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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 crate::p11::Context;
use crate::p11::{
self, PK11_AEADOp, PK11_CreateContextBySymKey, CKA_DECRYPT, CKA_ENCRYPT, CKA_NSS_MESSAGE,
CKG_GENERATE_COUNTER_XOR, CKG_NO_GENERATE, CKM_AES_GCM, CKM_CHACHA20_POLY1305,
CK_ATTRIBUTE_TYPE, CK_GENERATOR_FUNCTION, CK_MECHANISM_TYPE,
};
use crate::secstatus_to_res;
use crate::SECItemBorrowed;
use crate::{Error, SymKey};
use std::convert::TryFrom;
use std::convert::TryInto;
use std::mem;
use std::os::raw::c_int;
/// All the nonces are the same length. Exploit that.
pub const NONCE_LEN: usize = 12;
/// The portion of the nonce that is a counter.
const COUNTER_LEN: usize = mem::size_of::<SequenceNumber>();
/// The NSS API insists on us identifying the tag separately, which is awful.
/// All of the AEAD functions here have a tag of this length, so use a fixed offset.
const TAG_LEN: usize = 16;
pub type SequenceNumber = u64;
/// All the lengths used by `PK11_AEADOp` are signed. This converts to that.
fn c_int_len<T>(l: T) -> c_int
where
T: TryInto<c_int>,
T::Error: std::error::Error,
{
l.try_into().unwrap()
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Mode {
Encrypt,
Decrypt,
}
impl Mode {
fn p11mode(self) -> CK_ATTRIBUTE_TYPE {
CK_ATTRIBUTE_TYPE::from(
CKA_NSS_MESSAGE
| match self {
Self::Encrypt => CKA_ENCRYPT,
Self::Decrypt => CKA_DECRYPT,
},
)
}
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum AeadAlgorithms {
Aes128Gcm,
Aes256Gcm,
ChaCha20Poly1305,
}
pub struct Aead {
mode: Mode,
ctx: Context,
nonce_base: [u8; NONCE_LEN],
}
impl Aead {
fn mech(algorithm: AeadAlgorithms) -> p11::CK_MECHANISM_TYPE {
CK_MECHANISM_TYPE::from(match algorithm {
crate::aead::AeadAlgorithms::Aes128Gcm | crate::aead::AeadAlgorithms::Aes256Gcm => {
CKM_AES_GCM
}
crate::aead::AeadAlgorithms::ChaCha20Poly1305 => CKM_CHACHA20_POLY1305,
})
}
pub fn import_key(algorithm: AeadAlgorithms, key: &[u8]) -> Result<SymKey, Error> {
let slot = p11::Slot::internal().map_err(|_| crate::Error::InternalError)?;
let key_item = SECItemBorrowed::wrap(key);
let key_item_ptr = key_item.as_ref() as *const _ as *mut _;
let ptr = unsafe {
p11::PK11_ImportSymKey(
*slot,
Self::mech(algorithm),
p11::PK11Origin::PK11_OriginUnwrap,
p11::CK_ATTRIBUTE_TYPE::from(p11::CKA_ENCRYPT | p11::CKA_DECRYPT),
key_item_ptr,
std::ptr::null_mut(),
)
};
unsafe { SymKey::from_ptr(ptr) }
}
pub fn new(
mode: Mode,
algorithm: AeadAlgorithms,
key: &SymKey,
nonce_base: [u8; NONCE_LEN],
) -> Result<Self, crate::Error> {
crate::init();
let ptr = unsafe {
PK11_CreateContextBySymKey(
Self::mech(algorithm),
mode.p11mode(),
**key,
SECItemBorrowed::wrap(&nonce_base[..]).as_ref(),
)
};
Ok(Self {
mode,
ctx: unsafe { Context::from_ptr(ptr)? },
nonce_base,
})
}
pub fn seal(&mut self, aad: &[u8], pt: &[u8]) -> Result<Vec<u8>, crate::Error> {
crate::init();
assert_eq!(self.mode, Mode::Encrypt);
// A copy for the nonce generator to write into. But we don't use the value.
let mut nonce = self.nonce_base;
// Ciphertext with enough space for the tag.
// Even though we give the operation a separate buffer for the tag,
// reserve the capacity on allocation.
let mut ct = vec![0; pt.len() + TAG_LEN];
let mut ct_len: c_int = 0;
let mut tag = vec![0; TAG_LEN];
secstatus_to_res(unsafe {
PK11_AEADOp(
*self.ctx,
CK_GENERATOR_FUNCTION::from(CKG_GENERATE_COUNTER_XOR),
c_int_len(NONCE_LEN - COUNTER_LEN), // Fixed portion of the nonce.
nonce.as_mut_ptr(),
c_int_len(nonce.len()),
aad.as_ptr(),
c_int_len(aad.len()),
ct.as_mut_ptr(),
&mut ct_len,
c_int_len(ct.len()), // signed :(
tag.as_mut_ptr(),
c_int_len(tag.len()),
pt.as_ptr(),
c_int_len(pt.len()),
)
})?;
ct.truncate(usize::try_from(ct_len).unwrap());
debug_assert_eq!(ct.len(), pt.len());
ct.append(&mut tag);
Ok(ct)
}
pub fn open(
&mut self,
aad: &[u8],
seq: SequenceNumber,
ct: &[u8],
) -> Result<Vec<u8>, crate::Error> {
crate::init();
assert_eq!(self.mode, Mode::Decrypt);
let mut nonce = self.nonce_base;
for (i, n) in nonce.iter_mut().rev().take(COUNTER_LEN).enumerate() {
*n ^= u8::try_from((seq >> (8 * i)) & 0xff).unwrap();
}
let mut pt = vec![0; ct.len()]; // NSS needs more space than it uses for plaintext.
let mut pt_len: c_int = 0;
let pt_expected = ct.len().checked_sub(TAG_LEN).ok_or(Error::AeadTruncated)?;
secstatus_to_res(unsafe {
PK11_AEADOp(
*self.ctx,
CK_GENERATOR_FUNCTION::from(CKG_NO_GENERATE),
c_int_len(NONCE_LEN - COUNTER_LEN), // Fixed portion of the nonce.
nonce.as_mut_ptr(),
c_int_len(nonce.len()),
aad.as_ptr(),
c_int_len(aad.len()),
pt.as_mut_ptr(),
&mut pt_len,
c_int_len(pt.len()),
ct.as_ptr().add(pt_expected) as *mut _,
c_int_len(TAG_LEN),
ct.as_ptr(),
c_int_len(pt_expected),
)
})?;
let len = usize::try_from(pt_len).unwrap();
debug_assert_eq!(len, pt_expected);
pt.truncate(len);
Ok(pt)
}
}
#[cfg(test)]
mod test {
use super::{super::init, Aead, AeadAlgorithms, Mode, SequenceNumber, NONCE_LEN};
/// Check that the first invocation of encryption matches expected values.
/// Also check decryption of the same.
fn check0(
algorithm: AeadAlgorithms,
key: &[u8],
nonce: &[u8; NONCE_LEN],
aad: &[u8],
pt: &[u8],
ct: &[u8],
) {
init();
let k = Aead::import_key(algorithm, key).unwrap();
let mut enc = Aead::new(Mode::Encrypt, algorithm, &k, *nonce).unwrap();
let ciphertext = enc.seal(aad, pt).unwrap();
assert_eq!(&ciphertext[..], ct);
let mut dec = Aead::new(Mode::Decrypt, algorithm, &k, *nonce).unwrap();
let plaintext = dec.open(aad, 0, ct).unwrap();
assert_eq!(&plaintext[..], pt);
}
fn decrypt(
algorithm: AeadAlgorithms,
key: &[u8],
nonce: &[u8; NONCE_LEN],
seq: SequenceNumber,
aad: &[u8],
pt: &[u8],
ct: &[u8],
) {
let k = Aead::import_key(algorithm, key).unwrap();
let mut dec = Aead::new(Mode::Decrypt, algorithm, &k, *nonce).unwrap();
let plaintext = dec.open(aad, seq, ct).unwrap();
assert_eq!(&plaintext[..], pt);
}
/// This tests the AEAD in QUIC in combination with the HKDF code.
/// This is an AEAD-only example.
#[test]
fn quic_retry() {
const KEY: &[u8] = &[
0xbe, 0x0c, 0x69, 0x0b, 0x9f, 0x66, 0x57, 0x5a, 0x1d, 0x76, 0x6b, 0x54, 0xe3, 0x68,
0xc8, 0x4e,
];
const NONCE: &[u8; NONCE_LEN] = &[
0x46, 0x15, 0x99, 0xd3, 0x5d, 0x63, 0x2b, 0xf2, 0x23, 0x98, 0x25, 0xbb,
];
const AAD: &[u8] = &[
0x08, 0x83, 0x94, 0xc8, 0xf0, 0x3e, 0x51, 0x57, 0x08, 0xff, 0x00, 0x00, 0x00, 0x01,
0x00, 0x08, 0xf0, 0x67, 0xa5, 0x50, 0x2a, 0x42, 0x62, 0xb5, 0x74, 0x6f, 0x6b, 0x65,
0x6e,
];
const CT: &[u8] = &[
0x04, 0xa2, 0x65, 0xba, 0x2e, 0xff, 0x4d, 0x82, 0x90, 0x58, 0xfb, 0x3f, 0x0f, 0x24,
0x96, 0xba,
];
check0(AeadAlgorithms::Aes128Gcm, KEY, NONCE, AAD, &[], CT);
}
#[test]
fn quic_server_initial() {
const ALG: AeadAlgorithms = AeadAlgorithms::Aes128Gcm;
const KEY: &[u8] = &[
0xcf, 0x3a, 0x53, 0x31, 0x65, 0x3c, 0x36, 0x4c, 0x88, 0xf0, 0xf3, 0x79, 0xb6, 0x06,
0x7e, 0x37,
];
const NONCE_BASE: &[u8; NONCE_LEN] = &[
0x0a, 0xc1, 0x49, 0x3c, 0xa1, 0x90, 0x58, 0x53, 0xb0, 0xbb, 0xa0, 0x3e,
];
// Note that this integrates the sequence number of 1 from the example,
// otherwise we can't use a sequence number of 0 to encrypt.
const NONCE: &[u8; NONCE_LEN] = &[
0x0a, 0xc1, 0x49, 0x3c, 0xa1, 0x90, 0x58, 0x53, 0xb0, 0xbb, 0xa0, 0x3f,
];
const AAD: &[u8] = &[
0xc1, 0x00, 0x00, 0x00, 0x01, 0x00, 0x08, 0xf0, 0x67, 0xa5, 0x50, 0x2a, 0x42, 0x62,
0xb5, 0x00, 0x40, 0x75, 0x00, 0x01,
];
const PT: &[u8] = &[
0x02, 0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x40, 0x5a, 0x02, 0x00, 0x00, 0x56, 0x03,
0x03, 0xee, 0xfc, 0xe7, 0xf7, 0xb3, 0x7b, 0xa1, 0xd1, 0x63, 0x2e, 0x96, 0x67, 0x78,
0x25, 0xdd, 0xf7, 0x39, 0x88, 0xcf, 0xc7, 0x98, 0x25, 0xdf, 0x56, 0x6d, 0xc5, 0x43,
0x0b, 0x9a, 0x04, 0x5a, 0x12, 0x00, 0x13, 0x01, 0x00, 0x00, 0x2e, 0x00, 0x33, 0x00,
0x24, 0x00, 0x1d, 0x00, 0x20, 0x9d, 0x3c, 0x94, 0x0d, 0x89, 0x69, 0x0b, 0x84, 0xd0,
0x8a, 0x60, 0x99, 0x3c, 0x14, 0x4e, 0xca, 0x68, 0x4d, 0x10, 0x81, 0x28, 0x7c, 0x83,
0x4d, 0x53, 0x11, 0xbc, 0xf3, 0x2b, 0xb9, 0xda, 0x1a, 0x00, 0x2b, 0x00, 0x02, 0x03,
0x04,
];
const CT: &[u8] = &[
0x5a, 0x48, 0x2c, 0xd0, 0x99, 0x1c, 0xd2, 0x5b, 0x0a, 0xac, 0x40, 0x6a, 0x58, 0x16,
0xb6, 0x39, 0x41, 0x00, 0xf3, 0x7a, 0x1c, 0x69, 0x79, 0x75, 0x54, 0x78, 0x0b, 0xb3,
0x8c, 0xc5, 0xa9, 0x9f, 0x5e, 0xde, 0x4c, 0xf7, 0x3c, 0x3e, 0xc2, 0x49, 0x3a, 0x18,
0x39, 0xb3, 0xdb, 0xcb, 0xa3, 0xf6, 0xea, 0x46, 0xc5, 0xb7, 0x68, 0x4d, 0xf3, 0x54,
0x8e, 0x7d, 0xde, 0xb9, 0xc3, 0xbf, 0x9c, 0x73, 0xcc, 0x3f, 0x3b, 0xde, 0xd7, 0x4b,
0x56, 0x2b, 0xfb, 0x19, 0xfb, 0x84, 0x02, 0x2f, 0x8e, 0xf4, 0xcd, 0xd9, 0x37, 0x95,
0xd7, 0x7d, 0x06, 0xed, 0xbb, 0x7a, 0xaf, 0x2f, 0x58, 0x89, 0x18, 0x50, 0xab, 0xbd,
0xca, 0x3d, 0x20, 0x39, 0x8c, 0x27, 0x64, 0x56, 0xcb, 0xc4, 0x21, 0x58, 0x40, 0x7d,
0xd0, 0x74, 0xee,
];
check0(ALG, KEY, NONCE, AAD, PT, CT);
decrypt(ALG, KEY, NONCE_BASE, 1, AAD, PT, CT);
}
#[test]
fn quic_chacha() {
const ALG: AeadAlgorithms = AeadAlgorithms::ChaCha20Poly1305;
const KEY: &[u8] = &[
0xc6, 0xd9, 0x8f, 0xf3, 0x44, 0x1c, 0x3f, 0xe1, 0xb2, 0x18, 0x20, 0x94, 0xf6, 0x9c,
0xaa, 0x2e, 0xd4, 0xb7, 0x16, 0xb6, 0x54, 0x88, 0x96, 0x0a, 0x7a, 0x98, 0x49, 0x79,
0xfb, 0x23, 0xe1, 0xc8,
];
const NONCE_BASE: &[u8; NONCE_LEN] = &[
0xe0, 0x45, 0x9b, 0x34, 0x74, 0xbd, 0xd0, 0xe4, 0x4a, 0x41, 0xc1, 0x44,
];
// Note that this integrates the sequence number of 654360564 from the example,
// otherwise we can't use a sequence number of 0 to encrypt.
const NONCE: &[u8; NONCE_LEN] = &[
0xe0, 0x45, 0x9b, 0x34, 0x74, 0xbd, 0xd0, 0xe4, 0x6d, 0x41, 0x7e, 0xb0,
];
const AAD: &[u8] = &[0x42, 0x00, 0xbf, 0xf4];
const PT: &[u8] = &[0x01];
const CT: &[u8] = &[
0x65, 0x5e, 0x5c, 0xd5, 0x5c, 0x41, 0xf6, 0x90, 0x80, 0x57, 0x5d, 0x79, 0x99, 0xc2,
0x5a, 0x5b, 0xfb,
];
check0(ALG, KEY, NONCE, AAD, PT, CT);
// Now use the real nonce and sequence number from the example.
decrypt(ALG, KEY, NONCE_BASE, 654_360_564, AAD, PT, CT);
}
}