pkcs1/private_key/other_prime_info.rs
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//! PKCS#1 OtherPrimeInfo support.
use der::{
asn1::UintRef, DecodeValue, Encode, EncodeValue, Header, Length, Reader, Sequence, Writer,
};
/// PKCS#1 OtherPrimeInfo as defined in [RFC 8017 Appendix 1.2].
///
/// ASN.1 structure containing an additional prime in a multi-prime RSA key.
///
/// ```text
/// OtherPrimeInfo ::= SEQUENCE {
/// prime INTEGER, -- ri
/// exponent INTEGER, -- di
/// coefficient INTEGER -- ti
/// }
/// ```
///
/// [RFC 8017 Appendix 1.2]: https://datatracker.ietf.org/doc/html/rfc8017#appendix-A.1.2
#[derive(Clone)]
pub struct OtherPrimeInfo<'a> {
/// Prime factor `r_i` of `n`, where `i` >= 3.
pub prime: UintRef<'a>,
/// Exponent: `d_i = d mod (r_i - 1)`.
pub exponent: UintRef<'a>,
/// CRT coefficient: `t_i = (r_1 * r_2 * ... * r_(i-1))^(-1) mod r_i`.
pub coefficient: UintRef<'a>,
}
impl<'a> DecodeValue<'a> for OtherPrimeInfo<'a> {
fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> der::Result<Self> {
reader.read_nested(header.length, |reader| {
Ok(Self {
prime: reader.decode()?,
exponent: reader.decode()?,
coefficient: reader.decode()?,
})
})
}
}
impl EncodeValue for OtherPrimeInfo<'_> {
fn value_len(&self) -> der::Result<Length> {
self.prime.encoded_len()? + self.exponent.encoded_len()? + self.coefficient.encoded_len()?
}
fn encode_value(&self, writer: &mut impl Writer) -> der::Result<()> {
self.prime.encode(writer)?;
self.exponent.encode(writer)?;
self.coefficient.encode(writer)?;
Ok(())
}
}
impl<'a> Sequence<'a> for OtherPrimeInfo<'a> {}