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
|
//! network status documents: shared between votes, consensuses and md consensuses
use super::*;
use crate::types;
use authcert::DirAuthKeyCert;
mod ns_per_flavour_macros;
pub use ns_per_flavour_macros::*;
ns_per_flavour_macros::ns_export_flavoured_types! {
NetworkStatus, NetworkStatusSigned, Router,
}
/// `network-status-version` version value
#[derive(Debug, Clone, Copy, Eq, PartialEq, strum::EnumString, strum::Display)]
#[non_exhaustive]
pub enum NdaNetworkStatusVersion {
/// The currently supported version, `3`
#[strum(serialize = "3")]
V3,
}
impl NormalItemArgument for NdaNetworkStatusVersion {}
/// `params` value
#[derive(Clone, Debug, Default, Deftly)]
#[derive_deftly(ItemValueParseable)]
#[non_exhaustive]
pub struct NdiParams {
// Not implemented.
}
/// `r` sub-document
#[derive(Deftly, Clone, Debug)]
#[derive_deftly(ItemValueParseable)]
#[non_exhaustive]
pub struct NdiR {
/// nickname
pub nickname: types::Nickname,
/// identity
pub identity: String, // In non-demo, use a better type
}
/// `directory-signature` value
#[derive(Debug, Clone)]
#[non_exhaustive]
pub enum NdiDirectorySignature {
/// Known "hash function" name
Known {
/// H(KP\_auth\_id\_rsa)
h_kp_auth_id_rsa: pk::rsa::RsaIdentity,
/// H(kp\_auth\_sign\_rsa)
h_kp_auth_sign_rsa: pk::rsa::RsaIdentity,
/// RSA signature
rsa_signature: Vec<u8>,
/// Hash of the covered text
hash: DirectorySignatureHash,
},
/// Unknown "hash function" name
///
/// TODO torspec#350;
/// might have been an unknown algorithm, or might be invalid hex, or soemthing.
Unknown {},
}
define_derive_deftly! {
/// Ad-hoc derives for [`DirectorySignatureHash`] impls, avoiding copypasta bugs
DirectorySignatureHash expect items, beta_deftly:
impl $ttype {
/// If `algorithm` is an algorithm name, calculate the hash
fn parse_keyword_and_hash(algorithm: &str, body: &SignatureHashInputs) -> Option<Self> {
Some(match algorithm {
$(
${concat ${kebab_case $vname}} => {
let mut h = tor_llcrypto::d::$vname::new();
h.update(body.body().body());
h.update(body.signature_item_kw_spc);
Self::$vname(h.finalize().into())
}
)
_ => return None,
})
}
fn hash_slice_for_verification(&self) -> &[u8] {
match self { $(
$vpat => f_0,
) }
}
}
}
/// `directory-signature` hash algorithm argument
#[derive(Clone, Copy, Debug, Eq, PartialEq, strum::EnumString, Deftly)]
#[derive_deftly(DirectorySignatureHash)]
#[non_exhaustive]
pub enum DirectorySignatureHash {
/// SHA-1
Sha1([u8; 20]),
/// SHA-256
Sha256([u8; 32]),
}
/// Unsupported `vote-status` value
///
/// This message is not normally actually shown since our `ErrorProblem` doesn't contain it.
#[derive(Clone, Debug, Error)]
#[non_exhaustive]
#[error("invalid value for vote-status in network status document")]
pub struct InvalidNetworkStatusVoteStatus {}
impl SignatureItemParseable for NdiDirectorySignature {
// TODO torspec#350. That's why this manual impl is needed
fn from_unparsed_and_body<'s>(
mut input: UnparsedItem<'s>,
document_body: &SignatureHashInputs<'_>,
) -> Result<Self, EP> {
let object = input.object();
let args = input.args_mut();
let maybe_algorithm = args.clone().next().ok_or(EP::MissingArgument {
field: "algorithm/h_kp_auth_id_rsa",
})?;
let hash = if let Some(hash) =
DirectorySignatureHash::parse_keyword_and_hash(maybe_algorithm, document_body)
{
let _: &str = args.next().expect("we just peeked");
hash
} else if maybe_algorithm
.find(|c: char| !c.is_ascii_hexdigit())
.is_some()
{
// Not hex. Must be some unknown algorithm.
// There might be Object, but don't worry if not.
return Ok(NdiDirectorySignature::Unknown {});
} else {
DirectorySignatureHash::parse_keyword_and_hash("sha1", document_body)
.expect("sha1 is not valid?")
};
let rsa_signature = object.ok_or(EP::MissingObject)?.decode_data()?;
let mut fingerprint_arg = |field: &'static str| {
(|| {
args.next()
.ok_or(AE::Missing)?
.parse::<types::Fingerprint>()
.map_err(|_e| AE::Invalid)
.map(pk::rsa::RsaIdentity::from)
})()
.map_err(args.error_handler(field))
};
Ok(NdiDirectorySignature::Known {
rsa_signature,
h_kp_auth_id_rsa: fingerprint_arg("h_kp_auth_id_rsa")?,
h_kp_auth_sign_rsa: fingerprint_arg("h_kp_auth_sign_rsa")?,
hash,
})
}
}
/// Meat of the verification functions for network documents
///
/// Checks that at least `threshold` members of `trusted`
/// have signed this document (in `signatures`),
/// via some cert(s) in `certs`.
///
/// Does not check validity time.
fn verify_general_timeless(
signatures: &[NdiDirectorySignature],
trusted: &[pk::rsa::RsaIdentity],
certs: &[&DirAuthKeyCert],
threshold: usize,
) -> Result<(), VF> {
let mut ok = HashSet::<pk::rsa::RsaIdentity>::new();
for sig in signatures {
match sig {
NdiDirectorySignature::Known {
hash,
h_kp_auth_id_rsa,
h_kp_auth_sign_rsa,
rsa_signature,
} => {
let Some(authority) = ({
trusted
.iter()
.find(|trusted| **trusted == *h_kp_auth_id_rsa)
}) else {
// unknown kp_auth_id_rsa, ignore it
continue;
};
let Some(cert) = ({
certs
.iter()
.find(|cert| cert.dir_signing_key.to_rsa_identity() == *h_kp_auth_sign_rsa)
}) else {
// no cert for this kp_auth_sign_rsa, ignore it
continue;
};
let h = hash.hash_slice_for_verification();
let () = cert.dir_signing_key.verify(h, rsa_signature)?;
ok.insert(*authority);
}
NdiDirectorySignature::Unknown { .. } => {}
}
}
if ok.len() < threshold {
return Err(VF::InsufficientTrustedSigners);
}
Ok(())
}
|
