Revert identity change

Author: Alex Wolden

platformio.ini

@@ -349,9 +349,9 @@ build_flags =
   -D P_LORA_TX_LED=2    ; LED pin for TX indication
   -D PIN_VBAT_READ=35   ; Battery voltage reading (analog pin) 
   -D RADIO_CLASS=CustomSX1276
+  -D ARDUINO_LOOP_STACK_SIZE=16384
   -D WRAPPER_CLASS=CustomSX1276Wrapper
   -D LORA_TX_POWER=20
-  -D USE_ESP32_ENCRYPTION=true
 
 ; =============
 [LilyGo_T3S3_sx1262]

src/Identity.cpp

@@ -3,11 +3,6 @@
 #define ED25519_NO_SEED  1
 #include <ed_25519.h>
 
-// For weaker ESP32 boards, we use libsodium for cryptographic operations to reduce stack usage
-#ifdef USE_ESP32_ENCRYPTION
-#include <sodium.h>
-#endif
-
 namespace mesh {
 
 Identity::Identity() {
@@ -19,11 +14,7 @@ Identity::Identity(const char* pub_hex) {
 }
 
 bool Identity::verify(const uint8_t* sig, const uint8_t* message, int msg_len) const {
-  #ifdef USE_ESP32_ENCRYPTION
-    return crypto_sign_ed25519_verify_detached(sig, message, msg_len, pub_key) == 0;
-  #else
-    return ed25519_verify(sig, message, msg_len, pub_key);
-  #endif
+  return ed25519_verify(sig, message, msg_len, pub_key);
 }
 
 bool Identity::readFrom(Stream& s) {
@@ -41,29 +32,14 @@ void Identity::printTo(Stream& s) const {
 LocalIdentity::LocalIdentity() {
   memset(prv_key, 0, sizeof(prv_key));
 }
-
 LocalIdentity::LocalIdentity(const char* prv_hex, const char* pub_hex) : Identity(pub_hex) {
   Utils::fromHex(prv_key, PRV_KEY_SIZE, prv_hex);
 }
 
 LocalIdentity::LocalIdentity(RNG* rng) {
   uint8_t seed[SEED_SIZE];
   rng->random(seed, SEED_SIZE);
-  
-  #ifdef USE_ESP32_ENCRYPTION
-    // Use libsodium for keypair generation on ESP32 to reduce stack usage
-    // NOTE: Format differences between implementations:
-    // - The current ed25519 implementation (orlp/ed25519) uses a 64-byte private key format
-    // - Libsodium also uses a 64-byte format for Ed25519 secret keys, where:
-    //   * First 32 bytes: the actual private key seed
-    //   * Last 32 bytes: the corresponding public key
-    
-    // Generate keypair using libsodium with the provided seed
-    // This avoids the deep stack usage of the default implementation
-    crypto_sign_ed25519_seed_keypair(pub_key, prv_key, seed);
-  #else
-    ed25519_create_keypair(pub_key, prv_key, seed);
-  #endif
+  ed25519_create_keypair(pub_key, prv_key, seed);
 }
 
 bool LocalIdentity::readFrom(Stream& s) {
@@ -101,46 +77,17 @@ void LocalIdentity::readFrom(const uint8_t* src, size_t len) {
     memcpy(pub_key, &src[PRV_KEY_SIZE], PUB_KEY_SIZE);
   } else if (len == PRV_KEY_SIZE) {
     memcpy(prv_key, src, PRV_KEY_SIZE);
-    
-  #ifdef USE_ESP32_ENCRYPTION
-      // In libsodium, the private key already contains the public key in its last 32 bytes
-      // We can just extract it directly, avoiding the expensive derivation calculation
-      memcpy(pub_key, prv_key + 32, 32);
-  #else
-      // now need to re-calculate the pub_key
-      ed25519_derive_pub(pub_key, prv_key);
-  #endif
+    // now need to re-calculate the pub_key
+    ed25519_derive_pub(pub_key, prv_key);
   }
 }
 
 void LocalIdentity::sign(uint8_t* sig, const uint8_t* message, int msg_len) const {
-  #ifdef USE_ESP32_ENCRYPTION
-    crypto_sign_ed25519_detached(sig, NULL, message, msg_len, prv_key);
-  #else
-    ed25519_sign(sig, message, msg_len, pub_key, prv_key);
-  #endif
+  ed25519_sign(sig, message, msg_len, pub_key, prv_key);
 }
 
 void LocalIdentity::calcSharedSecret(uint8_t* secret, const uint8_t* other_pub_key) {
-  #ifdef USE_ESP32_ENCRYPTION
-    // NOTE: To calculate a shared secret with Ed25519 keys and libsodium, we need to:
-    // Convert the Ed25519 keys to Curve25519 (X25519) format
-    // Perform the key exchange using the converted keys
-    //
-    // The default implementation handles this conversion internally,
-    // but with libsodium we need to do these steps explicitly.    
-    unsigned char x25519_pk[crypto_scalarmult_curve25519_BYTES];
-    unsigned char x25519_sk[crypto_scalarmult_curve25519_BYTES];
-    
-    // Convert Ed25519 keys to Curve25519 keys for ECDH
-    crypto_sign_ed25519_pk_to_curve25519(x25519_pk, other_pub_key);
-    crypto_sign_ed25519_sk_to_curve25519(x25519_sk, prv_key);
-    
-    // Calculate shared secret using X25519
-    crypto_scalarmult_curve25519(secret, x25519_sk, x25519_pk);
-  #else
-    ed25519_key_exchange(secret, other_pub_key, prv_key);
-  #endif
+  ed25519_key_exchange(secret, other_pub_key, prv_key);
 }
 
 }