提交 25670f3e 编写于 作者: M Matt Caswell

Split extensions code into core extensions and server extensions code

Later we will have client extensions code too.

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
上级 4b299b8e
......@@ -2,7 +2,8 @@ LIBS=../libssl
SOURCE[../libssl]=\
pqueue.c packet.c \
statem/statem_srvr.c statem/statem_clnt.c s3_lib.c s3_enc.c record/rec_layer_s3.c \
statem/statem_lib.c statem/extensions.c s3_cbc.c s3_msg.c \
statem/statem_lib.c statem/extensions.c statem/extensions_srvr.c \
s3_cbc.c s3_msg.c \
methods.c t1_lib.c t1_enc.c tls13_enc.c t1_ext.c \
d1_lib.c record/rec_layer_d1.c d1_msg.c \
statem/statem_dtls.c d1_srtp.c \
......
......@@ -8,33 +8,9 @@
*/
#include <stdlib.h>
#include <openssl/ocsp.h>
#include "../ssl_locl.h"
#include "statem_locl.h"
static int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRP
static int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al);
#endif
#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_NEXTPROTONEG
static int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRTP
static int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al);
#endif
static int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al);
static int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al);
typedef struct {
/* The ID for the extension */
unsigned int type;
......@@ -535,640 +511,3 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
return 1;
}
/*
* Parse the client's renegotiation binding and abort if it's not right
*/
static int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al)
{
unsigned int ilen;
const unsigned char *data;
/* Parse the length byte */
if (!PACKET_get_1(pkt, &ilen)
|| !PACKET_get_bytes(pkt, &data, ilen)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_ENCODING_ERR);
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
/* Check that the extension matches */
if (ilen != s->s3->previous_client_finished_len) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
if (memcmp(data, s->s3->previous_client_finished,
s->s3->previous_client_finished_len)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
s->s3->send_connection_binding = 1;
return 1;
}
static int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al)
{
unsigned int servname_type;
PACKET sni, hostname;
/*-
* The servername extension is treated as follows:
*
* - Only the hostname type is supported with a maximum length of 255.
* - The servername is rejected if too long or if it contains zeros,
* in which case an fatal alert is generated.
* - The servername field is maintained together with the session cache.
* - When a session is resumed, the servername call back invoked in order
* to allow the application to position itself to the right context.
* - The servername is acknowledged if it is new for a session or when
* it is identical to a previously used for the same session.
* Applications can control the behaviour. They can at any time
* set a 'desirable' servername for a new SSL object. This can be the
* case for example with HTTPS when a Host: header field is received and
* a renegotiation is requested. In this case, a possible servername
* presented in the new client hello is only acknowledged if it matches
* the value of the Host: field.
* - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
* if they provide for changing an explicit servername context for the
* session, i.e. when the session has been established with a servername
* extension.
* - On session reconnect, the servername extension may be absent.
*
*/
if (!PACKET_as_length_prefixed_2(pkt, &sni)
/* ServerNameList must be at least 1 byte long. */
|| PACKET_remaining(&sni) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* Although the server_name extension was intended to be
* extensible to new name types, RFC 4366 defined the
* syntax inextensibility and OpenSSL 1.0.x parses it as
* such.
* RFC 6066 corrected the mistake but adding new name types
* is nevertheless no longer feasible, so act as if no other
* SNI types can exist, to simplify parsing.
*
* Also note that the RFC permits only one SNI value per type,
* i.e., we can only have a single hostname.
*/
if (!PACKET_get_1(&sni, &servname_type)
|| servname_type != TLSEXT_NAMETYPE_host_name
|| !PACKET_as_length_prefixed_2(&sni, &hostname)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (PACKET_contains_zero_byte(&hostname)) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->servername_done = 1;
} else {
/*
* TODO(openssl-team): if the SNI doesn't match, we MUST
* fall back to a full handshake.
*/
s->servername_done = s->session->tlsext_hostname
&& PACKET_equal(&hostname, s->session->tlsext_hostname,
strlen(s->session->tlsext_hostname));
}
return 1;
}
#ifndef OPENSSL_NO_SRP
static int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al)
{
PACKET srp_I;
if (!PACKET_as_length_prefixed_1(pkt, &srp_I)
|| PACKET_contains_zero_byte(&srp_I)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* TODO(openssl-team): currently, we re-authenticate the user
* upon resumption. Instead, we MUST ignore the login.
*/
if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
#endif
#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al)
{
PACKET ec_point_format_list;
if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list)
|| PACKET_remaining(&ec_point_format_list) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
return 1;
}
#endif /* OPENSSL_NO_EC */
static int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al)
{
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, PACKET_data(pkt),
PACKET_remaining(pkt),
s->tls_session_ticket_ext_cb_arg)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
static int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al)
{
PACKET supported_sig_algs;
if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
|| (PACKET_remaining(&supported_sig_algs) % 2) != 0
|| PACKET_remaining(&supported_sig_algs) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && !tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
PACKET_remaining(&supported_sig_algs))) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
static int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al)
{
if (!PACKET_get_1(pkt, (unsigned int *)&s->tlsext_status_type)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
const unsigned char *ext_data;
PACKET responder_id_list, exts;
if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* We remove any OCSP_RESPIDs from a previous handshake
* to prevent unbounded memory growth - CVE-2016-6304
*/
sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
if (PACKET_remaining(&responder_id_list) > 0) {
s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
if (s->tlsext_ocsp_ids == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
} else {
s->tlsext_ocsp_ids = NULL;
}
while (PACKET_remaining(&responder_id_list) > 0) {
OCSP_RESPID *id;
PACKET responder_id;
const unsigned char *id_data;
if (!PACKET_get_length_prefixed_2(&responder_id_list,
&responder_id)
|| PACKET_remaining(&responder_id) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
id_data = PACKET_data(&responder_id);
/* TODO(size_t): Convert d2i_* to size_t */
id = d2i_OCSP_RESPID(NULL, &id_data,
(int)PACKET_remaining(&responder_id));
if (id == NULL) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (id_data != PACKET_end(&responder_id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Read in request_extensions */
if (!PACKET_as_length_prefixed_2(pkt, &exts)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (PACKET_remaining(&exts) > 0) {
ext_data = PACKET_data(&exts);
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
X509_EXTENSION_free);
s->tlsext_ocsp_exts =
d2i_X509_EXTENSIONS(NULL, &ext_data,
(int)PACKET_remaining(&exts));
if (s->tlsext_ocsp_exts == NULL || ext_data != PACKET_end(&exts)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
} else
#endif
{
/*
* We don't know what to do with any other type so ignore it.
*/
s->tlsext_status_type = -1;
}
return 1;
}
#ifndef OPENSSL_NO_NEXTPROTONEG
static int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al)
{
if (s->s3->tmp.finish_md_len == 0) {
/*-
* We shouldn't accept this extension on a
* renegotiation.
*
* s->new_session will be set on renegotiation, but we
* probably shouldn't rely that it couldn't be set on
* the initial renegotiation too in certain cases (when
* there's some other reason to disallow resuming an
* earlier session -- the current code won't be doing
* anything like that, but this might change).
*
* A valid sign that there's been a previous handshake
* in this connection is if s->s3->tmp.finish_md_len >
* 0. (We are talking about a check that will happen
* in the Hello protocol round, well before a new
* Finished message could have been computed.)
*/
s->s3->next_proto_neg_seen = 1;
}
return 1;
}
#endif
/*
* Save the ALPN extension in a ClientHello.
* pkt: the contents of the ALPN extension, not including type and length.
* al: a pointer to the alert value to send in the event of a failure.
* returns: 1 on success, 0 on error.
*/
static int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al)
{
PACKET protocol_list, save_protocol_list, protocol;
if (s->s3->tmp.finish_md_len != 0)
return 1;
if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
|| PACKET_remaining(&protocol_list) < 2) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
save_protocol_list = protocol_list;
do {
/* Protocol names can't be empty. */
if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
|| PACKET_remaining(&protocol) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
} while (PACKET_remaining(&protocol_list) != 0);
if (!PACKET_memdup(&save_protocol_list,
&s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
#ifndef OPENSSL_NO_SRTP
static int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al)
{
SRTP_PROTECTION_PROFILE *sprof;
STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
unsigned int ct, mki_len, id;
int i, srtp_pref;
PACKET subpkt;
/* Ignore this if we have no SRTP profiles */
if (SSL_get_srtp_profiles(s) == NULL)
return 1;
/* Pull off the length of the cipher suite list and check it is even */
if (!PACKET_get_net_2(pkt, &ct)
|| (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
srvr = SSL_get_srtp_profiles(s);
s->srtp_profile = NULL;
/* Search all profiles for a match initially */
srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
while (PACKET_remaining(&subpkt)) {
if (!PACKET_get_net_2(&subpkt, &id)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* Only look for match in profiles of higher preference than
* current match.
* If no profiles have been have been configured then this
* does nothing.
*/
for (i = 0; i < srtp_pref; i++) {
sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
if (sprof->id == id) {
s->srtp_profile = sprof;
srtp_pref = i;
break;
}
}
}
/*
* Now extract the MKI value as a sanity check, but discard it for now
*/
if (!PACKET_get_1(pkt, &mki_len)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!PACKET_forward(pkt, mki_len)
|| PACKET_remaining(pkt)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
return 1;
}
#endif
static int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al)
{
if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC))
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
return 1;
}
/*
* Checks a list of |groups| to determine if the |group_id| is in it. If it is
* and |checkallow| is 1 then additionally check if the group is allowed to be
* used. Returns 1 if the group is in the list (and allowed if |checkallow| is
* 1) or 0 otherwise.
*/
static int check_in_list(SSL *s, unsigned int group_id,
const unsigned char *groups, size_t num_groups,
int checkallow)
{
size_t i;
if (groups == NULL || num_groups == 0)
return 0;
for (i = 0; i < num_groups; i++, groups += 2) {
unsigned int share_id = (groups[0] << 8) | (groups[1]);
if (group_id == share_id
&& (!checkallow || tls_curve_allowed(s, groups,
SSL_SECOP_CURVE_CHECK))) {
break;
}
}
/* If i == num_groups then not in the list */
return i < num_groups;
}
/*
* Process a key_share extension received in the ClientHello. |pkt| contains
* the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
* If a failure occurs then |*al| is set to an appropriate alert value.
*/
static int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al)
{
unsigned int group_id;
PACKET key_share_list, encoded_pt;
const unsigned char *clntcurves, *srvrcurves;
size_t clnt_num_curves, srvr_num_curves;
int group_nid, found = 0;
unsigned int curve_flags;
if (s->hit)
return 1;
/* Sanity check */
if (s->s3->peer_tmp != NULL) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
return 0;
}
/* Get our list of supported curves */
if (!tls1_get_curvelist(s, 0, &srvrcurves, &srvr_num_curves)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
/* Get the clients list of supported curves */
if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
while (PACKET_remaining(&key_share_list) > 0) {
if (!PACKET_get_net_2(&key_share_list, &group_id)
|| !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt)
|| PACKET_remaining(&encoded_pt) == 0) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
SSL_R_LENGTH_MISMATCH);
return 0;
}
/*
* If we already found a suitable key_share we loop through the
* rest to verify the structure, but don't process them.
*/
if (found)
continue;
/* Check if this share is in supported_groups sent from client */
if (!check_in_list(s, group_id, clntcurves, clnt_num_curves, 0)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
return 0;
}
/* Check if this share is for a group we can use */
if (!check_in_list(s, group_id, srvrcurves, srvr_num_curves, 1)) {
/* Share not suitable */
continue;
}
group_nid = tls1_ec_curve_id2nid(group_id, &curve_flags);
if (group_nid == 0) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
return 0;
}
if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) {
/* Can happen for some curves, e.g. X25519 */
EVP_PKEY *key = EVP_PKEY_new();
if (key == NULL || !EVP_PKEY_set_type(key, group_nid)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
EVP_PKEY_free(key);
return 0;
}
s->s3->peer_tmp = key;
} else {
/* Set up EVP_PKEY with named curve as parameters */
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
if (pctx == NULL
|| EVP_PKEY_paramgen_init(pctx) <= 0
|| EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx,
group_nid) <= 0
|| EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
EVP_PKEY_CTX_free(pctx);
return 0;
}
EVP_PKEY_CTX_free(pctx);
pctx = NULL;
}
s->s3->group_id = group_id;
if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
PACKET_data(&encoded_pt),
PACKET_remaining(&encoded_pt))) {
*al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_ECPOINT);
return 0;
}
found = 1;
}
return 1;
}
#ifndef OPENSSL_NO_EC
static int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al)
{
PACKET supported_groups_list;
/* Each group is 2 bytes and we must have at least 1. */
if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list)
|| PACKET_remaining(&supported_groups_list) == 0
|| (PACKET_remaining(&supported_groups_list) % 2) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit
&& !PACKET_memdup(&supported_groups_list,
&s->session->tlsext_supportedgroupslist,
&s->session->tlsext_supportedgroupslist_length)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
return 1;
}
#endif
static int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al)
{
/* The extension must always be empty */
if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
return 1;
}
/*
* Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/ocsp.h>
#include "../ssl_locl.h"
#include "statem_locl.h"
/*
* Parse the client's renegotiation binding and abort if it's not right
*/
int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al)
{
unsigned int ilen;
const unsigned char *data;
/* Parse the length byte */
if (!PACKET_get_1(pkt, &ilen)
|| !PACKET_get_bytes(pkt, &data, ilen)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_ENCODING_ERR);
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
/* Check that the extension matches */
if (ilen != s->s3->previous_client_finished_len) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
if (memcmp(data, s->s3->previous_client_finished,
s->s3->previous_client_finished_len)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
s->s3->send_connection_binding = 1;
return 1;
}
int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al)
{
unsigned int servname_type;
PACKET sni, hostname;
/*-
* The servername extension is treated as follows:
*
* - Only the hostname type is supported with a maximum length of 255.
* - The servername is rejected if too long or if it contains zeros,
* in which case an fatal alert is generated.
* - The servername field is maintained together with the session cache.
* - When a session is resumed, the servername call back invoked in order
* to allow the application to position itself to the right context.
* - The servername is acknowledged if it is new for a session or when
* it is identical to a previously used for the same session.
* Applications can control the behaviour. They can at any time
* set a 'desirable' servername for a new SSL object. This can be the
* case for example with HTTPS when a Host: header field is received and
* a renegotiation is requested. In this case, a possible servername
* presented in the new client hello is only acknowledged if it matches
* the value of the Host: field.
* - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
* if they provide for changing an explicit servername context for the
* session, i.e. when the session has been established with a servername
* extension.
* - On session reconnect, the servername extension may be absent.
*
*/
if (!PACKET_as_length_prefixed_2(pkt, &sni)
/* ServerNameList must be at least 1 byte long. */
|| PACKET_remaining(&sni) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* Although the server_name extension was intended to be
* extensible to new name types, RFC 4366 defined the
* syntax inextensibility and OpenSSL 1.0.x parses it as
* such.
* RFC 6066 corrected the mistake but adding new name types
* is nevertheless no longer feasible, so act as if no other
* SNI types can exist, to simplify parsing.
*
* Also note that the RFC permits only one SNI value per type,
* i.e., we can only have a single hostname.
*/
if (!PACKET_get_1(&sni, &servname_type)
|| servname_type != TLSEXT_NAMETYPE_host_name
|| !PACKET_as_length_prefixed_2(&sni, &hostname)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (PACKET_contains_zero_byte(&hostname)) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->servername_done = 1;
} else {
/*
* TODO(openssl-team): if the SNI doesn't match, we MUST
* fall back to a full handshake.
*/
s->servername_done = s->session->tlsext_hostname
&& PACKET_equal(&hostname, s->session->tlsext_hostname,
strlen(s->session->tlsext_hostname));
}
return 1;
}
#ifndef OPENSSL_NO_SRP
int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al)
{
PACKET srp_I;
if (!PACKET_as_length_prefixed_1(pkt, &srp_I)
|| PACKET_contains_zero_byte(&srp_I)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* TODO(openssl-team): currently, we re-authenticate the user
* upon resumption. Instead, we MUST ignore the login.
*/
if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
#endif
#ifndef OPENSSL_NO_EC
int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al)
{
PACKET ec_point_format_list;
if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list)
|| PACKET_remaining(&ec_point_format_list) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
return 1;
}
#endif /* OPENSSL_NO_EC */
int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al)
{
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, PACKET_data(pkt),
PACKET_remaining(pkt),
s->tls_session_ticket_ext_cb_arg)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al)
{
PACKET supported_sig_algs;
if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
|| (PACKET_remaining(&supported_sig_algs) % 2) != 0
|| PACKET_remaining(&supported_sig_algs) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && !tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
PACKET_remaining(&supported_sig_algs))) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al)
{
if (!PACKET_get_1(pkt, (unsigned int *)&s->tlsext_status_type)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
const unsigned char *ext_data;
PACKET responder_id_list, exts;
if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* We remove any OCSP_RESPIDs from a previous handshake
* to prevent unbounded memory growth - CVE-2016-6304
*/
sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
if (PACKET_remaining(&responder_id_list) > 0) {
s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
if (s->tlsext_ocsp_ids == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
} else {
s->tlsext_ocsp_ids = NULL;
}
while (PACKET_remaining(&responder_id_list) > 0) {
OCSP_RESPID *id;
PACKET responder_id;
const unsigned char *id_data;
if (!PACKET_get_length_prefixed_2(&responder_id_list,
&responder_id)
|| PACKET_remaining(&responder_id) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
id_data = PACKET_data(&responder_id);
/* TODO(size_t): Convert d2i_* to size_t */
id = d2i_OCSP_RESPID(NULL, &id_data,
(int)PACKET_remaining(&responder_id));
if (id == NULL) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (id_data != PACKET_end(&responder_id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Read in request_extensions */
if (!PACKET_as_length_prefixed_2(pkt, &exts)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (PACKET_remaining(&exts) > 0) {
ext_data = PACKET_data(&exts);
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
X509_EXTENSION_free);
s->tlsext_ocsp_exts =
d2i_X509_EXTENSIONS(NULL, &ext_data,
(int)PACKET_remaining(&exts));
if (s->tlsext_ocsp_exts == NULL || ext_data != PACKET_end(&exts)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
} else
#endif
{
/*
* We don't know what to do with any other type so ignore it.
*/
s->tlsext_status_type = -1;
}
return 1;
}
#ifndef OPENSSL_NO_NEXTPROTONEG
int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al)
{
if (s->s3->tmp.finish_md_len == 0) {
/*-
* We shouldn't accept this extension on a
* renegotiation.
*
* s->new_session will be set on renegotiation, but we
* probably shouldn't rely that it couldn't be set on
* the initial renegotiation too in certain cases (when
* there's some other reason to disallow resuming an
* earlier session -- the current code won't be doing
* anything like that, but this might change).
*
* A valid sign that there's been a previous handshake
* in this connection is if s->s3->tmp.finish_md_len >
* 0. (We are talking about a check that will happen
* in the Hello protocol round, well before a new
* Finished message could have been computed.)
*/
s->s3->next_proto_neg_seen = 1;
}
return 1;
}
#endif
/*
* Save the ALPN extension in a ClientHello.
* pkt: the contents of the ALPN extension, not including type and length.
* al: a pointer to the alert value to send in the event of a failure.
* returns: 1 on success, 0 on error.
*/
int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al)
{
PACKET protocol_list, save_protocol_list, protocol;
if (s->s3->tmp.finish_md_len != 0)
return 1;
if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
|| PACKET_remaining(&protocol_list) < 2) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
save_protocol_list = protocol_list;
do {
/* Protocol names can't be empty. */
if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
|| PACKET_remaining(&protocol) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
} while (PACKET_remaining(&protocol_list) != 0);
if (!PACKET_memdup(&save_protocol_list,
&s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
#ifndef OPENSSL_NO_SRTP
int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al)
{
SRTP_PROTECTION_PROFILE *sprof;
STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
unsigned int ct, mki_len, id;
int i, srtp_pref;
PACKET subpkt;
/* Ignore this if we have no SRTP profiles */
if (SSL_get_srtp_profiles(s) == NULL)
return 1;
/* Pull off the length of the cipher suite list and check it is even */
if (!PACKET_get_net_2(pkt, &ct)
|| (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
srvr = SSL_get_srtp_profiles(s);
s->srtp_profile = NULL;
/* Search all profiles for a match initially */
srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
while (PACKET_remaining(&subpkt)) {
if (!PACKET_get_net_2(&subpkt, &id)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
/*
* Only look for match in profiles of higher preference than
* current match.
* If no profiles have been have been configured then this
* does nothing.
*/
for (i = 0; i < srtp_pref; i++) {
sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
if (sprof->id == id) {
s->srtp_profile = sprof;
srtp_pref = i;
break;
}
}
}
/*
* Now extract the MKI value as a sanity check, but discard it for now
*/
if (!PACKET_get_1(pkt, &mki_len)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!PACKET_forward(pkt, mki_len)
|| PACKET_remaining(pkt)) {
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
return 1;
}
#endif
int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al)
{
if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC))
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
return 1;
}
/*
* Checks a list of |groups| to determine if the |group_id| is in it. If it is
* and |checkallow| is 1 then additionally check if the group is allowed to be
* used. Returns 1 if the group is in the list (and allowed if |checkallow| is
* 1) or 0 otherwise.
*/
static int check_in_list(SSL *s, unsigned int group_id,
const unsigned char *groups, size_t num_groups,
int checkallow)
{
size_t i;
if (groups == NULL || num_groups == 0)
return 0;
for (i = 0; i < num_groups; i++, groups += 2) {
unsigned int share_id = (groups[0] << 8) | (groups[1]);
if (group_id == share_id
&& (!checkallow || tls_curve_allowed(s, groups,
SSL_SECOP_CURVE_CHECK))) {
break;
}
}
/* If i == num_groups then not in the list */
return i < num_groups;
}
/*
* Process a key_share extension received in the ClientHello. |pkt| contains
* the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
* If a failure occurs then |*al| is set to an appropriate alert value.
*/
int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al)
{
unsigned int group_id;
PACKET key_share_list, encoded_pt;
const unsigned char *clntcurves, *srvrcurves;
size_t clnt_num_curves, srvr_num_curves;
int group_nid, found = 0;
unsigned int curve_flags;
if (s->hit)
return 1;
/* Sanity check */
if (s->s3->peer_tmp != NULL) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_LENGTH_MISMATCH);
return 0;
}
/* Get our list of supported curves */
if (!tls1_get_curvelist(s, 0, &srvrcurves, &srvr_num_curves)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
/* Get the clients list of supported curves */
if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR);
return 0;
}
while (PACKET_remaining(&key_share_list) > 0) {
if (!PACKET_get_net_2(&key_share_list, &group_id)
|| !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt)
|| PACKET_remaining(&encoded_pt) == 0) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
SSL_R_LENGTH_MISMATCH);
return 0;
}
/*
* If we already found a suitable key_share we loop through the
* rest to verify the structure, but don't process them.
*/
if (found)
continue;
/* Check if this share is in supported_groups sent from client */
if (!check_in_list(s, group_id, clntcurves, clnt_num_curves, 0)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_KEY_SHARE);
return 0;
}
/* Check if this share is for a group we can use */
if (!check_in_list(s, group_id, srvrcurves, srvr_num_curves, 1)) {
/* Share not suitable */
continue;
}
group_nid = tls1_ec_curve_id2nid(group_id, &curve_flags);
if (group_nid == 0) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE,
SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
return 0;
}
if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) {
/* Can happen for some curves, e.g. X25519 */
EVP_PKEY *key = EVP_PKEY_new();
if (key == NULL || !EVP_PKEY_set_type(key, group_nid)) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
EVP_PKEY_free(key);
return 0;
}
s->s3->peer_tmp = key;
} else {
/* Set up EVP_PKEY with named curve as parameters */
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
if (pctx == NULL
|| EVP_PKEY_paramgen_init(pctx) <= 0
|| EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx,
group_nid) <= 0
|| EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) {
*al = SSL_AD_INTERNAL_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB);
EVP_PKEY_CTX_free(pctx);
return 0;
}
EVP_PKEY_CTX_free(pctx);
pctx = NULL;
}
s->s3->group_id = group_id;
if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
PACKET_data(&encoded_pt),
PACKET_remaining(&encoded_pt))) {
*al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_ECPOINT);
return 0;
}
found = 1;
}
return 1;
}
#ifndef OPENSSL_NO_EC
int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al)
{
PACKET supported_groups_list;
/* Each group is 2 bytes and we must have at least 1. */
if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list)
|| PACKET_remaining(&supported_groups_list) == 0
|| (PACKET_remaining(&supported_groups_list) % 2) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit
&& !PACKET_memdup(&supported_groups_list,
&s->session->tlsext_supportedgroupslist,
&s->session->tlsext_supportedgroupslist_length)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
return 1;
}
#endif
int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al)
{
/* The extension must always be empty */
if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
return 1;
}
......@@ -155,3 +155,27 @@ __owur int tls_parse_extension(SSL *s, int type, int context, RAW_EXTENSION *ext
size_t numexts, int *al);
__owur int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
int *al);
/* Server Extension processing */
int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRP
int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al);
#endif
#ifndef OPENSSL_NO_EC
int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_NEXTPROTONEG
int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al);
#ifndef OPENSSL_NO_SRTP
int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al);
#endif
int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al);
int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al);
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