Fixed EncryptedIntroSet signing to use PrivateKey

We can generate both root and derived signatures from a PrivateKey, but
only root from a SecretKey, so just change it to use a PrivateKey.

llarp/service/identity.cpp

@@ -181,10 +181,8 @@ namespace llarp
       CryptoManager::instance()->xchacha20(buf, k, encrypted.nounce);
       encrypted.introsetPayload.resize(buf.sz);
       std::copy_n(buf.base, buf.sz, encrypted.introsetPayload.data());
-      /* FIXME
       if(not encrypted.Sign(derivedSignKey))
         return {};
-      */
       return encrypted;
     }
   }  // namespace service

llarp/service/intro_set.cpp

@@ -104,10 +104,11 @@ namespace llarp
     }
 
     bool
-    EncryptedIntroSet::Sign(const SecretKey& k)
+    EncryptedIntroSet::Sign(const PrivateKey& k)
     {
-      signedAt          = llarp::time_now_ms();
-      derivedSigningKey = k.toPublic();
+      signedAt = llarp::time_now_ms();
+      if (not k.toPublic(derivedSigningKey))
+        return false;
       sig.Zero();
       std::array< byte_t, MAX_INTROSET_SIZE + 128 > tmp;
       llarp_buffer_t buf(tmp);

llarp/service/intro_set.hpp

@@ -102,7 +102,7 @@ namespace llarp
       return i.print(out, -1, -1);
     }
 
-    /// public version of the intrset that is encrypted
+    /// public version of the introset that is encrypted
     struct EncryptedIntroSet
     {
       using Payload_t = std::vector< byte_t >;
@@ -115,7 +115,7 @@ namespace llarp
       Signature sig;
 
       bool
-      Sign(const SecretKey& k);
+      Sign(const PrivateKey& k);
 
       bool
       IsExpired(llarp_time_t now) const;

test/service/test_llarp_service_identity.cpp

@@ -316,11 +316,9 @@ TEST_F(RealCryptographyTest, TestEncryptAndSignIntroSet)
 
   const auto maybe = ident.EncryptAndSignIntroSet(I, now);
   ASSERT_TRUE(maybe.has_value());
-  llarp::LogInfo("introset=", maybe.value());
   ASSERT_TRUE(maybe->Verify(now));
   PubKey blind_key;
   const PubKey root_key(addr.as_array());
   auto crypto = CryptoManager::instance();
   ASSERT_TRUE(crypto->derive_subkey(blind_key, root_key, 1));
-  ASSERT_EQ(blind_key, root_key);
 }