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
363
364
365
use crate::error::{X509Error, X509Result};
use crate::extensions::*;
use crate::time::ASN1Time;
use crate::utils::format_serial;
use crate::x509::{
    parse_serial, parse_signature_value, AlgorithmIdentifier, ReasonCode, X509Name, X509Version,
};

#[cfg(feature = "verify")]
use crate::verify::verify_signature;
#[cfg(feature = "verify")]
use crate::x509::SubjectPublicKeyInfo;
use asn1_rs::{BitString, FromDer};
use der_parser::ber::Tag;
use der_parser::der::*;
use der_parser::num_bigint::BigUint;
use der_parser::oid::Oid;
use nom::combinator::{all_consuming, complete, map, opt};
use nom::multi::many0;
use nom::Offset;
use oid_registry::*;
use std::collections::HashMap;

/// An X.509 v2 Certificate Revocation List (CRL).
///
/// X.509 v2 CRLs are defined in [RFC5280](https://tools.ietf.org/html/rfc5280).
///
/// # Example
///
/// To parse a CRL and print information about revoked certificates:
///
/// ```rust
/// use x509_parser::prelude::FromDer;
/// use x509_parser::revocation_list::CertificateRevocationList;
///
/// # static DER: &'static [u8] = include_bytes!("../assets/example.crl");
/// #
/// # fn main() {
/// let res = CertificateRevocationList::from_der(DER);
/// match res {
///     Ok((_rem, crl)) => {
///         for revoked in crl.iter_revoked_certificates() {
///             println!("Revoked certificate serial: {}", revoked.raw_serial_as_string());
///             println!("  Reason: {}", revoked.reason_code().unwrap_or_default().1);
///         }
///     },
///     _ => panic!("CRL parsing failed: {:?}", res),
/// }
/// # }
/// ```
#[derive(Clone, Debug)]
pub struct CertificateRevocationList<'a> {
    pub tbs_cert_list: TbsCertList<'a>,
    pub signature_algorithm: AlgorithmIdentifier<'a>,
    pub signature_value: BitString<'a>,
}

impl<'a> CertificateRevocationList<'a> {
    /// Get the version of the encoded certificate
    pub fn version(&self) -> Option<X509Version> {
        self.tbs_cert_list.version
    }

    /// Get the certificate issuer.
    #[inline]
    pub fn issuer(&self) -> &X509Name {
        &self.tbs_cert_list.issuer
    }

    /// Get the date and time of the last (this) update.
    #[inline]
    pub fn last_update(&self) -> ASN1Time {
        self.tbs_cert_list.this_update
    }

    /// Get the date and time of the next update, if present.
    #[inline]
    pub fn next_update(&self) -> Option<ASN1Time> {
        self.tbs_cert_list.next_update
    }

    /// Return an iterator over the `RevokedCertificate` objects
    pub fn iter_revoked_certificates(&self) -> impl Iterator<Item = &RevokedCertificate<'a>> {
        self.tbs_cert_list.revoked_certificates.iter()
    }

    /// Get the CRL extensions.
    #[inline]
    pub fn extensions(&self) -> &[X509Extension] {
        &self.tbs_cert_list.extensions
    }

    /// Get the CRL number, if present
    ///
    /// Note that the returned value is a `BigUint`, because of the following RFC specification:
    /// <pre>
    /// Given the requirements above, CRL numbers can be expected to contain long integers.  CRL
    /// verifiers MUST be able to handle CRLNumber values up to 20 octets.  Conformant CRL issuers
    /// MUST NOT use CRLNumber values longer than 20 octets.
    /// </pre>
    pub fn crl_number(&self) -> Option<&BigUint> {
        self.extensions()
            .iter()
            .find(|&ext| ext.oid == OID_X509_EXT_CRL_NUMBER)
            .and_then(|ext| match ext.parsed_extension {
                ParsedExtension::CRLNumber(ref num) => Some(num),
                _ => None,
            })
    }

    /// Verify the cryptographic signature of this certificate revocation list
    ///
    /// `public_key` is the public key of the **signer**.
    ///
    /// Not all algorithms are supported, this function is limited to what `ring` supports.
    #[cfg(feature = "verify")]
    #[cfg_attr(docsrs, doc(cfg(feature = "verify")))]
    pub fn verify_signature(&self, public_key: &SubjectPublicKeyInfo) -> Result<(), X509Error> {
        verify_signature(
            public_key,
            &self.signature_algorithm,
            &self.signature_value,
            self.tbs_cert_list.raw,
        )
    }
}

/// <pre>
/// CertificateList  ::=  SEQUENCE  {
///      tbsCertList          TBSCertList,
///      signatureAlgorithm   AlgorithmIdentifier,
///      signatureValue       BIT STRING  }
/// </pre>
impl<'a> FromDer<'a, X509Error> for CertificateRevocationList<'a> {
    fn from_der(i: &'a [u8]) -> X509Result<Self> {
        parse_der_sequence_defined_g(|i, _| {
            let (i, tbs_cert_list) = TbsCertList::from_der(i)?;
            let (i, signature_algorithm) = AlgorithmIdentifier::from_der(i)?;
            let (i, signature_value) = parse_signature_value(i)?;
            let crl = CertificateRevocationList {
                tbs_cert_list,
                signature_algorithm,
                signature_value,
            };
            Ok((i, crl))
        })(i)
    }
}

/// The sequence TBSCertList contains information about the certificates that have
/// been revoked by the CA that issued the CRL.
///
/// RFC5280 definition:
///
/// <pre>
/// TBSCertList  ::=  SEQUENCE  {
///         version                 Version OPTIONAL,
///                                      -- if present, MUST be v2
///         signature               AlgorithmIdentifier,
///         issuer                  Name,
///         thisUpdate              Time,
///         nextUpdate              Time OPTIONAL,
///         revokedCertificates     SEQUENCE OF SEQUENCE  {
///             userCertificate         CertificateSerialNumber,
///             revocationDate          Time,
///             crlEntryExtensions      Extensions OPTIONAL
///                                      -- if present, version MUST be v2
///                                   } OPTIONAL,
///         crlExtensions           [0]  EXPLICIT Extensions OPTIONAL
///                                      -- if present, version MUST be v2
///                             }
/// </pre>
#[derive(Clone, Debug, PartialEq)]
pub struct TbsCertList<'a> {
    pub version: Option<X509Version>,
    pub signature: AlgorithmIdentifier<'a>,
    pub issuer: X509Name<'a>,
    pub this_update: ASN1Time,
    pub next_update: Option<ASN1Time>,
    pub revoked_certificates: Vec<RevokedCertificate<'a>>,
    extensions: Vec<X509Extension<'a>>,
    pub(crate) raw: &'a [u8],
}

impl<'a> TbsCertList<'a> {
    /// Returns the certificate extensions
    #[inline]
    pub fn extensions(&self) -> &[X509Extension] {
        &self.extensions
    }

    /// Returns an iterator over the certificate extensions
    #[inline]
    pub fn iter_extensions(&self) -> impl Iterator<Item = &X509Extension> {
        self.extensions.iter()
    }

    /// Searches for an extension with the given `Oid`.
    ///
    /// Note: if there are several extensions with the same `Oid`, the first one is returned.
    pub fn find_extension(&self, oid: &Oid) -> Option<&X509Extension> {
        self.extensions.iter().find(|&ext| ext.oid == *oid)
    }

    /// Builds and returns a map of extensions.
    ///
    /// If an extension is present twice, this will fail and return `DuplicateExtensions`.
    pub fn extensions_map(&self) -> Result<HashMap<Oid, &X509Extension>, X509Error> {
        self.extensions
            .iter()
            .try_fold(HashMap::new(), |mut m, ext| {
                if m.contains_key(&ext.oid) {
                    return Err(X509Error::DuplicateExtensions);
                }
                m.insert(ext.oid.clone(), ext);
                Ok(m)
            })
    }
}

impl<'a> AsRef<[u8]> for TbsCertList<'a> {
    fn as_ref(&self) -> &[u8] {
        self.raw
    }
}

impl<'a> FromDer<'a, X509Error> for TbsCertList<'a> {
    fn from_der(i: &'a [u8]) -> X509Result<Self> {
        let start_i = i;
        parse_der_sequence_defined_g(move |i, _| {
            let (i, version) =
                opt(map(parse_der_u32, X509Version))(i).or(Err(X509Error::InvalidVersion))?;
            let (i, signature) = AlgorithmIdentifier::from_der(i)?;
            let (i, issuer) = X509Name::from_der(i)?;
            let (i, this_update) = ASN1Time::from_der(i)?;
            let (i, next_update) = ASN1Time::from_der_opt(i)?;
            let (i, revoked_certificates) = opt(complete(parse_revoked_certificates))(i)?;
            let (i, extensions) = parse_extensions(i, Tag(0))?;
            let len = start_i.offset(i);
            let tbs = TbsCertList {
                version,
                signature,
                issuer,
                this_update,
                next_update,
                revoked_certificates: revoked_certificates.unwrap_or_default(),
                extensions,
                raw: &start_i[..len],
            };
            Ok((i, tbs))
        })(i)
    }
}

#[derive(Clone, Debug, PartialEq)]
pub struct RevokedCertificate<'a> {
    /// The Serial number of the revoked certificate
    pub user_certificate: BigUint,
    /// The date on which the revocation occurred is specified.
    pub revocation_date: ASN1Time,
    /// Additional information about revocation
    extensions: Vec<X509Extension<'a>>,
    pub(crate) raw_serial: &'a [u8],
}

impl<'a> RevokedCertificate<'a> {
    /// Return the serial number of the revoked certificate
    pub fn serial(&self) -> &BigUint {
        &self.user_certificate
    }

    /// Get the CRL entry extensions.
    #[inline]
    pub fn extensions(&self) -> &[X509Extension] {
        &self.extensions
    }

    /// Returns an iterator over the CRL entry extensions
    #[inline]
    pub fn iter_extensions(&self) -> impl Iterator<Item = &X509Extension> {
        self.extensions.iter()
    }

    /// Searches for a CRL entry extension with the given `Oid`.
    ///
    /// Note: if there are several extensions with the same `Oid`, the first one is returned.
    pub fn find_extension(&self, oid: &Oid) -> Option<&X509Extension> {
        self.extensions.iter().find(|&ext| ext.oid == *oid)
    }

    /// Builds and returns a map of CRL entry extensions.
    ///
    /// If an extension is present twice, this will fail and return `DuplicateExtensions`.
    pub fn extensions_map(&self) -> Result<HashMap<Oid, &X509Extension>, X509Error> {
        self.extensions
            .iter()
            .try_fold(HashMap::new(), |mut m, ext| {
                if m.contains_key(&ext.oid) {
                    return Err(X509Error::DuplicateExtensions);
                }
                m.insert(ext.oid.clone(), ext);
                Ok(m)
            })
    }

    /// Get the raw bytes of the certificate serial number
    pub fn raw_serial(&self) -> &[u8] {
        self.raw_serial
    }

    /// Get a formatted string of the certificate serial number, separated by ':'
    pub fn raw_serial_as_string(&self) -> String {
        format_serial(self.raw_serial)
    }

    /// Get the code identifying the reason for the revocation, if present
    pub fn reason_code(&self) -> Option<(bool, ReasonCode)> {
        self.find_extension(&OID_X509_EXT_REASON_CODE)
            .and_then(|ext| match ext.parsed_extension {
                ParsedExtension::ReasonCode(code) => Some((ext.critical, code)),
                _ => None,
            })
    }

    /// Get the invalidity date, if present
    ///
    /// The invalidity date is the date on which it is known or suspected that the private
    ///  key was compromised or that the certificate otherwise became invalid.
    pub fn invalidity_date(&self) -> Option<(bool, ASN1Time)> {
        self.find_extension(&OID_X509_EXT_INVALIDITY_DATE)
            .and_then(|ext| match ext.parsed_extension {
                ParsedExtension::InvalidityDate(date) => Some((ext.critical, date)),
                _ => None,
            })
    }
}

// revokedCertificates     SEQUENCE OF SEQUENCE  {
//     userCertificate         CertificateSerialNumber,
//     revocationDate          Time,
//     crlEntryExtensions      Extensions OPTIONAL
//                                   -- if present, MUST be v2
//                          }  OPTIONAL,
impl<'a> FromDer<'a, X509Error> for RevokedCertificate<'a> {
    fn from_der(i: &'a [u8]) -> X509Result<Self> {
        parse_der_sequence_defined_g(|i, _| {
            let (i, (raw_serial, user_certificate)) = parse_serial(i)?;
            let (i, revocation_date) = ASN1Time::from_der(i)?;
            let (i, extensions) = opt(complete(parse_extension_sequence))(i)?;
            let revoked = RevokedCertificate {
                user_certificate,
                revocation_date,
                extensions: extensions.unwrap_or_default(),
                raw_serial,
            };
            Ok((i, revoked))
        })(i)
    }
}

fn parse_revoked_certificates(i: &[u8]) -> X509Result<Vec<RevokedCertificate>> {
    parse_der_sequence_defined_g(|a, _| {
        all_consuming(many0(complete(RevokedCertificate::from_der)))(a)
    })(i)
}