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
|
use std::collections::HashMap;
use chrono::{DateTime, Duration, NaiveDateTime, Utc};
use hmac::Mac;
use hyper::{Body, Method, Request};
use sha2::{Digest, Sha256};
use garage_table::*;
use garage_util::data::Hash;
use garage_model::garage::Garage;
use garage_model::key_table::*;
use super::LONG_DATETIME;
use super::{compute_scope, signing_hmac};
use crate::encoding::uri_encode;
use crate::signature::error::*;
pub async fn check_payload_signature(
garage: &Garage,
service: &str,
request: &Request<Body>,
) -> Result<(Option<Key>, Option<Hash>), Error> {
let mut headers = HashMap::new();
for (key, val) in request.headers() {
headers.insert(key.to_string(), val.to_str()?.to_string());
}
if let Some(query) = request.uri().query() {
trace!("got query: {}", query);
let query_pairs = url::form_urlencoded::parse(query.as_bytes());
for (key, val) in query_pairs {
trace!("query pair: `{}` = `{}`", key, val);
headers.insert(key.to_lowercase(), val.to_string());
}
}
let authorization = if let Some(authorization) = headers.get("authorization") {
parse_authorization(authorization, &headers)?
} else if let Some(algorithm) = headers.get("x-amz-algorithm") {
parse_query_authorization(algorithm, &headers)?
} else {
let content_sha256 = headers.get("x-amz-content-sha256");
if let Some(content_sha256) = content_sha256.filter(|c| "UNSIGNED-PAYLOAD" != c.as_str()) {
let sha256 = hex::decode(content_sha256)
.ok()
.and_then(|bytes| Hash::try_from(&bytes))
.ok_or_bad_request("Invalid content sha256 hash")?;
return Ok((None, Some(sha256)));
} else {
return Ok((None, None));
}
};
let canonical_request = canonical_request(
request.method(),
request.uri(),
&headers,
&authorization.signed_headers,
&authorization.content_sha256,
service != "s3",
);
let (_, scope) = parse_credential(&authorization.credential)?;
let string_to_sign = string_to_sign(&authorization.date, &scope, &canonical_request);
trace!("canonical request:\n{}", canonical_request);
trace!("string to sign:\n{}", string_to_sign);
let key = verify_v4(
garage,
service,
&authorization.credential,
&authorization.date,
&authorization.signature,
string_to_sign.as_bytes(),
)
.await?;
let content_sha256 = if authorization.content_sha256 == "UNSIGNED-PAYLOAD" {
None
} else if authorization.content_sha256 == "STREAMING-AWS4-HMAC-SHA256-PAYLOAD" {
let bytes = hex::decode(authorization.signature).ok_or_bad_request("Invalid signature")?;
Some(Hash::try_from(&bytes).ok_or_bad_request("Invalid signature")?)
} else {
let bytes = hex::decode(authorization.content_sha256)
.ok_or_bad_request("Invalid content sha256 hash")?;
Some(Hash::try_from(&bytes).ok_or_bad_request("Invalid content sha256 hash")?)
};
Ok((Some(key), content_sha256))
}
struct Authorization {
credential: String,
signed_headers: String,
signature: String,
content_sha256: String,
date: DateTime<Utc>,
}
fn parse_authorization(
authorization: &str,
headers: &HashMap<String, String>,
) -> Result<Authorization, Error> {
let first_space = authorization
.find(' ')
.ok_or_bad_request("Authorization field to short")?;
let (auth_kind, rest) = authorization.split_at(first_space);
if auth_kind != "AWS4-HMAC-SHA256" {
return Err(Error::bad_request("Unsupported authorization method"));
}
let mut auth_params = HashMap::new();
for auth_part in rest.split(',') {
let auth_part = auth_part.trim();
let eq = auth_part
.find('=')
.ok_or_bad_request("Field without value in authorization header")?;
let (key, value) = auth_part.split_at(eq);
auth_params.insert(key.to_string(), value.trim_start_matches('=').to_string());
}
let cred = auth_params
.get("Credential")
.ok_or_bad_request("Could not find Credential in Authorization field")?;
let content_sha256 = headers
.get("x-amz-content-sha256")
.ok_or_bad_request("Missing X-Amz-Content-Sha256 field")?;
let date = headers
.get("x-amz-date")
.ok_or_bad_request("Missing X-Amz-Date field")
.map_err(Error::from)
.and_then(|d| parse_date(d))?;
if Utc::now() - date > Duration::hours(24) {
return Err(Error::bad_request("Date is too old".to_string()));
}
let auth = Authorization {
credential: cred.to_string(),
signed_headers: auth_params
.get("SignedHeaders")
.ok_or_bad_request("Could not find SignedHeaders in Authorization field")?
.to_string(),
signature: auth_params
.get("Signature")
.ok_or_bad_request("Could not find Signature in Authorization field")?
.to_string(),
content_sha256: content_sha256.to_string(),
date,
};
Ok(auth)
}
fn parse_query_authorization(
algorithm: &str,
headers: &HashMap<String, String>,
) -> Result<Authorization, Error> {
if algorithm != "AWS4-HMAC-SHA256" {
return Err(Error::bad_request(
"Unsupported authorization method".to_string(),
));
}
let cred = headers
.get("x-amz-credential")
.ok_or_bad_request("X-Amz-Credential not found in query parameters")?;
let signed_headers = headers
.get("x-amz-signedheaders")
.ok_or_bad_request("X-Amz-SignedHeaders not found in query parameters")?;
let signature = headers
.get("x-amz-signature")
.ok_or_bad_request("X-Amz-Signature not found in query parameters")?;
let content_sha256 = headers
.get("x-amz-content-sha256")
.map(|x| x.as_str())
.unwrap_or("UNSIGNED-PAYLOAD");
let duration = headers
.get("x-amz-expires")
.ok_or_bad_request("X-Amz-Expires not found in query parameters")?
.parse()
.map_err(|_| Error::bad_request("X-Amz-Expires is not a number".to_string()))?;
if duration > 7 * 24 * 3600 {
return Err(Error::bad_request(
"X-Amz-Exprires may not exceed a week".to_string(),
));
}
let date = headers
.get("x-amz-date")
.ok_or_bad_request("Missing X-Amz-Date field")
.map_err(Error::from)
.and_then(|d| parse_date(d))?;
if Utc::now() - date > Duration::seconds(duration) {
return Err(Error::bad_request("Date is too old".to_string()));
}
Ok(Authorization {
credential: cred.to_string(),
signed_headers: signed_headers.to_string(),
signature: signature.to_string(),
content_sha256: content_sha256.to_string(),
date,
})
}
fn parse_credential(cred: &str) -> Result<(String, String), Error> {
let first_slash = cred
.find('/')
.ok_or_bad_request("Credentials does not contain / in authorization field")?;
let (key_id, scope) = cred.split_at(first_slash);
Ok((
key_id.to_string(),
scope.trim_start_matches('/').to_string(),
))
}
pub fn string_to_sign(datetime: &DateTime<Utc>, scope_string: &str, canonical_req: &str) -> String {
let mut hasher = Sha256::default();
hasher.update(canonical_req.as_bytes());
[
"AWS4-HMAC-SHA256",
&datetime.format(LONG_DATETIME).to_string(),
scope_string,
&hex::encode(hasher.finalize().as_slice()),
]
.join("\n")
}
pub fn canonical_request(
method: &Method,
uri: &hyper::Uri,
headers: &HashMap<String, String>,
signed_headers: &str,
content_sha256: &str,
double_encode_path: bool,
) -> String {
let path: std::borrow::Cow<str> = if double_encode_path {
uri_encode(uri.path(), false).into()
} else {
uri.path().into()
};
[
method.as_str(),
&path,
&canonical_query_string(uri),
&canonical_header_string(headers, signed_headers),
"",
signed_headers,
content_sha256,
]
.join("\n")
}
fn canonical_header_string(headers: &HashMap<String, String>, signed_headers: &str) -> String {
let signed_headers_vec = signed_headers.split(';').collect::<Vec<_>>();
let mut items = headers
.iter()
.filter(|(key, _)| signed_headers_vec.contains(&key.as_str()))
.collect::<Vec<_>>();
items.sort_by(|(k1, _), (k2, _)| k1.cmp(k2));
items
.iter()
.map(|(key, value)| key.to_lowercase() + ":" + value.trim())
.collect::<Vec<_>>()
.join("\n")
}
fn canonical_query_string(uri: &hyper::Uri) -> String {
if let Some(query) = uri.query() {
let query_pairs = url::form_urlencoded::parse(query.as_bytes());
let mut items = query_pairs
.filter(|(key, _)| key != "X-Amz-Signature")
.map(|(key, value)| uri_encode(&key, true) + "=" + &uri_encode(&value, true))
.collect::<Vec<_>>();
items.sort();
items.join("&")
} else {
"".to_string()
}
}
pub fn parse_date(date: &str) -> Result<DateTime<Utc>, Error> {
let date: NaiveDateTime =
NaiveDateTime::parse_from_str(date, LONG_DATETIME).ok_or_bad_request("Invalid date")?;
Ok(DateTime::from_utc(date, Utc))
}
pub async fn verify_v4(
garage: &Garage,
service: &str,
credential: &str,
date: &DateTime<Utc>,
signature: &str,
payload: &[u8],
) -> Result<Key, Error> {
let (key_id, scope) = parse_credential(credential)?;
let scope_expected = compute_scope(date, &garage.config.s3_api.s3_region, service);
if scope != scope_expected {
return Err(Error::AuthorizationHeaderMalformed(scope.to_string()));
}
let key = garage
.key_table
.get(&EmptyKey, &key_id)
.await?
.filter(|k| !k.state.is_deleted())
.ok_or_else(|| Error::forbidden(format!("No such key: {}", &key_id)))?;
let key_p = key.params().unwrap();
let mut hmac = signing_hmac(
date,
&key_p.secret_key,
&garage.config.s3_api.s3_region,
service,
)
.ok_or_internal_error("Unable to build signing HMAC")?;
hmac.update(payload);
let our_signature = hex::encode(hmac.finalize().into_bytes());
if signature != our_signature {
return Err(Error::forbidden("Invalid signature".to_string()));
}
Ok(key)
}
|
