static long
dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
{
unsigned char wire[DTLS1_HM_HEADER_LENGTH];
unsigned long len, frag_off, frag_len;
int i,al;
struct hm_header_st msg_hdr;
redo:
/* see if we have the required fragment already */
if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
{
if (*ok) s->init_num = frag_len;
return frag_len;
}
/* read handshake message header */
i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
DTLS1_HM_HEADER_LENGTH, 0);
if (i <= 0) /* nbio, or an error */
{
s->rwstate=SSL_READING;
*ok = 0;
return i;
}
/* Handshake fails if message header is incomplete */
if (i != DTLS1_HM_HEADER_LENGTH)
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
/* parse the message fragment header */
dtls1_get_message_header(wire, &msg_hdr);
/*
* if this is a future (or stale) message it gets buffered
* (or dropped)--no further processing at this time
* While listening, we accept seq 1 (ClientHello with cookie)
* although we're still expecting seq 0 (ClientHello)
*/
if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
len = msg_hdr.msg_len;
frag_off = msg_hdr.frag_off;
frag_len = msg_hdr.frag_len;
if (frag_len && frag_len < len)
return dtls1_reassemble_fragment(s, &msg_hdr, ok);
if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
wire[0] == SSL3_MT_HELLO_REQUEST)
{
/* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them
* if their format is correct. Does not count for
* 'Finished' MAC. */
if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
{
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
wire, DTLS1_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
s->init_num = 0;
goto redo;
}
else /* Incorrectly formated Hello request */
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
}
if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
goto f_err;
/* XDTLS: ressurect this when restart is in place */
s->state=stn;
if ( frag_len > 0)
{
unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
&p[frag_off],frag_len,0);
/* XDTLS: fix this--message fragments cannot span multiple packets */
if (i <= 0)
{
s->rwstate=SSL_READING;
*ok = 0;
return i;
}
}
else
i = 0;
/* XDTLS: an incorrectly formatted fragment should cause the
* handshake to fail */
if (i != (int)frag_len)
{
al=SSL3_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
goto f_err;
}
*ok = 1;
/* Note that s->init_num is *not* used as current offset in
* s->init_buf->data, but as a counter summing up fragments'
* lengths: as soon as they sum up to handshake packet
* length, we assume we have got all the fragments. */
s->init_num = frag_len;
return frag_len;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
s->init_num = 0;
*ok=0;
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 */
}
/* Return up to 'len' payload bytes received in 'type' records.
* 'type' is one of the following:
*
* - SSL3_RT_HANDSHAKE (when dtls1_get_message calls us)
* - SSL3_RT_CHANGE_CIPHER_SPEC (when dtls1_read_change_cipher_spec calls us)
* - SSL3_RT_APPLICATION_DATA (when dtls1_read_app_data calls us)
*
* If we don't have stored data to work from, read a DTLS 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) and out of records. */
int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) {
int al, i, ret;
unsigned int n;
SSL3_RECORD *rr;
void (*cb)(const SSL *ssl, int type, int value) = NULL;
if ((type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE &&
type != SSL3_RT_CHANGE_CIPHER_SPEC) ||
(peek && type != SSL3_RT_APPLICATION_DATA)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
if (!s->in_handshake && SSL_in_init(s)) {
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0) {
return i;
}
if (i == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
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->s3->rrec;
/* Check for timeout */
if (DTLSv1_handle_timeout(s) > 0) {
goto start;
}
/* get new packet if necessary */
if (rr->length == 0) {
ret = dtls1_get_record(s);
if (ret <= 0) {
ret = dtls1_read_failed(s, ret);
/* anything other than a timeout is an error */
if (ret <= 0) {
return ret;
} else {
goto start;
}
}
}
/* we now have a packet which can be read and processed */
/* If the other end has shut down, throw anything we read away (even in
* 'peek' mode) */
if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
rr->length = 0;
s->rwstate = SSL_NOTHING;
return 0;
}
if (type == rr->type) {
/* 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->aead_read_ctx == NULL)) {
/* TODO(davidben): Is this check redundant with the handshake_func
* check? */
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
/* Discard empty records. */
if (rr->length == 0) {
goto start;
}
if (len <= 0) {
return len;
}
if ((unsigned int)len > rr->length) {
n = rr->length;
} else {
n = (unsigned int)len;
}
memcpy(buf, rr->data, n);
if (!peek) {
rr->length -= n;
rr->data += n;
if (rr->length == 0) {
/* The record has been consumed, so we may now clear the buffer. */
ssl_read_buffer_discard(s);
}
}
return n;
}
/* If we get here, then type != rr->type. */
/* If an alert record, process one alert out of the record. Note that we allow
* a single record to contain multiple alerts. */
if (rr->type == SSL3_RT_ALERT) {
/* Alerts may not be fragmented. */
if (rr->length < 2) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
goto f_err;
}
if (s->msg_callback) {
s->msg_callback(0, s->version, SSL3_RT_ALERT, rr->data, 2, s,
s->msg_callback_arg);
}
const uint8_t alert_level = rr->data[0];
const uint8_t alert_descr = rr->data[1];
rr->length -= 2;
rr->data += 2;
if (s->info_callback != NULL) {
cb = s->info_callback;
} else if (s->ctx->info_callback != NULL) {
cb = s->ctx->info_callback;
}
if (cb != NULL) {
uint16_t alert = (alert_level << 8) | alert_descr;
cb(s, SSL_CB_READ_ALERT, alert);
}
if (alert_level == SSL3_AL_WARNING) {
s->s3->warn_alert = alert_descr;
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
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;
OPENSSL_PUT_ERROR(SSL, 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;
SSL_CTX_remove_session(s->ctx, s->session);
return 0;
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
goto start;
}
/* Cross-epoch records are discarded, but we may receive out-of-order
* application data between ChangeCipherSpec and Finished or a ChangeCipherSpec
* before the appropriate point in the handshake. Those must be silently
* discarded.
*
* However, only allow the out-of-order records in the correct epoch.
* Application data must come in the encrypted epoch, and ChangeCipherSpec in
* the unencrypted epoch (we never renegotiate). Other cases fall through and
* fail with a fatal error. */
if ((rr->type == SSL3_RT_APPLICATION_DATA && s->aead_read_ctx != NULL) ||
(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC && s->aead_read_ctx == NULL)) {
rr->length = 0;
goto start;
}
if (rr->type == SSL3_RT_HANDSHAKE) {
if (type != SSL3_RT_APPLICATION_DATA) {
/* Out-of-order handshake record while looking for ChangeCipherSpec. Drop
* it silently. */
assert(type == SSL3_RT_CHANGE_CIPHER_SPEC);
rr->length = 0;
goto start;
}
/* Parse the first fragment header to determine if this is a pre-CCS or
* post-CCS handshake record. DTLS resets handshake message numbers on each
* handshake, so renegotiations and retransmissions are ambiguous. */
if (rr->length < DTLS1_HM_HEADER_LENGTH) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
goto f_err;
}
struct hm_header_st msg_hdr;
dtls1_get_message_header(rr->data, &msg_hdr);
if (msg_hdr.type == SSL3_MT_FINISHED) {
if (msg_hdr.frag_off == 0) {
/* Retransmit our last flight of messages. If the peer sends the second
* Finished, they may not have received ours. Only do this for the
* first fragment, in case the Finished was fragmented. */
if (dtls1_check_timeout_num(s) < 0) {
return -1;
}
dtls1_retransmit_buffered_messages(s);
}
rr->length = 0;
goto start;
}
/* Otherwise, this is a pre-CCS handshake message from an unsupported
* renegotiation attempt. Fall through to the error path. */
}
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
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,
int len, int peek)
{
int al, i, j, ret;
unsigned int 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))
return (-1);
}
if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
(type != SSL3_RT_HANDSHAKE)) ||
(peek && (type != SSL3_RT_APPLICATION_DATA))) {
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
return -1;
}
/*
* check whether there's a handshake message (client hello?) waiting
*/
if ((ret = have_handshake_fragment(s, type, buf, len))) {
*recvd_type = SSL3_RT_HANDSHAKE;
return ret;
}
/*
* Now s->rlayer.d->handshake_fragment_len == 0 if
* type == SSL3_RT_HANDSHAKE.
*/
if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s))
{
/* type == SSL3_RT_APPLICATION_DATA */
i = s->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
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;
/* get new packet if necessary */
if ((SSL3_RECORD_get_length(rr) == 0)
|| (s->rlayer.rstate == SSL_ST_READ_BODY)) {
ret = dtls1_get_record(s);
if (ret <= 0) {
ret = dtls1_read_failed(s, ret);
/* anything other than a timeout is an error */
if (ret <= 0)
return (ret);
else
goto start;
}
}
/*
* 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) {
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
return -1;
}
SSL3_RECORD_set_length(rr, 0);
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);
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)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
goto f_err;
}
if (recvd_type != NULL)
*recvd_type = SSL3_RECORD_get_type(rr);
if (len <= 0)
return (len);
if ((unsigned int)len > SSL3_RECORD_get_length(rr))
n = SSL3_RECORD_get_length(rr);
else
n = (unsigned int)len;
memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
if (!peek) {
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);
}
}
#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
return (n);
}
/*
* If we get here, then type != rr->type; if we have a handshake message,
* then it was unexpected (Hello Request or Client Hello).
*/
/*
* In case of record types for which we have 'fragment' storage, fill
* that so that we can process the data at a fixed place.
*/
{
unsigned int k, dest_maxlen = 0;
unsigned char *dest = NULL;
unsigned int *dest_len = NULL;
if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {
dest_maxlen = sizeof s->rlayer.d->handshake_fragment;
dest = s->rlayer.d->handshake_fragment;
dest_len = &s->rlayer.d->handshake_fragment_len;
} else if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
dest_maxlen = sizeof(s->rlayer.d->alert_fragment);
dest = s->rlayer.d->alert_fragment;
dest_len = &s->rlayer.d->alert_fragment_len;
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (SSL3_RECORD_get_type(rr) == DTLS1_RT_HEARTBEAT) {
/* We allow a 0 return */
if (dtls1_process_heartbeat(s, SSL3_RECORD_get_data(rr),
SSL3_RECORD_get_length(rr)) < 0) {
return -1;
}
/* Exit and notify application to read again */
SSL3_RECORD_set_length(rr, 0);
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
return (-1);
}
#endif
/* else it's a CCS message, or application data or wrong */
else if (SSL3_RECORD_get_type(rr) != SSL3_RT_CHANGE_CIPHER_SPEC) {
/*
* Application data while renegotiating is allowed. Try again
* reading.
*/
if (SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA) {
BIO *bio;
s->s3->in_read_app_data = 2;
bio = SSL_get_rbio(s);
s->rwstate = SSL_READING;
BIO_clear_retry_flags(bio);
BIO_set_retry_read(bio);
return (-1);
}
/* Not certain if this is the right error handling */
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
}
if (dest_maxlen > 0) {
/*
* XDTLS: In a pathological case, the Client Hello may be
* fragmented--don't always expect dest_maxlen bytes
*/
if (SSL3_RECORD_get_length(rr) < dest_maxlen) {
#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
/*
* for normal alerts rr->length is 2, while
* dest_maxlen is 7 if we were to handle this
* non-existing alert...
*/
FIX ME;
#endif
s->rlayer.rstate = SSL_ST_READ_HEADER;
SSL3_RECORD_set_length(rr, 0);
goto start;
}
/* now move 'n' bytes: */
for (k = 0; k < dest_maxlen; k++) {
dest[k] = SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)];
SSL3_RECORD_add_off(rr, 1);
SSL3_RECORD_add_length(rr, -1);
}
*dest_len = dest_maxlen;
}
}
/*-
* s->rlayer.d->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
* s->rlayer.d->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
* (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
*/
/* If we are a client, check for an incoming 'Hello Request': */
if ((!s->server) &&
(s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
(s->rlayer.d->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
(s->session != NULL) && (s->session->cipher != NULL)) {
s->rlayer.d->handshake_fragment_len = 0;
if ((s->rlayer.d->handshake_fragment[1] != 0) ||
(s->rlayer.d->handshake_fragment[2] != 0) ||
(s->rlayer.d->handshake_fragment[3] != 0)) {
al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
goto f_err;
}
/*
* no need to check sequence number on HELLO REQUEST messages
*/
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
s->rlayer.d->handshake_fragment, 4, s,
s->msg_callback_arg);
if (SSL_is_init_finished(s) &&
!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
!s->s3->renegotiate) {
s->d1->handshake_read_seq++;
s->new_session = 1;
ssl3_renegotiate(s);
if (ssl3_renegotiate_check(s)) {
i = s->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
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);
}
}
}
}
/*
* we either finished a handshake or ignored the request, now try
* again to obtain the (application) data we were asked for
*/
goto start;
}
if (s->rlayer.d->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
int alert_level = s->rlayer.d->alert_fragment[0];
int alert_descr = s->rlayer.d->alert_fragment[1];
s->rlayer.d->alert_fragment_len = 0;
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_ALERT,
s->rlayer.d->alert_fragment, 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;
s->rlayer.alert_count++;
if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
goto f_err;
}
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);
}
#if 0
/* XXX: this is a possible improvement in the future */
/* now check if it's a missing record */
if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
unsigned short seq;
unsigned int frag_off;
unsigned char *p = &(s->rlayer.d->alert_fragment[2]);
n2s(p, seq);
n2l3(p, frag_off);
dtls1_retransmit_message(s,
dtls1_get_queue_priority
(frag->msg_header.seq, 0), frag_off,
&found);
if (!found && SSL_in_init(s)) {
/*
* fprintf( stderr,"in init = %d\n", SSL_in_init(s));
*/
/*
* requested a message not yet sent, send an alert
* ourselves
*/
ssl3_send_alert(s, SSL3_AL_WARNING,
DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
}
}
#endif
} else if (alert_level == SSL3_AL_FATAL) {
char tmp[16];
s->rwstate = SSL_NOTHING;
s->s3->fatal_alert = alert_descr;
SSLerr(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;
SSL_CTX_remove_session(s->session_ctx, s->session);
return (0);
} else {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
goto f_err;
}
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);
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);
goto start;
}
/*
* Unexpected handshake message (Client Hello, or protocol violation)
*/
if ((s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
!ossl_statem_get_in_handshake(s)) {
struct hm_header_st msg_hdr;
/* this may just be a stale retransmit */
dtls1_get_message_header(rr->data, &msg_hdr);
if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch) {
SSL3_RECORD_set_length(rr, 0);
goto start;
}
/*
* 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)
return -1;
dtls1_retransmit_buffered_messages(s);
SSL3_RECORD_set_length(rr, 0);
goto start;
}
if (SSL_is_init_finished(s) &&
!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
ossl_statem_set_in_init(s, 1);
s->renegotiate = 1;
s->new_session = 1;
}
i = s->handshake_func(s);
if (i < 0)
return (i);
if (i == 0) {
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
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:
/* TLS just ignores unknown message types */
if (s->version == TLS1_VERSION) {
SSL3_RECORD_set_length(rr, 0);
goto start;
}
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
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
*/
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
goto f_err;
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 {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
goto f_err;
}
}
/* not reached */
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return (-1);
}
static long
dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
{
unsigned char *p;
unsigned long l, frag_off, frag_len;
int i,al;
struct hm_header_st msg_hdr;
unsigned long overlap;
/* see if we have the required fragment already */
if (dtls1_retrieve_buffered_fragment(s, &l))
{
/* compute MAC, remove fragment headers */
dtls1_process_handshake_fragment(s, l);
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->state = stn;
return 1;
}
/* get a handshake fragment from the record layer */
p = (unsigned char *)s->init_buf->data;
/* read handshake message header */
i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
DTLS1_HM_HEADER_LENGTH, 0);
if (i <= 0) /* nbio, or an error */
{
s->rwstate=SSL_READING;
*ok = 0;
return i;
}
OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
p += s->init_num;
/* parse the message fragment header */
dtls1_get_message_header(p, &msg_hdr);
/*
* if this is a future (or stale) message it gets buffered
* (or dropped)--no further processing at this time
*/
if ( msg_hdr.seq != s->d1->handshake_read_seq)
return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
l = msg_hdr.msg_len;
frag_off = msg_hdr.frag_off;
frag_len = msg_hdr.frag_len;
/* sanity checking */
if ( frag_off + frag_len > l)
{
al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
p[0] == SSL3_MT_HELLO_REQUEST)
{
/* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them
* if their format is correct. Does not count for
* 'Finished' MAC. */
if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
{
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, DTLS1_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
s->init_num = 0;
return dtls1_get_message_fragment(s, st1, stn,
max, ok);
}
else /* Incorrectly formated Hello request */
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
}
/* XDTLS: do a sanity check on the fragment */
s->init_num += i;
if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
{
/* BUF_MEM_grow takes an 'int' parameter */
if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
{
al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
+ DTLS1_HM_HEADER_LENGTH))
{
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
goto err;
}
/* Only do this test when we're reading the expected message.
* Stale messages will be dropped and future messages will be buffered */
if ( l > (unsigned long)max)
{
al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
s->s3->tmp.message_size=l;
}
if ( frag_len > (unsigned long)max)
{
al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
{
al=SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
+ DTLS1_HM_HEADER_LENGTH + s->init_num))
{
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
goto err;
}
if ( s->d1->r_msg_hdr.frag_off == 0)
{
s->s3->tmp.message_type = msg_hdr.type;
s->d1->r_msg_hdr.type = msg_hdr.type;
s->d1->r_msg_hdr.msg_len = l;
/* s->d1->r_msg_hdr.seq = seq_num; */
}
/* XDTLS: ressurect this when restart is in place */
s->state=stn;
/* next state (stn) */
p = (unsigned char *)s->init_buf->data;
if ( frag_len > 0)
{
i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
&p[s->init_num],
frag_len,0);
/* XDTLS: fix this--message fragments cannot span multiple packets */
if (i <= 0)
{
s->rwstate=SSL_READING;
*ok = 0;
return i;
}
}
else
i = 0;
/* XDTLS: an incorrectly formatted fragment should cause the
* handshake to fail */
OPENSSL_assert(i == (int)frag_len);
#if 0
/* Successfully read a fragment.
* It may be (1) out of order, or
* (2) it's a repeat, in which case we dump it
* (3) the one we are expecting next (maybe with overlap)
* If it is next one, it may overlap with previously read bytes
*/
/* case (1): buffer the future fragment
* (we can treat fragments from a future message the same
* as future fragments from the message being currently read, since
* they are sematically simply out of order.
*/
if ( msg_hdr.seq > s->d1->handshake_read_seq ||
frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
{
dtls1_buffer_handshake_fragment(s, &msg_hdr);
return DTLS1_HM_FRAGMENT_RETRY;
}
/* case (2): drop the entire fragment, and try again */
if ( msg_hdr.seq < s->d1->handshake_read_seq ||
frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
{
s->init_num -= DTLS1_HM_HEADER_LENGTH;
return DTLS1_HM_FRAGMENT_RETRY;
}
#endif
/* case (3): received a immediately useful fragment. Determine the
* possible overlap and copy the fragment.
*/
overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
/* retain the header for the first fragment */
if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
{
memmove(&(s->init_buf->data[s->init_num]),
&(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
frag_len - overlap);
s->init_num += frag_len - overlap;
}
else
s->init_num += frag_len;
dtls1_process_handshake_fragment(s, frag_len - overlap);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
(size_t)s->init_num, s,
s->msg_callback_arg);
*ok=1;
return s->init_num;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
s->init_num = 0;
err:
*ok=0;
return(-1);
}
