Files
OpenSK/src/api/attestation_store.rs
Julien Cretin 07a28fe611 Inline Helper
2022-07-14 12:50:39 +02:00

101 lines
2.9 KiB
Rust

use alloc::vec::Vec;
use persistent_store::{StoreError, StoreUpdate};
use crate::env::Env;
/// Identifies an attestation.
#[derive(Clone, PartialEq, Eq)]
pub enum Id {
Batch,
Enterprise,
}
#[cfg_attr(feature = "std", derive(Debug, PartialEq, Eq))]
pub struct Attestation {
/// ECDSA private key (big-endian).
pub private_key: [u8; 32],
pub certificate: Vec<u8>,
}
/// Stores enterprise or batch attestations.
pub trait AttestationStore {
/// Returns an attestation given its id, if it exists.
///
/// This should always return the attestation. Checking whether it is ok to use the attestation
/// is done in the CTAP library.
fn get(&mut self, id: &Id) -> Result<Option<Attestation>, Error>;
/// Sets the attestation for a given id.
///
/// This function may not be supported.
fn set(&mut self, id: &Id, attestation: Option<&Attestation>) -> Result<(), Error>;
}
/// Attestation store errors.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
#[non_exhaustive]
pub enum Error {
Storage,
Internal,
NoSupport,
}
/// Keys of the environment store reserved for the attestation store.
pub const STORAGE_KEYS: &[usize] = &[1, 2];
pub fn helper_get(env: &mut impl Env) -> Result<Option<Attestation>, Error> {
let private_key = env.store().find(PRIVATE_KEY_STORAGE_KEY)?;
let certificate = env.store().find(CERTIFICATE_STORAGE_KEY)?;
let (private_key, certificate) = match (private_key, certificate) {
(Some(x), Some(y)) => (x, y),
(None, None) => return Ok(None),
_ => return Err(Error::Internal),
};
if private_key.len() != 32 {
return Err(Error::Internal);
}
Ok(Some(Attestation {
private_key: *array_ref![private_key, 0, 32],
certificate,
}))
}
pub fn helper_set(env: &mut impl Env, attestation: Option<&Attestation>) -> Result<(), Error> {
let updates = match attestation {
None => [
StoreUpdate::Remove {
key: PRIVATE_KEY_STORAGE_KEY,
},
StoreUpdate::Remove {
key: CERTIFICATE_STORAGE_KEY,
},
],
Some(attestation) => [
StoreUpdate::Insert {
key: PRIVATE_KEY_STORAGE_KEY,
value: &attestation.private_key[..],
},
StoreUpdate::Insert {
key: CERTIFICATE_STORAGE_KEY,
value: &attestation.certificate[..],
},
],
};
Ok(env.store().transaction(&updates)?)
}
const PRIVATE_KEY_STORAGE_KEY: usize = STORAGE_KEYS[0];
const CERTIFICATE_STORAGE_KEY: usize = STORAGE_KEYS[1];
impl From<StoreError> for Error {
fn from(error: StoreError) -> Self {
match error {
StoreError::InvalidArgument
| StoreError::NoCapacity
| StoreError::NoLifetime
| StoreError::InvalidStorage => Error::Internal,
StoreError::StorageError => Error::Storage,
}
}
}