Initial commit

src/Identity.h

@@ -0,0 +1,75 @@
+#pragma once
+
+#include <Utils.h>
+#include <Stream.h>
+
+namespace mesh {
+
+/**
+ * \brief  An identity in the mesh, with given Ed25519 public key, ie. a party whose signatures can be VERIFIED.
+*/
+class Identity {
+public:
+  uint8_t pub_key[PUB_KEY_SIZE];
+
+  Identity();
+  Identity(const char* pub_hex);
+  Identity(const uint8_t* _pub) { memcpy(pub_key, _pub, PUB_KEY_SIZE); }
+
+  int copyHashTo(uint8_t* dest) const { 
+    memcpy(dest, pub_key, PATH_HASH_SIZE);    // hash is just prefix of pub_key
+    return PATH_HASH_SIZE;
+  }
+  bool isHashMatch(const uint8_t* hash) const {
+    return memcmp(hash, pub_key, PATH_HASH_SIZE) == 0;
+  }
+
+  /**
+   * \brief  Performs Ed25519 signature verification.
+   * \param sig IN - must be SIGNATURE_SIZE buffer.
+   * \param message IN - the original message which was signed.
+   * \param msg_len IN - the length in bytes of message.
+   * \returns true, if signature is valid.
+  */
+  bool verify(const uint8_t* sig, const uint8_t* message, int msg_len) const;
+
+  bool matches(const Identity& other) const { return memcmp(pub_key, other.pub_key, PUB_KEY_SIZE) == 0; }
+  bool matches(const uint8_t* other_pubkey) const { return memcmp(pub_key, other_pubkey, PUB_KEY_SIZE) == 0; }
+
+  bool readFrom(Stream& s);
+  bool writeTo(Stream& s) const;
+  void printTo(Stream& s) const;
+};
+
+/**
+ * \brief  An Identity generated on THIS device, ie. with public/private Ed25519 key pair being on this device.
+*/
+class LocalIdentity : public Identity {
+  uint8_t prv_key[PRV_KEY_SIZE];
+public:
+  LocalIdentity();
+  LocalIdentity(const char* prv_hex, const char* pub_hex);
+  LocalIdentity(RNG* rng);   // create new random
+
+  /**
+   * \brief  Ed25519 digital signature.
+   * \param sig OUT - must be SIGNATURE_SIZE buffer.
+   * \param message IN - the raw message bytes to sign.
+   * \param msg_len IN - the length in bytes of message.
+  */
+  void sign(uint8_t* sig, const uint8_t* message, int msg_len) const;
+
+  /**
+   * \brief  the ECDH key exhange, with Ed25519 public key transposed to Ex25519.
+   * \param  secret OUT - the 'shared secret' (must be PUB_KEY_SIZE bytes)
+   * \param  other IN - the second party in the exchange.
+  */
+  void calcSharedSecret(uint8_t* secret, const Identity& other);
+
+  bool readFrom(Stream& s);
+  bool writeTo(Stream& s) const;
+  void printTo(Stream& s) const;
+};
+
+}
+