nihilist/tor
1
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/core/tor.git synced 2024-09-21 13:34:59 +02:00
Code Issues Packages Projects Releases Wiki Activity

Merge remote-tracking branch 'rransom-tor/safecookie-022-v3' into maint-0.2.2

Browse Source
This commit is contained in:
Nick Mathewson 2012-03-26 14:03:29 -04:00
commit 6dcbfec82d
3 changed files with 164 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/or/connection.c
View File

@ -419,6 +419,7 @@ _connection_free(connection_t *conn)
}
if (conn->type == CONN_TYPE_CONTROL) {
control_connection_t *control_conn = TO_CONTROL_CONN(conn);
tor_free(control_conn->safecookie_client_hash);
tor_free(control_conn->incoming_cmd);
}

159
src/or/control.c
View File

@ -101,6 +101,12 @@ static int authentication_cookie_is_set = 0;
* read it off disk, it has permission to connect.) */
static char authentication_cookie[AUTHENTICATION_COOKIE_LEN];
#define SAFECOOKIE_SERVER_TO_CONTROLLER_CONSTANT \
"Tor safe cookie authentication server-to-controller hash"
#define SAFECOOKIE_CONTROLLER_TO_SERVER_CONSTANT \
"Tor safe cookie authentication controller-to-server hash"
#define SAFECOOKIE_SERVER_NONCE_LEN DIGEST256_LEN
/** A sufficiently large size to record the last bootstrap phase string. */
#define BOOTSTRAP_MSG_LEN 1024
@ -1078,6 +1084,32 @@ handle_control_authenticate(control_connection_t *conn, uint32_t len,
used_quoted_string = 1;
}
if (conn->safecookie_client_hash != NULL) {
/* The controller has chosen safe cookie authentication; the only
* acceptable authentication value is the controller-to-server
* response. */
tor_assert(authentication_cookie_is_set);
if (password_len != DIGEST256_LEN) {
log_warn(LD_CONTROL,
"Got safe cookie authentication response with wrong length "
"(%d)", (int)password_len);
errstr = "Wrong length for safe cookie response.";
goto err;
}
if (tor_memneq(conn->safecookie_client_hash, password, DIGEST256_LEN)) {
log_warn(LD_CONTROL,
"Got incorrect safe cookie authentication response");
errstr = "Safe cookie response did not match expected value.";
goto err;
}
tor_free(conn->safecookie_client_hash);
goto ok;
}
if (!options->CookieAuthentication && !options->HashedControlPassword &&
!options->HashedControlSessionPassword) {
/* if Tor doesn't demand any stronger authentication, then
@ -2758,8 +2790,10 @@ handle_control_protocolinfo(control_connection_t *conn, uint32_t len,
int passwd = (options->HashedControlPassword != NULL ||
options->HashedControlSessionPassword != NULL);
smartlist_t *mlist = smartlist_create();
if (cookies)
if (cookies) {
smartlist_add(mlist, (char*)"COOKIE");
smartlist_add(mlist, (char*)"SAFECOOKIE");
}
if (passwd)
smartlist_add(mlist, (char*)"HASHEDPASSWORD");
if (!cookies && !passwd)
@ -2787,6 +2821,121 @@ handle_control_protocolinfo(control_connection_t *conn, uint32_t len,
return 0;
}
/** Called when we get an AUTHCHALLENGE command. */
static int
handle_control_authchallenge(control_connection_t *conn, uint32_t len,
const char *body)
{
const char *cp = body;
char *client_nonce;
size_t client_nonce_len;
char server_hash[DIGEST256_LEN];
char server_hash_encoded[HEX_DIGEST256_LEN+1];
char server_nonce[SAFECOOKIE_SERVER_NONCE_LEN];
char server_nonce_encoded[(2*SAFECOOKIE_SERVER_NONCE_LEN) + 1];
cp += strspn(cp, " \t\n\r");
if (!strcasecmpstart(cp, "SAFECOOKIE")) {
cp += strlen("SAFECOOKIE");
} else {
connection_write_str_to_buf("513 AUTHCHALLENGE only supports SAFECOOKIE "
"authentication", conn);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
if (!authentication_cookie_is_set) {
connection_write_str_to_buf("515 Cookie authentication is disabled", conn);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
cp += strspn(cp, " \t\n\r");
if (*cp == '"') {
const char *newcp =
decode_escaped_string(cp, len - (cp - body),
&client_nonce, &client_nonce_len);
if (newcp == NULL) {
connection_write_str_to_buf("513 Invalid quoted client nonce",
conn);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
cp = newcp;
} else {
size_t client_nonce_encoded_len = strspn(cp, "0123456789ABCDEFabcdef");
client_nonce_len = client_nonce_encoded_len / 2;
client_nonce = tor_malloc_zero(client_nonce_len);
if (base16_decode(client_nonce, client_nonce_len,
cp, client_nonce_encoded_len) < 0) {
connection_write_str_to_buf("513 Invalid base16 client nonce",
conn);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
cp += client_nonce_encoded_len;
}
cp += strspn(cp, " \t\n\r");
if (*cp != '\0' ||
cp != body + len) {
connection_write_str_to_buf("513 Junk at end of AUTHCHALLENGE command",
conn);
connection_mark_for_close(TO_CONN(conn));
tor_free(client_nonce);
return -1;
}
tor_assert(!crypto_rand(server_nonce, SAFECOOKIE_SERVER_NONCE_LEN));
/* Now compute and send the server-to-controller response, and the
* server's nonce. */
tor_assert(authentication_cookie != NULL);
{
size_t tmp_len = (AUTHENTICATION_COOKIE_LEN +
client_nonce_len +
SAFECOOKIE_SERVER_NONCE_LEN);
char *tmp = tor_malloc_zero(tmp_len);
char *client_hash = tor_malloc_zero(DIGEST256_LEN);
memcpy(tmp, authentication_cookie, AUTHENTICATION_COOKIE_LEN);
memcpy(tmp + AUTHENTICATION_COOKIE_LEN, client_nonce, client_nonce_len);
memcpy(tmp + AUTHENTICATION_COOKIE_LEN + client_nonce_len,
server_nonce, SAFECOOKIE_SERVER_NONCE_LEN);
crypto_hmac_sha256(server_hash,
SAFECOOKIE_SERVER_TO_CONTROLLER_CONSTANT,
strlen(SAFECOOKIE_SERVER_TO_CONTROLLER_CONSTANT),
tmp,
tmp_len);
crypto_hmac_sha256(client_hash,
SAFECOOKIE_CONTROLLER_TO_SERVER_CONSTANT,
strlen(SAFECOOKIE_CONTROLLER_TO_SERVER_CONSTANT),
tmp,
tmp_len);
conn->safecookie_client_hash = client_hash;
tor_free(tmp);
}
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));
connection_printf_to_buf(conn,
"250 AUTHCHALLENGE SERVERHASH=%s "
"SERVERNONCE=%s\r\n",
server_hash_encoded,
server_nonce_encoded);
return 0;
}
/** Called when we get a USEFEATURE command: parse the feature list, and
* set up the control_connection's options properly. */
static int
@ -2888,7 +3037,10 @@ is_valid_initial_command(control_connection_t *conn, const char *cmd)
if (conn->_base.state == CONTROL_CONN_STATE_OPEN)
return 1;
if (!strcasecmp(cmd, "PROTOCOLINFO"))
return !conn->have_sent_protocolinfo;
return (!conn->have_sent_protocolinfo &&
conn->safecookie_client_hash == NULL);
if (!strcasecmp(cmd, "AUTHCHALLENGE"))
return (conn->safecookie_client_hash == NULL);
if (!strcasecmp(cmd, "AUTHENTICATE") ||
!strcasecmp(cmd, "QUIT"))
return 1;
@ -3104,6 +3256,9 @@ connection_control_process_inbuf(control_connection_t *conn)
} else if (!strcasecmp(conn->incoming_cmd, "PROTOCOLINFO")) {
if (handle_control_protocolinfo(conn, cmd_data_len, args))
return -1;
} else if (!strcasecmp(conn->incoming_cmd, "AUTHCHALLENGE")) {
if (handle_control_authchallenge(conn, cmd_data_len, args))
return -1;
} else {
connection_printf_to_buf(conn, "510 Unrecognized command \"%s\"\r\n",
conn->incoming_cmd);

6
src/or/or.h
View File

@ -1254,6 +1254,12 @@ typedef struct control_connection_t {
* connection. */
unsigned int is_owning_control_connection:1;
/** If we have sent an AUTHCHALLENGE reply on this connection and
* have not received a successful AUTHENTICATE command, points to
* the value which the client must send to authenticate itself;
* otherwise, NULL. */
char *safecookie_client_hash;
/** Amount of space allocated in incoming_cmd. */
uint32_t incoming_cmd_len;
/** Number of bytes currently stored in incoming_cmd. */