Dorian 38c146c477 feat(firmware): MeshCore message RX — decrypt DMs addressed to us
- vendor orlp/ed25519 (lib/ed25519, MIT — the exact lib MeshCore uses) for
  Curve25519 ECDH key exchange; switch identity/advert signing to it (same
  seed -> same pubkey, so peers still recognise us; sigs are byte-identical)
- store pubkeys from heard MeshCore adverts (contacts table) so a DM's
  1-byte src_hash can be resolved to a full sender key
- decode PAYLOAD_TYPE_TXT_MSG: ECDH shared secret, HMAC-SHA256 MAC check,
  AES-128-ECB decrypt, parse timestamp+text, drive the message modal
- verified end-to-end: real MeshCore node -> "hello from HP Pro Desk" decoded

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-01 18:30:20 +01:00

42 lines
980 B
C

#ifndef FE_H
#define FE_H
#include "fixedint.h"
/*
fe means field element.
Here the field is \Z/(2^255-19).
An element t, entries t[0]...t[9], represents the integer
t[0]+2^26 t[1]+2^51 t[2]+2^77 t[3]+2^102 t[4]+...+2^230 t[9].
Bounds on each t[i] vary depending on context.
*/
typedef int32_t fe[10];
void fe_0(fe h);
void fe_1(fe h);
void fe_frombytes(fe h, const unsigned char *s);
void fe_tobytes(unsigned char *s, const fe h);
void fe_copy(fe h, const fe f);
int fe_isnegative(const fe f);
int fe_isnonzero(const fe f);
void fe_cmov(fe f, const fe g, unsigned int b);
void fe_cswap(fe f, fe g, unsigned int b);
void fe_neg(fe h, const fe f);
void fe_add(fe h, const fe f, const fe g);
void fe_invert(fe out, const fe z);
void fe_sq(fe h, const fe f);
void fe_sq2(fe h, const fe f);
void fe_mul(fe h, const fe f, const fe g);
void fe_mul121666(fe h, fe f);
void fe_pow22523(fe out, const fe z);
void fe_sub(fe h, const fe f, const fe g);
#endif