mirror of
https://github.com/saymrwulf/betrusted-curve25519-dalek-source.git
synced 2026-09-04 20:24:07 +00:00
add fallback to field operations
this falls back to fiat-crypto primitives if the hw engine is unavailable.
This commit is contained in:
bunnie
parent
0b052f5f79
commit
94a47207d5
1 changed files with 185 additions and 96 deletions
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@ -24,8 +24,34 @@ use core::ops::{Sub, SubAssign};
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use subtle::Choice;
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use subtle::ConditionallySelectable;
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use core::fmt::Debug;
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use fiat_crypto::curve25519_32::*;
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use zeroize::Zeroize;
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#[derive(Copy, Clone)]
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pub struct FieldElement2625(pub(crate) fiat_25519_tight_field_element);
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impl Debug for FieldElement2625 {
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fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
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write!(f, "FieldElement2625({:?})", &(self.0).0[..])
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}
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}
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#[cfg(feature = "zeroize")]
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impl Zeroize for FieldElement2625 {
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fn zeroize(&mut self) {
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(self.0).0.zeroize();
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}
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}
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impl FieldElement2625 {
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pub(crate) const fn from_limbs(limbs: [u32; 10]) -> FieldElement2625 {
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FieldElement2625(fiat_25519_tight_field_element(limbs))
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}
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pub const ZERO: FieldElement2625 = FieldElement2625::from_limbs([0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
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}
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/// A `Engine25519` represents an element of the field
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/// \\( \mathbb Z / (2\^{255} - 19)\\).
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///
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@ -50,102 +76,169 @@ use zeroize::Zeroize;
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/// outside of the `curve25519_dalek::field` module.
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#[derive(Copy, Clone, Debug)]
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pub struct Engine25519(
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pub (crate) [u8; 32]
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);
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pub struct Engine25519(pub(crate) [u8; 32]);
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pub(crate) enum EngineOp {
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Mul,
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Add,
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Sub,
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}
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pub fn bytes_to_fiat(data: &[u8; 32]) -> FieldElement2625 {
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let mut temp = [0u8; 32];
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temp.copy_from_slice(data);
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temp[31] &= 127u8;
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let mut output = fiat_25519_tight_field_element([0u32; 10]);
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fiat_25519_from_bytes(&mut output, &temp);
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FieldElement2625(output)
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}
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pub fn fiat_to_bytes(fiat_rep: &fiat_25519_tight_field_element) -> [u8; 32] {
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let mut bytes = [0u8; 32];
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fiat_25519_to_bytes(&mut bytes, fiat_rep);
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bytes
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}
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#[allow(unused_qualifications)]
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pub(crate) fn engine(a: &[u8; 32], b: &[u8; 32], op: EngineOp) -> Engine25519 {
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use utralib::generated::*;
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use crate::backend::serial::u32e::*;
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crate::backend::serial::u32e::ensure_engine();
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let mut engine = utralib::CSR::new(unsafe{ENGINE_BASE.unwrap()}.as_mut_ptr() as *mut u32);
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let mcode: &'static mut [u32] = unsafe{
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core::slice::from_raw_parts_mut(ENGINE_MEM.unwrap().as_mut_ptr() as *mut u32, 1024)
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};
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let rf: [&'static mut [u32]; 3] = [
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unsafe{core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 0 * 32) as *mut u32, 8)},
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unsafe{core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 1 * 32) as *mut u32, 8)},
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unsafe{core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 2 * 32) as *mut u32, 8)},
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];
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match crate::backend::serial::u32e::ensure_engine() {
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Ok(_) => {
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let mut engine =
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utralib::CSR::new(unsafe { ENGINE_BASE.unwrap() }.as_mut_ptr() as *mut u32);
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let mcode: &'static mut [u32] = unsafe {
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core::slice::from_raw_parts_mut(ENGINE_MEM.unwrap().as_mut_ptr() as *mut u32, 1024)
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};
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let rf: [&'static mut [u32]; 3] = [
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unsafe {
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core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 0 * 32) as *mut u32,
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8,
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)
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},
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unsafe {
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core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 1 * 32) as *mut u32,
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8,
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)
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},
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unsafe {
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core::slice::from_raw_parts_mut(
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(ENGINE_MEM.unwrap().as_mut_ptr() as usize + 0x1_0000 + 2 * 32) as *mut u32,
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8,
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)
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},
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];
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match op {
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EngineOp::Mul => {
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let prog = assemble_engine25519!(
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start:
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mul %2, %0, %1
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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match op {
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EngineOp::Mul => {
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let prog = assemble_engine25519!(
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start:
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mul %2, %0, %1
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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}
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EngineOp::Add => {
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let prog = assemble_engine25519!(
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start:
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add %2, %0, %1
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trd %30, %2
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sub %2, %2, %30
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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}
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EngineOp::Sub => {
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let prog = assemble_engine25519!(
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start:
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sub %1, #3, %1
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add %2, %0, %1
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trd %30, %2
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sub %2, %2, %30
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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}
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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},
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EngineOp::Add => {
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let prog = assemble_engine25519!(
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start:
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add %2, %0, %1
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trd %30, %2
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sub %2, %2, %30
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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// copy a arg
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for (src, dst) in a.chunks_exact(4).zip(rf[0].iter_mut()) {
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let bytes: [u8; 4] = [src[0], src[1], src[2], src[3]];
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unsafe {
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(dst as *mut u32).write_volatile(u32::from_le_bytes(bytes));
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}
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/* this is a bad idea: src[0..4].try_into().unwrap()
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because "unwrap()" adds in a whole bunch of string formatting stuff, adds +16k or so to the binary size
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*/
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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},
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EngineOp::Sub => {
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let prog = assemble_engine25519!(
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start:
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sub %1, #3, %1
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add %2, %0, %1
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trd %30, %2
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sub %2, %2, %30
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fin
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);
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for (&src, dest) in prog.iter().zip(mcode.iter_mut()) {
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*dest = src;
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// copy b arg
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for (src, dst) in b.chunks_exact(4).zip(rf[1].iter_mut()) {
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let bytes: [u8; 4] = [src[0], src[1], src[2], src[3]];
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unsafe {
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(dst as *mut u32).write_volatile(u32::from_le_bytes(bytes));
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}
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}
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engine.wfo(utra::engine::MPLEN_MPLEN, prog.len() as u32);
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},
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}
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// copy a arg
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for (src, dst) in a.chunks_exact(4).zip(rf[0].iter_mut()) {
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let bytes: [u8; 4] = [src[0], src[1], src[2], src[3]];
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unsafe{ (dst as *mut u32).write_volatile(u32::from_le_bytes(bytes));}
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/* this is a bad idea: src[0..4].try_into().unwrap()
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because "unwrap()" adds in a whole bunch of string formatting stuff, adds +16k or so to the binary size
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*/
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}
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// copy b arg
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for (src, dst) in b.chunks_exact(4).zip(rf[1].iter_mut()) {
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let bytes: [u8; 4] = [src[0], src[1], src[2], src[3]];
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unsafe{ (dst as *mut u32).write_volatile(u32::from_le_bytes(bytes));}
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}
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engine.wfo(utra::engine::CONTROL_GO, 1);
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while engine.rf(utra::engine::STATUS_RUNNING) != 0 {}
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engine.wfo(utra::engine::CONTROL_GO, 1);
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while engine.rf(utra::engine::STATUS_RUNNING) != 0 {}
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// return result, always in reg 2
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let mut result: [u8; 32] = [0; 32];
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for (&src, dst) in rf[2].iter().zip(result.chunks_exact_mut(4)) {
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for (&sb, db) in src.to_le_bytes().iter().zip(dst.iter_mut()) {
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*db = sb;
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}
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}
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// return result, always in reg 2
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let mut result: [u8; 32] = [0; 32];
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for (&src, dst) in rf[2].iter().zip(result.chunks_exact_mut(4)) {
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for (&sb, db) in src.to_le_bytes().iter().zip(dst.iter_mut()) {
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*db = sb;
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Engine25519 { 0: result }
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}
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_ => {
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// fallback to fiat crypto field arithmetic...
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log::warn!("Hardware acceleration unavailable, falling back to software");
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let fiat_a = bytes_to_fiat(a);
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let fiat_b = bytes_to_fiat(b);
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match op {
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EngineOp::Mul => {
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let mut self_loose = fiat_25519_loose_field_element([0; 10]);
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fiat_25519_relax(&mut self_loose, &fiat_a.0);
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let mut rhs_loose = fiat_25519_loose_field_element([0; 10]);
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fiat_25519_relax(&mut rhs_loose, &fiat_b.0);
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let mut output = FieldElement2625::ZERO;
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fiat_25519_carry_mul(&mut output.0, &self_loose, &rhs_loose);
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Engine25519 {
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0: fiat_to_bytes(&output.0),
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}
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}
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EngineOp::Add => {
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let mut result_loose = fiat_25519_loose_field_element([0; 10]);
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fiat_25519_add(&mut result_loose, &fiat_a.0, &fiat_b.0);
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let mut output = FieldElement2625::ZERO;
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fiat_25519_carry(&mut output.0, &result_loose);
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Engine25519 {
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0: fiat_to_bytes(&output.0),
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}
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}
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EngineOp::Sub => {
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let mut result_loose = fiat_25519_loose_field_element([0; 10]);
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fiat_25519_sub(&mut result_loose, &fiat_a.0, &fiat_b.0);
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let mut output = FieldElement2625::ZERO;
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fiat_25519_carry(&mut output.0, &result_loose);
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Engine25519 {
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0: fiat_to_bytes(&output.0),
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}
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}
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}
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}
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}
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Engine25519 {
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0: result
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}
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}
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@ -210,11 +303,7 @@ impl<'a> Neg for &'a Engine25519 {
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}
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impl ConditionallySelectable for Engine25519 {
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fn conditional_select(
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a: &Engine25519,
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b: &Engine25519,
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choice: Choice,
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) -> Engine25519 {
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fn conditional_select(a: &Engine25519, b: &Engine25519, choice: Choice) -> Engine25519 {
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Engine25519([
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u8::conditional_select(&a.0[0], &b.0[0], choice),
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u8::conditional_select(&a.0[1], &b.0[1], choice),
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@ -330,22 +419,23 @@ impl Engine25519 {
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}
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/// Construct zero.
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pub const ZERO: Engine25519 = Engine25519([ 0 ; 32 ]);
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pub const ZERO: Engine25519 = Engine25519([0; 32]);
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/// Construct one.
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pub const ONE: Engine25519 = Engine25519([ 1, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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]);
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pub const ONE: Engine25519 = Engine25519([
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1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0,
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]);
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/// Construct -1.
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pub const MINUS_ONE: Engine25519 =
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Engine25519([236, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 127]);
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pub const MINUS_ONE: Engine25519 = Engine25519([
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236, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 127,
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]);
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/// Given `k > 0`, return `self^(2^k)`.
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pub fn pow2k(&self, k: u32) -> Engine25519 {
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debug_assert!( k > 0 );
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debug_assert!(k > 0);
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let mut z = self.square();
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for _ in 1..k {
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z = z.square();
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@ -364,12 +454,11 @@ impl Engine25519 {
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/// encoding of every field element should decode, re-encode to
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/// the canonical encoding, and check that the input was
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/// canonical.
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pub fn from_bytes(data: &[u8; 32]) -> Engine25519 { //FeFromBytes
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pub fn from_bytes(data: &[u8; 32]) -> Engine25519 {
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//FeFromBytes
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let mut mask_data = data.clone();
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mask_data[31] &= 0x7F; // mask off the high bit per comment above
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Engine25519 {
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0: mask_data,
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}
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Engine25519 { 0: mask_data }
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}
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/// Serialize this `FieldElement51` to a 32-byte array. The
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