Skip to content

Commit

Permalink
[feat] ROM ALIAS FMC DICE changes for MLDSA support
Browse files Browse the repository at this point in the history
  • Loading branch information
@mhatrevi
mhatrevi committed Nov 20, 2024
1 parent 98df8cb commit cf0bbde
Show file tree
Hide file tree
Showing 2 changed files with 45 additions and 27 deletions.
56 changes: 37 additions & 19 deletions rom/dev/src/flow/cold_reset/fmc_alias.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,10 +48,15 @@ impl FmcAliasLayer {
) -> CaliptraResult<()> {
cprintln!("[afmc] ++");
cprintln!("[afmc] CDI.KEYID = {}", KEY_ID_ROM_FMC_CDI as u8);
cprintln!("[afmc] SUBJECT.KEYID = {}", KEY_ID_FMC_ECDSA_PRIV_KEY as u8);
cprintln!(
"[afmc] ECC AUTHORITY.KEYID = {}",
input.ecc_auth_key_pair.priv_key as u8
"[afmc] ECC SUBJECT.KEYID = {}, MLDSA SUBJECT.KEYID = {}",
KEY_ID_FMC_ECDSA_PRIV_KEY as u8,
KEY_ID_FMC_MLDSA_KEYPAIR_SEED as u8
);
cprintln!(
"[afmc] ECC AUTHORITY.KEYID = {}, MLDSA AUTHORITY.KEYID = {}",
input.ecc_auth_key_pair.priv_key as u8,
input.mldsa_auth_key_pair.key_pair_seed as u8
);

// We use the value of PCR0 as the measurement for deriving the CDI.
Expand All @@ -62,31 +67,34 @@ impl FmcAliasLayer {
measurement.0.zeroize();
result?;

// Derive DICE Key Pair from CDI
let ecc_key_pair =
Self::derive_key_pair(env, KEY_ID_ROM_FMC_CDI, KEY_ID_FMC_ECDSA_PRIV_KEY)?;
// Derive DICE ECC and MLDSA Key Pairs from CDI
let (ecc_key_pair, mldsa_key_pair) = Self::derive_key_pair(
env,
KEY_ID_ROM_FMC_CDI,
KEY_ID_FMC_ECDSA_PRIV_KEY,
KEY_ID_FMC_MLDSA_KEYPAIR_SEED,
)?;

// Generate the Subject Serial Number and Subject Key Identifier.
//
// This information will be used by next DICE Layer while generating
// certificates
let ecc_subj_sn = X509::subj_sn(env, &PubKey::Ecc(&ecc_key_pair.pub_key))?;
let mldsa_subj_sn = X509::subj_sn(env, &PubKey::Mldsa(&mldsa_key_pair.pub_key))?;
report_boot_status(FmcAliasSubjIdSnGenerationComplete.into());

let ecc_subj_key_id = X509::subj_key_id(env, &PubKey::Ecc(&ecc_key_pair.pub_key))?;
let mldsa_subj_key_id = X509::subj_key_id(env, &PubKey::Mldsa(&mldsa_key_pair.pub_key))?;
report_boot_status(FmcAliasSubjKeyIdGenerationComplete.into());

// Generate the output for next layer
let mut output = DiceOutput {
ecc_subj_key_pair: ecc_key_pair,
ecc_subj_sn,
ecc_subj_key_id,
mldsa_subj_key_id: [0; 20],
mldsa_subj_key_pair: MlDsaKeyPair {
key_pair_seed: KEY_ID_FMC_MLDSA_KEYPAIR_SEED,
pub_key: Default::default(),
},
mldsa_subj_sn: [0; 64],
mldsa_subj_key_pair: mldsa_key_pair,
mldsa_subj_sn,
mldsa_subj_key_id,
};

// Generate FMC Alias Certificate
Expand All @@ -111,7 +119,7 @@ impl FmcAliasLayer {
fn derive_cdi(env: &mut RomEnv, measurements: &Array4x12, cdi: KeyId) -> CaliptraResult<()> {
let mut measurements: [u8; 48] = measurements.into();

let result = Crypto::hmac384_kdf(env, cdi, b"fmc_alias_cdi", Some(&measurements), cdi);
let result = Crypto::hmac384_kdf(env, cdi, b"alias_fmc_cdi", Some(&measurements), cdi);
measurements.zeroize();
result?;
report_boot_status(FmcAliasDeriveCdiComplete.into());
Expand All @@ -124,7 +132,8 @@ impl FmcAliasLayer {
///
/// * `env` - ROM Environment
/// * `cdi` - Composite Device Identity
/// * `priv_key` - Key slot to store the private key into
/// * `ecc_priv_key` - Key slot to store the ECC private key into
/// * `mldsa_keypair_seed` - Key slot to store the MLDSA key pair seed
///
/// # Returns
///
Expand All @@ -133,16 +142,23 @@ impl FmcAliasLayer {
fn derive_key_pair(
env: &mut RomEnv,
cdi: KeyId,
priv_key: KeyId,
) -> CaliptraResult<Ecc384KeyPair> {
let result = Crypto::ecc384_key_gen(env, cdi, b"fmc_alias_keygen", priv_key);
ecc_priv_key: KeyId,
mldsa_keypair_seed: KeyId,
) -> CaliptraResult<(Ecc384KeyPair, MlDsaKeyPair)> {
let result = Crypto::ecc384_key_gen(env, cdi, b"alias_fmc_ecc_key", ecc_priv_key);
if cfi_launder(result.is_ok()) {
cfi_assert!(result.is_ok());
report_boot_status(FmcAliasKeyPairDerivationComplete.into());
} else {
cfi_assert!(result.is_err());
}
result
let ecc_keypair = result?;

// Derive the MLDSA Key Pair.
let mldsa_key_pair =
Crypto::mldsa_key_gen(env, cdi, b"alias_fmc_mldsa_key", mldsa_keypair_seed)?;

report_boot_status(FmcAliasKeyPairDerivationComplete.into());
Ok((ecc_keypair, mldsa_key_pair))
}

/// Generate Local Device ID Certificate Signature
Expand Down Expand Up @@ -240,6 +256,8 @@ impl FmcAliasLayer {
// Copy TBS to DCCM.
copy_tbs(tbs.tbs(), TbsType::FmcaliasTbs, env)?;

// [CAP2][TODO] Generate MLDSA certificate signature, TBS.

report_boot_status(FmcAliasCertSigGenerationComplete.into());
Ok(())
}
Expand Down
16 changes: 8 additions & 8 deletions test/src/derive.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -420,14 +420,14 @@ impl FmcAliasKey {
pub fn derive(pcr0: &Pcr0, ldevid: &LDevId) -> Self {
let mut cdi: [u32; 12] = transmute!(hmac384_kdf(
swap_word_bytes(&ldevid.cdi).as_bytes(),
b"fmc_alias_cdi",
b"alias_fmc_cdi",
Some(swap_word_bytes(&pcr0.0).as_bytes()),
));
swap_word_bytes_inplace(&mut cdi);

let mut priv_key_seed: [u32; 12] = transmute!(hmac384_kdf(
swap_word_bytes(&cdi).as_bytes(),
b"fmc_alias_keygen",
b"alias_fmc_ecc_key",
None
));
swap_word_bytes_inplace(&mut priv_key_seed);
Expand Down Expand Up @@ -519,13 +519,13 @@ fn test_derive_fmc_alias_key() {
assert_eq!(
fmc_alias_key,
FmcAliasKey {
cdi: [
0xf4fb8b09, 0xc9233adb, 0x3dfade39, 0xb656f0ef, 0x151404dc, 0xf4fe787a, 0x0664baea,
0xe9d2de59, 0x22401c7c, 0x59087111, 0xd3aeb5b1, 0x368742da
],
priv_key: [
0x81a4f53c, 0xeb0749ca, 0x77b0fe32, 0x33fd9798, 0x7412f652, 0xded8f8a5, 0x39a9ebbd,
0x75ce2870, 0xb5f62bb3, 0x25376504, 0xa34f286c, 0x849ea86c,
0xB0490161, 0xA1D2393A, 0x752E2F60, 0x4BB9A01E, 0x293B9E47, 0x61698007, 0x2CED9BAF,
0x1F828679, 0xCB5054CD, 0xFD0EB072, 0x8D6BE59F, 0x75C55332
],
cdi: [
0xCEAA7956, 0x4E5A8809, 0x7F1BF1B8, 0xA3A9C903, 0x37B4335F, 0xEA8A93D2, 0x5D02F1BF,
0x16B1A537, 0xFE5DB006, 0xD8427583, 0x72C836F1, 0x9BE74AF5,
],
}
);
Expand Down

0 comments on commit cf0bbde

Please sign in to comment.