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//! Implementation of Sequoia crypto API using the Nettle cryptographic library.
use crate::types::*;
use nettle::random::{Random, Yarrow};
pub mod aead;
pub mod asymmetric;
pub mod ecdh;
pub mod hash;
pub mod kdf;
pub mod symmetric;
pub struct Backend(());
impl super::interface::Backend for Backend {
fn backend() -> String {
let (major, minor) = nettle::version();
format!(
"Nettle {}.{} (Cv448: {:?}, OCB: {:?})",
major, minor,
nettle::curve448::IS_SUPPORTED,
nettle::aead::OCB_IS_SUPPORTED,
)
}
fn random(buf: &mut [u8]) -> crate::Result<()> {
Yarrow::default().random(buf);
Ok(())
}
}
impl AEADAlgorithm {
/// Returns the best AEAD mode supported by the backend.
///
/// This SHOULD return OCB, which is the mandatory-to-implement
/// algorithm and the most performing one, but fall back to any
/// supported algorithm.
pub(crate) const fn const_default() -> AEADAlgorithm {
if nettle::aead::OCB_IS_SUPPORTED {
AEADAlgorithm::OCB
} else {
AEADAlgorithm::EAX
}
}
pub(crate) fn is_supported_by_backend(&self) -> bool {
use self::AEADAlgorithm::*;
match &self {
EAX
=> true,
OCB
=> nettle::aead::OCB_IS_SUPPORTED,
GCM
=> true,
Private(_) | Unknown(_)
=> false,
}
}
#[cfg(test)]
pub(crate) fn supports_symmetric_algo(&self, algo: &SymmetricAlgorithm) -> bool {
match &self {
AEADAlgorithm::EAX =>
match algo {
SymmetricAlgorithm::AES128 |
SymmetricAlgorithm::AES192 |
SymmetricAlgorithm::AES256 |
SymmetricAlgorithm::Twofish |
SymmetricAlgorithm::Camellia128 |
SymmetricAlgorithm::Camellia192 |
SymmetricAlgorithm::Camellia256 => true,
_ => false,
},
AEADAlgorithm::OCB =>
match algo {
SymmetricAlgorithm::AES128 |
SymmetricAlgorithm::AES192 |
SymmetricAlgorithm::AES256 |
SymmetricAlgorithm::Twofish |
SymmetricAlgorithm::Camellia128 |
SymmetricAlgorithm::Camellia192 |
SymmetricAlgorithm::Camellia256 => true,
_ => false,
},
AEADAlgorithm::GCM =>
match algo {
SymmetricAlgorithm::AES128 |
SymmetricAlgorithm::AES192 |
SymmetricAlgorithm::AES256 |
SymmetricAlgorithm::Twofish |
SymmetricAlgorithm::Camellia128 |
SymmetricAlgorithm::Camellia192 |
SymmetricAlgorithm::Camellia256 => true,
_ => false,
},
_ => false
}
}
}
|
