Mercurial > dovecot > core-2.2
view src/pop3-login/pop3-proxy.c @ 14681:ca37d1577291
Added o_stream_nsend*() and related functions to make delayed error handling safer.
Once o_stream_nsend*() is called, o_stream_nfinish() must be called before
stream is destroyed to finish checking if there were any errors. If
something failed and the stream is just wanted to be closed,
o_stream_ignore_last_errors() can be called.
For streams where errors don't really make any difference (network sockets)
you can call o_stream_set_no_error_handling() immediately after creating the
stream.
author | Timo Sirainen <tss@iki.fi> |
---|---|
date | Mon, 25 Jun 2012 00:01:59 +0300 |
parents | fbb1ecb9b888 |
children | 90710c6c3beb |
line wrap: on
line source
/* Copyright (c) 2004-2012 Dovecot authors, see the included COPYING file */ #include "login-common.h" #include "ioloop.h" #include "istream.h" #include "ostream.h" #include "base64.h" #include "safe-memset.h" #include "str.h" #include "str-sanitize.h" #include "client.h" #include "pop3-proxy.h" static void proxy_free_password(struct client *client) { if (client->proxy_password == NULL) return; safe_memset(client->proxy_password, 0, strlen(client->proxy_password)); i_free_and_null(client->proxy_password); } static void get_plain_auth(struct client *client, string_t *dest) { string_t *str; str = t_str_new(128); str_append(str, client->proxy_user); str_append_c(str, '\0'); str_append(str, client->proxy_master_user); str_append_c(str, '\0'); str_append(str, client->proxy_password); base64_encode(str_data(str), str_len(str), dest); } static void proxy_send_login(struct pop3_client *client, struct ostream *output) { string_t *str; i_assert(client->common.proxy_ttl > 0); if (client->proxy_xclient) { /* remote supports XCLIENT, send it */ o_stream_nsend_str(output, t_strdup_printf( "XCLIENT ADDR=%s PORT=%u SESSION=%s TTL=%u\r\n", net_ip2addr(&client->common.ip), client->common.remote_port, client_get_session_id(&client->common), client->common.proxy_ttl - 1)); client->common.proxy_state = POP3_PROXY_XCLIENT; } else { client->common.proxy_state = POP3_PROXY_LOGIN1; } str = t_str_new(128); if (client->common.proxy_master_user == NULL) { /* send USER command */ str_append(str, "USER "); str_append(str, client->common.proxy_user); str_append(str, "\r\n"); } else { /* master user login - use AUTH PLAIN. */ str_append(str, "AUTH PLAIN\r\n"); } o_stream_nsend(output, str_data(str), str_len(str)); } int pop3_proxy_parse_line(struct client *client, const char *line) { struct pop3_client *pop3_client = (struct pop3_client *)client; struct ostream *output; enum login_proxy_ssl_flags ssl_flags; string_t *str; i_assert(!client->destroyed); output = login_proxy_get_ostream(client->login_proxy); switch (client->proxy_state) { case POP3_PROXY_BANNER: /* this is a banner */ if (strncmp(line, "+OK", 3) != 0) { client_log_err(client, t_strdup_printf( "proxy: Remote returned invalid banner: %s", str_sanitize(line, 160))); client_proxy_failed(client, TRUE); return -1; } pop3_client->proxy_xclient = strncmp(line+3, " [XCLIENT]", 10) == 0; ssl_flags = login_proxy_get_ssl_flags(client->login_proxy); if ((ssl_flags & PROXY_SSL_FLAG_STARTTLS) == 0) { proxy_send_login(pop3_client, output); } else { o_stream_nsend_str(output, "STLS\r\n"); client->proxy_state = POP3_PROXY_STARTTLS; } return 0; case POP3_PROXY_STARTTLS: if (strncmp(line, "+OK", 3) != 0) { client_log_err(client, t_strdup_printf( "proxy: Remote STLS failed: %s", str_sanitize(line, 160))); client_proxy_failed(client, TRUE); return -1; } if (login_proxy_starttls(client->login_proxy) < 0) { client_proxy_failed(client, TRUE); return -1; } /* i/ostreams changed. */ output = login_proxy_get_ostream(client->login_proxy); proxy_send_login(pop3_client, output); return 1; case POP3_PROXY_XCLIENT: if (strncmp(line, "+OK", 3) != 0) { client_log_err(client, t_strdup_printf( "proxy: Remote XCLIENT failed: %s", str_sanitize(line, 160))); client_proxy_failed(client, TRUE); return -1; } client->proxy_state = POP3_PROXY_LOGIN1; return 0; case POP3_PROXY_LOGIN1: str = t_str_new(128); if (client->proxy_master_user == NULL) { if (strncmp(line, "+OK", 3) != 0) break; /* USER successful, send PASS */ str_append(str, "PASS "); str_append(str, client->proxy_password); str_append(str, "\r\n"); } else { if (*line != '+') break; /* AUTH successful, send the authentication data */ get_plain_auth(client, str); str_append(str, "\r\n"); } o_stream_nsend(output, str_data(str), str_len(str)); proxy_free_password(client); client->proxy_state = POP3_PROXY_LOGIN2; return 0; case POP3_PROXY_LOGIN2: if (strncmp(line, "+OK", 3) != 0) break; /* Login successful. Send this line to client. */ line = t_strconcat(line, "\r\n", NULL); o_stream_nsend_str(client->output, line); client_proxy_finish_destroy_client(client); return 1; } /* Login failed. Pass through the error message to client. If the backend server isn't Dovecot, the error message may be different from Dovecot's "user doesn't exist" error. This would allow an attacker to find out what users exist in the system. The optimal way to handle this would be to replace the backend's "password failed" error message with Dovecot's AUTH_FAILED_MSG, but this would require a new setting and the sysadmin to actually bother setting it properly. So for now we'll just forward the error message. This shouldn't be a real problem since of course everyone will be using only Dovecot as their backend :) */ if (strncmp(line, "-ERR ", 5) != 0) { client_send_reply(client, POP3_CMD_REPLY_ERROR, AUTH_FAILED_MSG); } else { client_send_raw(client, t_strconcat(line, "\r\n", NULL)); } if (client->set->auth_verbose) { if (strncmp(line, "-ERR ", 5) == 0) line += 5; client_proxy_log_failure(client, line); } client->proxy_auth_failed = TRUE; client_proxy_failed(client, FALSE); return -1; } void pop3_proxy_reset(struct client *client) { client->proxy_state = POP3_PROXY_BANNER; } void pop3_proxy_error(struct client *client, const char *text) { client_send_reply(client, POP3_CMD_REPLY_ERROR, text); }