/*
* Parse the client's renegotiation binding and abort if it's not right
*/
int ssl_parse_clienthello_renegotiate_ext(SSL *s, PACKET *pkt, int *al)
{
unsigned int ilen;
unsigned char *d;
/* Parse the length byte */
if (!PACKET_get_1(pkt, &ilen)
|| !PACKET_get_bytes(pkt, &d, ilen)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
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_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
if (memcmp(d, s->s3->previous_client_finished,
s->s3->previous_client_finished_len)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,
SSL_R_RENEGOTIATION_MISMATCH);
*al = SSL_AD_HANDSHAKE_FAILURE;
return 0;
}
#ifdef OPENSSL_RI_DEBUG
fprintf(stderr, "%s RI extension received by server\n",
ilen ? "Non-empty" : "Empty");
#endif
s->s3->send_connection_binding = 1;
return 1;
}
/*
* Process a psk_kex_modes 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_ctos_psk_kex_modes(SSL *s, PACKET *pkt, unsigned int context,
X509 *x, size_t chainidx, int *al)
{
#ifndef OPENSSL_NO_TLS1_3
PACKET psk_kex_modes;
unsigned int mode;
if (!PACKET_as_length_prefixed_1(pkt, &psk_kex_modes)
|| PACKET_remaining(&psk_kex_modes) == 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while (PACKET_get_1(&psk_kex_modes, &mode)) {
if (mode == TLSEXT_KEX_MODE_KE_DHE)
s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE_DHE;
else if (mode == TLSEXT_KEX_MODE_KE)
s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE;
}
#endif
return 1;
}
/*-
* 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.
*/
int tls_parse_ctos_server_name(SSL *s, PACKET *pkt, unsigned int context,
X509 *x, size_t chainidx, int *al)
{
unsigned int servname_type;
PACKET sni, hostname;
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 intent was for server_name to be extensible, RFC 4366
* was not clear about it; and so OpenSSL among other implementations,
* always and only allows a 'host_name' name types.
* 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;
}
OPENSSL_free(s->session->ext.hostname);
s->session->ext.hostname = NULL;
if (!PACKET_strndup(&hostname, &s->session->ext.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->ext.hostname
&& PACKET_equal(&hostname, s->session->ext.hostname,
strlen(s->session->ext.hostname));
}
return 1;
}
int tls_parse_ctos_use_srtp(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
size_t chainidx, int *al)
{
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_CTOS_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_CTOS_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++) {
SRTP_PROTECTION_PROFILE *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_CTOS_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_CTOS_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
return 1;
}
int tls_parse_ctos_status_request(SSL *s, PACKET *pkt, unsigned int context,
X509 *x, size_t chainidx, int *al)
{
PACKET responder_id_list, exts;
/* Not defined if we get one of these in a client Certificate */
if (x != NULL)
return 1;
if (!PACKET_get_1(pkt, (unsigned int *)&s->ext.status_type)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp) {
/*
* We don't know what to do with any other type so ignore it.
*/
s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
return 1;
}
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->ext.ocsp.ids, OCSP_RESPID_free);
if (PACKET_remaining(&responder_id_list) > 0) {
s->ext.ocsp.ids = sk_OCSP_RESPID_new_null();
if (s->ext.ocsp.ids == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
} else {
s->ext.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->ext.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) {
const unsigned char *ext_data = PACKET_data(&exts);
sk_X509_EXTENSION_pop_free(s->ext.ocsp.exts,
X509_EXTENSION_free);
s->ext.ocsp.exts =
d2i_X509_EXTENSIONS(NULL, &ext_data, (int)PACKET_remaining(&exts));
if (s->ext.ocsp.exts == NULL || ext_data != PACKET_end(&exts)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
return 1;
}
int DTLSv1_listen(SSL *s, BIO_ADDR *client)
{
int next, n, ret = 0, clearpkt = 0;
unsigned char cookie[DTLS1_COOKIE_LENGTH];
unsigned char seq[SEQ_NUM_SIZE];
const unsigned char *data;
unsigned char *p, *buf;
unsigned long reclen, fragoff, fraglen, msglen;
unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
BIO *rbio, *wbio;
BUF_MEM *bufm;
BIO_ADDR *tmpclient = NULL;
PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
/* Ensure there is no state left over from a previous invocation */
if (!SSL_clear(s))
return -1;
ERR_clear_error();
rbio = SSL_get_rbio(s);
wbio = SSL_get_wbio(s);
if (!rbio || !wbio) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);
return -1;
}
/*
* We only peek at incoming ClientHello's until we're sure we are going to
* to respond with a HelloVerifyRequest. If its a ClientHello with a valid
* cookie then we leave it in the BIO for accept to handle.
*/
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
/*
* Note: This check deliberately excludes DTLS1_BAD_VER because that version
* requires the MAC to be calculated *including* the first ClientHello
* (without the cookie). Since DTLSv1_listen is stateless that cannot be
* supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
* SSL_accept)
*/
if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
return -1;
}
if (s->init_buf == NULL) {
if ((bufm = BUF_MEM_new()) == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
return -1;
}
if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) {
BUF_MEM_free(bufm);
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
return -1;
}
s->init_buf = bufm;
}
buf = (unsigned char *)s->init_buf->data;
do {
/* Get a packet */
clear_sys_error();
/*
* Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
* + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
* the record header as well, but we do here. We've set up init_buf to
* be the standard size for simplicity. In practice we shouldn't ever
* receive a ClientHello as long as this. If we do it will get dropped
* in the record length check below.
*/
n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
if (n <= 0) {
if (BIO_should_retry(rbio)) {
/* Non-blocking IO */
goto end;
}
return -1;
}
/* If we hit any problems we need to clear this packet from the BIO */
clearpkt = 1;
if (!PACKET_buf_init(&pkt, buf, n)) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* Parse the received record. If there are any problems with it we just
* dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
* resilient in the face of invalid records (e.g., invalid formatting,
* length, MAC, etc.). In general, invalid records SHOULD be silently
* discarded, thus preserving the association; however, an error MAY be
* logged for diagnostic purposes."
*/
/* this packet contained a partial record, dump it */
if (n < DTLS1_RT_HEADER_LENGTH) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
/* Get the record header */
if (!PACKET_get_1(&pkt, &rectype)
|| !PACKET_get_1(&pkt, &versmajor)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (rectype != SSL3_RT_HANDSHAKE) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/*
* Check record version number. We only check that the major version is
* the same.
*/
if (versmajor != DTLS1_VERSION_MAJOR) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
goto end;
}
if (!PACKET_forward(&pkt, 1)
/* Save the sequence number: 64 bits, with top 2 bytes = epoch */
|| !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
|| !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* We allow data remaining at the end of the packet because there could
* be a second record (but we ignore it)
*/
/* This is an initial ClientHello so the epoch has to be 0 */
if (seq[0] != 0 || seq[1] != 0) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Get a pointer to the raw message for the later callback */
data = PACKET_data(&msgpkt);
/* Finished processing the record header, now process the message */
if (!PACKET_get_1(&msgpkt, &msgtype)
|| !PACKET_get_net_3(&msgpkt, &msglen)
|| !PACKET_get_net_2(&msgpkt, &msgseq)
|| !PACKET_get_net_3(&msgpkt, &fragoff)
|| !PACKET_get_net_3(&msgpkt, &fraglen)
|| !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
|| PACKET_remaining(&msgpkt) != 0) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
if (msgtype != SSL3_MT_CLIENT_HELLO) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
goto end;
}
/* Message sequence number can only be 0 or 1 */
if (msgseq > 2) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
goto end;
}
/*
* We don't support fragment reassembly for ClientHellos whilst
* listening because that would require server side state (which is
* against the whole point of the ClientHello/HelloVerifyRequest
* mechanism). Instead we only look at the first ClientHello fragment
* and require that the cookie must be contained within it.
*/
if (fragoff != 0 || fraglen > msglen) {
/* Non initial ClientHello fragment (or bad fragment) */
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
goto end;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
fraglen + DTLS1_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Verify client version is supported
*/
if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
s->method->version != DTLS_ANY_VERSION) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
goto end;
}
if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
|| !PACKET_get_length_prefixed_1(&msgpayload, &session)
|| !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
/*
* Could be malformed or the cookie does not fit within the initial
* ClientHello fragment. Either way we can't handle it.
*/
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
goto end;
}
/*
* Check if we have a cookie or not. If not we need to send a
* HelloVerifyRequest.
*/
if (PACKET_remaining(&cookiepkt) == 0) {
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/*
* We have a cookie, so lets check it.
*/
if (s->ctx->app_verify_cookie_cb == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
/* This is fatal */
return -1;
}
if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
PACKET_remaining(&cookiepkt)) ==
0) {
/*
* We treat invalid cookies in the same was as no cookie as
* per RFC6347
*/
next = LISTEN_SEND_VERIFY_REQUEST;
} else {
/* Cookie verification succeeded */
next = LISTEN_SUCCESS;
}
}
if (next == LISTEN_SEND_VERIFY_REQUEST) {
/*
* There was no cookie in the ClientHello so we need to send a
* HelloVerifyRequest. If this fails we do not worry about trying
* to resend, we just drop it.
*/
/*
* Dump the read packet, we don't need it any more. Ignore return
* value
*/
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
/* Generate the cookie */
if (s->ctx->app_gen_cookie_cb == NULL ||
s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
cookielen > 255) {
SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
/* This is fatal */
return -1;
}
p = &buf[DTLS1_RT_HEADER_LENGTH];
msglen = dtls_raw_hello_verify_request(p + DTLS1_HM_HEADER_LENGTH,
cookie, cookielen);
*p++ = DTLS1_MT_HELLO_VERIFY_REQUEST;
/* Message length */
l2n3(msglen, p);
/* Message sequence number is always 0 for a HelloVerifyRequest */
s2n(0, p);
/*
* We never fragment a HelloVerifyRequest, so fragment offset is 0
* and fragment length is message length
*/
l2n3(0, p);
l2n3(msglen, p);
/* Set reclen equal to length of whole handshake message */
reclen = msglen + DTLS1_HM_HEADER_LENGTH;
/* Add the record header */
p = buf;
*(p++) = SSL3_RT_HANDSHAKE;
/*
* Special case: for hello verify request, client version 1.0 and we
* haven't decided which version to use yet send back using version
* 1.0 header: otherwise some clients will ignore it.
*/
if (s->method->version == DTLS_ANY_VERSION) {
*(p++) = DTLS1_VERSION >> 8;
*(p++) = DTLS1_VERSION & 0xff;
} else {
*(p++) = s->version >> 8;
*(p++) = s->version & 0xff;
}
/*
* Record sequence number is always the same as in the received
* ClientHello
*/
memcpy(p, seq, SEQ_NUM_SIZE);
p += SEQ_NUM_SIZE;
/* Length */
s2n(reclen, p);
/*
* Set reclen equal to length of whole record including record
* header
*/
reclen += DTLS1_RT_HEADER_LENGTH;
if (s->msg_callback)
s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
if ((tmpclient = BIO_ADDR_new()) == NULL) {
SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
goto end;
}
/*
* This is unnecessary if rbio and wbio are one and the same - but
* maybe they're not. We ignore errors here - some BIOs do not
* support this.
*/
if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
(void)BIO_dgram_set_peer(wbio, tmpclient);
}
BIO_ADDR_free(tmpclient);
tmpclient = NULL;
if (BIO_write(wbio, buf, reclen) < (int)reclen) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
return -1;
}
if (BIO_flush(wbio) <= 0) {
if (BIO_should_retry(wbio)) {
/*
* Non-blocking IO...but we're stateless, so we're just
* going to drop this packet.
*/
goto end;
}
return -1;
}
}
/*-
* Return up to 'len' payload bytes received in 'type' records.
* 'type' is one of the following:
*
* - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
* - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
* - 0 (during a shutdown, no data has to be returned)
*
* If we don't have stored data to work from, read a SSL/TLS record first
* (possibly multiple records if we still don't have anything to return).
*
* This function must handle any surprises the peer may have for us, such as
* Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
* messages are treated as if they were handshake messages *if* the |recd_type|
* argument is non NULL.
* Also if record payloads contain fragments too small to process, we store
* them until there is enough for the respective protocol (the record protocol
* may use arbitrary fragmentation and even interleaving):
* Change cipher spec protocol
* just 1 byte needed, no need for keeping anything stored
* Alert protocol
* 2 bytes needed (AlertLevel, AlertDescription)
* Handshake protocol
* 4 bytes needed (HandshakeType, uint24 length) -- we just have
* to detect unexpected Client Hello and Hello Request messages
* here, anything else is handled by higher layers
* Application data protocol
* none of our business
*/
int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
size_t len, int peek, size_t *readbytes)
{
int i, j, iret;
size_t n;
SSL3_RECORD *rr;
void (*cb) (const SSL *ssl, int type2, int val) = NULL;
if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
/* Not initialized yet */
if (!ssl3_setup_buffers(s)) {
/* SSLfatal() already called */
return -1;
}
}
if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
(type != SSL3_RT_HANDSHAKE)) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
}
if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) {
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
/* SSLfatal() already called if appropriate */
if (i < 0)
return i;
if (i == 0)
return -1;
}
start:
s->rwstate = SSL_NOTHING;
/*-
* s->s3.rrec.type - is the type of record
* s->s3.rrec.data, - data
* s->s3.rrec.off, - offset into 'data' for next read
* s->s3.rrec.length, - number of bytes.
*/
rr = s->rlayer.rrec;
/*
* We are not handshaking and have no data yet, so process data buffered
* during the last handshake in advance, if any.
*/
if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) {
pitem *item;
item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
if (item) {
#ifndef OPENSSL_NO_SCTP
/* Restore bio_dgram_sctp_rcvinfo struct */
if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
sizeof(rdata->recordinfo), &rdata->recordinfo);
}
#endif
dtls1_copy_record(s, item);
OPENSSL_free(item->data);
pitem_free(item);
}
}
/* Check for timeout */
if (dtls1_handle_timeout(s) > 0) {
goto start;
} else if (ossl_statem_in_error(s)) {
/* dtls1_handle_timeout() has failed with a fatal error */
return -1;
}
/* get new packet if necessary */
if ((SSL3_RECORD_get_length(rr) == 0)
|| (s->rlayer.rstate == SSL_ST_READ_BODY)) {
RECORD_LAYER_set_numrpipes(&s->rlayer, 0);
iret = dtls1_get_record(s);
if (iret <= 0) {
iret = dtls1_read_failed(s, iret);
/*
* Anything other than a timeout is an error. SSLfatal() already
* called if appropriate.
*/
if (iret <= 0)
return iret;
else
goto start;
}
RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
}
/*
* Reset the count of consecutive warning alerts if we've got a non-empty
* record that isn't an alert.
*/
if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT
&& SSL3_RECORD_get_length(rr) != 0)
s->rlayer.alert_count = 0;
/* we now have a packet which can be read and processed */
if (s->s3.change_cipher_spec /* set when we receive ChangeCipherSpec,
* reset by ssl3_get_finished */
&& (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
/*
* We now have application data between CCS and Finished. Most likely
* the packets were reordered on their way, so buffer the application
* data for later processing rather than dropping the connection.
*/
if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
SSL3_RECORD_get_seq_num(rr)) < 0) {
/* SSLfatal() already called */
return -1;
}
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
/*
* If the other end has shut down, throw anything we read away (even in
* 'peek' mode)
*/
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
s->rwstate = SSL_NOTHING;
return 0;
}
if (type == SSL3_RECORD_get_type(rr)
|| (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC
&& type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
/*
* SSL3_RT_APPLICATION_DATA or
* SSL3_RT_HANDSHAKE or
* SSL3_RT_CHANGE_CIPHER_SPEC
*/
/*
* make sure that we are not getting application data when we are
* doing a handshake for the first time
*/
if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
(s->enc_read_ctx == NULL)) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_APP_DATA_IN_HANDSHAKE);
return -1;
}
if (recvd_type != NULL)
*recvd_type = SSL3_RECORD_get_type(rr);
if (len == 0) {
/*
* Mark a zero length record as read. This ensures multiple calls to
* SSL_read() with a zero length buffer will eventually cause
* SSL_pending() to report data as being available.
*/
if (SSL3_RECORD_get_length(rr) == 0)
SSL3_RECORD_set_read(rr);
return 0;
}
if (len > SSL3_RECORD_get_length(rr))
n = SSL3_RECORD_get_length(rr);
else
n = len;
memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
if (peek) {
if (SSL3_RECORD_get_length(rr) == 0)
SSL3_RECORD_set_read(rr);
} else {
SSL3_RECORD_sub_length(rr, n);
SSL3_RECORD_add_off(rr, n);
if (SSL3_RECORD_get_length(rr) == 0) {
s->rlayer.rstate = SSL_ST_READ_HEADER;
SSL3_RECORD_set_off(rr, 0);
SSL3_RECORD_set_read(rr);
}
}
#ifndef OPENSSL_NO_SCTP
/*
* We might had to delay a close_notify alert because of reordered
* app data. If there was an alert and there is no message to read
* anymore, finally set shutdown.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
s->d1->shutdown_received
&& !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
#endif
*readbytes = n;
return 1;
}
/*
* If we get here, then type != rr->type; if we have a handshake message,
* then it was unexpected (Hello Request or Client Hello).
*/
if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
unsigned int alert_level, alert_descr;
unsigned char *alert_bytes = SSL3_RECORD_get_data(rr)
+ SSL3_RECORD_get_off(rr);
PACKET alert;
if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr))
|| !PACKET_get_1(&alert, &alert_level)
|| !PACKET_get_1(&alert, &alert_descr)
|| PACKET_remaining(&alert) != 0) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_INVALID_ALERT);
return -1;
}
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s,
s->msg_callback_arg);
if (s->info_callback != NULL)
cb = s->info_callback;
else if (s->ctx->info_callback != NULL)
cb = s->ctx->info_callback;
if (cb != NULL) {
j = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, j);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3.warn_alert = alert_descr;
SSL3_RECORD_set_read(rr);
s->rlayer.alert_count++;
if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_TOO_MANY_WARN_ALERTS);
return -1;
}
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
#ifndef OPENSSL_NO_SCTP
/*
* With SCTP and streams the socket may deliver app data
* after a close_notify alert. We have to check this first so
* that nothing gets discarded.
*/
if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
s->d1->shutdown_received = 1;
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
return -1;
}
#endif
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
return 0;
}
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3.fatal_alert = alert_descr;
SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS1_READ_BYTES,
SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
s->shutdown |= SSL_RECEIVED_SHUTDOWN;
SSL3_RECORD_set_read(rr);
SSL_CTX_remove_session(s->session_ctx, s->session);
return 0;
} else {
SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNKNOWN_ALERT_TYPE);
return -1;
}
goto start;
}
if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
* shutdown */
s->rwstate = SSL_NOTHING;
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
return 0;
}
if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
/*
* We can't process a CCS now, because previous handshake messages
* are still missing, so just drop it.
*/
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
/*
* Unexpected handshake message (Client Hello, or protocol violation)
*/
if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) &&
!ossl_statem_get_in_handshake(s)) {
struct hm_header_st msg_hdr;
/*
* This may just be a stale retransmit. Also sanity check that we have
* at least enough record bytes for a message header
*/
if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch
|| SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) {
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
goto start;
}
dtls1_get_message_header(rr->data, &msg_hdr);
/*
* If we are server, we may have a repeated FINISHED of the client
* here, then retransmit our CCS and FINISHED.
*/
if (msg_hdr.type == SSL3_MT_FINISHED) {
if (dtls1_check_timeout_num(s) < 0) {
/* SSLfatal) already called */
return -1;
}
if (dtls1_retransmit_buffered_messages(s) <= 0) {
/* Fail if we encountered a fatal error */
if (ossl_statem_in_error(s))
return -1;
}
SSL3_RECORD_set_length(rr, 0);
SSL3_RECORD_set_read(rr);
if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
/* no read-ahead left? */
BIO *bio;
s->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return -1;
}
}
goto start;
}
/*
* To get here we must be trying to read app data but found handshake
* data. But if we're trying to read app data, and we're not in init
* (which is tested for at the top of this function) then init must be
* finished
*/
if (!ossl_assert(SSL_is_init_finished(s))) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
}
/* We found handshake data, so we're going back into init */
ossl_statem_set_in_init(s, 1);
i = s->handshake_func(s);
/* SSLfatal() called if appropriate */
if (i < 0)
return i;
if (i == 0)
return -1;
if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
/* no read-ahead left? */
BIO *bio;
/*
* In the case where we try to read application data, but we
* trigger an SSL handshake, we return -1 with the retry
* option set. Otherwise renegotiation may cause nasty
* problems in the blocking world
*/
s->rwstate = SSL_READING;
bio = SSL_get_rbio(s);
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return -1;
}
}
goto start;
}
switch (SSL3_RECORD_get_type(rr)) {
default:
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNEXPECTED_RECORD);
return -1;
case SSL3_RT_CHANGE_CIPHER_SPEC:
case SSL3_RT_ALERT:
case SSL3_RT_HANDSHAKE:
/*
* we already handled all of these, with the possible exception of
* SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
* that should not happen when type != rr->type
*/
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
ERR_R_INTERNAL_ERROR);
return -1;
case SSL3_RT_APPLICATION_DATA:
/*
* At this point, we were expecting handshake data, but have
* application data. If the library was running inside ssl3_read()
* (i.e. in_read_app_data is set) and it makes sense to read
* application data at this point (session renegotiation not yet
* started), we will indulge it.
*/
if (s->s3.in_read_app_data &&
(s->s3.total_renegotiations != 0) &&
ossl_statem_app_data_allowed(s)) {
s->s3.in_read_app_data = 2;
return -1;
} else {
SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
SSL_R_UNEXPECTED_RECORD);
return -1;
}
}
/* not reached */
}
static int watchccs_write(BIO *bio, const char *in, int inl)
{
int ret = 0;
BIO *next = BIO_next(bio);
PACKET pkt, msg, msgbody, sessionid;
unsigned int rectype, recvers, msgtype, expectedrecvers;
if (inl <= 0)
return 0;
if (next == NULL)
return 0;
BIO_clear_retry_flags(bio);
if (!PACKET_buf_init(&pkt, (const unsigned char *)in, inl))
return 0;
/* We assume that we always write complete records each time */
while (PACKET_remaining(&pkt)) {
if (!PACKET_get_1(&pkt, &rectype)
|| !PACKET_get_net_2(&pkt, &recvers)
|| !PACKET_get_length_prefixed_2(&pkt, &msg))
return 0;
expectedrecvers = TLS1_2_VERSION;
if (rectype == SSL3_RT_HANDSHAKE) {
if (!PACKET_get_1(&msg, &msgtype)
|| !PACKET_get_length_prefixed_3(&msg, &msgbody))
return 0;
if (msgtype == SSL3_MT_CLIENT_HELLO) {
chseen++;
/*
* Skip legacy_version (2 bytes) and Random (32 bytes) to read
* session_id.
*/
if (!PACKET_forward(&msgbody, 34)
|| !PACKET_get_length_prefixed_1(&msgbody, &sessionid))
return 0;
if (chseen == 1) {
expectedrecvers = TLS1_VERSION;
/* Save the session id for later */
chsessidlen = PACKET_remaining(&sessionid);
if (!PACKET_copy_bytes(&sessionid, chsessid, chsessidlen))
return 0;
} else {
/*
* Check the session id for the second ClientHello is the
* same as the first one.
*/
if (PACKET_remaining(&sessionid) != chsessidlen
|| (chsessidlen > 0
&& memcmp(chsessid, PACKET_data(&sessionid),
chsessidlen) != 0))
badsessid = 1;
}
} else if (msgtype == SSL3_MT_SERVER_HELLO) {
shseen++;
/*
* Skip legacy_version (2 bytes) and Random (32 bytes) to read
* session_id.
*/
if (!PACKET_forward(&msgbody, 34)
|| !PACKET_get_length_prefixed_1(&msgbody, &sessionid))
return 0;
/*
* Check the session id is the same as the one in the
* ClientHello
*/
if (PACKET_remaining(&sessionid) != chsessidlen
|| (chsessidlen > 0
&& memcmp(chsessid, PACKET_data(&sessionid),
chsessidlen) != 0))
badsessid = 1;
}
} else if (rectype == SSL3_RT_CHANGE_CIPHER_SPEC) {
if (bio == s_to_c_fbio) {
/*
* Server writing. We shouldn't have written any app data
* yet, and we should have seen both the ClientHello and the
* ServerHello
*/
if (!sappdataseen
&& chseen == 1
&& shseen == 1
&& !sccsseen)
sccsseen = 1;
else
badccs = 1;
} else if (!cappdataseen) {
/*
* Client writing. We shouldn't have written any app data
* yet, and we should have seen the ClientHello
*/
if (shseen == 1 && !ccsaftersh)
ccsaftersh = 1;
else if (shseen == 0 && !ccsbeforesh)
ccsbeforesh = 1;
else
badccs = 1;
} else {
badccs = 1;
}
} else if(rectype == SSL3_RT_APPLICATION_DATA) {
if (bio == s_to_c_fbio)
sappdataseen = 1;
else
cappdataseen = 1;
}
if (recvers != expectedrecvers)
badvers = 1;
}
ret = BIO_write(next, in, inl);
if (ret <= 0 && BIO_should_write(next))
BIO_set_retry_write(bio);
return ret;
}
