Fix return code for truncated DTLS fragment.
[openssl.git] / ssl / d1_both.c
index 2180c6d4da7d4774cd6af0dc8924a79fb5ee8aa9..ac0fcaa8fcfb896cce9330a45b5b9cc7d3dd9478 100644 (file)
@@ -158,7 +158,6 @@ static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1
 /* XDTLS:  figure out the right values */
 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 
-static unsigned int dtls1_min_mtu(void);
 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);
@@ -215,6 +214,12 @@ dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 static void
 dtls1_hm_fragment_free(hm_fragment *frag)
        {
+
+       if (frag->msg_header.is_ccs)
+               {
+               EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
+               EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
+               }
        if (frag->fragment) OPENSSL_free(frag->fragment);
        if (frag->reassembly) OPENSSL_free(frag->reassembly);
        OPENSSL_free(frag);
@@ -228,14 +233,14 @@ int dtls1_do_write(SSL *s, int type)
        unsigned int len, frag_off, mac_size, blocksize;
 
        /* AHA!  Figure out the MTU, and stick to the right size */
-       if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
+       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())
+               if (s->d1->mtu < dtls1_min_mtu())
                        {
                        s->d1->mtu = 0;
                        s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
@@ -264,11 +269,10 @@ int dtls1_do_write(SSL *s, int type)
                        return ret;
                mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
                }
-
-       OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
-
 #endif
 
+       OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
+
        if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
                OPENSSL_assert(s->init_num == 
                        (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
@@ -315,9 +319,10 @@ int dtls1_do_write(SSL *s, int type)
                                s->init_off -= DTLS1_HM_HEADER_LENGTH;
                                s->init_num += DTLS1_HM_HEADER_LENGTH;
 
-                               /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
-                               if ( len <= DTLS1_HM_HEADER_LENGTH)  
-                                       len += DTLS1_HM_HEADER_LENGTH;
+                               if ( s->init_num > curr_mtu)
+                                       len = curr_mtu;
+                               else
+                                       len = s->init_num;
                                }
 
                        dtls1_fix_message_header(s, frag_off, 
@@ -582,6 +587,16 @@ dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
                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)
@@ -590,21 +605,14 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
        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));
@@ -622,10 +630,20 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                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)
                {
@@ -669,18 +687,22 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                item = pitem_new(seq64be, frag);
                if (item == NULL)
                        {
-                       goto err;
                        i = -1;
+                       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;
        }
@@ -732,9 +754,12 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                }
        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;
@@ -746,7 +771,9 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                        /* 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;
                        }
 
@@ -758,14 +785,21 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                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;
        }
@@ -779,6 +813,7 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
        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)
                {
@@ -795,7 +830,13 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
                *ok = 0;
                return i;
                }
-       OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
+       /* 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);
@@ -831,8 +872,7 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *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 */
                        {
@@ -867,7 +907,12 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 
        /* XDTLS:  an incorrectly formatted fragment should cause the 
         * handshake to fail */
-       OPENSSL_assert(i == (int)frag_len);
+       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;
 
@@ -1075,7 +1120,11 @@ int dtls1_read_failed(SSL *s, int code)
                return code;
                }
 
-       if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
+#ifndef OPENSSL_NO_HEARTBEATS
+       if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
+#else
+       if (!SSL_in_init(s))  /* done, no need to send a retransmit */
+#endif
                {
                BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
                return code;
@@ -1151,6 +1200,8 @@ dtls1_buffer_message(SSL *s, int is_ccs)
        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);
 
@@ -1367,7 +1418,7 @@ dtls1_write_message_header(SSL *s, unsigned char *p)
        return p;
        }
 
-static unsigned int 
+unsigned int 
 dtls1_min_mtu(void)
        {
        return (g_probable_mtu[(sizeof(g_probable_mtu) / 
@@ -1408,3 +1459,181 @@ dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
 
        ccs_hdr->type = *(data++);
        }
+
+int dtls1_shutdown(SSL *s)
+       {
+       int ret;
+#ifndef OPENSSL_NO_SCTP
+       if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+           !(s->shutdown & SSL_SENT_SHUTDOWN))
+               {
+               ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
+               if (ret < 0) return -1;
+
+               if (ret == 0)
+                       BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
+               }
+#endif
+       ret = ssl3_shutdown(s);
+#ifndef OPENSSL_NO_SCTP
+       BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
+#endif
+       return ret;
+       }
+
+#ifndef OPENSSL_NO_HEARTBEATS
+int
+dtls1_process_heartbeat(SSL *s)
+       {
+       unsigned char *p = &s->s3->rrec.data[0], *pl;
+       unsigned short hbtype;
+       unsigned int payload;
+       unsigned int padding = 16; /* Use minimum padding */
+
+       if (s->msg_callback)
+               s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
+                       &s->s3->rrec.data[0], s->s3->rrec.length,
+                       s, s->msg_callback_arg);
+
+       /* Read type and payload length first */
+       if (1 + 2 + 16 > s->s3->rrec.length)
+               return 0; /* silently discard */
+       hbtype = *p++;
+       n2s(p, payload);
+       if (1 + 2 + payload + 16 > s->s3->rrec.length)
+               return 0; /* silently discard per RFC 6520 sec. 4 */
+       pl = p;
+
+       if (hbtype == TLS1_HB_REQUEST)
+               {
+               unsigned char *buffer, *bp;
+               unsigned int write_length = 1 /* heartbeat type */ +
+                                           2 /* heartbeat length */ +
+                                           payload + padding;
+               int r;
+
+               if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
+                       return 0;
+
+               /* Allocate memory for the response, size is 1 byte
+                * message type, plus 2 bytes payload length, plus
+                * payload, plus padding
+                */
+               buffer = OPENSSL_malloc(write_length);
+               bp = buffer;
+
+               /* Enter response type, length and copy payload */
+               *bp++ = TLS1_HB_RESPONSE;
+               s2n(payload, bp);
+               memcpy(bp, pl, payload);
+               bp += payload;
+               /* Random padding */
+               RAND_pseudo_bytes(bp, padding);
+
+               r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
+
+               if (r >= 0 && s->msg_callback)
+                       s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                               buffer, write_length,
+                               s, s->msg_callback_arg);
+
+               OPENSSL_free(buffer);
+
+               if (r < 0)
+                       return r;
+               }
+       else if (hbtype == TLS1_HB_RESPONSE)
+               {
+               unsigned int seq;
+
+               /* We only send sequence numbers (2 bytes unsigned int),
+                * and 16 random bytes, so we just try to read the
+                * sequence number */
+               n2s(pl, seq);
+
+               if (payload == 18 && seq == s->tlsext_hb_seq)
+                       {
+                       dtls1_stop_timer(s);
+                       s->tlsext_hb_seq++;
+                       s->tlsext_hb_pending = 0;
+                       }
+               }
+
+       return 0;
+       }
+
+int
+dtls1_heartbeat(SSL *s)
+       {
+       unsigned char *buf, *p;
+       int ret;
+       unsigned int payload = 18; /* Sequence number + random bytes */
+       unsigned int padding = 16; /* Use minimum padding */
+
+       /* Only send if peer supports and accepts HB requests... */
+       if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
+           s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
+               {
+               SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
+               return -1;
+               }
+
+       /* ...and there is none in flight yet... */
+       if (s->tlsext_hb_pending)
+               {
+               SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
+               return -1;
+               }
+
+       /* ...and no handshake in progress. */
+       if (SSL_in_init(s) || s->in_handshake)
+               {
+               SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
+               return -1;
+               }
+
+       /* Check if padding is too long, payload and padding
+        * must not exceed 2^14 - 3 = 16381 bytes in total.
+        */
+       OPENSSL_assert(payload + padding <= 16381);
+
+       /* Create HeartBeat message, we just use a sequence number
+        * as payload to distuingish different messages and add
+        * some random stuff.
+        *  - Message Type, 1 byte
+        *  - Payload Length, 2 bytes (unsigned int)
+        *  - Payload, the sequence number (2 bytes uint)
+        *  - Payload, random bytes (16 bytes uint)
+        *  - Padding
+        */
+       buf = OPENSSL_malloc(1 + 2 + payload + padding);
+       p = buf;
+       /* Message Type */
+       *p++ = TLS1_HB_REQUEST;
+       /* Payload length (18 bytes here) */
+       s2n(payload, p);
+       /* Sequence number */
+       s2n(s->tlsext_hb_seq, p);
+       /* 16 random bytes */
+       RAND_pseudo_bytes(p, 16);
+       p += 16;
+       /* Random padding */
+       RAND_pseudo_bytes(p, padding);
+
+       ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
+       if (ret >= 0)
+               {
+               if (s->msg_callback)
+                       s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                               buf, 3 + payload + padding,
+                               s, s->msg_callback_arg);
+
+               dtls1_start_timer(s);
+               s->tlsext_hb_pending = 1;
+               }
+
+       OPENSSL_free(buf);
+
+       return ret;
+       }
+#endif