Add connection token generation

3 files changed, 78 insertions, 25 deletions

diff --git a/include/signer/noscrypt_signer.hpp b/include/signer/noscrypt_signer.hpp
index b4ea5f7..d2135da 100644
--- a/include/signer/noscrypt_signer.hpp
+++ b/include/signer/noscrypt_signer.hpp
@@ -26,8 +26,8 @@ public:
 
     void receiveConnection(std::string connectionToken) override;
 
-    void initiateConnection(
-        std::string relay,
+    std::string initiateConnection(
+        std::vector<std::string> relays,
         std::string name,
         std::string url,
         std::string description) override;
@@ -39,6 +39,9 @@ private:
 
     std::string _localPrivateKey;
     std::string _localPublicKey;
+
+    ///< A list of relays that will be used to connect to the remote signer.
+    std::vector<std::string> _relays;
     
     /**
      * @brief Initializes the noscrypt library context into the class's `context` property.
@@ -57,11 +60,11 @@ private:
 
     #pragma region Logging
 
-    void _logNoscryptInitResult(NCResult result);
+    void _logNoscryptInitResult(NCResult initResult);
 
-    void _logNoscryptSecretKeyResult(NCResult result);
+    void _logNoscryptSecretValidationResult(NCResult secretValidationResult);
 
-    void _logNoscryptPublicKeyResult(NCResult result);
+    void _logNoscryptPubkeyGenerationResult(NCResult pubkeyGenerationResult);
 
     #pragma endregion
 };
diff --git a/include/signer/signer.hpp b/include/signer/signer.hpp
index 319f739..c774d1d 100644
--- a/include/signer/signer.hpp
+++ b/include/signer/signer.hpp
@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "data/data.hpp"
 
@@ -30,10 +31,28 @@ class INostrConnectSigner : public ISigner
 public:
     virtual ~INostrConnectSigner() = default;
 
+    /**
+     * @brief Establishes a connection to a remote signer using a connection token generated by the
+     * signer.
+     * @param connectionToken A connection token string beginning with `bunker://`, as defined by
+     * NIP-46.
+     * @remark A typical use case for this method would be for the user to paste a signer-generated
+     * connection token into a client application, which would then call this method to establish a
+     * connection to the remote signer.
+     */
     virtual void receiveConnection(std::string connectionToken) = 0;
 
-    virtual void initiateConnection(
-        std::string relay,
+    /**
+     * @brief Generates a connection token that a remote signer may use to establish a connection
+     * to the client.
+     * @param relays A list of one or more relays the client will use to communicate with the
+     * remote signer.
+     * @returns A connection token string beginning with `nostrconnect://`, as specified by NIP-46,
+     * that may be provided to a remote signer to establish a connection to the client.  Returns an
+     * empty string if the connection token generation fails.
+     */
+    virtual std::string initiateConnection(
+        std::vector<std::string> relays,
         std::string name,
         std::string url,
         std::string description) = 0;
diff --git a/src/signer/noscrypt_signer.cpp b/src/signer/noscrypt_signer.cpp
index fa391d1..5d966ba 100644
--- a/src/signer/noscrypt_signer.cpp
+++ b/src/signer/noscrypt_signer.cpp
@@ -34,13 +34,44 @@ void nostr::signer::NoscryptSigner::receiveConnection(string connectionToken)
     // Receive the connection token here.
 };
 
-void nostr::signer::NoscryptSigner::initiateConnection(
-    string relay,
+string nostr::signer::NoscryptSigner::initiateConnection(
+    vector<string> relays,
     string name,
     string url,
     string description)
 {
-    // Initiate the connection here.
+    // Return an empty string if the local keypair is invalid.
+    if (this->_localPrivateKey.empty() || this->_localPublicKey.empty())
+    {
+        PLOG_ERROR << "A valid local keypair is required to connect to a remote signer.";
+        return string();
+    }
+
+    // Return an empty string if no relays are provided.
+    if (relays.empty())
+    {
+        PLOG_ERROR << "At least one relay must be provided to connect to a remote signer.";
+        return string();
+    }
+
+    // Store the provided relay list to be used for sending and receving connection events.
+    this->_relays = relays;
+
+    // Generate the connection token.
+    stringstream ss;
+    ss << "nostrconnect://" << this->_localPublicKey;
+    for (int i = 0; i < relays.size(); i++)
+    {
+        ss << (i == 0 ? "?" : "&");
+        ss << "relay=" << relays[i];
+    }
+    ss << "&metadata={";
+    ss << "\"name\":\"" << name << "\",";
+    ss << "\"url\":\"" << url << "\",";
+    ss << "\"description\":\"" << description << "\"";
+    ss << "}";
+
+    return ss.str();
 };
 
 void nostr::signer::NoscryptSigner::sign(shared_ptr<data::Event> event)
@@ -63,10 +94,10 @@ shared_ptr<NCContext> nostr::signer::NoscryptSigner::_initNoscryptContext()
     uniform_int_distribution<> dist(0, contextStructSize);
     generate_n(randomEntropy.get(), contextStructSize, [&]() { return dist(gen); });
 
-    NCResult result = NCInitContext(context.get(), randomEntropy.get());
-    this->_logNoscryptInitResult(result);
+    NCResult initResult = NCInitContext(context.get(), randomEntropy.get());
+    this->_logNoscryptInitResult(initResult);
 
-    if (result != NC_SUCCESS)
+    if (initResult != NC_SUCCESS)
     {
         return nullptr;
     }
@@ -95,10 +126,10 @@ tuple<string, string> nostr::signer::NoscryptSigner::_createLocalKeypair()
     generate_n(secretKey.get()->key, NC_SEC_KEY_SIZE, [&]() { return dist(gen); });
 
     // Check the validity of the secret key.
-    NCResult result = NCValidateSecretKey(this->_noscryptContext.get(), secretKey.get());
-    this->_logNoscryptSecretKeyResult(result);
+    NCResult secretValidationResult = NCValidateSecretKey(this->_noscryptContext.get(), secretKey.get());
+    this->_logNoscryptSecretValidationResult(secretValidationResult);
 
-    if (result != NC_SUCCESS)
+    if (secretValidationResult != NC_SUCCESS)
     {
         // Return empty strings if the secret key generation fails.
         return make_tuple(string(), string());
@@ -114,13 +145,13 @@ tuple<string, string> nostr::signer::NoscryptSigner::_createLocalKeypair()
 
     // Use noscrypt to derive the public key from its private counterpart.
     unique_ptr<NCPublicKey> pubkey(new NCPublicKey);
-    NCResult result = NCGetPublicKey(
+    NCResult pubkeyGenerationResult = NCGetPublicKey(
         this->_noscryptContext.get(),
         secretKey.get(),
         pubkey.get());
-    this->_logNoscryptPublicKeyResult(result);
+    this->_logNoscryptPubkeyGenerationResult(pubkeyGenerationResult);
 
-    if (result != NC_SUCCESS)
+    if (pubkeyGenerationResult != NC_SUCCESS)
     {
         // Return empty strings if the pubkey generation fails.
         return make_tuple(string(), string());
@@ -140,9 +171,9 @@ tuple<string, string> nostr::signer::NoscryptSigner::_createLocalKeypair()
 
 #pragma region Logging
 
-void nostr::signer::NoscryptSigner::_logNoscryptInitResult(NCResult result)
+void nostr::signer::NoscryptSigner::_logNoscryptInitResult(NCResult initResult)
 {
-    switch (result) {
+    switch (initResult) {
     case NC_SUCCESS:
         PLOG_INFO << "noscrypt - success";
         break;
@@ -169,9 +200,9 @@ void nostr::signer::NoscryptSigner::_logNoscryptInitResult(NCResult result)
     }
 };
 
-void nostr::signer::NoscryptSigner::_logNoscryptSecretKeyResult(NCResult result)
+void nostr::signer::NoscryptSigner::_logNoscryptSecretValidationResult(NCResult secretValidationResult)
 {
-    switch (result) {
+    switch (secretValidationResult) {
     case NC_SUCCESS:
         PLOG_INFO << "noscrypt - success: Generated a valid secret key.";
         break;
@@ -198,9 +229,9 @@ void nostr::signer::NoscryptSigner::_logNoscryptSecretKeyResult(NCResult result)
     }
 };
 
-void nostr::signer::NoscryptSigner::_logNoscryptPublicKeyResult(NCResult result)
+void nostr::signer::NoscryptSigner::_logNoscryptPubkeyGenerationResult(NCResult pubkeyGenerationResult)
 {
-    switch (result) {
+    switch (pubkeyGenerationResult) {
     case NC_SUCCESS:
         PLOG_INFO << "noscrypt - success: Generated a valid public key.";
         break;