FTPS with PL/SQL

Doing a FTP-job with PL/SQL is not difficult.
A basic implementation of RFC 959 can be written in a few hundred lines. See for instance ORACLE-BASE, How to FTP with Oracle PL/SQL or Oracle FAQ’s
But what if you want to secure your FTP transmission. Google doesn’t find any pure PL/SQL solutions, only java solutions with a PL/SQL wrapper.
Securing FTP transmission can be done in two ways: SFTP and FTPS.
SFTP stands for SSH File Transfer Protocol. This protocol is not based on the plain FTP protocol, implementing this in PL/SQL is not more difficult, it’s just a lot more work. You will not find anything about SFTP in this posting, maybe I will talk about that later (but see here an example)
FTPS stands for FTP Secure, RFC 4217 – Securing FTP with TLS. And it’s secured with the TLS protocol. Oracle has added support for this protocol to utl_tcp in version 11.2.0.2, UTP_TCP.
As with https you need a certificate (chain) of the server in a Oracle Wallet.
You have pass the path of this wallet to the utl_tcp.open_connection procedure

t_conn := utl_tcp.open_connection( p_host
, p_port
, wallet_path => p_wallet_path
, wallet_password => p_wallet_password
); -- open connection

And you tell the server that you want to secure the connection
write_cmd( t_conn, 'AUTH', 'TLS' )

If the server is OK with that, do it.
utl_tcp.secure_connection( t_conn );

That’s enough to secure the control channel of the FTP connection!
Doing the same for the data channel requires just two more commands
write_cmd( t_conn, 'PBSZ', '0' )
write_cmd( t_conn, 'PROT', 'P' )

A complete example:
declare
t_conn utl_tcp.connection;
t_blob blob;
t_clob clob;
t_reply number;
type tp_dir_listing is table of varchar2(32767) index by pls_integer;
t_dir_listing tp_dir_listing;
--
g_response varchar2(1000 char);
g_wallet_path     varchar2(1000 char);
g_wallet_password varchar2(1000 char);
--
function read_reply( p_conn in out nocopy utl_tcp.connection, p_verbose boolean := true )
return number
is
t_line varchar(32767);
t_code varchar2(3 char);
begin
t_line := utl_tcp.get_line( p_conn, true );
if nvl( length( t_line ), 0 )  0
and instr( t_tmp, '(', 1, 2 ) = 0
and instr( t_tmp, ')' ) > 0
and instr( t_tmp, ')', 1, 2 ) = 0
)
then
t_tmp := substr( t_tmp, instr( t_tmp, '(' ) + 1 );
t_tmp := substr( t_tmp, 1, instr( t_tmp, ')' ) - 1 );
else
t_tmp := translate( t_tmp, '1234567890,' || t_tmp, '1234567890,' );
end if;
t_host := substr( t_tmp, 1, instr( t_tmp, ',', 1, 4 ) - 1 );
t_host := replace( t_host, ',', '.' );
t_tmp := substr( t_tmp, instr( t_tmp, ',', 1, 4 ) + 1 );
t_port := to_number( substr( t_tmp, 1, instr( t_tmp, ',' ) - 1 ) );
t_port := t_port * 256;
t_port := t_port + to_number( substr( t_tmp, instr( t_tmp, ',' ) + 1 ) );
t_conn := utl_tcp.open_connection( t_host, t_port, wallet_path => g_wallet_path, wallet_password => g_wallet_password );
return t_conn;
end;
--
function write_cmd( p_conn in out nocopy utl_tcp.connection, p_cmd varchar2, p_param varchar2 := '' )
return number
is
t_dummy pls_integer;
begin
t_dummy := utl_tcp.write_line( p_conn, p_cmd || rtrim( ' ' || p_param ) );
return read_reply( p_conn );
end;
--
function open_data_channel( p_conn in out nocopy utl_tcp.connection )
return utl_tcp.connection
is
t_tmp varchar2(32767);
t_host varchar2(1000 char);
t_port pls_integer;
t_conn utl_tcp.connection;
begin
if write_cmd( p_conn, 'PASV' ) != 227
then
raise_application_error( -20001, 'Could not set PASSIVE: ' || g_response, true );
end if;
t_tmp := g_response;
if (   instr( t_tmp, '(' ) > 0
and instr( t_tmp, '(', 1, 2 ) = 0
and instr( t_tmp, ')' ) > 0
and instr( t_tmp, ')', 1, 2 ) = 0
)
then
t_tmp := substr( t_tmp, instr( t_tmp, '(' ) + 1 );
t_tmp := substr( t_tmp, 1, instr( t_tmp, ')' ) - 1 );
else
t_tmp := translate( t_tmp, '1234567890,' || t_tmp, '1234567890,' );
end if;
t_host := substr( t_tmp, 1, instr( t_tmp, ',', 1, 4 ) - 1 );
t_host := replace( t_host, ',', '.' );
t_tmp := substr( t_tmp, instr( t_tmp, ',', 1, 4 ) + 1 );
t_port := to_number( substr( t_tmp, 1, instr( t_tmp, ',' ) - 1 ) );
t_port := t_port * 256;
t_port := t_port + to_number( substr( t_tmp, instr( t_tmp, ',' ) + 1 ) );
t_conn := utl_tcp.open_connection( t_host, t_port, wallet_path => g_wallet_path, wallet_password => g_wallet_password );
return t_conn;
end;
--
function login
( p_host varchar2
, p_usr  varchar2 := null
, p_pw   varchar2 := null
, p_port number := 21
, p_account varchar2 := null
, p_wallet_path varchar2 := null
, p_wallet_password varchar2 := null
)
return utl_tcp.connection
is
t_reply number;
t_conn utl_tcp.connection;
t_usr varchar2(1000 char);
t_pw  varchar2(1000 char);
t_acc varchar2(1000 char);
begin
t_conn := utl_tcp.open_connection( p_host, p_port, wallet_path => p_wallet_path, wallet_password => p_wallet_password ); -- open connection
case read_reply( t_conn )
when 120
then
raise_application_error( -20001, 'FTP server not ready: ' || g_response, true );
when 421
then
raise_application_error( -20001, 'FTP server not available: ' || g_response, true );
else
null;
end case;
if write_cmd( t_conn, 'AUTH', 'TLS' ) = 234
then
utl_tcp.secure_connection( t_conn );
if     write_cmd( t_conn, 'PBSZ', '0' ) = 200
and write_cmd( t_conn, 'PROT', 'P' ) = 200
then
g_wallet_path     := p_wallet_path;
g_wallet_password := p_wallet_password;
end if;
end if;
if p_usr is null
then
t_usr := 'anonymous';
t_pw  := 'anonymous@mysite.com';
t_acc := '*********';
else
t_usr := p_usr;
t_pw  := p_pw;
t_acc := p_account;
end if;
t_reply := write_cmd( t_conn, 'USER', t_usr );
if t_reply = 331
then
t_reply := write_cmd( t_conn, 'PASS', t_pw );
end if;
if t_reply = 332
then
t_reply := write_cmd( t_conn, 'ACCT', t_acc );
end if;
if t_reply not in ( 230, 202 )
then
raise_application_error( -20001, 'Could not log in: ' || g_response, true );
end if;
return t_conn;
end;
--
procedure get_file
( p_conn in out nocopy utl_tcp.connection
, p_path in varchar2
, p_file in out blob
)
is
t_reply number;
t_buf raw(32767);
t_cnt pls_integer;
t_conn utl_tcp.connection;
begin
t_reply := write_cmd( p_conn, 'TYPE', 'I' );
t_conn := open_data_channel( p_conn );
t_reply := write_cmd( p_conn, 'RETR', p_path );
if t_reply in ( 125, 150 )
then
if g_wallet_path is not null
then
utl_tcp.secure_connection( t_conn );
end if;
dbms_lob.createtemporary( p_file, true );
begin
loop
t_cnt := utl_tcp.read_raw( t_conn, t_buf, 32767 );
dbms_lob.writeappend( p_file, t_cnt, t_buf );
end loop;
exception
when utl_tcp.end_of_input
then
null;
end;
utl_tcp.close_connection( t_conn );
t_reply := read_reply( p_conn );
end if;
if t_reply not in ( 226, 250 )
then
raise_application_error( -20001, 'Could not retrieve file: ' || g_response, true );
end if;
end;
--
procedure get_file
( p_conn in out nocopy utl_tcp.connection
, p_path in varchar2
, p_file in out clob
)
is
t_reply number;
t_buf varchar2(32767);
t_cnt pls_integer;
t_conn utl_tcp.connection;
begin
t_reply := write_cmd( p_conn, 'TYPE', 'A' );
t_conn := open_data_channel( p_conn );
t_reply := write_cmd( p_conn, 'RETR', p_path );
if t_reply in ( 125, 150 )
then
if g_wallet_path is not null
then
utl_tcp.secure_connection( t_conn );
end if;
dbms_lob.createtemporary( p_file, true );
begin
loop
t_buf := utl_i18n.raw_to_char( utl_tcp.get_raw( t_conn, 32767 ), 'US7ASCII' );
dbms_lob.writeappend( p_file, length( t_buf ), t_buf );
end loop;
exception
when utl_tcp.end_of_input
then
null;
end;
utl_tcp.close_connection( t_conn );
t_reply := read_reply( p_conn );
end if;
if t_reply not in ( 226, 250 )
then
raise_application_error( -20001, 'Could not retrieve file: ' || g_response, true );
end if;
end;
--
procedure nlst
( p_conn in out nocopy utl_tcp.connection
, p_dir_listing in out tp_dir_listing
, p_path in varchar2 := null
)
is
t_reply number;
t_conn utl_tcp.connection;
begin
p_dir_listing.delete;
t_reply := write_cmd( p_conn, 'TYPE', 'A' );
t_conn := open_data_channel( p_conn );
t_reply := write_cmd( p_conn, 'NLST', p_path );
if t_reply in ( 125, 150 )
then
if g_wallet_path is not null
then
utl_tcp.secure_connection( t_conn );
end if;
begin
loop
p_dir_listing( p_dir_listing.count + 1 ) := utl_tcp.get_line( t_conn, true );
end loop;
exception
when utl_tcp.end_of_input
then
null;
end;
utl_tcp.close_connection( t_conn );
t_reply := read_reply( p_conn );
end if;
if t_reply != 226
then
raise_application_error( -20001, 'Could not get NLST: ' || g_response, true );
end if;
end;
--
begin
t_conn := login( 'localhost', p_wallet_path => 'file:C:\oracle\wallet', p_wallet_password => 'amis.rules.again' );
--  get_file( t_conn, '/my_dir/my_ascii_file.txt', t_clob );
nlst( t_conn, t_dir_listing, '*.txt' );
t_reply := write_cmd( t_conn, 'QUIT' );
utl_tcp.close_connection( t_conn );
end;

You will find the same example here