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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::{
error::*,
pk11::sym_key::import_sym_key,
util::{ensure_nss_initialized, map_nss_secstatus, ScopedPtr},
};
use std::{
mem,
os::raw::{c_uchar, c_uint},
};
const AES_GCM_TAG_LENGTH: usize = 16;
#[derive(Debug, Copy, Clone)]
pub enum Operation {
Encrypt,
Decrypt,
}
pub fn aes_gcm_crypt(
key: &[u8],
nonce: &[u8],
aad: &[u8],
data: &[u8],
operation: Operation,
) -> Result<Vec<u8>> {
let mut gcm_params = nss_sys::CK_GCM_PARAMS {
pIv: nonce.as_ptr() as nss_sys::CK_BYTE_PTR,
ulIvLen: nss_sys::CK_ULONG::try_from(nonce.len())?,
ulIvBits: nss_sys::CK_ULONG::try_from(
nonce.len().checked_mul(8).ok_or(ErrorKind::InternalError)?,
)?,
pAAD: aad.as_ptr() as nss_sys::CK_BYTE_PTR,
ulAADLen: nss_sys::CK_ULONG::try_from(aad.len())?,
ulTagBits: nss_sys::CK_ULONG::try_from(AES_GCM_TAG_LENGTH * 8)?,
};
let mut params = nss_sys::SECItem {
type_: nss_sys::SECItemType::siBuffer as u32,
data: &mut gcm_params as *mut _ as *mut c_uchar,
len: c_uint::try_from(mem::size_of::<nss_sys::CK_GCM_PARAMS>())?,
};
common_crypt(
nss_sys::CKM_AES_GCM.into(),
key,
data,
AES_GCM_TAG_LENGTH,
&mut params,
operation,
)
}
pub fn aes_cbc_crypt(
key: &[u8],
nonce: &[u8],
data: &[u8],
operation: Operation,
) -> Result<Vec<u8>> {
let mut params = nss_sys::SECItem {
type_: nss_sys::SECItemType::siBuffer as u32,
data: nonce.as_ptr() as *mut c_uchar,
len: c_uint::try_from(nonce.len())?,
};
common_crypt(
nss_sys::CKM_AES_CBC_PAD.into(),
key,
data,
usize::try_from(nss_sys::AES_BLOCK_SIZE)?, // CBC mode might pad the result.
&mut params,
operation,
)
}
pub fn common_crypt(
mech: nss_sys::CK_MECHANISM_TYPE,
key: &[u8],
data: &[u8],
extra_data_len: usize,
params: &mut nss_sys::SECItem,
operation: Operation,
) -> Result<Vec<u8>> {
ensure_nss_initialized();
// Most of the following code is inspired by the Firefox WebCrypto implementation:
// CKA_ENCRYPT always is fine.
let sym_key = import_sym_key(mech, nss_sys::CKA_ENCRYPT.into(), key)?;
// Initialize the output buffer (enough space for padding / a full tag).
let result_max_len = data
.len()
.checked_add(extra_data_len)
.ok_or(ErrorKind::InternalError)?;
let mut out_len: c_uint = 0;
let mut out = vec![0u8; result_max_len];
let result_max_len_uint = c_uint::try_from(result_max_len)?;
let data_len = c_uint::try_from(data.len())?;
let f = match operation {
Operation::Decrypt => nss_sys::PK11_Decrypt,
Operation::Encrypt => nss_sys::PK11_Encrypt,
};
map_nss_secstatus(|| unsafe {
f(
sym_key.as_mut_ptr(),
mech,
params,
out.as_mut_ptr(),
&mut out_len,
result_max_len_uint,
data.as_ptr(),
data_len,
)
})?;
out.truncate(usize::try_from(out_len)?);
Ok(out)
}