client-authenticate.c revision 48fc20cea83c68d4484af70bf88b85ed133f444d
/* Copyright (C) 2002 Timo Sirainen */
#include "common.h"
#include "base64.h"
#include "buffer.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "safe-memset.h"
#include "str.h"
#include "imap-parser.h"
#include "auth-client.h"
#include "../auth/auth-mech-desc.h"
#include "client.h"
#include "client-authenticate.h"
#include "auth-common.h"
#include "master.h"
const char *client_authenticate_get_capabilities(int secured)
{
static enum auth_mech cached_auth_mechs = 0;
static char *cached_capability = NULL;
enum auth_mech auth_mechs;
string_t *str;
int i;
auth_mechs = auth_client_get_available_mechs(auth_client);
if (auth_mechs == cached_auth_mechs)
return cached_capability;
cached_auth_mechs = auth_mechs;
i_free(cached_capability);
str = t_str_new(128);
for (i = 0; i < AUTH_MECH_COUNT; i++) {
if ((auth_mechs & auth_mech_desc[i].mech) &&
auth_mech_desc[i].name != NULL &&
(secured || !auth_mech_desc[i].plaintext ||
!disable_plaintext_auth)) {
str_append_c(str, ' ');
str_append(str, "AUTH=");
str_append(str, auth_mech_desc[i].name);
}
}
cached_capability = i_strdup_empty(str_c(str));
return cached_capability;
}
static struct auth_mech_desc *auth_mech_find(const char *name)
{
int i;
for (i = 0; i < AUTH_MECH_COUNT; i++) {
if (auth_mech_desc[i].name != NULL &&
strcasecmp(auth_mech_desc[i].name, name) == 0)
return &auth_mech_desc[i];
}
return NULL;
}
static void client_auth_abort(struct imap_client *client, const char *msg)
{
client->authenticating = FALSE;
if (client->common.auth_request != NULL) {
auth_client_request_abort(client->common.auth_request);
client->common.auth_request = NULL;
}
client_send_tagline(client, msg != NULL ?
t_strconcat("NO ", msg, NULL) :
"NO Authentication failed.");
o_stream_flush(client->output);
/* get back to normal client input */
if (client->common.io != NULL)
io_remove(client->common.io);
client->common.io = client->common.fd == -1 ? NULL :
io_add(client->common.fd, IO_READ, client_input, client);
client_unref(client);
}
static void master_callback(struct client *_client, int success)
{
struct imap_client *client = (struct imap_client *) _client;
const char *reason = NULL;
if (success) {
reason = t_strconcat("Login: ", client->common.virtual_user,
NULL);
} else {
reason = t_strconcat("Internal login failure: ",
client->common.virtual_user, NULL);
client_send_line(client, "* BYE Internal login failure.");
}
client_destroy(client, reason);
}
static void client_send_auth_data(struct imap_client *client,
const unsigned char *data, size_t size)
{
buffer_t *buf;
t_push();
buf = buffer_create_dynamic(pool_datastack_create(),
size*2, (size_t)-1);
buffer_append(buf, "+ ", 2);
base64_encode(data, size, buf);
buffer_append(buf, "\r\n", 2);
o_stream_send(client->output, buffer_get_data(buf, NULL),
buffer_get_used_size(buf));
o_stream_flush(client->output);
t_pop();
}
static void login_callback(struct auth_request *request,
struct auth_client_request_reply *reply,
const unsigned char *data, void *context)
{
struct imap_client *client = context;
const char *error;
const void *ptr;
size_t size;
switch (auth_callback(request, reply, data, &client->common,
master_callback, &error)) {
case -1:
/* login failed */
client_auth_abort(client, error);
break;
case 0:
/* continue */
ptr = buffer_get_data(client->plain_login, &size);
auth_client_request_continue(request, ptr, size);
buffer_set_used_size(client->plain_login, 0);
break;
default:
/* success, we should be able to log in. if we fail, just
disconnect the client. */
client->authenticating = FALSE;
client_send_tagline(client, "OK Logged in.");
client_unref(client);
}
}
int cmd_login(struct imap_client *client, struct imap_arg *args)
{
const char *user, *pass, *error;
/* two arguments: username and password */
if (args[0].type != IMAP_ARG_ATOM && args[0].type != IMAP_ARG_STRING)
return FALSE;
if (args[1].type != IMAP_ARG_ATOM && args[1].type != IMAP_ARG_STRING)
return FALSE;
if (args[2].type != IMAP_ARG_EOL)
return FALSE;
user = IMAP_ARG_STR(&args[0]);
pass = IMAP_ARG_STR(&args[1]);
if (!client->secured && disable_plaintext_auth) {
client_send_line(client,
"* BAD [ALERT] Plaintext authentication is disabled, "
"but your client sent password in plaintext anyway. "
"If anyone was listening, the password was exposed.");
client_send_tagline(client,
"NO Plaintext authentication disabled.");
return TRUE;
}
/* authorization ID \0 authentication ID \0 pass */
buffer_set_used_size(client->plain_login, 0);
buffer_append_c(client->plain_login, '\0');
buffer_append(client->plain_login, user, strlen(user));
buffer_append_c(client->plain_login, '\0');
buffer_append(client->plain_login, pass, strlen(pass));
client_ref(client);
client->common.auth_request =
auth_client_request_new(auth_client, AUTH_MECH_PLAIN,
AUTH_PROTOCOL_IMAP, login_callback,
client, &error);
if (client->common.auth_request == NULL) {
client_send_tagline(client, t_strconcat(
"NO Login failed: ", error, NULL));
client_unref(client);
return TRUE;
}
/* don't read any input from client until login is finished */
if (client->common.io != NULL) {
io_remove(client->common.io);
client->common.io = NULL;
}
client->authenticating = TRUE;
return TRUE;
}
static void authenticate_callback(struct auth_request *request,
struct auth_client_request_reply *reply,
const unsigned char *data, void *context)
{
struct imap_client *client = context;
const char *error;
switch (auth_callback(request, reply, data, &client->common,
master_callback, &error)) {
case -1:
/* login failed */
client_auth_abort(client, error);
break;
case 0:
/* continue */
client_send_auth_data(client, data, reply->data_size);
break;
default:
/* success, we should be able to log in. if we fail, just
disconnect the client. */
client->authenticating = FALSE;
client_send_tagline(client, "OK Logged in.");
client_unref(client);
}
}
static void client_auth_input(void *context)
{
struct imap_client *client = context;
buffer_t *buf;
char *line;
size_t linelen, bufsize;
if (!client_read(client)) {
client_unref(client);
return;
}
if (client->skip_line) {
if (i_stream_next_line(client->input) == NULL)
return;
client->skip_line = FALSE;
}
/* @UNSAFE */
line = i_stream_next_line(client->input);
if (line == NULL)
return;
if (strcmp(line, "*") == 0) {
client_auth_abort(client, "Authentication aborted");
return;
}
linelen = strlen(line);
buf = buffer_create_static_hard(pool_datastack_create(), linelen);
if (base64_decode((const unsigned char *) line, linelen,
NULL, buf) <= 0) {
/* failed */
client_auth_abort(client, "Invalid base64 data");
} else if (client->common.auth_request == NULL) {
client_auth_abort(client, "Don't send unrequested data");
} else {
auth_client_request_continue(client->common.auth_request,
buffer_get_data(buf, NULL),
buffer_get_used_size(buf));
}
/* clear sensitive data */
safe_memset(line, 0, linelen);
bufsize = buffer_get_used_size(buf);
safe_memset(buffer_free_without_data(buf), 0, bufsize);
}
int cmd_authenticate(struct imap_client *client, struct imap_arg *args)
{
struct auth_mech_desc *mech;
const char *mech_name, *error;
/* we want only one argument: authentication mechanism name */
if (args[0].type != IMAP_ARG_ATOM && args[0].type != IMAP_ARG_STRING)
return FALSE;
if (args[1].type != IMAP_ARG_EOL)
return FALSE;
mech_name = IMAP_ARG_STR(&args[0]);
if (*mech_name == '\0')
return FALSE;
mech = auth_mech_find(mech_name);
if (mech == NULL) {
client_send_tagline(client,
"NO Unsupported authentication mechanism.");
return TRUE;
}
if (!client->secured && mech->plaintext && disable_plaintext_auth) {
client_send_tagline(client,
"NO Plaintext authentication disabled.");
return TRUE;
}
client_ref(client);
client->common.auth_request =
auth_client_request_new(auth_client, mech->mech,
AUTH_PROTOCOL_IMAP,
authenticate_callback,
client, &error);
if (client->common.auth_request != NULL) {
/* following input data will go to authentication */
if (client->common.io != NULL)
io_remove(client->common.io);
client->common.io = io_add(client->common.fd, IO_READ,
client_auth_input, client);
client->authenticating = TRUE;
} else {
client_send_tagline(client, t_strconcat(
"NO Authentication failed: ", error, NULL));
client_unref(client);
}
return TRUE;
}