#include <openssl/evp.h>
#include <openssl/x509.h>
+#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
+
+#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
+ if ((end) - (start) <= 8) { \
+ int ii; \
+ for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
+ } else { \
+ int ii; \
+ bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
+ for (ii = (((start) >> 3) + 1); ii < ((end) >> 3); ii++) bitmask[ii] = 0xff; \
+ bitmask[((end) >> 3)] |= bitmask_end_values[((end) & 7)]; \
+ } }
+
+#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
+ int ii; \
+ is_complete = 1; \
+ if (bitmask[((msg_len) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
+ if (is_complete) for (ii = 0; ii < ((msg_len) >> 3); ii++) \
+ if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
+
+#if 0
+#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
+ int ii; \
+ printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
+ printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
+ printf("\n"); }
+#endif
+
+static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
+static unsigned char bitmask_end_values[] = {0x00, 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};
long max, int *ok);
static hm_fragment *
-dtls1_hm_fragment_new(unsigned long frag_len)
+dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
{
hm_fragment *frag = NULL;
unsigned char *buf = NULL;
+ unsigned char *bitmask = NULL;
frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
if ( frag == NULL)
/* zero length fragment gets zero frag->fragment */
frag->fragment = buf;
+ /* Initialize reassembly bitmask if necessary */
+ if (reassembly)
+ {
+ bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
+ if (bitmask == NULL)
+ {
+ if (buf != NULL) OPENSSL_free(buf);
+ OPENSSL_free(frag);
+ return NULL;
+ }
+ memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
+ }
+
+ frag->reassembly = bitmask;
+
return frag;
}
dtls1_hm_fragment_free(hm_fragment *frag)
{
if (frag->fragment) OPENSSL_free(frag->fragment);
+ if (frag->reassembly) OPENSSL_free(frag->reassembly);
OPENSSL_free(frag);
}
{
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 */
}
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));
- }
+ 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;
+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;
- /* 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) ;
+ 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);
return 0;
frag = (hm_fragment *)item->data;
+
+ /* Don't return if reassembly still in progress */
+ if (frag->reassembly != NULL)
+ return 0;
if ( s->d1->handshake_read_seq == frag->msg_header.seq)
{
}
+static int
+dtls1_reassemble_fragment(SSL *s, 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;
+
+ if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
+ 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;
+
+ /* Try to find item in queue */
+ memset(seq64be,0,sizeof(seq64be));
+ seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
+ seq64be[7] = (unsigned char) msg_hdr->seq;
+ item = pqueue_find(s->d1->buffered_messages, seq64be);
+
+ if (item == NULL)
+ {
+ frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
+ if ( frag == NULL)
+ goto err;
+ memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
+ frag->msg_header.frag_len = frag->msg_header.msg_len;
+ frag->msg_header.frag_off = 0;
+ }
+ else
+ frag = (hm_fragment*) item->data;
+
+ /* If message is already reassembled, this must be a
+ * retransmit and can be dropped.
+ */
+ if (frag->reassembly == NULL)
+ {
+ unsigned char devnull [256];
+
+ while (frag_len)
+ {
+ i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
+ devnull,
+ frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
+ if (i<=0) goto err;
+ frag_len -= i;
+ }
+ return DTLS1_HM_FRAGMENT_RETRY;
+ }
+
+ /* 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)
+ goto err;
+
+ RSMBLY_BITMASK_MARK(frag->reassembly, msg_hdr->frag_off,
+ msg_hdr->frag_off + frag_len);
+
+ RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, msg_hdr->msg_len,
+ is_complete)
+
+ if (is_complete)
+ {
+ OPENSSL_free(frag->reassembly);
+ frag->reassembly = NULL;
+ }
+
+ 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;
+ i = -1;
+ }
+
+ pqueue_insert(s->d1->buffered_messages, item);
+ }
+
+ return DTLS1_HM_FRAGMENT_RETRY;
+
+err:
+ if (frag != NULL) dtls1_hm_fragment_free(frag);
+ if (item != NULL) OPENSSL_free(item);
+ *ok = 0;
+ return i;
+ }
+
+
static int
dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
{
pq_64bit_assign_word(&seq64, msg_hdr->seq);
item = pqueue_find(s->d1->buffered_messages, seq64);
pq_64bit_free(&seq64);
-
+
+ /* 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)
+ item = NULL;
+
/* Discard the message if sequence number was already there, is
* too far in the future, already in the queue or if we received
* a FINISHED before the SERVER_HELLO, which then must be a stale
frag_len -= i;
}
}
+ else
+ {
+ if (frag_len && frag_len < msg_hdr->msg_len)
+ return dtls1_reassemble_fragment(s, msg_hdr, ok);
- if (frag_len)
- {
- frag = dtls1_hm_fragment_new(frag_len);
+ frag = dtls1_hm_fragment_new(frag_len, 0);
if ( frag == NULL)
goto err;
memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
- /* 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)
- goto err;
+ if (frag_len)
+ {
+ /* 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)
+ goto err;
+ }
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64, msg_hdr->seq);
goto err;
pqueue_insert(s->d1->buffered_messages, item);
- }
+ }
return DTLS1_HM_FRAGMENT_RETRY;
dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
{
unsigned char wire[DTLS1_HM_HEADER_LENGTH];
- unsigned long l, frag_off, frag_len;
+ 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;
+ if (*ok) s->init_num = frag_len;
return frag_len;
}
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;
+ 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)
{
* 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;
+ s->init_num = frag_len;
return frag_len;
f_err:
* been serialized */
OPENSSL_assert(s->init_off == 0);
- frag = dtls1_hm_fragment_new(s->init_num);
+ frag = dtls1_hm_fragment_new(s->init_num, 0);
memcpy(frag->fragment, s->init_buf->data, s->init_num);