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Explicitly exclude code when disabling support features
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This will ensure that the DPE codesize is smaller when some
features are disabled.
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@sree-revoori1
sree-revoori1 committed May 4, 2024
1 parent 98c844b commit e24c6ae
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Showing 7 changed files with 202 additions and 115 deletions.
169 changes: 91 additions & 78 deletions dpe/src/commands/certify_key.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,9 @@ use caliptra_cfi_lib_git::cfi_launder;
use caliptra_cfi_lib_git::{cfi_assert, cfi_assert_eq};
use cfg_if::cfg_if;
use crypto::{Crypto, Hasher};
use platform::{Platform, PlatformError, MAX_ISSUER_NAME_SIZE, MAX_KEY_IDENTIFIER_SIZE};
use platform::{Platform, PlatformError, MAX_KEY_IDENTIFIER_SIZE};
#[cfg(not(feature = "disable_x509"))]
use platform::MAX_ISSUER_NAME_SIZE;

#[repr(C)]
#[derive(Debug, PartialEq, Eq, zerocopy::FromBytes, zerocopy::AsBytes)]
Expand Down Expand Up @@ -104,6 +106,7 @@ impl CommandExecution for CertifyKeyCmd {
#[cfg(not(feature = "no-cfi"))]
cfi_assert!(key_pair.is_err());
}
#[allow(unused_variables)]
let (priv_key, pub_key) = key_pair?;

let mut subj_serial = [0u8; DPE_PROFILE.get_hash_size() * 2];
Expand Down Expand Up @@ -158,91 +161,101 @@ impl CommandExecution for CertifyKeyCmd {
subject_alt_name,
};

let mut issuer_name = [0u8; MAX_ISSUER_NAME_SIZE];
let issuer_len = env.platform.get_issuer_name(&mut issuer_name)?;

let mut cert = [0u8; MAX_CERT_SIZE];
let cert_size = match self.format {
Self::FORMAT_X509 => {
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(self.format, Self::FORMAT_X509);
let mut tbs_buffer = [0u8; MAX_CERT_SIZE];
let mut tbs_writer = CertWriter::new(&mut tbs_buffer, true);
if issuer_len > MAX_ISSUER_NAME_SIZE {
return Err(DpeErrorCode::InternalError);
}
let cert_validity = env.platform.get_cert_validity()?;
let mut bytes_written = tbs_writer.encode_ecdsa_tbs(
/*serial=*/
&subject_name.serial.bytes()[..20], // Serial number must be truncated to 20 bytes
&issuer_name[..issuer_len],
&subject_name,
&pub_key,
&measurements,
&cert_validity,
)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}
#[cfg(not(feature = "disable_x509"))]
{
let mut issuer_name = [0u8; MAX_ISSUER_NAME_SIZE];
let issuer_len = env.platform.get_issuer_name(&mut issuer_name)?;
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(self.format, Self::FORMAT_X509);
let mut tbs_buffer = [0u8; MAX_CERT_SIZE];
let mut tbs_writer = CertWriter::new(&mut tbs_buffer, true);
if issuer_len > MAX_ISSUER_NAME_SIZE {
return Err(DpeErrorCode::InternalError);
}
let cert_validity = env.platform.get_cert_validity()?;
let mut bytes_written = tbs_writer.encode_ecdsa_tbs(
/*serial=*/
&subject_name.serial.bytes()[..20], // Serial number must be truncated to 20 bytes
&issuer_name[..issuer_len],
&subject_name,
&pub_key,
&measurements,
&cert_validity,
)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}

let tbs_digest = env
.crypto
.hash(DPE_PROFILE.alg_len(), &tbs_buffer[..bytes_written])?;
let sig = env
.crypto
.ecdsa_sign_with_alias(DPE_PROFILE.alg_len(), &tbs_digest)?;

let mut cert_writer = CertWriter::new(&mut cert, true);
bytes_written =
cert_writer.encode_ecdsa_certificate(&tbs_buffer[..bytes_written], &sig)?;
u32::try_from(bytes_written).map_err(|_| DpeErrorCode::InternalError)?
let tbs_digest = env
.crypto
.hash(DPE_PROFILE.alg_len(), &tbs_buffer[..bytes_written])?;
let sig = env
.crypto
.ecdsa_sign_with_alias(DPE_PROFILE.alg_len(), &tbs_digest)?;

let mut cert_writer = CertWriter::new(&mut cert, true);
bytes_written =
cert_writer.encode_ecdsa_certificate(&tbs_buffer[..bytes_written], &sig)?;
u32::try_from(bytes_written).map_err(|_| DpeErrorCode::InternalError)?
}
#[cfg(feature = "disable_x509")]
Err(DpeErrorCode::InternalError)?
}
Self::FORMAT_CSR => {
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(self.format, Self::FORMAT_CSR);
let mut cert_req_info_buffer = [0u8; MAX_CERT_SIZE];
let mut cert_req_info_writer = CertWriter::new(&mut cert_req_info_buffer, true);
let mut bytes_written = cert_req_info_writer.encode_certification_request_info(
&pub_key,
&subject_name,
&measurements,
)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}
#[cfg(not(feature = "disable_csr"))]
{
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(self.format, Self::FORMAT_CSR);
let mut cert_req_info_buffer = [0u8; MAX_CERT_SIZE];
let mut cert_req_info_writer = CertWriter::new(&mut cert_req_info_buffer, true);
let mut bytes_written = cert_req_info_writer
.encode_certification_request_info(
&pub_key,
&subject_name,
&measurements,
)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}

let cert_req_info_digest = env.crypto.hash(
DPE_PROFILE.alg_len(),
&cert_req_info_buffer[..bytes_written],
)?;
// The PKCS#10 CSR is self-signed so the private key signs it instead of the alias key.
let cert_req_info_sig = env.crypto.ecdsa_sign_with_derived(
DPE_PROFILE.alg_len(),
&cert_req_info_digest,
&priv_key,
&pub_key,
)?;

let mut csr_buffer = [0u8; MAX_CERT_SIZE];
let mut csr_writer = CertWriter::new(&mut csr_buffer, true);
bytes_written = csr_writer
.encode_csr(&cert_req_info_buffer[..bytes_written], &cert_req_info_sig)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}
let cert_req_info_digest = env.crypto.hash(
DPE_PROFILE.alg_len(),
&cert_req_info_buffer[..bytes_written],
)?;
// The PKCS#10 CSR is self-signed so the private key signs it instead of the alias key.
let cert_req_info_sig = env.crypto.ecdsa_sign_with_derived(
DPE_PROFILE.alg_len(),
&cert_req_info_digest,
&priv_key,
&pub_key,
)?;

let mut csr_buffer = [0u8; MAX_CERT_SIZE];
let mut csr_writer = CertWriter::new(&mut csr_buffer, true);
bytes_written = csr_writer
.encode_csr(&cert_req_info_buffer[..bytes_written], &cert_req_info_sig)?;
if bytes_written > MAX_CERT_SIZE {
return Err(DpeErrorCode::InternalError);
}

let csr_digest = env
.crypto
.hash(DPE_PROFILE.alg_len(), &csr_buffer[..bytes_written])?;
let csr_sig = env
.crypto
.ecdsa_sign_with_alias(DPE_PROFILE.alg_len(), &csr_digest)?;
let sid = env.platform.get_signer_identifier()?;

let mut cms_writer = CertWriter::new(&mut cert, true);
bytes_written =
cms_writer.encode_cms(&csr_buffer[..bytes_written], &csr_sig, &sid)?;
u32::try_from(bytes_written).map_err(|_| DpeErrorCode::InternalError)?
let csr_digest = env
.crypto
.hash(DPE_PROFILE.alg_len(), &csr_buffer[..bytes_written])?;
let csr_sig = env
.crypto
.ecdsa_sign_with_alias(DPE_PROFILE.alg_len(), &csr_digest)?;
let sid = env.platform.get_signer_identifier()?;

let mut cms_writer = CertWriter::new(&mut cert, true);
bytes_written =
cms_writer.encode_cms(&csr_buffer[..bytes_written], &csr_sig, &sid)?;
u32::try_from(bytes_written).map_err(|_| DpeErrorCode::InternalError)?
}
#[cfg(feature = "disable_csr")]
Err(DpeErrorCode::InternalError)?
}
_ => return Err(DpeErrorCode::InvalidArgument),
};
Expand Down
60 changes: 33 additions & 27 deletions dpe/src/commands/derive_context.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -181,6 +181,7 @@ impl CommandExecution for DeriveContextCmd {
|| (!dpe.support.retain_parent_context() && self.retains_parent())
|| (!dpe.support.is_ca() && self.allows_ca())
|| (!dpe.support.x509() && self.allows_x509())
|| (!dpe.support.recursive() && self.is_recursive())
{
return Err(DpeErrorCode::ArgumentNotSupported);
}
Expand Down Expand Up @@ -217,34 +218,39 @@ impl CommandExecution for DeriveContextCmd {
}

if self.is_recursive() {
let mut tmp_context = dpe.contexts[parent_idx];
if tmp_context.tci.tci_type != self.tci_type {
return Err(DpeErrorCode::InvalidArgument);
} else {
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(tmp_context.tci.tci_type, self.tci_type);
#[cfg(not(feature = "disable_recursive"))]
{
let mut tmp_context = dpe.contexts[parent_idx];
if tmp_context.tci.tci_type != self.tci_type {
return Err(DpeErrorCode::InvalidArgument);
} else {
#[cfg(not(feature = "no-cfi"))]
cfi_assert_eq(tmp_context.tci.tci_type, self.tci_type);
}
dpe.add_tci_measurement(
env,
&mut tmp_context,
&TciMeasurement(self.data),
target_locality,
)?;

// Rotate the handle if it isn't the default context.
dpe.roll_onetime_use_handle(env, parent_idx)?;

dpe.contexts[parent_idx] = Context {
handle: dpe.contexts[parent_idx].handle,
..tmp_context
};

// No child context created so handle is unmeaningful
Ok(Response::DeriveContext(DeriveContextResp {
handle: ContextHandle::default(),
parent_handle: dpe.contexts[parent_idx].handle,
resp_hdr: ResponseHdr::new(DpeErrorCode::NoError),
}))
}
dpe.add_tci_measurement(
env,
&mut tmp_context,
&TciMeasurement(self.data),
target_locality,
)?;

// Rotate the handle if it isn't the default context.
dpe.roll_onetime_use_handle(env, parent_idx)?;

dpe.contexts[parent_idx] = Context {
handle: dpe.contexts[parent_idx].handle,
..tmp_context
};

// No child context created so handle is unmeaningful
Ok(Response::DeriveContext(DeriveContextResp {
handle: ContextHandle::default(),
parent_handle: dpe.contexts[parent_idx].handle,
resp_hdr: ResponseHdr::new(DpeErrorCode::NoError),
}))
#[cfg(feature = "disable_recursive")]
Err(DpeErrorCode::InternalError)?
} else {
let child_idx = dpe
.get_next_inactive_context_pos()
Expand Down
7 changes: 6 additions & 1 deletion dpe/src/commands/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ pub use self::get_certificate_chain::GetCertificateChainCmd;
pub use self::initialize_context::InitCtxCmd;

pub use self::certify_key::{CertifyKeyCmd, CertifyKeyFlags};

#[cfg(not(feature = "disable_rotate_context"))]
pub use self::rotate_context::{RotateCtxCmd, RotateCtxFlags};
pub use self::sign::{SignCmd, SignFlags};

Expand All @@ -27,6 +27,7 @@ mod derive_context;
mod destroy_context;
mod get_certificate_chain;
mod initialize_context;
#[cfg(not(feature = "disable_rotate_context"))]
mod rotate_context;
mod sign;

Expand All @@ -37,6 +38,7 @@ pub enum Command {
DeriveContext(DeriveContextCmd),
CertifyKey(CertifyKeyCmd),
Sign(SignCmd),
#[cfg(not(feature = "disable_rotate_context"))]
RotateCtx(RotateCtxCmd),
DestroyCtx(DestroyCtxCmd),
GetCertificateChain(GetCertificateChainCmd),
Expand All @@ -48,6 +50,7 @@ impl Command {
pub const DERIVE_CONTEXT: u32 = 0x08;
pub const CERTIFY_KEY: u32 = 0x09;
pub const SIGN: u32 = 0x0A;
#[cfg(not(feature = "disable_rotate_context"))]
pub const ROTATE_CONTEXT_HANDLE: u32 = 0x0e;
pub const DESTROY_CONTEXT: u32 = 0x0f;
pub const GET_CERTIFICATE_CHAIN: u32 = 0x10;
Expand All @@ -67,6 +70,7 @@ impl Command {
Command::DERIVE_CONTEXT => Self::parse_command(Command::DeriveContext, bytes),
Command::CERTIFY_KEY => Self::parse_command(Command::CertifyKey, bytes),
Command::SIGN => Self::parse_command(Command::Sign, bytes),
#[cfg(not(feature = "disable_rotate_context"))]
Command::ROTATE_CONTEXT_HANDLE => Self::parse_command(Command::RotateCtx, bytes),
Command::DESTROY_CONTEXT => Self::parse_command(Command::DestroyCtx, bytes),
Command::GET_CERTIFICATE_CHAIN => {
Expand Down Expand Up @@ -94,6 +98,7 @@ impl From<Command> for u32 {
Command::DeriveContext(_) => Command::DERIVE_CONTEXT,
Command::CertifyKey(_) => Command::CERTIFY_KEY,
Command::Sign(_) => Command::SIGN,
#[cfg(not(feature = "disable_rotate_context"))]
Command::RotateCtx(_) => Command::ROTATE_CONTEXT_HANDLE,
Command::DestroyCtx(_) => Command::DESTROY_CONTEXT,
Command::GetCertificateChain(_) => Command::GET_CERTIFICATE_CHAIN,
Expand Down
19 changes: 13 additions & 6 deletions dpe/src/commands/sign.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,9 @@ use caliptra_cfi_lib_git::cfi_launder;
#[cfg(not(feature = "no-cfi"))]
use caliptra_cfi_lib_git::{cfi_assert, cfi_assert_eq, cfi_assert_ne};
use cfg_if::cfg_if;
use crypto::{Crypto, CryptoBuf, Digest, EcdsaSig, HmacSig};
use crypto::{Crypto, Digest, EcdsaSig};
#[cfg(not(feature = "disable_is_symmetric"))]
use crypto::{CryptoBuf, HmacSig};

#[repr(C)]
#[derive(Debug, PartialEq, Eq, zerocopy::AsBytes, zerocopy::FromBytes)]
Expand Down Expand Up @@ -86,6 +88,7 @@ impl SignCmd {
/// * `idx` - The index of the context where the measurement hash is computed from
/// * `digest` - The data to be signed
#[cfg_attr(not(feature = "no-cfi"), cfi_impl_fn)]
#[cfg(not(feature = "disable_is_symmetric"))]
fn hmac_sign(
&self,
dpe: &mut DpeInstance,
Expand Down Expand Up @@ -138,15 +141,19 @@ impl CommandExecution for SignCmd {
}
}

let algs = DPE_PROFILE.alg_len();
let digest = Digest::new(&self.digest)?;

let EcdsaSig { r, s } = if !self.uses_symmetric() {
self.ecdsa_sign(dpe, env, idx, &digest)?
} else {
let r = self.hmac_sign(dpe, env, idx, &digest)?;
let s = CryptoBuf::default(algs);
EcdsaSig { r, s }
#[cfg(not(feature = "disable_is_symmetric"))]
{
let algs = DPE_PROFILE.alg_len();
let r = self.hmac_sign(dpe, env, idx, &digest)?;
let s = CryptoBuf::default(algs);
EcdsaSig { r, s }
}
#[cfg(feature = "disable_is_symmetric")]
Err(DpeErrorCode::InternalError)?
};

let sig_r_or_hmac: [u8; DPE_PROFILE.get_ecc_int_size()] = r
Expand Down
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