nihilist/tor
1
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/core/tor.git synced 2024-11-10 21:23:58 +01:00
Code Issues Packages Projects Releases Wiki Activity

Implement Extended ORPort authentication.

Browse Source
This commit is contained in:
George Kadianakis 2012-12-05 18:39:21 +02:00 committed by Nick Mathewson
parent 93b9f85d41
commit 4a55e39997
2 changed files with 243 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

244
src/or/connection_or.c
View File

@ -2495,6 +2495,10 @@ connection_ext_or_transition(or_connection_t *conn)
#define EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN 32
#define EXT_OR_PORT_AUTH_COOKIE_FILE_LEN EXT_OR_PORT_AUTH_COOKIE_LEN+EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN
#define EXT_OR_PORT_AUTH_COOKIE_HEADER "! Extended ORPort Auth Cookie !\x0a"
#define EXT_OR_PORT_AUTH_HASH_LEN DIGEST256_LEN
#define EXT_OR_PORT_AUTH_NONCE_LEN 32
#define EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST "ExtORPort authentication server-to-client hash"
#define EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST "ExtORPort authentication client-to-server hash"
/** If true, we've set ext_or_auth_cookie to a secret code and stored
* it to disk. */
@ -2569,6 +2573,194 @@ init_ext_or_auth_cookie_authentication(int is_enabled)
#define EXT_OR_CMD_BT_DENY 0x1001
#define EXT_OR_CMD_BT_CONTROL 0x1002
/** DOCDOCDOC
Return -1 on error. 0 on unsufficient data. 1 on correct.
*/
static int
connection_ext_or_auth_neg_auth_type(connection_t *conn) /* XXX unit tests */
{
char authtype[1] = {0};
if (connection_get_inbuf_len(conn) < 1)
return 0;
if (connection_fetch_from_buf(authtype, 1, conn) < 0)
return -1;
log_warn(LD_GENERAL, "Client wants us to use %d auth type", authtype[0]);
if (authtype[0] != 1) /* '1' is the only auth type supported atm */
return -1;
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE; /* XXX maybe do state transition in process_inbuf ? */
return 1;
}
static int
connection_ext_or_auth_handle_client_nonce(connection_t *conn)
{
char server_hash[EXT_OR_PORT_AUTH_HASH_LEN] = {0};
char client_nonce[EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
char server_nonce[EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
char reply[EXT_OR_PORT_AUTH_COOKIE_LEN+EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
if (!ext_or_auth_cookie_is_set) { /* this should not happen */
log_warn(LD_BUG, "Extended ORPort authentication cookie was not set. "
"That's weird since we should have done that on startup. "
"This might be a Tor bug, please file a bug report. ");
return -1;
}
if (connection_get_inbuf_len(conn) < EXT_OR_PORT_AUTH_NONCE_LEN)
return 0;
if (connection_fetch_from_buf(client_nonce, EXT_OR_PORT_AUTH_NONCE_LEN, conn) < 0) /* XXX check-spaces */
return -1;
/* Get our nonce */
if (crypto_rand(server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN) < 0)
return -1;
{ /* set up macs */
size_t hmac_s_msg_len = strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST) +
2*EXT_OR_PORT_AUTH_NONCE_LEN;
size_t hmac_c_msg_len = strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST) +
2*EXT_OR_PORT_AUTH_NONCE_LEN;
char *hmac_s_msg = tor_malloc_zero(hmac_s_msg_len);
char *hmac_c_msg = tor_malloc_zero(hmac_c_msg_len);
char *correct_client_hash = tor_malloc_zero(EXT_OR_PORT_AUTH_HASH_LEN);
memcpy(hmac_s_msg,
EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST,
strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST));
memcpy(hmac_s_msg + strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST),
client_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_s_msg + strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST) +
EXT_OR_PORT_AUTH_NONCE_LEN,
server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_c_msg,
EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST,
strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST));
memcpy(hmac_c_msg + strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST),
client_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_c_msg + strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST) +
EXT_OR_PORT_AUTH_NONCE_LEN,
server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
crypto_hmac_sha256(server_hash,
ext_or_auth_cookie,
EXT_OR_PORT_AUTH_COOKIE_LEN,
hmac_s_msg,
hmac_s_msg_len);
crypto_hmac_sha256(correct_client_hash,
ext_or_auth_cookie,
EXT_OR_PORT_AUTH_COOKIE_LEN,
hmac_c_msg,
hmac_c_msg_len);
/* Store the client hash we generated. We will need to compare it
with the hash sent by the client. */
TO_OR_CONN(conn)->ext_or_auth_correct_client_hash = correct_client_hash;
tor_free(hmac_s_msg);
tor_free(hmac_c_msg);
}
{ /* debug logging */ /* XXX disable this codepath if not logging on debug? */
char server_hash_encoded[(2*EXT_OR_PORT_AUTH_HASH_LEN) + 1];
char server_nonce_encoded[(2*EXT_OR_PORT_AUTH_NONCE_LEN) + 1];
char client_nonce_encoded[(2*EXT_OR_PORT_AUTH_NONCE_LEN) + 1];
base16_encode(server_hash_encoded, sizeof(server_hash_encoded),
server_hash, sizeof(server_hash));
base16_encode(server_nonce_encoded, sizeof(server_nonce_encoded),
server_nonce, sizeof(server_nonce));
base16_encode(client_nonce_encoded, sizeof(client_nonce_encoded),
client_nonce, sizeof(client_nonce));
log_warn(LD_GENERAL, "server_hash: '%s'\nserver_nonce: '%s'\nclient_nonce: '%s'",
server_hash_encoded, server_nonce_encoded, client_nonce_encoded);
}
{ /* write reply: (server_hash, server_nonce) */
memcpy(reply, server_hash, EXT_OR_PORT_AUTH_HASH_LEN);
memcpy(reply + EXT_OR_PORT_AUTH_HASH_LEN, server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
connection_write_to_buf(reply, sizeof(reply), conn);
}
log_warn(LD_GENERAL, "Got client nonce, and sent our own nonce and hash.");
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH;
return 1;
}
#define connection_ext_or_auth_send_result_success(c) \
connection_ext_or_auth_send_result(c, 1)
#define connection_ext_or_auth_send_result_fail(c) \
connection_ext_or_auth_send_result(c, 0)
static void
connection_ext_or_auth_send_result(connection_t *conn, int success)
{
if (success)
connection_write_to_buf("\x01", 1, conn);
else
connection_write_to_buf("\x00", 1, conn);
}
static int
connection_ext_or_auth_handle_client_hash(connection_t *conn)
{
char provided_client_hash[EXT_OR_PORT_AUTH_HASH_LEN] = {0};
if (connection_get_inbuf_len(conn) < EXT_OR_PORT_AUTH_HASH_LEN)
return 0;
if (connection_fetch_from_buf(provided_client_hash, EXT_OR_PORT_AUTH_HASH_LEN, conn) < 0)
return -1;
if (tor_memneq(TO_OR_CONN(conn)->ext_or_auth_correct_client_hash,
provided_client_hash, EXT_OR_PORT_AUTH_HASH_LEN)) {
log_warn(LD_GENERAL, "Incorrect client hash. Authentication failed.");
connection_ext_or_auth_send_result_fail(conn);
return -1;
}
log_warn(LD_GENERAL, "Got client's hash and it was legit.");
/* send positive auth result */
connection_ext_or_auth_send_result_success(conn);
conn->state = EXT_OR_CONN_STATE_OPEN;
return 1;
}
/** DOCDOCDOC
Return -1 on error. 0 on unsufficient data. 1 on correct.
*/
static int
connection_ext_or_auth_process_inbuf(or_connection_t *or_conn)
{
connection_t *conn = TO_CONN(or_conn);
switch (conn->state) { /* Functionify */
case EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE:
return connection_ext_or_auth_neg_auth_type(conn);
case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE:
return connection_ext_or_auth_handle_client_nonce(conn);
case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH:
return connection_ext_or_auth_handle_client_hash(conn);
default:
log_warn(LD_BUG, "Encountered unexpected connection state %d while trying "
"to process Extended ORPort authentication data.", conn->state);
return -1;
}
}
/** Process Extended ORPort messages from <b>or_conn</b>. */
int
connection_ext_or_process_inbuf(or_connection_t *or_conn)
@ -2577,11 +2769,27 @@ connection_ext_or_process_inbuf(or_connection_t *or_conn)
ext_or_cmd_t *command;
int r;
/* If we are still in the authentication stage, process traffic as
authentication data: */
while (conn->state <= EXT_OR_CONN_STATE_AUTH_MAX) {
log_warn(LD_GENERAL, "Got Extended ORPort authentication data (%u).",
(unsigned int) connection_get_inbuf_len(conn));
r = connection_ext_or_auth_process_inbuf(or_conn);
if (r < 0) {
connection_mark_for_close(conn);
return -1;
} else if (r == 0) {
return 0;
}
/* if r > 0, loop and process more data (if any). */
}
while (1) {
log_warn(LD_GENERAL, "Got Extended ORPort data.");
command = NULL;
r = connection_fetch_ext_or_cmd_from_buf(conn, &command);
if (r < 0)
return -1;
goto err;
else if (r == 0)
return 0; /* need to wait for more data */
@ -2602,6 +2810,9 @@ connection_ext_or_process_inbuf(or_connection_t *or_conn)
conn->state = EXT_OR_CONN_STATE_FLUSHING;
connection_stop_reading(conn);
} else if (command->cmd == EXT_OR_CMD_TB_USERADDR) {
/* XXX Put this in a function of its own. We need to empasize
that we change the address and port of this connection. */
/* Copy address string. */
tor_addr_t addr;
uint16_t port;
@ -2612,8 +2823,6 @@ connection_ext_or_process_inbuf(or_connection_t *or_conn)
memcpy(addr_str, command->body, command->len);
addr_str[command->len] = 0;
log_debug(LD_NET, "Received USERADDR: '%s'!", addr_str);
res = tor_addr_port_split(LOG_INFO, addr_str, &address_part, &port);
tor_free(addr_str);
if (res<0)
@ -2624,6 +2833,18 @@ connection_ext_or_process_inbuf(or_connection_t *or_conn)
if (res<0)
goto err;
{
char *old_address = tor_dup_addr(&conn->addr);
char *new_address = tor_dup_addr(&addr);
log_warn(LD_NET, "Received USERADDR." /* XXX FIX ALL LOG SEVERITIES AND MESSAGES */
"We rewrite our address from '%s:%u' to '%s:%u'.",
safe_str(old_address), conn->port, safe_str(new_address), port);
tor_free(old_address);
tor_free(new_address);
}
/* record the address */
tor_addr_copy(&conn->addr, &addr);
conn->port = port;
@ -2639,6 +2860,7 @@ connection_ext_or_process_inbuf(or_connection_t *or_conn)
err:
ext_or_cmd_free(command);
connection_mark_for_close(conn);
return -1;
}
@ -2654,3 +2876,19 @@ connection_ext_or_finished_flushing(or_connection_t *conn)
}
return 0;
}
/* DOCDOCDOC */
int
connection_ext_or_start_auth(or_connection_t *or_conn)
{
connection_t *conn = TO_CONN(or_conn);
char authtypes[2] = "\x01\x00"; /* We only support authtype '1' for now. */
log_warn(LD_GENERAL,
"ExtORPort authentication: Sending supported authentication types");
connection_write_to_buf(authtypes, sizeof(authtypes), conn);
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE;
return 0;
}

2
src/or/connection_or.h
View File

@ -45,6 +45,8 @@ void connection_or_close_for_error(or_connection_t *orconn, int flush);
void connection_or_report_broken_states(int severity, int domain);
int connection_ext_or_start_auth(or_connection_t *or_conn);
int connection_tls_start_handshake(or_connection_t *conn, int receiving);
int connection_tls_continue_handshake(or_connection_t *conn);