static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
/* XDTLS: figure out the right values */
-static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
+static const unsigned int g_probable_mtu[] = {1500, 512, 256};
-static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
unsigned long frag_len);
static unsigned char *dtls1_write_message_header(SSL *s,
return frag;
}
-static void
-dtls1_hm_fragment_free(hm_fragment *frag)
+void dtls1_hm_fragment_free(hm_fragment *frag)
{
if (frag->msg_header.is_ccs)
OPENSSL_free(frag);
}
+static int dtls1_query_mtu(SSL *s)
+{
+ if(s->d1->link_mtu)
+ {
+ s->d1->mtu = s->d1->link_mtu-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
+ s->d1->link_mtu = 0;
+ }
+
+ /* AHA! Figure out the MTU, and stick to the right size */
+ if (s->d1->mtu < dtls1_min_mtu(s))
+ {
+ if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
+ {
+ s->d1->mtu =
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
+
+ /* I've seen the kernel return bogus numbers when it doesn't know
+ * (initial write), so just make sure we have a reasonable number */
+ if (s->d1->mtu < dtls1_min_mtu(s))
+ {
+ /* Set to min mtu */
+ s->d1->mtu = dtls1_min_mtu(s);
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
+ s->d1->mtu, NULL);
+ }
+ }
+ else
+ return 0;
+ }
+ return 1;
+}
+
/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
int dtls1_do_write(SSL *s, int type)
{
int curr_mtu;
unsigned int len, frag_off, mac_size, blocksize;
- /* AHA! Figure out the MTU, and stick to the right size */
- if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
- {
- s->d1->mtu =
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
-
- /* I've seen the kernel return bogus numbers when it doesn't know
- * (initial write), so just make sure we have a reasonable number */
- if (s->d1->mtu < dtls1_min_mtu())
- {
- s->d1->mtu = 0;
- s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
- s->d1->mtu, NULL);
- }
- }
+ if(!dtls1_query_mtu(s))
+ return -1;
#if 0
mtu = s->d1->mtu;
}
#endif
- OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
+ OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something reasonable now */
if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
OPENSSL_assert(s->init_num ==
len = s->init_num;
}
+ if ( len < DTLS1_HM_HEADER_LENGTH )
+ {
+ /*
+ * len is so small that we really can't do anything sensible
+ * so fail
+ */
+ return -1;
+ }
dtls1_fix_message_header(s, frag_off,
len - DTLS1_HM_HEADER_LENGTH);
dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
-
- OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
}
ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
*/
if ( BIO_ctrl(SSL_get_wbio(s),
BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
- s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
- BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
+ {
+ if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
+ {
+ if(!dtls1_query_mtu(s))
+ return -1;
+ }
+ else
+ return -1;
+ }
else
+ {
return(-1);
+ }
}
else
{
return 0;
}
+/* dtls1_max_handshake_message_len returns the maximum number of bytes
+ * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
+ * be greater if the maximum certificate list size requires it. */
+static unsigned long dtls1_max_handshake_message_len(const SSL *s)
+ {
+ unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
+ if (max_len < (unsigned long)s->max_cert_list)
+ return s->max_cert_list;
+ return max_len;
+ }
static int
-dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
+dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
{
hm_fragment *frag = NULL;
pitem *item = NULL;
int i = -1, is_complete;
unsigned char seq64be[8];
- unsigned long frag_len = msg_hdr->frag_len, max_len;
+ unsigned long frag_len = msg_hdr->frag_len;
- if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
+ if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
+ msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
goto err;
- /* Determine maximum allowed message size. Depends on (user set)
- * maximum certificate length, but 16k is minimum.
- */
- if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
- max_len = s->max_cert_list;
- else
- max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
-
- if ((msg_hdr->frag_off+frag_len) > max_len)
- goto err;
+ if (frag_len == 0)
+ return DTLS1_HM_FRAGMENT_RETRY;
/* Try to find item in queue */
memset(seq64be,0,sizeof(seq64be));
frag->msg_header.frag_off = 0;
}
else
+ {
frag = (hm_fragment*) item->data;
+ if (frag->msg_header.msg_len != msg_hdr->msg_len)
+ {
+ item = NULL;
+ frag = NULL;
+ goto err;
+ }
+ }
+
/* If message is already reassembled, this must be a
- * retransmit and can be dropped.
+ * retransmit and can be dropped. In this case item != NULL and so frag
+ * does not need to be freed.
*/
if (frag->reassembly == NULL)
{
/* read the body of the fragment (header has already been read */
i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
frag->fragment + msg_hdr->frag_off,frag_len,0);
- if (i<=0 || (unsigned long)i!=frag_len)
+ if ((unsigned long)i!=frag_len)
+ i=-1;
+ if (i<=0)
goto err;
RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
if (item == NULL)
{
- memset(seq64be,0,sizeof(seq64be));
- seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
- seq64be[7] = (unsigned char)(msg_hdr->seq);
-
item = pitem_new(seq64be, frag);
if (item == NULL)
{
goto err;
}
- pqueue_insert(s->d1->buffered_messages, item);
+ item = pqueue_insert(s->d1->buffered_messages, item);
+ /* pqueue_insert fails iff a duplicate item is inserted.
+ * However, |item| cannot be a duplicate. If it were,
+ * |pqueue_find|, above, would have returned it and control
+ * would never have reached this branch. */
+ OPENSSL_assert(item != NULL);
}
return DTLS1_HM_FRAGMENT_RETRY;
err:
- if (frag != NULL) dtls1_hm_fragment_free(frag);
- if (item != NULL) OPENSSL_free(item);
+ if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
*ok = 0;
return i;
}
static int
-dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
+dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
{
int i=-1;
hm_fragment *frag = NULL;
/* If we already have an entry and this one is a fragment,
* don't discard it and rather try to reassemble it.
*/
- if (item != NULL && frag_len < msg_hdr->msg_len)
+ if (item != NULL && frag_len != msg_hdr->msg_len)
item = NULL;
/* Discard the message if sequence number was already there, is
}
else
{
- if (frag_len && frag_len < msg_hdr->msg_len)
+ if (frag_len != msg_hdr->msg_len)
return dtls1_reassemble_fragment(s, msg_hdr, ok);
+ if (frag_len > dtls1_max_handshake_message_len(s))
+ goto err;
+
frag = dtls1_hm_fragment_new(frag_len, 0);
if ( frag == NULL)
goto err;
/* read the body of the fragment (header has already been read */
i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
frag->fragment,frag_len,0);
- if (i<=0 || (unsigned long)i!=frag_len)
+ if ((unsigned long)i!=frag_len)
+ i = -1;
+ if (i<=0)
goto err;
}
- memset(seq64be,0,sizeof(seq64be));
- seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
- seq64be[7] = (unsigned char)(msg_hdr->seq);
-
item = pitem_new(seq64be, frag);
if ( item == NULL)
goto err;
- pqueue_insert(s->d1->buffered_messages, item);
+ item = pqueue_insert(s->d1->buffered_messages, item);
+ /* pqueue_insert fails iff a duplicate item is inserted.
+ * However, |item| cannot be a duplicate. If it were,
+ * |pqueue_find|, above, would have returned it. Then, either
+ * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
+ * to NULL and it will have been processed with
+ * |dtls1_reassemble_fragment|, above, or the record will have
+ * been discarded. */
+ OPENSSL_assert(item != NULL);
}
return DTLS1_HM_FRAGMENT_RETRY;
err:
- if ( frag != NULL) dtls1_hm_fragment_free(frag);
- if ( item != NULL) OPENSSL_free(item);
+ if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
*ok = 0;
return i;
}
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)
{
s->msg_callback_arg);
s->init_num = 0;
- return dtls1_get_message_fragment(s, st1, stn,
- max, ok);
+ goto redo;
}
else /* Incorrectly formated Hello request */
{
OPENSSL_assert(s->init_off == 0);
frag = dtls1_hm_fragment_new(s->init_num, 0);
+ if (!frag)
+ return 0;
memcpy(frag->fragment, s->init_buf->data, s->init_num);
return p;
}
-unsigned int
-dtls1_min_mtu(void)
+unsigned int
+dtls1_link_min_mtu(void)
{
return (g_probable_mtu[(sizeof(g_probable_mtu) /
sizeof(g_probable_mtu[0])) - 1]);
}
-static unsigned int
-dtls1_guess_mtu(unsigned int curr_mtu)
+unsigned int
+dtls1_min_mtu(SSL *s)
{
- unsigned int i;
-
- if ( curr_mtu == 0 )
- return g_probable_mtu[0] ;
-
- for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
- if ( curr_mtu > g_probable_mtu[i])
- return g_probable_mtu[i];
-
- return curr_mtu;
+ return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
}
+
void
dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
{
/* Read type and payload length first */
if (1 + 2 + 16 > s->s3->rrec.length)
return 0; /* silently discard */
+ if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
+ return 0; /* silently discard per RFC 6520 sec. 4 */
+
hbtype = *p++;
n2s(p, payload);
if (1 + 2 + payload + 16 > s->s3->rrec.length)
projects / openssl.git / blobdiff