Add heartbeat extension bounds check.
[openssl.git] / ssl / d1_both.c
index 833af4561042d3850f74e662e0473f3108db61b0..2e8cf681ed0976e2b16460170fda27c77cfec6cc 100644 (file)
 
 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
                        if ((end) - (start) <= 8) { \
-                               unsigned long ii; \
+                               long ii; \
                                for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
                        } else { \
-                               unsigned long ii; \
+                               long 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)]; \
+                               for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
+                               bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
                        } }
 
 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
-                       unsigned long ii; \
+                       long ii; \
+                       OPENSSL_assert((msg_len) > 0); \
                        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 (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
+                       if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
+                               if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
 
 #if 0
 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
-                       int ii; \
+                       long 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};
+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 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);
@@ -214,6 +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);
@@ -227,14 +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);
@@ -263,11 +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);
@@ -314,9 +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, 
@@ -463,20 +469,9 @@ again:
 
        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);
+       /* 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;
@@ -658,11 +653,11 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
        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_MARK(frag->reassembly, (long)msg_hdr->frag_off,
+                           (long)(msg_hdr->frag_off + frag_len));
 
-       RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, msg_hdr->msg_len,
-                                  is_complete)
+       RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
+                                  is_complete);
 
        if (is_complete)
                {
@@ -805,16 +800,24 @@ 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);
 
        /* 
         * if this is a future (or stale) message it gets buffered
-        * (or dropped)--no further processing at this time 
+        * (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)
+       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;
@@ -875,7 +878,12 @@ 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;
 
@@ -1083,7 +1091,11 @@ 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;
@@ -1321,7 +1333,8 @@ unsigned char *
 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
                        unsigned long len, unsigned long frag_off, unsigned long frag_len)
        {
-       if ( frag_off == 0)
+       /* Don't change sequence numbers while listening */
+       if (frag_off == 0 && !s->d1->listen)
                {
                s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
                s->d1->next_handshake_write_seq++;
@@ -1374,7 +1387,7 @@ 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) / 
@@ -1415,3 +1428,181 @@ 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