pkcs1/
version.rs

1//! PKCS#1 version identifier.
2
3use crate::Error;
4use der::{Decode, Encode, FixedTag, Reader, Tag, Writer};
5
6/// Version identifier for PKCS#1 documents as defined in
7/// [RFC 8017 Appendix 1.2].
8///
9/// > version is the version number, for compatibility with future
10/// > revisions of this document.  It SHALL be 0 for this version of the
11/// > document, unless multi-prime is used; in which case, it SHALL be 1.
12///
13/// ```text
14/// Version ::= INTEGER { two-prime(0), multi(1) }
15///    (CONSTRAINED BY
16///    {-- version must be multi if otherPrimeInfos present --})
17/// ```
18///
19/// [RFC 8017 Appendix 1.2]: https://datatracker.ietf.org/doc/html/rfc8017#appendix-A.1.2
20#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
21#[repr(u8)]
22pub enum Version {
23    /// Denotes a `two-prime` key
24    TwoPrime = 0,
25
26    /// Denotes a `multi` (i.e. multi-prime) key
27    Multi = 1,
28}
29
30impl Version {
31    /// Is this a multi-prime RSA key?
32    pub fn is_multi(self) -> bool {
33        self == Self::Multi
34    }
35}
36
37impl From<Version> for u8 {
38    fn from(version: Version) -> Self {
39        version as u8
40    }
41}
42
43impl TryFrom<u8> for Version {
44    type Error = Error;
45    fn try_from(byte: u8) -> Result<Version, Error> {
46        match byte {
47            0 => Ok(Version::TwoPrime),
48            1 => Ok(Version::Multi),
49            _ => Err(Error::Version),
50        }
51    }
52}
53
54impl<'a> Decode<'a> for Version {
55    fn decode<R: Reader<'a>>(decoder: &mut R) -> der::Result<Self> {
56        Version::try_from(u8::decode(decoder)?).map_err(|_| Self::TAG.value_error())
57    }
58}
59
60impl Encode for Version {
61    fn encoded_len(&self) -> der::Result<der::Length> {
62        der::Length::ONE.for_tlv()
63    }
64
65    fn encode(&self, writer: &mut impl Writer) -> der::Result<()> {
66        u8::from(*self).encode(writer)
67    }
68}
69
70impl FixedTag for Version {
71    const TAG: Tag = Tag::Integer;
72}
pkcs1/version.rs

pkcs1/
version.rs
