/* Obtain handshake message of message type 'mt' (any if mt == -1),
* maximum acceptable body length 'max'.
* Read an entire handshake message. Handshake messages arrive in
* fragments.
*/
long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
int i, al;
struct hm_header_st *msg_hdr;
unsigned char *p;
unsigned long msg_len;
/* s3->tmp is used to store messages that are unexpected, caused
* by the absence of an optional handshake message */
if (s->s3->tmp.reuse_message)
{
s->s3->tmp.reuse_message=0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt))
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok=1;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
msg_hdr = &s->d1->r_msg_hdr;
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
again:
i = dtls1_get_message_fragment(s, st1, stn, max, ok);
if ( i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
goto again;
else if ( i <= 0 && !*ok)
return i;
p = (unsigned char *)s->init_buf->data;
msg_len = msg_hdr->msg_len;
/* reconstruct message header */
*(p++) = msg_hdr->type;
l2n3(msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_len,p);
if (s->version != DTLS1_BAD_VER) {
p -= DTLS1_HM_HEADER_LENGTH;
msg_len += DTLS1_HM_HEADER_LENGTH;
}
ssl3_finish_mac(s, p, msg_len);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, msg_len,
s, s->msg_callback_arg);
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
/* Don't change sequence numbers while listening */
if (!s->d1->listen)
s->d1->handshake_read_seq++;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
*ok = 0;
return -1;
}
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;
/* 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;
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;
}
}
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);
}
/* Obtain handshake message of message type 'mt' (any if mt == -1),
* maximum acceptable body length 'max'.
* Read an entire handshake message. Handshake messages arrive in
* fragments.
*/
long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
int i, al;
struct hm_header_st *msg_hdr;
/* s3->tmp is used to store messages that are unexpected, caused
* by the absence of an optional handshake message */
if (s->s3->tmp.reuse_message)
{
s->s3->tmp.reuse_message=0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt))
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok=1;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
msg_hdr = &s->d1->r_msg_hdr;
do
{
if ( msg_hdr->frag_off == 0)
{
/* s->d1->r_message_header.msg_len = 0; */
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
}
i = dtls1_get_message_fragment(s, st1, stn, max, ok);
if ( i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
continue;
else if ( i <= 0 && !*ok)
return i;
/* Note that s->init_sum is used 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. Overlapping fragments would cause
* premature termination, so we don't expect overlaps.
* Well, handling overlaps would require something more
* drastic. Indeed, as it is now there is no way to
* tell if out-of-order fragment from the middle was
* the last. '>=' is the best/least we can do to control
* the potential damage caused by malformed overlaps. */
if ((unsigned int)s->init_num >= msg_hdr->msg_len)
{
unsigned char *p = (unsigned char *)s->init_buf->data;
unsigned long msg_len = msg_hdr->msg_len;
/* reconstruct message header as if it was
* sent in single fragment */
*(p++) = msg_hdr->type;
l2n3(msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_len,p);
if (s->client_version != DTLS1_BAD_VER)
p -= DTLS1_HM_HEADER_LENGTH,
msg_len += DTLS1_HM_HEADER_LENGTH;
ssl3_finish_mac(s, p, msg_len);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, msg_len,
s, s->msg_callback_arg);
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
s->d1->handshake_read_seq++;
/* we just read a handshake message from the other side:
* this means that we don't need to retransmit of the
* buffered messages.
* XDTLS: may be able clear out this
* buffer a little sooner (i.e if an out-of-order
* handshake message/record is received at the record
* layer.
* XDTLS: exception is that the server needs to
* know that change cipher spec and finished messages
* have been received by the client before clearing this
* buffer. this can simply be done by waiting for the
* first data segment, but is there a better way? */
dtls1_clear_record_buffer(s);
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num;
}
else
msg_hdr->frag_off = i;
} while(1) ;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
*ok = 0;
return -1;
}
/* Obtain handshake message of message type 'mt' (any if mt == -1),
* maximum acceptable body length 'max'.
* Read an entire handshake message. Handshake messages arrive in
* fragments.
*/
long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
int i, al;
struct hm_header_st *msg_hdr;
unsigned char *p;
unsigned long msg_len;
/* s3->tmp is used to store messages that are unexpected, caused
* by the absence of an optional handshake message */
if (s->s3->tmp.reuse_message)
{
s->s3->tmp.reuse_message=0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt))
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok=1;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
msg_hdr = &s->d1->r_msg_hdr;
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
again:
i = dtls1_get_message_fragment(s, st1, stn, max, ok);
if ( i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
goto again;
else if ( i <= 0 && !*ok)
return i;
p = (unsigned char *)s->init_buf->data;
msg_len = msg_hdr->msg_len;
/* reconstruct message header */
*(p++) = msg_hdr->type;
l2n3(msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_len,p);
if (s->version != DTLS1_BAD_VER) {
p -= DTLS1_HM_HEADER_LENGTH;
msg_len += DTLS1_HM_HEADER_LENGTH;
}
ssl3_finish_mac(s, p, msg_len);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, msg_len,
s, s->msg_callback_arg);
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
s->d1->handshake_read_seq++;
/* we just read a handshake message from the other side:
* this means that we don't need to retransmit of the
* buffered messages.
* XDTLS: may be able clear out this
* buffer a little sooner (i.e if an out-of-order
* handshake message/record is received at the record
* layer.
* XDTLS: exception is that the server needs to
* know that change cipher spec and finished messages
* have been received by the client before clearing this
* buffer. this can simply be done by waiting for the
* first data segment, but is there a better way? */
dtls1_clear_record_buffer(s);
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
*ok = 0;
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);
}
/* Obtain handshake message of message type 'mt' (any if mt == -1),
* maximum acceptable body length 'max'.
* Read an entire handshake message. Handshake messages arrive in
* fragments.
*/
long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
int i, al;
/* s3->tmp is used to store messages that are unexpected, caused
* by the absence of an optional handshake message */
if (s->s3->tmp.reuse_message)
{
s->s3->tmp.reuse_message=0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt))
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok=1;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
do
{
if ( s->d1->r_msg_hdr.frag_off == 0)
{
/* s->d1->r_message_header.msg_len = 0; */
memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
}
i = dtls1_get_message_fragment(s, st1, stn, max, ok);
if ( i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
continue;
else if ( i <= 0 && !*ok)
return i;
if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
{
memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
s->d1->handshake_read_seq++;
/* we just read a handshake message from the other side:
* this means that we don't need to retransmit of the
* buffered messages.
* XDTLS: may be able clear out this
* buffer a little sooner (i.e if an out-of-order
* handshake message/record is received at the record
* layer.
* XDTLS: exception is that the server needs to
* know that change cipher spec and finished messages
* have been received by the client before clearing this
* buffer. this can simply be done by waiting for the
* first data segment, but is there a better way? */
dtls1_clear_record_buffer(s);
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num - DTLS1_HM_HEADER_LENGTH;
}
else
s->d1->r_msg_hdr.frag_off = i;
} while(1) ;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
*ok = 0;
return -1;
}
