aboutsummaryrefslogtreecommitdiff
path: root/src/algorithm.rs
blob: 5f4b5e8c241186e54f528870897a66d0beea9265 (plain)
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
//! X.509 `AlgorithmIdentifier`

use crate::{Error, Result};
use core::cmp::Ordering;
use der::{
    asn1::{AnyRef, Choice, ObjectIdentifier},
    Decode, DecodeValue, DerOrd, Encode, EncodeValue, Header, Length, Reader, Sequence, ValueOrd,
    Writer,
};

#[cfg(feature = "alloc")]
use der::asn1::Any;

/// X.509 `AlgorithmIdentifier` as defined in [RFC 5280 Section 4.1.1.2].
///
/// ```text
/// AlgorithmIdentifier  ::=  SEQUENCE  {
///      algorithm               OBJECT IDENTIFIER,
///      parameters              ANY DEFINED BY algorithm OPTIONAL  }
/// ```
///
/// [RFC 5280 Section 4.1.1.2]: https://tools.ietf.org/html/rfc5280#section-4.1.1.2
#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
pub struct AlgorithmIdentifier<Params> {
    /// Algorithm OID, i.e. the `algorithm` field in the `AlgorithmIdentifier`
    /// ASN.1 schema.
    pub oid: ObjectIdentifier,

    /// Algorithm `parameters`.
    pub parameters: Option<Params>,
}

impl<'a, Params> DecodeValue<'a> for AlgorithmIdentifier<Params>
where
    Params: Choice<'a>,
{
    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> der::Result<Self> {
        reader.read_nested(header.length, |reader| {
            Ok(Self {
                oid: reader.decode()?,
                parameters: reader.decode()?,
            })
        })
    }
}

impl<Params> EncodeValue for AlgorithmIdentifier<Params>
where
    Params: Encode,
{
    fn value_len(&self) -> der::Result<Length> {
        self.oid.encoded_len()? + self.parameters.encoded_len()?
    }

    fn encode_value(&self, writer: &mut impl Writer) -> der::Result<()> {
        self.oid.encode(writer)?;
        self.parameters.encode(writer)?;
        Ok(())
    }
}

impl<'a, Params> Sequence<'a> for AlgorithmIdentifier<Params> where Params: Choice<'a> + Encode {}

impl<'a, Params> TryFrom<&'a [u8]> for AlgorithmIdentifier<Params>
where
    Params: Choice<'a> + Encode,
{
    type Error = Error;

    fn try_from(bytes: &'a [u8]) -> Result<Self> {
        Ok(Self::from_der(bytes)?)
    }
}

impl<Params> ValueOrd for AlgorithmIdentifier<Params>
where
    Params: DerOrd,
{
    fn value_cmp(&self, other: &Self) -> der::Result<Ordering> {
        match self.oid.der_cmp(&other.oid)? {
            Ordering::Equal => self.parameters.der_cmp(&other.parameters),
            other => Ok(other),
        }
    }
}

/// `AlgorithmIdentifier` reference which has `AnyRef` parameters.
pub type AlgorithmIdentifierRef<'a> = AlgorithmIdentifier<AnyRef<'a>>;

/// `AlgorithmIdentifier` with `ObjectIdentifier` parameters.
pub type AlgorithmIdentifierWithOid = AlgorithmIdentifier<ObjectIdentifier>;

/// `AlgorithmIdentifier` reference which has `Any` parameters.
#[cfg(feature = "alloc")]
pub type AlgorithmIdentifierOwned = AlgorithmIdentifier<Any>;

impl<Params> AlgorithmIdentifier<Params> {
    /// Assert the `algorithm` OID is an expected value.
    pub fn assert_algorithm_oid(&self, expected_oid: ObjectIdentifier) -> Result<ObjectIdentifier> {
        if self.oid == expected_oid {
            Ok(expected_oid)
        } else {
            Err(Error::OidUnknown { oid: expected_oid })
        }
    }
}

impl<'a> AlgorithmIdentifierRef<'a> {
    /// Assert `parameters` is an OID and has the expected value.
    pub fn assert_parameters_oid(
        &self,
        expected_oid: ObjectIdentifier,
    ) -> Result<ObjectIdentifier> {
        let actual_oid = self.parameters_oid()?;

        if actual_oid == expected_oid {
            Ok(actual_oid)
        } else {
            Err(Error::OidUnknown { oid: expected_oid })
        }
    }

    /// Assert the values of the `algorithm` and `parameters` OIDs.
    pub fn assert_oids(
        &self,
        algorithm: ObjectIdentifier,
        parameters: ObjectIdentifier,
    ) -> Result<()> {
        self.assert_algorithm_oid(algorithm)?;
        self.assert_parameters_oid(parameters)?;
        Ok(())
    }

    /// Get the `parameters` field as an [`AnyRef`].
    ///
    /// Returns an error if `parameters` are `None`.
    pub fn parameters_any(&self) -> Result<AnyRef<'a>> {
        self.parameters.ok_or(Error::AlgorithmParametersMissing)
    }

    /// Get the `parameters` field as an [`ObjectIdentifier`].
    ///
    /// Returns an error if it is absent or not an OID.
    pub fn parameters_oid(&self) -> Result<ObjectIdentifier> {
        Ok(ObjectIdentifier::try_from(self.parameters_any()?)?)
    }

    /// Convert to a pair of [`ObjectIdentifier`]s.
    ///
    /// This method is helpful for decomposing in match statements. Note in
    /// particular that `NULL` parameters are treated the same as missing
    /// parameters.
    ///
    /// Returns an error if parameters are present but not an OID.
    pub fn oids(&self) -> der::Result<(ObjectIdentifier, Option<ObjectIdentifier>)> {
        Ok((
            self.oid,
            match self.parameters {
                None => None,
                Some(p) => match p {
                    AnyRef::NULL => None,
                    _ => Some(p.decode_as::<ObjectIdentifier>()?),
                },
            },
        ))
    }
}

#[cfg(feature = "alloc")]
mod allocating {
    use super::*;
    use der::referenced::*;

    impl<'a> RefToOwned<'a> for AlgorithmIdentifierRef<'a> {
        type Owned = AlgorithmIdentifierOwned;
        fn ref_to_owned(&self) -> Self::Owned {
            AlgorithmIdentifier {
                oid: self.oid,
                parameters: self.parameters.ref_to_owned(),
            }
        }
    }

    impl OwnedToRef for AlgorithmIdentifierOwned {
        type Borrowed<'a> = AlgorithmIdentifierRef<'a>;
        fn owned_to_ref(&self) -> Self::Borrowed<'_> {
            AlgorithmIdentifier {
                oid: self.oid,
                parameters: self.parameters.owned_to_ref(),
            }
        }
    }
}