IF: Use bls12_381::pop_prove to generate POP and add get_pop_str method to libfc

libraries/libfc/include/fc/crypto/bls_private_key.hpp

@@ -28,6 +28,7 @@ namespace fc::crypto::blslib {
 
          bls_public_key     get_public_key() const;
          bls_signature      sign( const std::vector<uint8_t>& message ) const;
+         std::string        get_pop_str() const;
 
          static bls_private_key generate();
 
@@ -45,4 +46,4 @@ namespace fc {
    void from_variant(const variant& var, crypto::blslib::bls_private_key& vo);
 } // namespace fc
 
-FC_REFLECT(crypto::blslib::bls_private_key, (_sk) )
+FC_REFLECT(crypto::blslib::bls_private_key, (_sk) )

libraries/libfc/src/crypto/bls_private_key.cpp

@@ -13,6 +13,14 @@ namespace fc::crypto::blslib {
       return bls_public_key(pk);
    }
 
+   std::string bls_private_key::get_pop_str() const
+   {
+      bls12_381::g2 proof = bls12_381::pop_prove(_sk);
+      constexpr bool raw = true;
+      std::array<uint8_t, 192> bytes = proof.toAffineBytesLE(raw);
+      return fc::crypto::blslib::serialize_base64<std::array<uint8_t, 192>>(bytes);
+   }
+
    bls_signature bls_private_key::sign( const std::vector<uint8_t>& message ) const
    {
       bls12_381::g2 sig = bls12_381::sign(_sk, message);

programs/leap-util/actions/bls.cpp

@@ -55,7 +55,7 @@ int bls_actions::create_key() {
    const bls_public_key public_key = private_key.get_public_key();
 
    // generate pop
-   const std::string pop_str = generate_pop_str(private_key);
+   const std::string pop_str = private_key.get_pop_str();
 
    // prepare output
    std::string out_str = "Private key: " + private_key.to_string({}) + "\n";
@@ -106,20 +106,10 @@ int bls_actions::create_pop() {
    // create private key object using input private key string
    const bls_private_key private_key = bls_private_key(private_key_str);
    const bls_public_key public_key = private_key.get_public_key();
-   std::string pop_str = generate_pop_str(private_key); 
+   std::string pop_str = private_key.get_pop_str();
 
    std::cout << "Proof of Possession: " << pop_str << "\n";
    std::cout << "Public key: " <<  public_key.to_string({}) << "\n";
 
    return 0;
 }
-
-std::string bls_actions::generate_pop_str(const bls_private_key& private_key) {
-   const bls_public_key public_key = private_key.get_public_key();
-
-   const std::array<uint8_t, 96> msg = public_key._pkey.toAffineBytesLE(true); // true means raw
-   const std::vector<uint8_t> msg_vector = std::vector<uint8_t>(msg.begin(), msg.end());
-   const bls_signature pop = private_key.sign(msg_vector);
-
-   return pop.to_string({});
-}

tests/leap_util_bls_test.py

@@ -100,13 +100,12 @@ def check_create_key_results(rslts):
     # check each output has valid value
     assert "PVT_BLS_" in results["Private key"]
     assert "PUB_BLS_" in results["Public key"]
-    assert "SIG_BLS_" in results["Proof of Possession"]
 
 def get_results(rslts):
     # sample output looks like
     # Private key: PVT_BLS_kRhJJ2MsM+/CddO...
     # Public key: PUB_BLS_lbUE8922wUfX0Iy5...
-    # Proof of Possession: SIG_BLS_olZfcFw...
+    # Proof of Possession: 3jwkVUUYahHgsnmnEA...
     pattern = r'(\w+[^:]*): ([^\n]+)'
     matched= re.findall(pattern, rslts)