client-authenticate.c revision 35029c417d7992a62b3b7e5af38126b141ca7722
/* Copyright (C) 2002-2004 Timo Sirainen */
#include "common.h"
#include "base64.h"
#include "buffer.h"
#include "hex-binary.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "safe-memset.h"
#include "str.h"
#include "str-sanitize.h"
#include "auth-client.h"
#include "../pop3/capability.h"
#include "ssl-proxy.h"
#include "master.h"
#include "auth-common.h"
#include "client.h"
#include "client-authenticate.h"
#include "ssl-proxy.h"
/* Used only for string sanitization while verbose_auth is set. */
#define MAX_MECH_NAME 64
int cmd_capa(struct pop3_client *client, const char *args __attr_unused__)
{
const struct auth_mech_desc *mech;
unsigned int i, count;
string_t *str;
str = t_str_new(128);
str_append(str, "SASL");
mech = auth_client_get_available_mechs(auth_client, &count);
for (i = 0; i < count; i++) {
/* a) transport is secured
b) auth mechanism isn't plaintext
c) we allow insecure authentication
- but don't advertise AUTH=PLAIN, as RFC 2595 requires
*/
if (mech[i].advertise &&
(client->secured || !mech[i].plaintext)) {
str_append_c(str, ' ');
str_append(str, mech[i].name);
}
}
client_send_line(client, t_strconcat("+OK\r\n" POP3_CAPABILITY_REPLY,
(ssl_initialized && !client->tls) ?
"STLS\r\n" : "",
str_c(str),
"\r\n.", NULL));
return TRUE;
}
static void client_auth_abort(struct pop3_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;
}
if (msg != NULL && verbose_auth)
client_syslog(client, "Authentication failed: %s", msg);
client_send_line(client, msg != NULL ? t_strconcat("-ERR ", msg, NULL) :
"-ERR Authentication failed.");
/* 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 pop3_client *client = (struct pop3_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. "
"Error report written to server log.");
}
client_destroy(client, reason);
}
static void client_send_auth_data(struct pop3_client *client,
const unsigned char *data, size_t size)
{
buffer_t *buf;
const void *buf_data;
size_t buf_size;
ssize_t ret;
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);
buf_data = buffer_get_data(buf, &buf_size);
if ((ret = o_stream_send(client->output, buf_data, buf_size)) < 0)
client_destroy(client, "Disconnected");
else if ((size_t)ret != buf_size)
client_destroy(client, "Transmit buffer full");
t_pop();
}
static void login_callback(struct auth_request *request,
struct auth_client_request_reply *reply,
const unsigned char *data, void *context)
{
struct pop3_client *client = context;
const char *error;
switch (auth_callback(request, reply, data, &client->common,
master_callback, &error)) {
case -1:
case 0:
/* login failed */
client_auth_abort(client, error);
break;
default:
/* success, we should be able to log in. if we fail, just
disconnect the client. */
client->authenticating = FALSE;
client_send_line(client, "+OK Logged in.");
client_unref(client);
}
}
static enum auth_client_request_new_flags
client_get_auth_flags(struct pop3_client *client)
{
enum auth_client_request_new_flags auth_flags = 0;
if (client->common.proxy != NULL &&
ssl_proxy_has_valid_client_cert(client->common.proxy))
auth_flags |= AUTH_CLIENT_FLAG_SSL_VALID_CLIENT_CERT;
if (client->tls)
auth_flags |= AUTH_CLIENT_FLAG_SSL_ENABLED;
return auth_flags;
}
int cmd_user(struct pop3_client *client, const char *args)
{
if (!client->secured && disable_plaintext_auth) {
if (verbose_auth) {
client_syslog(client, "Login failed: "
"Plaintext authentication disabled");
}
client_send_line(client,
"-ERR Plaintext authentication disabled.");
return TRUE;
}
i_free(client->last_user);
client->last_user = i_strdup(args);
client_send_line(client, "+OK");
return TRUE;
}
int cmd_pass(struct pop3_client *client, const char *args)
{
const char *error;
struct auth_request_info info;
string_t *plain_login;
if (client->last_user == NULL) {
client_send_line(client, "-ERR No username given.");
return TRUE;
}
/* authorization ID \0 authentication ID \0 pass */
plain_login = t_str_new(128);
str_append_c(plain_login, '\0');
str_append(plain_login, client->last_user);
str_append_c(plain_login, '\0');
str_append(plain_login, args);
memset(&info, 0, sizeof(info));
info.mech = "PLAIN";
info.protocol = "POP3";
info.flags = client_get_auth_flags(client);
info.local_ip = client->common.local_ip;
info.remote_ip = client->common.ip;
info.initial_resp_data = str_data(plain_login);
info.initial_resp_size = str_len(plain_login);
client_ref(client);
client->common.auth_request =
auth_client_request_new(auth_client, NULL, &info,
login_callback, client, &error);
if (client->common.auth_request == NULL) {
if (verbose_auth)
client_syslog(client, "Login failed: %s", error);
client_send_line(client,
t_strconcat("-ERR 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 pop3_client *client = context;
const char *error;
if (!client->authenticating) {
/* client aborted */
i_assert(reply == NULL);
return;
}
switch (auth_callback(request, reply, data, &client->common,
master_callback, &error)) {
case -1:
/* login failed */
client_auth_abort(client, error);
break;
case 0:
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_line(client, "+OK Logged in.");
client_unref(client);
}
}
static void client_auth_input(void *context)
{
struct pop3_client *client = context;
buffer_t *buf;
char *line;
size_t linelen, bufsize;
if (!client_read(client))
return;
/* @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(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_auth(struct pop3_client *client, const char *args)
{
struct auth_request_info info;
const struct auth_mech_desc *mech;
const char *mech_name, *error, *p;
string_t *buf;
size_t argslen;
if (*args == '\0') {
/* Old-style SASL discovery, used by MS Outlook */
int i, count;
client_send_line(client, "+OK");
mech = auth_client_get_available_mechs(auth_client, &count);
for (i = 0; i < count; i++) {
if (mech[i].advertise) {
client_send_line(client, mech[i].name);
}
}
client_send_line(client, ".");
return TRUE;
}
/* <mechanism name> <initial response> */
p = strchr(args, ' ');
if (p == NULL) {
mech_name = args;
args = "";
} else {
mech_name = t_strdup_until(args, p);
args = p+1;
}
mech = auth_client_find_mech(auth_client, mech_name);
if (mech == NULL) {
if (verbose_auth) {
client_syslog(client, "Authenticate %s failed: "
"Unsupported mechanism",
str_sanitize(mech_name, MAX_MECH_NAME));
}
client_send_line(client,
"-ERR Unsupported authentication mechanism.");
return TRUE;
}
if (!client->secured && mech->plaintext && disable_plaintext_auth) {
if (verbose_auth) {
client_syslog(client, "Authenticate %s failed: "
"Plaintext authentication disabled",
str_sanitize(mech_name, MAX_MECH_NAME));
}
client_send_line(client,
"-ERR Plaintext authentication disabled.");
return TRUE;
}
argslen = strlen(args);
buf = buffer_create_static_hard(pool_datastack_create(), argslen);
if (base64_decode(args, argslen, NULL, buf) <= 0) {
/* failed */
client_send_line(client, "-ERR Invalid base64 data.");
return TRUE;
}
memset(&info, 0, sizeof(info));
info.mech = mech->name;
info.protocol = "POP3";
info.flags = client_get_auth_flags(client);
info.local_ip = client->common.local_ip;
info.remote_ip = client->common.ip;
info.initial_resp_data = str_data(buf);
info.initial_resp_size = str_len(buf);
client_ref(client);
client->common.auth_request =
auth_client_request_new(auth_client, NULL, &info,
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 {
if (verbose_auth) {
client_syslog(client, "Authenticate %s failed: %s",
str_sanitize(mech_name, MAX_MECH_NAME),
error);
}
client_send_line(client, t_strconcat(
"-ERR Authentication failed: ", error, NULL));
client_unref(client);
}
return TRUE;
}
int cmd_apop(struct pop3_client *client, const char *args)
{
struct auth_request_info info;
const char *error, *p;
buffer_t *apop_data;
if (client->apop_challenge == NULL) {
if (verbose_auth)
client_syslog(client, "APOP failed: APOP not enabled");
client_send_line(client, "-ERR APOP not enabled.");
return TRUE;
}
/* <username> <md5 sum in hex> */
p = strchr(args, ' ');
if (p == NULL || strlen(p+1) != 32) {
if (verbose_auth) {
client_syslog(client, "APOP failed: "
"Invalid parameters");
}
client_send_line(client, "-ERR Invalid parameters.");
return TRUE;
}
/* APOP challenge \0 username \0 APOP response */
apop_data = buffer_create_dynamic(pool_datastack_create(),
128, (size_t)-1);
buffer_append(apop_data, client->apop_challenge,
strlen(client->apop_challenge)+1);
buffer_append(apop_data, args, (size_t)(p-args));
buffer_append_c(apop_data, '\0');
if (hex_to_binary(p+1, apop_data) <= 0) {
if (verbose_auth) {
client_syslog(client, "APOP failed: "
"Invalid characters in MD5 response");
}
client_send_line(client,
"-ERR Invalid characters in MD5 response.");
return TRUE;
}
memset(&info, 0, sizeof(info));
info.mech = "APOP";
info.protocol = "POP3";
info.flags = client_get_auth_flags(client);
info.local_ip = client->common.local_ip;
info.remote_ip = client->common.ip;
info.initial_resp_data =
buffer_get_data(apop_data, &info.initial_resp_size);
client_ref(client);
o_stream_uncork(client->output);
client->common.auth_request =
auth_client_request_new(auth_client, &client->auth_id, &info,
login_callback, client, &error);
if (client->common.auth_request != NULL) {
/* 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;
} else if (error == NULL) {
/* the auth connection was lost. we have no choice
but to fail the APOP logins completely since the
challenge is auth connection-specific. disconnect. */
client_destroy(client, "APOP auth connection lost");
client_unref(client);
} else {
if (verbose_auth)
client_syslog(client, "APOP failed: %s", error);
client_send_line(client,
t_strconcat("-ERR Login failed: ", error, NULL));
client_unref(client);
}
return TRUE;
}