macaroon 0.3.0

Fully functional implementation of macaroons in Rust
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

// Examples from libmacaroons reference implementation README:
// https://github.com/rescrv/libmacaroons

use base64;
use macaroon::{ByteString, Caveat, Format, Macaroon, MacaroonKey, Verifier};

fn bytes_to_hex(bytes: &[u8]) -> String {
    bytes
        .iter()
        .map(|b| format!("{:02x}", b).to_string())
        .collect::<Vec<String>>()
        .join("")
}

#[test]
fn creating_macaroons() {
    let root_key = MacaroonKey::generate(b"this is our super secret key; only we should know it");
    let mac = Macaroon::create(
        Some("http://mybank/".into()),
        &root_key,
        "we used our secret key".into(),
    )
    .unwrap();

    assert_eq!(mac.identifier(), "we used our secret key".into());
    assert_eq!(mac.location(), Some("http://mybank/".into()));

    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "e3d9e02908526c4c0039ae15114115d97fdd68bf2ba379b342aaf0f617d0552f"
    );

    let b64_standard = "MDAxY2xvY2F0aW9uIGh0dHA6Ly9teWJhbmsvCjAwMjZpZGVudGlmaWVyIHdlIHVzZWQgb3VyIHNlY3JldCBrZXkKMDAyZnNpZ25hdHVyZSDj2eApCFJsTAA5rhURQRXZf91ovyujebNCqvD2F9BVLwo";
    let b64_url_safe =
        base64::encode_config(base64::decode(b64_standard).unwrap(), base64::URL_SAFE);
    assert_eq!(mac.serialize(Format::V1).unwrap(), b64_url_safe);
}

#[test]
fn adding_caveats() {
    let root_key = MacaroonKey::generate(b"this is our super secret key; only we should know it");
    let mut mac = Macaroon::create(
        Some("http://mybank".into()),
        &root_key,
        "we used our secret key".into(),
    )
    .unwrap();
    mac.add_first_party_caveat("account = 3735928559".into());
    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "1efe4763f290dbce0c1d08477367e11f4eee456a64933cf662d79772dbb82128"
    );

    mac.add_first_party_caveat("time < 2020-01-01T00:00".into());
    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "b5f06c8c8ef92f6c82c6ff282cd1f8bd1849301d09a2db634ba182536a611c49"
    );

    mac.add_first_party_caveat("email = alice@example.org".into());
    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "ddf553e46083e55b8d71ab822be3d8fcf21d6bf19c40d617bb9fb438934474b6"
    );

    // serialize and deserialize using V1
    let mac2 = Macaroon::deserialize(&mac.serialize(Format::V1).unwrap()).unwrap();
    assert_eq!(
        bytes_to_hex(mac2.signature().as_ref()),
        "ddf553e46083e55b8d71ab822be3d8fcf21d6bf19c40d617bb9fb438934474b6"
    );
}

// this doesn't actually implement datetime checking, because we don't have 'chrono' or similar
// pulled in. Instead, just doing string/byte comparison, which should just about work for these
// test cases.
fn check_time(caveat: &ByteString) -> bool {
    let caveat: &[u8] = caveat.as_ref();
    if !caveat.starts_with(b"time < ") {
        return false;
    }
    // around time the doc was written, between 2014 and 2020
    let now = b"2018-01-01T00:00";
    if caveat.len() != now.len() + 7 {
        return false;
    }
    let when = &caveat[7..];
    String::from_utf8_lossy(now) < String::from_utf8_lossy(when)
}

#[test]
fn test_check_time() {
    assert_eq!(check_time(&"time < 2020-01-01T00:00".into()), true);
    assert_eq!(check_time(&"time < 2014-01-01T00:00".into()), false);
    assert_eq!(check_time(&"account = 3735928559".into()), false);
}

#[test]
fn verifying_macaroons() {
    let key = MacaroonKey::generate(b"this is our super secret key; only we should know it");
    let mut mac = Macaroon::create(
        Some("http://mybank/".into()),
        &key,
        "we used our secret key".into(),
    )
    .unwrap();
    mac.add_first_party_caveat("account = 3735928559".into());
    mac.add_first_party_caveat("time < 2020-01-01T00:00".into());
    mac.add_first_party_caveat("email = alice@example.org".into());

    let mut ver = Verifier::default();
    assert!(ver.verify(&mac, &key, Default::default()).is_err());
    ver.satisfy_exact("account = 3735928559".into());
    ver.satisfy_exact("email = alice@example.org".into());
    ver.satisfy_exact("IP = 127.0.0.1".into());
    ver.satisfy_exact("browser = Chrome".into());
    ver.satisfy_exact("action = deposit".into());
    ver.satisfy_general(check_time);

    assert!(ver.verify(&mac, &key, Default::default()).is_ok());

    // additional caveat which we are prepared for
    let mut mac_action = mac.clone();
    mac_action.add_first_party_caveat("action = deposit".into());
    assert!(ver.verify(&mac_action, &key, Default::default()).is_ok());

    // additional caveat which we are not prepared for
    let mut mac_os = mac.clone();
    mac_os.add_first_party_caveat("OS = Windows XP".into());
    assert!(ver.verify(&mac_os, &key, Default::default()).is_err());

    // wrong secret key used in verification
    let wrong_key = MacaroonKey::generate(b"this is not the secret we were looking for");
    assert!(ver.verify(&mac, &wrong_key, Default::default()).is_err());

    // "Incompetent hackers trying to change the signature"
    let b64_standard = "MDAxY2xvY2F0aW9uIGh0dHA6Ly9teWJhbmsvCjAwMjZpZGVudGlmaWVyIHdlIHVzZWQgb3VyIHNlY3JldCBrZXkKMDAxZGNpZCBhY2NvdW50ID0gMzczNTkyODU1OQowMDIwY2lkIHRpbWUgPCAyMDIwLTAxLTAxVDAwOjAwCjAwMjJjaWQgZW1haWwgPSBhbGljZUBleGFtcGxlLm9yZwowMDJmc2lnbmF0dXJlID8f19FL+bkC9p/aoMmIecC7GxdOcLVyUnrv6lJMM7NSCg==";
    let bad_mac = Macaroon::deserialize(b64_standard).unwrap();
    assert_eq!(mac.location(), bad_mac.location());
    assert_eq!(mac.identifier(), bad_mac.identifier());
    assert_eq!(mac.caveats(), bad_mac.caveats());
    assert_ne!(mac.signature(), bad_mac.signature());
    assert!(ver.verify(&bad_mac, &key, Default::default()).is_err());
}

#[test]
fn third_party_macaroons() {
    let key = MacaroonKey::generate(
        b"this is a different super-secret key; never use the same secret twice",
    );
    let mut mac = Macaroon::create(
        Some("http://mybank/".into()),
        &key,
        "we used our other secret key".into(),
    )
    .unwrap();
    mac.add_first_party_caveat("account = 3735928559".into());
    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "1434e674ad84fdfdc9bc1aa00785325c8b6d57341fc7ce200ba4680c80786dda"
    );

    let caveat_key = MacaroonKey::generate(b"4; guaranteed random by a fair toss of the dice");
    mac.add_third_party_caveat(
        "http://auth.mybank/".into(),
        &caveat_key,
        "this was how we remind auth of key/pred".into(),
    );
    // In the example, libsodium none generation is overriden, so the verifier_id is always the
    // same:
    // "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA027FAuBYhtHwJ58FX6UlVNFtFsGxQHS7uD_w_dedwv4Jjw7UorCREw5rXbRqIKhr"
    // We don't do that here, so can't actually verify that the signatures match perfectly.
    match &mac.third_party_caveats()[0] {
        Caveat::FirstParty(_) => assert!(false),
        Caveat::ThirdParty(tp) => {
            assert_eq!(tp.location(), "http://auth.mybank/");
            assert_eq!(tp.id(), "this was how we remind auth of key/pred".into());
            /*
            assert_eq!(tp.verifier_id(),
                base64::decode_config("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA027FAuBYhtHwJ58FX6UlVNFtFsGxQHS7uD_w_dedwv4Jjw7UorCREw5rXbRqIKhr", base64::URL_SAFE).unwrap().into(),
            );
            */
        }
    };
    /*
    assert_eq!(
        bytes_to_hex(mac.signature().as_ref()),
        "d27db2fd1f22760e4c3dae8137e2d8fc1df6c0741c18aed4b97256bf78d1f55c"
    );
    */

    let mut discharge_mac = Macaroon::create(
        Some("http://auth.mybank/".into()),
        &caveat_key,
        "this was how we remind auth of key/pred".into(),
    )
    .unwrap();
    discharge_mac.add_first_party_caveat("time < 2020-01-01T00:00".into());
    assert_eq!(
        bytes_to_hex(discharge_mac.signature().as_ref()),
        "2ed1049876e9d5840950274b579b0770317df54d338d9d3039c7c67d0d91d63c"
    );

    let mut bound_mac = discharge_mac.clone();
    mac.bind(&mut bound_mac);
    /*
    assert_eq!(
        bytes_to_hex(discharge_mac.signature().as_ref()),
        "d115ef1c133b1126978d5ab27f69d99ba9d0468cd6c1b7e47b8c1c59019cb019"
    );
    */

    let mut ver = Verifier::default();
    ver.satisfy_exact("account = 3735928559".into());
    ver.satisfy_exact("time < 2020-01-01T00:00".into());
    assert!(ver.verify(&mac, &key, vec![discharge_mac]).is_err());
    assert!(ver.verify(&mac, &key, vec![bound_mac]).is_ok());
}