- {
- 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);
- }
-
-int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
- {
- unsigned char *p,*d;
- int i;
- unsigned long l;
-
- if (s->state == a)
- {
- d=(unsigned char *)s->init_buf->data;
- p= &(d[DTLS1_HM_HEADER_LENGTH]);
-
- i=s->method->ssl3_enc->final_finish_mac(s,
- sender,slen,s->s3->tmp.finish_md);
- s->s3->tmp.finish_md_len = i;
- memcpy(p, s->s3->tmp.finish_md, i);
- p+=i;
- l=i;
-
-#ifdef OPENSSL_SYS_WIN16
- /* MSVC 1.5 does not clear the top bytes of the word unless
- * I do this.
- */
- l&=0xffff;
-#endif
-
- d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
- s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
- s->init_off=0;
+{
+ 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);
+}