/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_mail.h>
#include <ngx_mail_pop3_module.h>
static ngx_int_t ngx_mail_pop3_user(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c,
ngx_int_t stls);
static ngx_int_t ngx_mail_pop3_stls(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c);
static u_char pop3_greeting[] = "+OK POP3 ready" CRLF;
static u_char pop3_ok[] = "+OK" CRLF;
static u_char pop3_next[] = "+ " CRLF;
static u_char pop3_username[] = "+ VXNlcm5hbWU6" CRLF;
static u_char pop3_password[] = "+ UGFzc3dvcmQ6" CRLF;
static u_char pop3_invalid_command[] = "-ERR invalid command" CRLF;
void
ngx_mail_pop3_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
{
u_char *p;
ngx_mail_core_srv_conf_t *cscf;
ngx_mail_pop3_srv_conf_t *pscf;
pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
if (pscf->auth_methods
& (NGX_MAIL_AUTH_APOP_ENABLED|NGX_MAIL_AUTH_CRAM_MD5_ENABLED))
{
if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
ngx_mail_session_internal_server_error(s);
return;
}
s->out.data = ngx_pnalloc(c->pool, sizeof(pop3_greeting) + s->salt.len);
if (s->out.data == NULL) {
ngx_mail_session_internal_server_error(s);
return;
}
p = ngx_cpymem(s->out.data, pop3_greeting, sizeof(pop3_greeting) - 3);
*p++ = ' ';
p = ngx_cpymem(p, s->salt.data, s->salt.len);
s->out.len = p - s->out.data;
} else {
ngx_str_set(&s->out, pop3_greeting);
}
c->read->handler = ngx_mail_pop3_init_protocol;
ngx_add_timer(c->read, cscf->timeout);
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_close_connection(c);
}
ngx_mail_send(c->write);
}
void
ngx_mail_pop3_init_protocol(ngx_event_t *rev)
{
ngx_connection_t *c;
ngx_mail_session_t *s;
c = rev->data;
c->log->action = "in auth state";
if (rev->timedout) {
ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
c->timedout = 1;
ngx_mail_close_connection(c);
return;
}
s = c->data;
if (s->buffer == NULL) {
if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t))
== NGX_ERROR)
{
ngx_mail_session_internal_server_error(s);
return;
}
s->buffer = ngx_create_temp_buf(c->pool, 128);
if (s->buffer == NULL) {
ngx_mail_session_internal_server_error(s);
return;
}
}
s->mail_state = ngx_pop3_start;
c->read->handler = ngx_mail_pop3_auth_state;
ngx_mail_pop3_auth_state(rev);
}
void
ngx_mail_pop3_auth_state(ngx_event_t *rev)
{
ngx_int_t rc;
ngx_connection_t *c;
ngx_mail_session_t *s;
c = rev->data;
s = c->data;
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 auth state");
if (rev->timedout) {
ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
c->timedout = 1;
ngx_mail_close_connection(c);
return;
}
if (s->out.len) {
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 send handler busy");
s->blocked = 1;
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_close_connection(c);
return;
}
return;
}
s->blocked = 0;
rc = ngx_mail_read_command(s, c);
if (rc == NGX_AGAIN) {
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_session_internal_server_error(s);
return;
}
return;
}
if (rc == NGX_ERROR) {
return;
}
ngx_str_set(&s->out, pop3_ok);
if (rc == NGX_OK) {
switch (s->mail_state) {
case ngx_pop3_start:
switch (s->command) {
case NGX_POP3_USER:
rc = ngx_mail_pop3_user(s, c);
break;
case NGX_POP3_CAPA:
rc = ngx_mail_pop3_capa(s, c, 1);
break;
case NGX_POP3_APOP:
rc = ngx_mail_pop3_apop(s, c);
break;
case NGX_POP3_AUTH:
rc = ngx_mail_pop3_auth(s, c);
break;
case NGX_POP3_QUIT:
s->quit = 1;
break;
case NGX_POP3_NOOP:
break;
case NGX_POP3_STLS:
rc = ngx_mail_pop3_stls(s, c);
break;
default:
rc = NGX_MAIL_PARSE_INVALID_COMMAND;
break;
}
break;
case ngx_pop3_user:
switch (s->command) {
case NGX_POP3_PASS:
rc = ngx_mail_pop3_pass(s, c);
break;
case NGX_POP3_CAPA:
rc = ngx_mail_pop3_capa(s, c, 0);
break;
case NGX_POP3_QUIT:
s->quit = 1;
break;
case NGX_POP3_NOOP:
break;
default:
rc = NGX_MAIL_PARSE_INVALID_COMMAND;
break;
}
break;
/* suppress warnings */
case ngx_pop3_passwd:
break;
case ngx_pop3_auth_login_username:
rc = ngx_mail_auth_login_username(s, c, 0);
ngx_str_set(&s->out, pop3_password);
s->mail_state = ngx_pop3_auth_login_password;
break;
case ngx_pop3_auth_login_password:
rc = ngx_mail_auth_login_password(s, c);
break;
case ngx_pop3_auth_plain:
rc = ngx_mail_auth_plain(s, c, 0);
break;
case ngx_pop3_auth_cram_md5:
rc = ngx_mail_auth_cram_md5(s, c);
break;
case ngx_pop3_auth_external:
rc = ngx_mail_auth_external(s, c, 0);
break;
}
}
if (s->buffer->pos < s->buffer->last) {
s->blocked = 1;
}
switch (rc) {
case NGX_DONE:
ngx_mail_auth(s, c);
return;
case NGX_ERROR:
ngx_mail_session_internal_server_error(s);
return;
case NGX_MAIL_PARSE_INVALID_COMMAND:
s->mail_state = ngx_pop3_start;
s->state = 0;
ngx_str_set(&s->out, pop3_invalid_command);
/* fall through */
case NGX_OK:
s->args.nelts = 0;
if (s->buffer->pos == s->buffer->last) {
s->buffer->pos = s->buffer->start;
s->buffer->last = s->buffer->start;
}
if (s->state) {
s->arg_start = s->buffer->pos;
}
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_session_internal_server_error(s);
return;
}
ngx_mail_send(c->write);
}
}
static ngx_int_t
ngx_mail_pop3_user(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg;
#if (NGX_MAIL_SSL)
if (ngx_mail_starttls_only(s, c)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
#endif
if (s->args.nelts != 1) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
arg = s->args.elts;
s->login.len = arg[0].len;
s->login.data = ngx_pnalloc(c->pool, s->login.len);
if (s->login.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->login.data, arg[0].data, s->login.len);
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"pop3 login: \"%V\"", &s->login);
s->mail_state = ngx_pop3_user;
return NGX_OK;
}
static ngx_int_t
ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg;
if (s->args.nelts != 1) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
arg = s->args.elts;
s->passwd.len = arg[0].len;
s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
if (s->passwd.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->passwd.data, arg[0].data, s->passwd.len);
#if (NGX_DEBUG_MAIL_PASSWD)
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"pop3 passwd: \"%V\"", &s->passwd);
#endif
return NGX_DONE;
}
static ngx_int_t
ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c, ngx_int_t stls)
{
ngx_mail_pop3_srv_conf_t *pscf;
pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
#if (NGX_MAIL_SSL)
if (stls && c->ssl == NULL) {
ngx_mail_ssl_conf_t *sslcf;
sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
s->out = pscf->starttls_capability;
return NGX_OK;
}
if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
s->out = pscf->starttls_only_capability;
return NGX_OK;
}
}
#endif
s->out = pscf->capability;
return NGX_OK;
}
static ngx_int_t
ngx_mail_pop3_stls(ngx_mail_session_t *s, ngx_connection_t *c)
{
#if (NGX_MAIL_SSL)
ngx_mail_ssl_conf_t *sslcf;
if (c->ssl == NULL) {
sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
if (sslcf->starttls) {
s->buffer->pos = s->buffer->start;
s->buffer->last = s->buffer->start;
c->read->handler = ngx_mail_starttls_handler;
return NGX_OK;
}
}
#endif
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
static ngx_int_t
ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg;
ngx_mail_pop3_srv_conf_t *pscf;
#if (NGX_MAIL_SSL)
if (ngx_mail_starttls_only(s, c)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
#endif
if (s->args.nelts != 2) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
if (!(pscf->auth_methods & NGX_MAIL_AUTH_APOP_ENABLED)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
arg = s->args.elts;
s->login.len = arg[0].len;
s->login.data = ngx_pnalloc(c->pool, s->login.len);
if (s->login.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->login.data, arg[0].data, s->login.len);
s->passwd.len = arg[1].len;
s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
if (s->passwd.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
"pop3 apop: \"%V\" \"%V\"", &s->login, &s->passwd);
s->auth_method = NGX_MAIL_AUTH_APOP;
return NGX_DONE;
}
static ngx_int_t
ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_int_t rc;
ngx_mail_pop3_srv_conf_t *pscf;
#if (NGX_MAIL_SSL)
if (ngx_mail_starttls_only(s, c)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
#endif
pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
if (s->args.nelts == 0) {
s->out = pscf->auth_capability;
s->state = 0;
return NGX_OK;
}
rc = ngx_mail_auth_parse(s, c);
switch (rc) {
case NGX_MAIL_AUTH_LOGIN:
ngx_str_set(&s->out, pop3_username);
s->mail_state = ngx_pop3_auth_login_username;
return NGX_OK;
case NGX_MAIL_AUTH_LOGIN_USERNAME:
ngx_str_set(&s->out, pop3_password);
s->mail_state = ngx_pop3_auth_login_password;
return ngx_mail_auth_login_username(s, c, 1);
case NGX_MAIL_AUTH_PLAIN:
ngx_str_set(&s->out, pop3_next);
s->mail_state = ngx_pop3_auth_plain;
return NGX_OK;
case NGX_MAIL_AUTH_CRAM_MD5:
if (!(pscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
s->mail_state = ngx_pop3_auth_cram_md5;
return NGX_OK;
}
return NGX_ERROR;
case NGX_MAIL_AUTH_EXTERNAL:
if (!(pscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
ngx_str_set(&s->out, pop3_username);
s->mail_state = ngx_pop3_auth_external;
return NGX_OK;
}
return rc;
}