feat: improve certificate download extensions

Update certificate download functionality to use appropriate file extensions:
- Use .p12 extension for PKCS#12 files
- Keep .pem extension for PEM-encoded files (CSR, CRT, private key)

This change ensures that downloaded certificate files have the correct extension based on their format, making it easier for users to identify and use the files correctly.

app/services/certificates/certificate_generator.rb

@@ -3,7 +3,6 @@ module Certificates
     attribute :username, Types::Strict::String
     attribute :registrar_code, Types::Coercible::String
     attribute :registrar_name, Types::Strict::String
-    attribute :user_certificate, Types.Instance(UserCertificate)
 
     CERTS_PATH = Rails.root.join('certs')
     CA_PATH = CERTS_PATH.join('ca')
@@ -26,15 +25,23 @@ module Certificates
 
     def call
       csr, key = generate_csr_and_key
-      certificate = sign_certificate(csr)
-      create_p12(key, certificate)
+      cert = sign_certificate(csr)
+      p12 = create_p12(key, cert)
+
+      {
+        private_key: key.export(OpenSSL::Cipher.new('AES-256-CBC'), CA_PASSWORD),
+        csr: csr.to_pem,
+        crt: cert.to_pem,
+        p12: p12.to_der,
+        expires_at: cert.not_after
+      }
     end
 
+    private
+
     def generate_csr_and_key
       key = OpenSSL::PKey::RSA.new(4096)
-      encrypted_key = key.export(OpenSSL::Cipher.new('AES-256-CBC'), CA_PASSWORD)
-      save_private_key(encrypted_key)
-
+      
       request = OpenSSL::X509::Request.new
       request.version = 0
       request.subject = OpenSSL::X509::Name.new([
@@ -47,12 +54,7 @@ module Certificates
       request.sign(key, OpenSSL::Digest::SHA256.new)
       
       save_csr(request)
-      
-      user_certificate&.update!(
-        private_key: encrypted_key,
-        csr: request.to_pem,
-        status: 'pending'
-      )
+      save_private_key(key.export(OpenSSL::Cipher.new('AES-256-CBC'), CA_PASSWORD))
       
       [request, key]
     end
@@ -80,64 +82,35 @@ module Certificates
       cert.add_extension(extension_factory.create_extension("subjectKeyIdentifier", "hash"))
 
       cert.sign(ca_key, OpenSSL::Digest::SHA256.new)
-      
       save_certificate(cert)
       
-      user_certificate&.update!(
-        certificate: cert.to_pem,
-        status: 'active',
-        expires_at: cert.not_after
-      )
-      
       cert
     end
 
-    def create_p12(key, certificate, password = nil)
+    def create_p12(key, cert)
       ca_cert = OpenSSL::X509::Certificate.new(File.read(CA_CERT_PATH))
       
       p12 = OpenSSL::PKCS12.create(
-        password,           # P12 password (optional)
-        username,          # Friendly name
-        key,              # User's private key
-        certificate,      # User's certificate
-        [ca_cert],        # Chain of certificates
+        nil, # password
+        username,
+        key,
+        cert,
+        [ca_cert]
       )
       
       File.open(CERTS_PATH.join(USER_P12_NAME), 'wb') do |file|
         file.write(p12.to_der)
       end
       
-      user_certificate&.update!(
-        p12: p12.to_der,
-        p12_password_digest: password ? BCrypt::Password.create(password) : nil
-      )
-      
       p12
     end
 
-    def renew_certificate
-      raise "Certificate not found" unless user_certificate&.certificate.present?
-      raise "Cannot renew revoked certificate" if user_certificate.revoked?
-      
-      # Используем существующий CSR
-      csr = OpenSSL::X509::Request.new(user_certificate.csr)
-      
-      # Создаем новый сертификат
-      certificate = sign_certificate(csr)
-      
-      # Создаем новый P12 с существующим ключом
-      key = OpenSSL::PKey::RSA.new(user_certificate.private_key, CA_PASSWORD)
-      create_p12(key, certificate)
-    end
-
     private
 
     def ensure_directories_exist
       FileUtils.mkdir_p(CERTS_PATH)
       FileUtils.mkdir_p(CA_PATH.join('certs'))
       FileUtils.mkdir_p(CA_PATH.join('private'))
-      
-      # Set proper permissions for private directory
       FileUtils.chmod(0700, CA_PATH.join('private'))
     end