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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use crate::{
ec::{PrivateKey, PublicKey},
error::*,
pk11::types::SymKey,
util::{ensure_nss_initialized, map_nss_secstatus, sec_item_as_slice, ScopedPtr},
};
pub fn ecdh_agreement(priv_key: &PrivateKey, pub_key: &PublicKey) -> Result<Vec<u8>> {
ensure_nss_initialized();
if priv_key.curve() != pub_key.curve() {
return Err(ErrorKind::InternalError.into());
}
// The following code is adapted from:
// CKM_SHA512_HMAC and CKA_SIGN are key type and usage attributes of the
// derived symmetric key and don't matter because we ignore them anyway.
let sym_key = unsafe {
SymKey::from_ptr(nss_sys::PK11_PubDeriveWithKDF(
priv_key.as_mut_ptr(),
pub_key.as_mut_ptr(),
nss_sys::PR_FALSE,
std::ptr::null_mut(),
std::ptr::null_mut(),
nss_sys::CKM_ECDH1_DERIVE.into(),
nss_sys::CKM_SHA512_HMAC.into(),
nss_sys::CKA_SIGN.into(),
0,
nss_sys::CKD_NULL.into(),
std::ptr::null_mut(),
std::ptr::null_mut(),
))?
};
map_nss_secstatus(|| unsafe { nss_sys::PK11_ExtractKeyValue(sym_key.as_mut_ptr()) })?;
// This doesn't leak, because the SECItem* returned by PK11_GetKeyData
// just refers to a buffer managed by `sym_key` which we copy into `buf`.
let mut key_data = unsafe { *nss_sys::PK11_GetKeyData(sym_key.as_mut_ptr()) };
let buf = unsafe { sec_item_as_slice(&mut key_data)? };
Ok(buf.to_vec())
}