diff --git a/test/net/ftp/test_ftp.rb b/test/net/ftp/test_ftp.rb
index 6f726e1090..76f136c152 100644
--- a/test/net/ftp/test_ftp.rb
+++ b/test/net/ftp/test_ftp.rb
@@ -5,6 +5,7 @@
 require "ostruct"
 require "stringio"
 require "tempfile"
+require_relative '..\utils'
 
 class FTPTest < Test::Unit::TestCase
   SERVER_NAME = "localhost"
@@ -14,9 +15,6 @@ class FTPTest < Test::Unit::TestCase
     rescue SocketError
       "127.0.0.1"
     end
-  CA_FILE = File.expand_path("../fixtures/cacert.pem", __dir__)
-  SERVER_KEY = File.expand_path("../fixtures/server.key", __dir__)
-  SERVER_CERT = File.expand_path("../fixtures/server.crt", __dir__)
 
   def setup
     @thread = nil
@@ -1731,7 +1729,7 @@ def test_tls_with_ca_file
           begin
             Net::FTP.new(SERVER_NAME,
                          :port => port,
-                         :ssl => { :ca_file => CA_FILE })
+                         :ssl => { :ca_file => Net::TestUtils::CA_FILE })
           rescue SystemCallError
             skip $!
           end
@@ -1756,7 +1754,7 @@ def test_tls_post_connection_check
           # so the following code should raise a SSLError.
           Net::FTP.new(SERVER_ADDR,
                        :port => port,
-                       :ssl => { :ca_file => CA_FILE })
+                       :ssl => { :ca_file => Net::TestUtils::CA_FILE })
         end
       end
     end
@@ -1772,14 +1770,7 @@ def test_active_private_data_connection
           sock.print("220 (test_ftp).\r\n")
           commands.push(sock.gets)
           sock.print("234 AUTH success.\r\n")
-          ctx = OpenSSL::SSL::SSLContext.new
-          ctx.ca_file = CA_FILE
-          ctx.key = File.open(SERVER_KEY) { |f|
-            OpenSSL::PKey::RSA.new(f)
-          }
-          ctx.cert = File.open(SERVER_CERT) { |f|
-            OpenSSL::X509::Certificate.new(f)
-          }
+          ctx = Net::TestUtils.create_ssl_ctx
           sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
           sock.sync_close = true
           begin
@@ -1817,7 +1808,7 @@ def test_active_private_data_connection
       end
       ftp = Net::FTP.new(SERVER_NAME,
                          port: port,
-                         ssl: { ca_file: CA_FILE },
+                         ssl: { ca_file: Net::TestUtils::CA_FILE },
                          passive: false)
       begin
         assert_equal("AUTH TLS\r\n", commands.shift)
@@ -1849,14 +1840,7 @@ def test_passive_private_data_connection
           sock.print("220 (test_ftp).\r\n")
           commands.push(sock.gets)
           sock.print("234 AUTH success.\r\n")
-          ctx = OpenSSL::SSL::SSLContext.new
-          ctx.ca_file = CA_FILE
-          ctx.key = File.open(SERVER_KEY) { |f|
-            OpenSSL::PKey::RSA.new(f)
-          }
-          ctx.cert = File.open(SERVER_CERT) { |f|
-            OpenSSL::X509::Certificate.new(f)
-          }
+          ctx = Net::TestUtils.create_ssl_ctx
           sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
           sock.sync_close = true
           begin
@@ -1894,7 +1878,7 @@ def test_passive_private_data_connection
       end
       ftp = Net::FTP.new(SERVER_NAME,
                          port: port,
-                         ssl: { ca_file: CA_FILE },
+                         ssl: { ca_file: Net::TestUtils::CA_FILE },
                          passive: true)
       begin
         assert_equal("AUTH TLS\r\n", commands.shift)
@@ -1926,14 +1910,7 @@ def test_active_clear_data_connection
           sock.print("220 (test_ftp).\r\n")
           commands.push(sock.gets)
           sock.print("234 AUTH success.\r\n")
-          ctx = OpenSSL::SSL::SSLContext.new
-          ctx.ca_file = CA_FILE
-          ctx.key = File.open(SERVER_KEY) { |f|
-            OpenSSL::PKey::RSA.new(f)
-          }
-          ctx.cert = File.open(SERVER_CERT) { |f|
-            OpenSSL::X509::Certificate.new(f)
-          }
+          ctx = Net::TestUtils.create_ssl_ctx
           sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
           sock.sync_close = true
           begin
@@ -1964,7 +1941,7 @@ def test_active_clear_data_connection
       end
       ftp = Net::FTP.new(SERVER_NAME,
                          port: port,
-                         ssl: { ca_file: CA_FILE },
+                         ssl: { ca_file: Net::TestUtils::CA_FILE },
                          private_data_connection: false,
                          passive: false)
       begin
@@ -1995,14 +1972,7 @@ def test_passive_clear_data_connection
           sock.print("220 (test_ftp).\r\n")
           commands.push(sock.gets)
           sock.print("234 AUTH success.\r\n")
-          ctx = OpenSSL::SSL::SSLContext.new
-          ctx.ca_file = CA_FILE
-          ctx.key = File.open(SERVER_KEY) { |f|
-            OpenSSL::PKey::RSA.new(f)
-          }
-          ctx.cert = File.open(SERVER_CERT) { |f|
-            OpenSSL::X509::Certificate.new(f)
-          }
+          ctx = Net::TestUtils.create_ssl_ctx
           sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
           sock.sync_close = true
           begin
@@ -2033,7 +2003,7 @@ def test_passive_clear_data_connection
       end
       ftp = Net::FTP.new(SERVER_NAME,
                          port: port,
-                         ssl: { ca_file: CA_FILE },
+                         ssl: { ca_file: Net::TestUtils::CA_FILE },
                          private_data_connection: false,
                          passive: true)
       begin
@@ -2068,7 +2038,7 @@ def test_tls_connect_timeout
         assert_raise(Net::OpenTimeout) do
           Net::FTP.new(SERVER_NAME,
                        port: port,
-                       ssl: { ca_file: CA_FILE },
+                       ssl: { ca_file: Net::TestUtils::CA_FILE },
                        ssl_handshake_timeout: 0.1)
         end
         @thread.join
@@ -2087,14 +2057,7 @@ def test_abort_tls
       sock.print("220 (test_ftp).\r\n")
       commands.push(sock.gets)
       sock.print("234 AUTH success.\r\n")
-      ctx = OpenSSL::SSL::SSLContext.new
-      ctx.ca_file = CA_FILE
-      ctx.key = File.open(SERVER_KEY) { |f|
-        OpenSSL::PKey::RSA.new(f)
-      }
-      ctx.cert = File.open(SERVER_CERT) { |f|
-        OpenSSL::X509::Certificate.new(f)
-      }
+      ctx = Net::TestUtils.create_ssl_ctx
       sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
       sock.sync_close = true
       sock.accept
@@ -2115,7 +2078,7 @@ def test_abort_tls
       begin
         ftp = Net::FTP.new(SERVER_NAME,
                            port: server.port,
-                           ssl: { ca_file: CA_FILE })
+                           ssl: { ca_file: Net::TestUtils::CA_FILE })
         assert_equal("AUTH TLS\r\n", commands.shift)
         assert_equal("PBSZ 0\r\n", commands.shift)
         assert_equal("PROT P\r\n", commands.shift)
@@ -2170,14 +2133,7 @@ def tls_test
         sock.print("220 (test_ftp).\r\n")
         commands.push(sock.gets)
         sock.print("234 AUTH success.\r\n")
-        ctx = OpenSSL::SSL::SSLContext.new
-        ctx.ca_file = CA_FILE
-        ctx.key = File.open(SERVER_KEY) { |f|
-          OpenSSL::PKey::RSA.new(f)
-        }
-        ctx.cert = File.open(SERVER_CERT) { |f|
-          OpenSSL::X509::Certificate.new(f)
-        }
+        ctx = Net::TestUtils.create_ssl_ctx
         sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
         sock.sync_close = true
         begin
diff --git a/test/net/imap/test_imap.rb b/test/net/imap/test_imap.rb
index 5e2dd71c53..4035c0680b 100644
--- a/test/net/imap/test_imap.rb
+++ b/test/net/imap/test_imap.rb
@@ -2,11 +2,9 @@
 
 require "net/imap"
 require "test/unit"
+require_relative '..\utils'
 
 class IMAPTest < Test::Unit::TestCase
-  CA_FILE = File.expand_path("../fixtures/cacert.pem", __dir__)
-  SERVER_KEY = File.expand_path("../fixtures/server.key", __dir__)
-  SERVER_CERT = File.expand_path("../fixtures/server.crt", __dir__)
 
   SERVER_ADDR = "127.0.0.1"
 
@@ -83,7 +81,7 @@ def test_imaps_with_ca_file
           begin
             Net::IMAP.new("localhost",
                           :port => port,
-                          :ssl => { :ca_file => CA_FILE })
+                          :ssl => { :ca_file => Net::TestUtils::CA_FILE })
           rescue SystemCallError
             skip $!
           end
@@ -108,7 +106,7 @@ def test_imaps_post_connection_check
           # so the following code should raise a SSLError.
           Net::IMAP.new(SERVER_ADDR,
                         :port => port,
-                        :ssl => { :ca_file => CA_FILE })
+                        :ssl => { :ca_file => Net::TestUtils::CA_FILE })
         end
       end
     end
@@ -119,7 +117,7 @@ def test_starttls
       imap = nil
       starttls_test do |port|
         imap = Net::IMAP.new("localhost", :port => port)
-        imap.starttls(:ca_file => CA_FILE)
+        imap.starttls(:ca_file => Net::TestUtils::CA_FILE)
         imap
       end
     rescue SystemCallError
@@ -652,14 +650,7 @@ def test_append_fail
   def imaps_test
     server = create_tcp_server
     port = server.addr[1]
-    ctx = OpenSSL::SSL::SSLContext.new
-    ctx.ca_file = CA_FILE
-    ctx.key = File.open(SERVER_KEY) { |f|
-      OpenSSL::PKey::RSA.new(f)
-    }
-    ctx.cert = File.open(SERVER_CERT) { |f|
-      OpenSSL::X509::Certificate.new(f)
-    }
+    ctx = Net::TestUtils.create_ssl_ctx
     ssl_server = OpenSSL::SSL::SSLServer.new(server, ctx)
     ths = Thread.start do
       begin
@@ -697,14 +688,7 @@ def starttls_test
         sock.print("* OK test server\r\n")
         sock.gets
         sock.print("RUBY0001 OK completed\r\n")
-        ctx = OpenSSL::SSL::SSLContext.new
-        ctx.ca_file = CA_FILE
-        ctx.key = File.open(SERVER_KEY) { |f|
-          OpenSSL::PKey::RSA.new(f)
-        }
-        ctx.cert = File.open(SERVER_CERT) { |f|
-          OpenSSL::X509::Certificate.new(f)
-        }
+        ctx = Net::TestUtils.create_ssl_ctx
         sock = OpenSSL::SSL::SSLSocket.new(sock, ctx)
         sock.sync_close = true
         sock.accept
diff --git a/test/net/smtp/test_smtp.rb b/test/net/smtp/test_smtp.rb
index 23e1542d8f..8906ff0b88 100644
--- a/test/net/smtp/test_smtp.rb
+++ b/test/net/smtp/test_smtp.rb
@@ -2,12 +2,10 @@
 require 'net/smtp'
 require 'stringio'
 require 'test/unit'
+require_relative '..\utils'
 
 module Net
   class TestSMTP < Test::Unit::TestCase
-    CA_FILE = File.expand_path("../fixtures/cacert.pem", __dir__)
-    SERVER_KEY = File.expand_path("../fixtures/server.key", __dir__)
-    SERVER_CERT = File.expand_path("../fixtures/server.crt", __dir__)
 
     class FakeSocket
       attr_reader :write_io
@@ -105,14 +103,7 @@ def test_crlf_injection
 
     def test_tls_connect
       servers = Socket.tcp_server_sockets("localhost", 0)
-      ctx = OpenSSL::SSL::SSLContext.new
-      ctx.ca_file = CA_FILE
-      ctx.key = File.open(SERVER_KEY) { |f|
-        OpenSSL::PKey::RSA.new(f)
-      }
-      ctx.cert = File.open(SERVER_CERT) { |f|
-        OpenSSL::X509::Certificate.new(f)
-      }
+      ctx = Net::TestUtils.create_ssl_ctx
       begin
         sock = nil
         Thread.start do
diff --git a/test/net/utils.rb b/test/net/utils.rb
index e69de29bb2..d026e7f172 100644
--- a/test/net/utils.rb
+++ b/test/net/utils.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Net::TestUtils
+  CA_FILE     = File.join(__dir__, "fixtures/cacert.pem")
+  SERVER_KEY  = File.join(__dir__, "fixtures/server.key")
+  SERVER_CERT = File.join(__dir__, "fixtures/server.crt")
+
+  def self.create_ssl_ctx
+    ctx = OpenSSL::SSL::SSLContext.new
+    ctx.ca_file = CA_FILE
+    ctx.key  = OpenSSL::PKey::RSA.new( File.read(SERVER_KEY) )
+    ctx.cert = OpenSSL::X509::Certificate.new( File.read(SERVER_CERT) )
+    ctx
+  end
+end