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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::{
ffi::CString,
os::raw::{c_char, c_uint},
ptr::{addr_of_mut, null_mut},
};
use neqo_common::qtrace;
use crate::{
err::{ssl::SSL_ERROR_ECH_RETRY_WITH_ECH, Error, Res},
experimental_api, null_safe_slice,
p11::{
self, Item, PrivateKey, PublicKey, SECITEM_FreeItem, SECItem, SECKEYPrivateKey,
SECKEYPublicKey, Slot,
},
ssl::{PRBool, PRFileDesc},
};
pub use crate::{
p11::{HpkeAeadId as AeadId, HpkeKdfId as KdfId, HpkeKemId as KemId},
ssl::HpkeSymmetricSuite as SymmetricSuite,
};
experimental_api!(SSL_EnableTls13GreaseEch(
fd: *mut PRFileDesc,
enabled: PRBool,
));
experimental_api!(SSL_GetEchRetryConfigs(
fd: *mut PRFileDesc,
config: *mut SECItem,
));
experimental_api!(SSL_SetClientEchConfigs(
fd: *mut PRFileDesc,
config_list: *const u8,
config_list_len: c_uint,
));
experimental_api!(SSL_SetServerEchConfigs(
fd: *mut PRFileDesc,
pk: *const SECKEYPublicKey,
sk: *const SECKEYPrivateKey,
record: *const u8,
record_len: c_uint,
));
experimental_api!(SSL_EncodeEchConfigId(
config_id: u8,
public_name: *const c_char,
max_name_len: c_uint,
kem_id: KemId::Type,
pk: *const SECKEYPublicKey,
hpke_suites: *const SymmetricSuite,
hpke_suite_count: c_uint,
out: *mut u8,
out_len: *mut c_uint,
max_len: c_uint,
));
/// Convert any result that contains an ECH error into a result with an `EchRetry`.
pub fn convert_ech_error(fd: *mut PRFileDesc, err: Error) -> Error {
if let Error::NssError {
code: SSL_ERROR_ECH_RETRY_WITH_ECH,
..
} = &err
{
let mut item = Item::make_empty();
if unsafe { SSL_GetEchRetryConfigs(fd, &mut item).is_err() } {
return Error::InternalError;
}
let buf = unsafe {
let slc = null_safe_slice(item.data, item.len);
let buf = Vec::from(slc);
SECITEM_FreeItem(&mut item, PRBool::from(false));
buf
};
Error::EchRetry(buf)
} else {
err
}
}
/// Generate a key pair for encrypted client hello (ECH).
///
/// # Errors
///
/// When NSS fails to generate a key pair or when the KEM is not supported.
///
/// # Panics
///
/// When underlying types aren't large enough to hold keys. So never.
pub fn generate_keys() -> Res<(PrivateKey, PublicKey)> {
let slot = Slot::internal()?;
let oid_data = unsafe { p11::SECOID_FindOIDByTag(p11::SECOidTag::SEC_OID_CURVE25519) };
let oid = unsafe { oid_data.as_ref() }.ok_or(Error::InternalError)?;
let oid_slc = unsafe { null_safe_slice(oid.oid.data, oid.oid.len) };
let mut params: Vec<u8> = Vec::with_capacity(oid_slc.len() + 2);
params.push(u8::try_from(p11::SEC_ASN1_OBJECT_ID).unwrap());
params.push(u8::try_from(oid.oid.len).unwrap());
params.extend_from_slice(oid_slc);
let mut public_ptr: *mut SECKEYPublicKey = null_mut();
let mut param_item = Item::wrap(¶ms);
// If we have tracing on, try to ensure that key data can be read.
let insensitive_secret_ptr = if log::log_enabled!(log::Level::Trace) {
unsafe {
p11::PK11_GenerateKeyPairWithOpFlags(
*slot,
p11::CK_MECHANISM_TYPE::from(p11::CKM_EC_KEY_PAIR_GEN),
addr_of_mut!(param_item).cast(),
&mut public_ptr,
p11::PK11_ATTR_SESSION | p11::PK11_ATTR_INSENSITIVE | p11::PK11_ATTR_PUBLIC,
p11::CK_FLAGS::from(p11::CKF_DERIVE),
p11::CK_FLAGS::from(p11::CKF_DERIVE),
null_mut(),
)
}
} else {
null_mut()
};
assert_eq!(insensitive_secret_ptr.is_null(), public_ptr.is_null());
let secret_ptr = if insensitive_secret_ptr.is_null() {
unsafe {
p11::PK11_GenerateKeyPairWithOpFlags(
*slot,
p11::CK_MECHANISM_TYPE::from(p11::CKM_EC_KEY_PAIR_GEN),
addr_of_mut!(param_item).cast(),
&mut public_ptr,
p11::PK11_ATTR_SESSION | p11::PK11_ATTR_SENSITIVE | p11::PK11_ATTR_PRIVATE,
p11::CK_FLAGS::from(p11::CKF_DERIVE),
p11::CK_FLAGS::from(p11::CKF_DERIVE),
null_mut(),
)
}
} else {
insensitive_secret_ptr
};
assert_eq!(secret_ptr.is_null(), public_ptr.is_null());
let sk = PrivateKey::from_ptr(secret_ptr)?;
let pk = PublicKey::from_ptr(public_ptr)?;
qtrace!("Generated key pair: sk={:?} pk={:?}", sk, pk);
Ok((sk, pk))
}
/// Encode a configuration for encrypted client hello (ECH).
///
/// # Errors
///
/// When NSS fails to generate a valid configuration encoding (i.e., unlikely).
pub fn encode_config(config: u8, public_name: &str, pk: &PublicKey) -> Res<Vec<u8>> {
// A sensible fixed value for the maximum length of a name.
const MAX_NAME_LEN: c_uint = 64;
// Enable a selection of suites.
// NSS supports SHA-512 as well, which could be added here.
const SUITES: &[SymmetricSuite] = &[
SymmetricSuite {
kdfId: KdfId::HpkeKdfHkdfSha256,
aeadId: AeadId::HpkeAeadAes128Gcm,
},
SymmetricSuite {
kdfId: KdfId::HpkeKdfHkdfSha256,
aeadId: AeadId::HpkeAeadChaCha20Poly1305,
},
SymmetricSuite {
kdfId: KdfId::HpkeKdfHkdfSha384,
aeadId: AeadId::HpkeAeadAes128Gcm,
},
SymmetricSuite {
kdfId: KdfId::HpkeKdfHkdfSha384,
aeadId: AeadId::HpkeAeadChaCha20Poly1305,
},
];
let name = CString::new(public_name)?;
let mut encoded = [0; 1024];
let mut encoded_len = 0;
unsafe {
SSL_EncodeEchConfigId(
config,
name.as_ptr(),
MAX_NAME_LEN,
KemId::HpkeDhKemX25519Sha256,
**pk,
SUITES.as_ptr(),
c_uint::try_from(SUITES.len())?,
encoded.as_mut_ptr(),
&mut encoded_len,
c_uint::try_from(encoded.len())?,
)?;
}
Ok(Vec::from(&encoded[..usize::try_from(encoded_len)?]))
}