Add RSA keypair generation and signing implementation for Overte authentication

src/RSAKeypair.hpp

@@ -0,0 +1,32 @@
+// RSAKeypair.hpp - RSA keypair generation and signing for Overte authentication
+#pragma once
+
+#include <vector>
+#include <string>
+#include <cstdint>
+
+class RSAKeypair {
+public:
+    RSAKeypair();
+    ~RSAKeypair();
+    
+    // Generate a new 2048-bit RSA keypair
+    bool generate();
+    
+    // Sign plaintext with SHA256 + RSA
+    std::vector<uint8_t> sign(const std::vector<uint8_t>& plaintext) const;
+    
+    // Get DER-encoded keys
+    std::vector<uint8_t> getPublicKeyDER() const { return m_publicKey; }
+    std::vector<uint8_t> getPrivateKeyDER() const { return m_privateKey; }
+    
+    // Set keys from DER encoding (for loading from file)
+    void setKeys(const std::vector<uint8_t>& publicKey, const std::vector<uint8_t>& privateKey);
+    
+    // Check if keypair is valid
+    bool isValid() const { return !m_privateKey.empty() && !m_publicKey.empty(); }
+    
+private:
+    std::vector<uint8_t> m_publicKey;
+    std::vector<uint8_t> m_privateKey;
+};