
144 let recv_window = 5000;
145 let signer = Signer::new(api_key, api_secret, recv_window, Some(|| 1658384314791));
146 let query = "category=option&symbol=BTC-29JUL22-25000-C";
147 let expected = "8b050bb7b9d53a91c42e16a7aa94a485d7aad9c7d08023a6249a184331a52ae7";
148
149 let (signature, timestamp) = signer.sign(query);
150
151 assert_eq!(signature, expected);
152 assert_eq!(timestamp.len(), 13);
153 }
154
155 #[test]
156 fn sign_post_request() {
157 let api_key = SensitiveString("API_KEY".to_string());
158 let api_secret = SensitiveString("API_SECRET".to_string());
159 let recv_window = 5000;
160 let signer = Signer::new(api_key, api_secret, recv_window, Some(|| 1658385579423));
161 let json = r#"{"category":"option"}"#;
162 let expected = "1b9b318f05208c9113f2612b2a6d76ca29427e6d8148937c03d6505f8c00804c";
163
164 let (signature, timestamp) = signer.sign(json);
165
166 assert_eq!(signature, expected);
167 assert_eq!(timestamp.len(), 13);
168 }
169
170 #[test]
171 fn sign_at_matches_sign_with_the_same_time() {
172 let signer = Signer::new(
173 "API_KEY".into(),
174 "API_SECRET".into(),
175 5000,
176 Some(|| 1658384314791),
177 );
178 let query = "category=option&symbol=BTC-29JUL22-25000-C";
179
180 let (signature, _) = signer.sign(query);
181
182 assert_eq!(signer.sign_at(query, 1658384314791), signature);
183 }
184}